refactor(web): extract asset grid layout logic into AssetLayout component

- Extracts the asset grid rendering logic from `MonthSegment` into a dedicated `AssetLayout` component - Simplifies `MonthSegment` by delegating layout responsibilities while maintaining all existing functionality - Renames `customLayout` prop to `customThumbnailLayout` for clarity across Timeline components ## Changes - Created new `AssetLayout.svelte` component that handles: - Asset grid rendering with proper positioning - Animation transitions - Filtering of intersecting viewer assets - Updated `MonthSegment.svelte` to use `AssetLayout` via composition pattern - Renamed `customLayout` to `customThumbnailLayout` in Timeline and related components - Moved thumbnail click and selection logic to Timeline parent component using snippets
refactor(web): consolidate asset operations in PhotostreamManager base class
2025-09-30 00:08:14 +00:00 · 2025-09-30 00:00:50 +00:00 · 2025-09-29 01:26:59 +00:00
30 changed files with 1044 additions and 1311 deletions
--- a/server/src/services/notification.service.ts
+++ b/server/src/services/notification.service.ts
@@ -161,7 +161,24 @@ export class NotificationService extends BaseService {

    const [asset] = await this.assetRepository.getByIdsWithAllRelationsButStacks([assetId]);
    if (asset) {
-      this.eventRepository.clientSend('on_asset_update', userId, mapAsset(asset));
+      // need to specify authDto to this mapAsset request, because it tries to prevent
+      // leaking information PR#7580 which expects a userId in the auth options object
+      this.eventRepository.clientSend(
+        'on_asset_update',
+        userId,
+        mapAsset(asset, {
+          auth: {
+            user: {
+              id: userId,
+              isAdmin: false,
+              name: '',
+              email: '',
+              quotaUsageInBytes: 0,
+              quotaSizeInBytes: null,
+            },
+          },
+        }),
+      );
    }
  }

--- a/web/src/lib/components/assets/thumbnail/thumbnail.svelte
+++ b/web/src/lib/components/assets/thumbnail/thumbnail.svelte
@@ -121,7 +121,6 @@

  const onMouseLeave = () => {
    mouseOver = false;
-    onMouseEvent?.({ isMouseOver: false, selectedGroupIndex: groupIndex });
  };

  let timer: ReturnType<typeof setTimeout> | null = null;
--- a/web/src/lib/components/timeline/Photostream.svelte
+++ b/web/src/lib/components/timeline/Photostream.svelte
@@ -1,279 +0,0 @@
-<script lang="ts">
-  import { page } from '$app/state';
-  import { resizeObserver, type OnResizeCallback } from '$lib/actions/resize-observer';
-  import HotModuleReload from '$lib/elements/HotModuleReload.svelte';
-  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
-  import type { PhotostreamSegment } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
-
-  import { assetViewingStore } from '$lib/stores/asset-viewing.store';
-  import { mobileDevice } from '$lib/stores/mobile-device.svelte';
-  import { onMount, type Snippet } from 'svelte';
-  import type { UpdatePayload } from 'vite';
-
-  interface Props {
-    segment: Snippet<
-      [
-        {
-          segment: PhotostreamSegment;
-          scrollToFunction: (top: number) => void;
-          onScrollCompensationMonthInDOM: (compensation: { heightDelta?: number; scrollTop?: number }) => void;
-        },
-      ]
-    >;
-    skeleton: Snippet<
-      [
-        {
-          segment: PhotostreamSegment;
-        },
-      ]
-    >;
-
-    showScrollbar?: boolean;
-    /** `true` if this asset grid responds to navigation events; if `true`, then look at the
-     `AssetViewingStore.gridScrollTarget` and load and scroll to the asset specified, and
-     additionally, update the page location/url with the asset as the asset-grid is scrolled */
-    enableRouting: boolean;
-    timelineManager: PhotostreamManager;
-
-    showSkeleton?: boolean;
-    isShowDeleteConfirmation?: boolean;
-    styleMarginRightOverride?: string;
-
-    header?: Snippet<[scrollToFunction: (top: number) => void]>;
-    children?: Snippet;
-    empty?: Snippet;
-    handleTimelineScroll?: () => void;
-  }
-
-  let {
-    segment,
-
-    enableRouting,
-    timelineManager = $bindable(),
-    showSkeleton = $bindable(true),
-    styleMarginRightOverride,
-    isShowDeleteConfirmation = $bindable(false),
-    showScrollbar,
-    children,
-    skeleton,
-    empty,
-    header,
-    handleTimelineScroll = () => {},
-  }: Props = $props();
-
-  let { gridScrollTarget } = assetViewingStore;
-
-  let element: HTMLElement | undefined = $state();
-  let timelineElement: HTMLElement | undefined = $state();
-
-  const maxMd = $derived(mobileDevice.maxMd);
-  const isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
-
-  $effect(() => {
-    const layoutOptions = maxMd
-      ? {
-          rowHeight: 100,
-          headerHeight: 32,
-        }
-      : {
-          rowHeight: 235,
-          headerHeight: 48,
-        };
-    timelineManager.setLayoutOptions(layoutOptions);
-  });
-
-  const scrollTo = (top: number) => {
-    if (element) {
-      element.scrollTo({ top });
-    }
-    updateSlidingWindow();
-  };
-
-  const scrollBy = (y: number) => {
-    if (element) {
-      element.scrollBy(0, y);
-    }
-    updateSlidingWindow();
-  };
-
-  const handleTriggeredScrollCompensation = (compensation: { heightDelta?: number; scrollTop?: number }) => {
-    const { heightDelta, scrollTop } = compensation;
-    if (heightDelta !== undefined) {
-      scrollBy(heightDelta);
-    } else if (scrollTop !== undefined) {
-      scrollTo(scrollTop);
-    }
-    timelineManager.clearScrollCompensation();
-  };
-
-  const getAssetHeight = (assetId: string, monthGroup: PhotostreamSegment) => {
-    // the following method may trigger any layouts, so need to
-    // handle any scroll compensation that may have been set
-    const height = monthGroup.findAssetAbsolutePosition(assetId);
-
-    // this is in a while loop, since scrollCompensations invoke scrolls
-    // which may load months, triggering more scrollCompensations. Call
-    // this in a loop, until no more layouts occur.
-    while (timelineManager.scrollCompensation.monthGroup) {
-      handleTriggeredScrollCompensation(timelineManager.scrollCompensation);
-    }
-    return height;
-  };
-
-  export const scrollToAssetId = async (assetId: string) => {
-    const monthGroup = await timelineManager.findSegmentForAssetId(assetId);
-    if (!monthGroup) {
-      return false;
-    }
-
-    const height = getAssetHeight(assetId, monthGroup);
-    scrollTo(height);
-    return true;
-  };
-
-  export const completeAfterNavigate = async ({ scrollToAssetQueryParam }: { scrollToAssetQueryParam: boolean }) => {
-    if (timelineManager.viewportHeight === 0 || timelineManager.viewportWidth === 0) {
-      // this can happen if you do the following navigation order
-      // /photos?at=<id>, /photos/<id>, http://example.com, browser back, browser back
-      const rect = element?.getBoundingClientRect();
-      if (rect) {
-        timelineManager.viewportHeight = rect.height;
-        timelineManager.viewportWidth = rect.width;
-      }
-    }
-    if (scrollToAssetQueryParam) {
-      const scrollTarget = $gridScrollTarget?.at;
-      let scrolled = false;
-      if (scrollTarget) {
-        scrolled = await scrollToAssetId(scrollTarget);
-      }
-      if (!scrolled) {
-        // if the asset is not found, scroll to the top
-        scrollTo(0);
-      }
-    }
-    showSkeleton = false;
-  };
-
-  const updateIsScrolling = () => (timelineManager.scrolling = true);
-  // Yes, updateSlideWindow() is called by the onScroll event. However, if you also just scrolled
-  // by explicitly invoking element.scrollX functions, there may be a delay with enough time to
-  // set the intersecting property of the monthGroup to false, then true, which causes the DOM
-  // nodes to be recreated, causing bad perf, and also, disrupting focus of those elements.
-  // Also note: don't throttle, debounce, or otherwise do this function async - it causes flicker
-  const updateSlidingWindow = () => timelineManager.updateSlidingWindow(element?.scrollTop || 0);
-
-  const topSectionResizeObserver: OnResizeCallback = ({ height }) => (timelineManager.topSectionHeight = height);
-
-  onMount(() => {
-    if (!enableRouting) {
-      showSkeleton = false;
-    }
-  });
-</script>
-
-<HotModuleReload
-  onAfterUpdate={(payload: UpdatePayload) => {
-    // when hmr happens, skeleton is initialized to true by default
-    // normally, loading asset-grid is part of a navigation event, and the completion of
-    // that event triggers a scroll-to-asset, if necessary, when then clears the skeleton.
-    // this handler will run the navigation/scroll-to-asset handler when hmr is performed,
-    // preventing skeleton from showing after hmr
-    const finishHmr = () => {
-      const asset = page.url.searchParams.get('at');
-      if (asset) {
-        $gridScrollTarget = { at: asset };
-      }
-      void completeAfterNavigate({ scrollToAssetQueryParam: true });
-    };
-    const assetGridUpdate = payload.updates.some((update) => update.path.endsWith('Photostream.svelte'));
-    if (assetGridUpdate) {
-      // wait 500ms for the update to be fully swapped in
-      setTimeout(finishHmr, 500);
-    }
-  }}
-/>
-
-{@render header?.(scrollTo)}
-
-<!-- Right margin MUST be equal to the width of scrubber -->
-<section
-  id="asset-grid"
-  class={[
-    'h-full overflow-y-auto outline-none',
-    { 'scrollbar-hidden': !showScrollbar },
-    { 'm-0': isEmpty },
-    { 'ms-0': !isEmpty },
-  ]}
-  style:margin-right={styleMarginRightOverride}
-  style:scrollbar-width={showScrollbar ? 'auto' : 'none'}
-  tabindex="-1"
-  bind:clientHeight={timelineManager.viewportHeight}
-  bind:clientWidth={null, (v: number) => ((timelineManager.viewportWidth = v), updateSlidingWindow())}
-  bind:this={element}
-  onscroll={() => (handleTimelineScroll(), updateSlidingWindow(), updateIsScrolling())}
->
-  <section
-    bind:this={timelineElement}
-    id="virtual-timeline"
-    class:invisible={showSkeleton}
-    style:height={timelineManager.timelineHeight + 'px'}
-  >
-    <section
-      use:resizeObserver={topSectionResizeObserver}
-      class:invisible={showSkeleton}
-      style:position="absolute"
-      style:left="0"
-      style:right="0"
-    >
-      {@render children?.()}
-      {#if isEmpty}
-        <!-- (optional) empty placeholder -->
-        {@render empty?.()}
-      {/if}
-    </section>
-
-    {#each timelineManager.months as monthGroup (monthGroup.id)}
-      {@const shouldDisplay = monthGroup.intersecting}
-      {@const absoluteHeight = monthGroup.top}
-      <div
-        class="month-group"
-        style:height={monthGroup.height + 'px'}
-        style:position="absolute"
-        style:transform={`translate3d(0,${absoluteHeight}px,0)`}
-        style:width="100%"
-      >
-        {#if !shouldDisplay}
-          {@render skeleton({ segment: monthGroup })}
-        {:else}
-          {@render segment({
-            segment: monthGroup,
-            scrollToFunction: scrollTo,
-            onScrollCompensationMonthInDOM: handleTriggeredScrollCompensation,
-          })}
-        {/if}
-      </div>
-    {/each}
-    <!-- spacer for lead-out -->
-    <div
-      class="h-[60px]"
-      style:position="absolute"
-      style:left="0"
-      style:right="0"
-      style:transform={`translate3d(0,${timelineManager.timelineHeight}px,0)`}
-    ></div>
-  </section>
-</section>
-
-<style>
-  #asset-grid {
-    contain: strict;
-    scrollbar-width: none;
-  }
-  .month-group {
-    contain: layout size paint;
-    transform-style: flat;
-    backface-visibility: hidden;
-    transform-origin: center center;
-  }
-</style>
--- a/web/src/lib/components/timeline/PhotostreamWithScrubber.svelte
+++ b/web/src/lib/components/timeline/PhotostreamWithScrubber.svelte
@@ -1,198 +0,0 @@
-<script lang="ts">
-  import Photostream from '$lib/components/timeline/Photostream.svelte';
-  import Scrubber from '$lib/components/timeline/Scrubber.svelte';
-  import type { PhotostreamSegment } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
-  import { findMonthAtScrollPosition } from '$lib/managers/timeline-manager/internal/search-support.svelte';
-  import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
-
-  import type { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
-  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
-  import { type ScrubberListenerWithScrollTo, type TimelineYearMonth } from '$lib/utils/timeline-util';
-  import type { Snippet } from 'svelte';
-
-  interface Props {
-    /** `true` if this timeline responds to navigation events; if `true`, then look at the
-     `AssetViewingStore.gridScrollTarget` and load and scroll to the asset specified, and
-     additionally, update the page location/url with the asset as the asset-grid is scrolled */
-    enableRouting: boolean;
-    timelineManager: TimelineManager;
-
-    showSkeleton?: boolean;
-    isShowDeleteConfirmation?: boolean;
-
-    segment: Snippet<
-      [
-        {
-          segment: PhotostreamSegment;
-          onScrollCompensationMonthInDOM: (compensation: { heightDelta?: number; scrollTop?: number }) => void;
-        },
-      ]
-    >;
-    skeleton: Snippet<
-      [
-        {
-          segment: PhotostreamSegment;
-        },
-      ]
-    >;
-    children?: Snippet;
-    empty?: Snippet;
-  }
-
-  let {
-    enableRouting,
-    timelineManager = $bindable(),
-
-    showSkeleton = true,
-    isShowDeleteConfirmation = $bindable(false),
-    segment,
-    skeleton,
-    children,
-    empty,
-  }: Props = $props();
-
-  const VIEWPORT_MULTIPLIER = 2; // Used to determine if timeline is "small"
-
-  // The percentage of scroll through the month that is currently intersecting the top boundary of the viewport.
-  // Note: There may be multiple months visible within the viewport at any given time.
-  let viewportTopMonthScrollPercent = $state(0);
-  // The timeline month intersecting the top position of the viewport
-  let viewportTopMonth: TimelineYearMonth | undefined = $state(undefined);
-  // Overall scroll percentage through the entire timeline (0-1)
-  let timelineScrollPercent: number = $state(0);
-  // Indicates whether the viewport is currently in the lead-out section (after all months)
-  let isInLeadOutSection = $state(false);
-  // Width of the scrubber component in pixels, used to adjust timeline margins
-  let scrubberWidth: number = $state(0);
-
-  // note: don't throttle, debounce, or otherwise make this function async - it causes flicker
-  // this function updates the scrubber position based on the current scroll position in the timeline
-  const handleTimelineScroll = () => {
-    isInLeadOutSection = false;
-
-    // Handle edge cases: small timeline (limited scroll) or lead-in area scrolling
-    const top = timelineManager.visibleWindow.top;
-    if (isSmallTimeline() || top < timelineManager.topSectionHeight) {
-      calculateTimelineScrollPercent();
-      return;
-    }
-
-    // Handle normal month scrolling
-    handleMonthScroll();
-  };
-
-  const handleMonthScroll = () => {
-    const scrollPosition = timelineManager.visibleWindow.top;
-    const months = timelineManager.months;
-    const maxScrollPercent = timelineManager.getMaxScrollPercent();
-
-    // Find the month at the current scroll position
-    const searchResult = findMonthAtScrollPosition(months, scrollPosition, maxScrollPercent);
-
-    if (searchResult) {
-      viewportTopMonth = searchResult.month;
-      viewportTopMonthScrollPercent = searchResult.monthScrollPercent;
-      isInLeadOutSection = false;
-      return;
-    }
-
-    // We're in lead-out section
-    isInLeadOutSection = true;
-    timelineScrollPercent = 1;
-    resetScrubberMonth();
-  };
-
-  const resetScrubberMonth = () => {
-    viewportTopMonth = undefined;
-    viewportTopMonthScrollPercent = 0;
-  };
-
-  const calculateTimelineScrollPercent = () => {
-    const maxScroll = timelineManager.getMaxScroll();
-    timelineScrollPercent = Math.min(1, timelineManager.visibleWindow.top / maxScroll);
-    resetScrubberMonth();
-  };
-
-  const handleOverallPercentScroll = (percent: number, scrollTo?: (offset: number) => void) => {
-    const maxScroll = timelineManager.getMaxScroll();
-    const offset = maxScroll * percent;
-    scrollTo?.(offset);
-  };
-
-  const findMonthGroup = (target: TimelineYearMonth) => {
-    return timelineManager.months.find(
-      ({ yearMonth }) => yearMonth.year === target.year && yearMonth.month === target.month,
-    );
-  };
-
-  const isSmallTimeline = () => {
-    return timelineManager.timelineHeight < timelineManager.viewportHeight * VIEWPORT_MULTIPLIER;
-  };
-
-  // note: don't throttle, debounce, or otherwise make this function async - it causes flicker
-  // this function scrolls the timeline to the specified month group and offset, based on scrubber interaction
-  const onScrub: ScrubberListenerWithScrollTo = (scrubberData) => {
-    const { scrubberMonth, overallScrollPercent, scrubberMonthScrollPercent, scrollToFunction } = scrubberData;
-
-    // Handle edge case or no month selected
-    if (!scrubberMonth || isSmallTimeline()) {
-      handleOverallPercentScroll(overallScrollPercent, scrollToFunction);
-      return;
-    }
-
-    // Find and scroll to the selected month
-    const monthGroup = findMonthGroup(scrubberMonth);
-    if (monthGroup) {
-      scrollToPositionWithinMonth(monthGroup, scrubberMonthScrollPercent, scrollToFunction);
-    }
-  };
-
-  const scrollToPositionWithinMonth = (
-    monthGroup: MonthGroup,
-    monthGroupScrollPercent: number,
-    handleScrollTop?: (top: number) => void,
-  ) => {
-    const topOffset = monthGroup.top;
-    const maxScrollPercent = timelineManager.getMaxScrollPercent();
-    const delta = monthGroup.height * monthGroupScrollPercent;
-    const scrollToTop = (topOffset + delta) * maxScrollPercent;
-
-    handleScrollTop?.(scrollToTop);
-  };
-  let baseTimelineViewer: Photostream | undefined = $state();
-  export const scrollToAsset = async (asset: TimelineAsset) =>
-    (await baseTimelineViewer?.scrollToAssetId(asset.id)) ?? false;
-  export const completeAfterNavigate = (args: { scrollToAssetQueryParam: boolean }) =>
-    baseTimelineViewer?.completeAfterNavigate(args);
-</script>
-
-<Photostream
-  bind:this={baseTimelineViewer}
-  {enableRouting}
-  {timelineManager}
-  {showSkeleton}
-  {isShowDeleteConfirmation}
-  styleMarginRightOverride={scrubberWidth + 'px'}
-  {handleTimelineScroll}
-  {segment}
-  {skeleton}
-  {children}
-  {empty}
->
-  {#snippet header(scrollToFunction)}
-    {#if timelineManager.months.length > 0}
-      <Scrubber
-        {timelineManager}
-        height={timelineManager.viewportHeight}
-        timelineTopOffset={timelineManager.topSectionHeight}
-        timelineBottomOffset={timelineManager.bottomSectionHeight}
-        {isInLeadOutSection}
-        {timelineScrollPercent}
-        {viewportTopMonthScrollPercent}
-        {viewportTopMonth}
-        onScrub={(scrubberData) => onScrub({ ...scrubberData, scrollToFunction })}
-        bind:scrubberWidth
-      />
-    {/if}
-  {/snippet}
-</Photostream>
--- a/web/src/lib/components/timeline/SelectableDay.svelte
+++ b/web/src/lib/components/timeline/SelectableDay.svelte
@@ -1,62 +0,0 @@
-<script lang="ts">
-  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
-  import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
-
-  import { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
-
-  import type { Snippet } from 'svelte';
-
-  interface Props {
-    content: Snippet<
-      [
-        {
-          onDayGroupSelect: (dayGroup: DayGroup, asset: TimelineAsset[]) => void;
-          onDayGroupAssetSelect: (dayGroup: DayGroup, asset: TimelineAsset) => void;
-        },
-      ]
-    >;
-    onAssetSelect: (asset: TimelineAsset) => void;
-    assetInteraction: AssetInteraction;
-  }
-
-  let { content, assetInteraction, onAssetSelect }: Props = $props();
-
-  // called when clicking asset with shift key pressed or with mouse
-  const onDayGroupAssetSelect = (dayGroup: DayGroup, asset: TimelineAsset) => {
-    onAssetSelect(asset);
-
-    const assetsInDayGroup = dayGroup.getAssets();
-    const groupTitle = dayGroup.groupTitle;
-
-    // Check if all assets are selected in a group to toggle the group selection's icon
-    const selectedAssetsInGroupCount = assetsInDayGroup.filter((asset) =>
-      assetInteraction.hasSelectedAsset(asset.id),
-    ).length;
-    // if all assets are selected in a group, add the group to selected group
-    if (selectedAssetsInGroupCount == assetsInDayGroup.length) {
-      assetInteraction.addGroupToMultiselectGroup(groupTitle);
-    } else {
-      assetInteraction.removeGroupFromMultiselectGroup(groupTitle);
-    }
-  };
-
-  const onDayGroupSelect = (dayGroup: DayGroup, assets: TimelineAsset[]) => {
-    const group = dayGroup.groupTitle;
-    if (assetInteraction.selectedGroup.has(group)) {
-      assetInteraction.removeGroupFromMultiselectGroup(group);
-      for (const asset of assets) {
-        assetInteraction.removeAssetFromMultiselectGroup(asset.id);
-      }
-    } else {
-      assetInteraction.addGroupToMultiselectGroup(group);
-      for (const asset of assets) {
-        onAssetSelect(asset);
-      }
-    }
-  };
-</script>
-
-{@render content({
-  onDayGroupSelect,
-  onDayGroupAssetSelect,
-})}
--- a/web/src/lib/components/timeline/SelectableSegment.svelte
+++ b/web/src/lib/components/timeline/SelectableSegment.svelte
@@ -1,208 +0,0 @@
-<script lang="ts">
-  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
-  import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
-  import { isSelectingAllAssets } from '$lib/stores/assets-store.svelte';
-  import { navigate } from '$lib/utils/navigation';
-
-  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
-  import type { PhotostreamSegment } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
-  import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
-  import { searchStore } from '$lib/stores/search.svelte';
-  import type { Snippet } from 'svelte';
-
-  interface Props {
-    content: Snippet<
-      [
-        {
-          onAssetOpen: (asset: TimelineAsset) => void;
-          onAssetSelect: (asset: TimelineAsset) => void;
-          onAssetHover: (asset: TimelineAsset | null) => void;
-        },
-      ]
-    >;
-    segment: PhotostreamSegment;
-    isSelectionMode: boolean;
-    singleSelect: boolean;
-    timelineManager: PhotostreamManager;
-    assetInteraction: AssetInteraction;
-    onAssetOpen?: (asset: TimelineAsset, defaultAssetOpen: () => void) => void;
-    onAssetSelect?: (asset: TimelineAsset) => void;
-
-    onScrollCompensationMonthInDOM: (compensation: { heightDelta?: number; scrollTop?: number }) => void;
-  }
-
-  let {
-    segment,
-    content,
-    isSelectionMode,
-    singleSelect,
-    assetInteraction,
-    timelineManager,
-    onAssetOpen,
-    onAssetSelect,
-    onScrollCompensationMonthInDOM,
-  }: Props = $props();
-
-  let shiftKeyIsDown = $state(false);
-  let isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
-  let lastMouseHoverAsset: TimelineAsset | null = $state(null);
-
-  $effect(() => {
-    if (shiftKeyIsDown && lastMouseHoverAsset) {
-      void selectAssetCandidates(lastMouseHoverAsset);
-    }
-    if (isEmpty) {
-      assetInteraction.clearMultiselect();
-    }
-  });
-
-  const defaultAssetOpen = (asset: TimelineAsset) => {
-    if (isSelectionMode || assetInteraction.selectionActive) {
-      handleAssetSelect(asset);
-      return;
-    }
-    void navigate({ targetRoute: 'current', assetId: asset.id });
-  };
-
-  const handleOnAssetOpen = (asset: TimelineAsset) => {
-    if (onAssetOpen) {
-      onAssetOpen(asset, () => defaultAssetOpen(asset));
-      return;
-    }
-    defaultAssetOpen(asset);
-  };
-
-  // called when clicking asset with shift key pressed or with mouse
-  const handleAssetSelect = (asset: TimelineAsset) => {
-    handleSelectAssets(asset);
-
-    if (timelineManager.assetCount == assetInteraction.selectedAssets.length) {
-      isSelectingAllAssets.set(true);
-    } else {
-      isSelectingAllAssets.set(false);
-    }
-  };
-
-  const onKeyDown = (event: KeyboardEvent) => {
-    if (searchStore.isSearchEnabled) {
-      return;
-    }
-
-    if (event.key === 'Shift') {
-      event.preventDefault();
-      shiftKeyIsDown = true;
-      assetInteraction.clearAssetSelectionCandidates();
-      if (lastMouseHoverAsset) {
-        void selectAssetCandidates(lastMouseHoverAsset);
-        return;
-      }
-      if (!assetInteraction.assetSelectionStart) {
-        assetInteraction.setAssetSelectionStart(assetInteraction.selectedAssets.at(-1) ?? null);
-      }
-    }
-  };
-
-  const onKeyUp = (event: KeyboardEvent) => {
-    if (searchStore.isSearchEnabled) {
-      return;
-    }
-
-    if (event.key === 'Shift') {
-      event.preventDefault();
-      shiftKeyIsDown = false;
-      assetInteraction.clearAssetSelectionCandidates();
-    }
-  };
-
-  const handleOnHover = (asset: TimelineAsset | null) => {
-    if (asset) {
-      if (assetInteraction.selectionActive) {
-        void selectAssetCandidates(asset);
-      }
-      lastMouseHoverAsset = asset;
-    }
-  };
-
-  const handleSelectAssets = (asset: TimelineAsset) => {
-    if (!asset) {
-      return;
-    }
-    onAssetSelect?.(asset);
-
-    if (singleSelect) {
-      return;
-    }
-
-    const rangeSelection = assetInteraction.assetSelectionCandidates.length > 0;
-    const deselect = assetInteraction.hasSelectedAsset(asset.id);
-
-    // Select/deselect already loaded assets
-    if (deselect) {
-      for (const candidate of assetInteraction.assetSelectionCandidates) {
-        assetInteraction.removeAssetFromMultiselectGroup(candidate.id);
-      }
-      assetInteraction.removeAssetFromMultiselectGroup(asset.id);
-    } else {
-      for (const candidate of assetInteraction.assetSelectionCandidates) {
-        handleSelectAsset(candidate);
-      }
-      handleSelectAsset(asset);
-    }
-
-    assetInteraction.clearAssetSelectionCandidates();
-
-    if (assetInteraction.assetSelectionStart && rangeSelection) {
-      const assets = timelineManager.retrieveLoadedRange(assetInteraction.assetSelectionStart, asset);
-      for (const asset of assets) {
-        if (deselect) {
-          assetInteraction.removeAssetFromMultiselectGroup(asset.id);
-        } else {
-          handleSelectAsset(asset);
-        }
-      }
-    }
-    assetInteraction.setAssetSelectionStart(deselect ? null : asset);
-    return null;
-  };
-
-  const handleSelectAsset = (asset: TimelineAsset) => {
-    if ('albumAssets' in timelineManager) {
-      const tm = timelineManager as TimelineManager;
-      if (tm.albumAssets.has(asset.id)) {
-        return;
-      }
-    }
-
-    assetInteraction.selectAsset(asset);
-  };
-
-  const selectAssetCandidates = (endAsset: TimelineAsset) => {
-    if (!shiftKeyIsDown) {
-      return;
-    }
-
-    const startAsset = assetInteraction.assetSelectionStart;
-    if (!startAsset) {
-      return;
-    }
-    const assets = assetsSnapshot(timelineManager.retrieveLoadedRange(startAsset, endAsset));
-    assetInteraction.setAssetSelectionCandidates(assets);
-  };
-
-  $effect.root(() => {
-    if (timelineManager.scrollCompensation.monthGroup === segment) {
-      onScrollCompensationMonthInDOM(timelineManager.scrollCompensation);
-    }
-  });
-</script>
-
-<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} />
-
-{@render content({
-  onAssetOpen: handleOnAssetOpen,
-  onAssetSelect: (asset) => {
-    void handleSelectAssets(asset);
-  },
-  onAssetHover: handleOnHover,
-})}
--- a/web/src/lib/components/timeline/Timeline.svelte
+++ b/web/src/lib/components/timeline/Timeline.svelte
@@ -1,26 +1,36 @@
 <script lang="ts">
  import { afterNavigate, beforeNavigate } from '$app/navigation';
-  import { page } from '$app/state';
+  import { page } from '$app/stores';
+  import { resizeObserver, type OnResizeCallback } from '$lib/actions/resize-observer';
  import Thumbnail from '$lib/components/assets/thumbnail/thumbnail.svelte';
  import MonthSegment from '$lib/components/timeline/MonthSegment.svelte';
-  import PhotostreamWithScrubber from '$lib/components/timeline/PhotostreamWithScrubber.svelte';
-  import SelectableDay from '$lib/components/timeline/SelectableDay.svelte';
-  import SelectableSegment from '$lib/components/timeline/SelectableSegment.svelte';
+  import Scrubber from '$lib/components/timeline/Scrubber.svelte';
  import TimelineAssetViewer from '$lib/components/timeline/TimelineAssetViewer.svelte';
  import TimelineKeyboardActions from '$lib/components/timeline/actions/TimelineKeyboardActions.svelte';
  import { AssetAction } from '$lib/constants';
+  import HotModuleReload from '$lib/elements/HotModuleReload.svelte';
  import Portal from '$lib/elements/Portal.svelte';
  import Skeleton from '$lib/elements/Skeleton.svelte';
+  import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
  import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+  import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
  import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
  import { assetViewingStore } from '$lib/stores/asset-viewing.store';
-  import { isAssetViewerRoute, navigate } from '$lib/utils/navigation';
-  import { getSegmentIdentifier, getTimes } from '$lib/utils/timeline-util';
+  import { isSelectingAllAssets } from '$lib/stores/assets-store.svelte';
+  import { mobileDevice } from '$lib/stores/mobile-device.svelte';
+  import { navigate } from '$lib/utils/navigation';
+  import {
+    getSegmentIdentifier,
+    getTimes,
+    type ScrubberListener,
+    type TimelineYearMonth,
+  } from '$lib/utils/timeline-util';
  import { type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';
  import { DateTime } from 'luxon';
-  import { type Snippet } from 'svelte';
+  import { onMount, type Snippet } from 'svelte';
+  import type { UpdatePayload } from 'vite';

  interface Props {
    isSelectionMode?: boolean;
@@ -44,12 +54,22 @@
    album?: AlbumResponseDto | null;
    person?: PersonResponseDto | null;
    isShowDeleteConfirmation?: boolean;
-    onAssetOpen?: (asset: TimelineAsset, defaultAssetOpen: () => void) => void;
-    onAssetSelect?: (asset: TimelineAsset) => void;
+    onSelect?: (asset: TimelineAsset) => void;
    onEscape?: () => void;
    children?: Snippet;
    empty?: Snippet;
    customThumbnailLayout?: Snippet<[TimelineAsset]>;
+    onThumbnailClick?: (
+      asset: TimelineAsset,
+      timelineManager: TimelineManager,
+      dayGroup: DayGroup,
+      onClick: (
+        timelineManager: TimelineManager,
+        assets: TimelineAsset[],
+        groupTitle: string,
+        asset: TimelineAsset,
+      ) => void,
+    ) => void;
  }

  let {
@@ -65,149 +85,694 @@
    album = null,
    person = null,
    isShowDeleteConfirmation = $bindable(false),
-
-    onAssetSelect,
-    onAssetOpen,
+    onSelect = () => {},
    onEscape = () => {},
    children,
    empty,
    customThumbnailLayout,
+    onThumbnailClick,
  }: Props = $props();

  let { isViewing: showAssetViewer, asset: viewingAsset, gridScrollTarget } = assetViewingStore;

-  let viewer: PhotostreamWithScrubber | undefined = $state();
-  let showSkeleton: boolean = $state(true);
+  let element: HTMLElement | undefined = $state();

-  // tri-state boolean
-  let initialLoadWasAssetViewer: boolean | null = null;
-  let hasNavigatedToOrFromAssetViewer: boolean = false;
-  let timelineScrollPositionInitialized = false;
+  let timelineElement: HTMLElement | undefined = $state();
+  let showSkeleton = $state(true);
+  // The percentage of scroll through the month that is currently intersecting the top boundary of the viewport.
+  // Note: There may be multiple months visible within the viewport at any given time.
+  let viewportTopMonthScrollPercent = $state(0);
+  // The timeline month intersecting the top position of the viewport
+  let viewportTopMonth: { year: number; month: number } | undefined = $state(undefined);
+  // Overall scroll percentage through the entire timeline (0-1)
+  let timelineScrollPercent: number = $state(0);
+  let scrubberWidth = $state(0);

-  beforeNavigate(({ from, to }) => {
-    timelineManager.suspendTransitions = true;
-    hasNavigatedToOrFromAssetViewer = isAssetViewerRoute(to) || isAssetViewerRoute(from);
+  // 60 is the bottom spacer element at 60px
+  let bottomSectionHeight = 60;
+  // Indicates whether the viewport is currently in the lead-out section (after all months)
+  let isInLeadOutSection = $state(false);
+
+  const isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
+  const maxMd = $derived(mobileDevice.maxMd);
+  const usingMobileDevice = $derived(mobileDevice.pointerCoarse);
+
+  $effect(() => {
+    const layoutOptions = maxMd
+      ? {
+          rowHeight: 100,
+          headerHeight: 32,
+        }
+      : {
+          rowHeight: 235,
+          headerHeight: 48,
+        };
+    timelineManager.setLayoutOptions(layoutOptions);
  });

-  const completeAfterNavigate = () => {
-    const assetViewerPage = !!(page.route.id?.endsWith('/[[assetId=id]]') && page.params.assetId);
-    let isInitial = false;
-    // Set initial load state only once
-    if (initialLoadWasAssetViewer === null) {
-      initialLoadWasAssetViewer = assetViewerPage && !hasNavigatedToOrFromAssetViewer;
-      isInitial = true;
+  const scrollTo = (top: number) => {
+    if (element) {
+      element.scrollTo({ top });
+    }
+  };
+  const scrollTop = (top: number) => {
+    if (element) {
+      element.scrollTop = top;
+    }
+  };
+  const scrollBy = (y: number) => {
+    if (element) {
+      element.scrollBy(0, y);
+    }
+  };
+  const scrollToTop = () => {
+    scrollTo(0);
+  };
+
+  const getAssetHeight = (assetId: string, monthGroup: MonthGroup) => {
+    // the following method may trigger any layouts, so need to
+    // handle any scroll compensation that may have been set
+    const height = monthGroup!.findAssetAbsolutePosition(assetId);
+
+    while (timelineManager.scrollCompensation.monthGroup) {
+      handleScrollCompensation(timelineManager.scrollCompensation);
+      timelineManager.clearScrollCompensation();
+    }
+    return height;
+  };
+
+  const assetIsVisible = (assetTop: number): boolean => {
+    if (!element) {
+      return false;
    }

-    let scrollToAssetQueryParam = false;
-    if (
-      !timelineScrollPositionInitialized &&
-      ((isInitial && !assetViewerPage) || // Direct timeline load
-        (!isInitial && hasNavigatedToOrFromAssetViewer)) // Navigated from asset viewer
-    ) {
-      scrollToAssetQueryParam = true;
-      timelineScrollPositionInitialized = true;
+    const { clientHeight, scrollTop } = element;
+    return assetTop >= scrollTop && assetTop < scrollTop + clientHeight;
+  };
+
+  const scrollToAssetId = async (assetId: string) => {
+    const monthGroup = await timelineManager.findMonthGroupForAsset(assetId);
+    if (!monthGroup) {
+      return false;
    }

-    return viewer?.completeAfterNavigate({ scrollToAssetQueryParam });
-  };
-  afterNavigate(({ complete }) => void complete.then(completeAfterNavigate, completeAfterNavigate));
+    const height = getAssetHeight(assetId, monthGroup);

-  const onViewerClose = async (asset: { id: string }) => {
-    assetViewingStore.showAssetViewer(false);
-    showSkeleton = true;
-    $gridScrollTarget = { at: asset.id };
-    await navigate({ targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget });
+    // If the asset is already visible, then don't scroll.
+    if (assetIsVisible(height)) {
+      return true;
+    }
+
+    scrollTo(height);
+    updateSlidingWindow();
+    return true;
  };

+  const scrollToAsset = (asset: TimelineAsset) => {
+    const monthGroup = timelineManager.getMonthGroupByAssetId(asset.id);
+    if (!monthGroup) {
+      return false;
+    }
+    const height = getAssetHeight(asset.id, monthGroup);
+    scrollTo(height);
+    updateSlidingWindow();
+    return true;
+  };
+
+  const completeNav = async () => {
+    const scrollTarget = $gridScrollTarget?.at;
+    let scrolled = false;
+    if (scrollTarget) {
+      scrolled = await scrollToAssetId(scrollTarget);
+    }
+    if (!scrolled) {
+      // if the asset is not found, scroll to the top
+      scrollToTop();
+    }
+    showSkeleton = false;
+  };
+
+  beforeNavigate(() => (timelineManager.suspendTransitions = true));
+
+  afterNavigate((nav) => {
+    const { complete } = nav;
+    complete.then(completeNav, completeNav);
+  });
+
+  const handleAfterUpdate = (payload: UpdatePayload) => {
+    const timelineUpdate = payload.updates.some(
+      (update) => update.path.endsWith('Timeline.svelte') || update.path.endsWith('assets-store.ts'),
+    );
+
+    if (timelineUpdate) {
+      setTimeout(() => {
+        const asset = $page.url.searchParams.get('at');
+        if (asset) {
+          $gridScrollTarget = { at: asset };
+          void navigate(
+            { targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget },
+            { replaceState: true, forceNavigate: true },
+          );
+        } else {
+          scrollToTop();
+        }
+        showSkeleton = false;
+      }, 500);
+    }
+  };
+
+  const handleBeforeUpdate = (payload: UpdatePayload) => {
+    const timelineUpdate = payload.updates.some((update) => update.path.endsWith('Timeline.svelte'));
+    if (timelineUpdate) {
+      timelineManager.destroy();
+    }
+  };
+
+  const updateIsScrolling = () => (timelineManager.scrolling = true);
+  // note: don't throttle, debounch, or otherwise do this function async - it causes flicker
+  const updateSlidingWindow = () => timelineManager.updateSlidingWindow(element?.scrollTop || 0);
+
+  const handleScrollCompensation = ({ heightDelta, scrollTop }: { heightDelta?: number; scrollTop?: number }) => {
+    if (heightDelta !== undefined) {
+      scrollBy(heightDelta);
+    } else if (scrollTop !== undefined) {
+      scrollTo(scrollTop);
+    }
+    // Yes, updateSlideWindow() is called by the onScroll event triggered as a result of
+    // the above calls. However, this delay is enough time to set the intersecting property
+    // of the monthGroup to false, then true, which causes the DOM nodes to be recreated,
+    // causing bad perf, and also, disrupting focus of those elements.
+    updateSlidingWindow();
+  };
+
+  const topSectionResizeObserver: OnResizeCallback = ({ height }) => (timelineManager.topSectionHeight = height);
+
+  onMount(() => {
+    if (!enableRouting) {
+      showSkeleton = false;
+    }
+  });
+
+  const getMaxScrollPercent = () => {
+    const totalHeight = timelineManager.timelineHeight + bottomSectionHeight + timelineManager.topSectionHeight;
+    return (totalHeight - timelineManager.viewportHeight) / totalHeight;
+  };
+
+  const getMaxScroll = () => {
+    if (!element || !timelineElement) {
+      return 0;
+    }
+    return (
+      timelineManager.topSectionHeight + bottomSectionHeight + (timelineElement.clientHeight - element.clientHeight)
+    );
+  };
+
+  const scrollToMonthGroupAndOffset = (monthGroup: MonthGroup, monthGroupScrollPercent: number) => {
+    const topOffset = monthGroup.top;
+    const maxScrollPercent = getMaxScrollPercent();
+    const delta = monthGroup.height * monthGroupScrollPercent;
+    const scrollToTop = (topOffset + delta) * maxScrollPercent;
+
+    scrollTop(scrollToTop);
+  };
+
+  // note: don't throttle, debounce, or otherwise make this function async - it causes flicker
+  // this function scrolls the timeline to the specified month group and offset, based on scrubber interaction
+  const onScrub: ScrubberListener = (scrubberData) => {
+    const { scrubberMonth, overallScrollPercent, scrubberMonthScrollPercent } = scrubberData;
+
+    if (!scrubberMonth || timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
+      // edge case - scroll limited due to size of content, must adjust - use use the overall percent instead
+      const maxScroll = getMaxScroll();
+      const offset = maxScroll * overallScrollPercent;
+      scrollTop(offset);
+    } else {
+      const monthGroup = timelineManager.months.find(
+        ({ yearMonth: { year, month } }) => year === scrubberMonth.year && month === scrubberMonth.month,
+      );
+      if (!monthGroup) {
+        return;
+      }
+      scrollToMonthGroupAndOffset(monthGroup, scrubberMonthScrollPercent);
+    }
+  };
+
+  // note: don't throttle, debounch, or otherwise make this function async - it causes flicker
+  const handleTimelineScroll = () => {
+    isInLeadOutSection = false;
+
+    if (!element) {
+      return;
+    }
+
+    if (timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
+      // edge case - scroll limited due to size of content, must adjust -  use the overall percent instead
+      const maxScroll = getMaxScroll();
+      timelineScrollPercent = Math.min(1, element.scrollTop / maxScroll);
+
+      viewportTopMonth = undefined;
+      viewportTopMonthScrollPercent = 0;
+    } else {
+      let top = element.scrollTop;
+      if (top < timelineManager.topSectionHeight) {
+        // in the lead-in area
+        viewportTopMonth = undefined;
+        viewportTopMonthScrollPercent = 0;
+        const maxScroll = getMaxScroll();
+
+        timelineScrollPercent = Math.min(1, element.scrollTop / maxScroll);
+        return;
+      }
+
+      let maxScrollPercent = getMaxScrollPercent();
+      let found = false;
+
+      const monthsLength = timelineManager.months.length;
+      for (let i = -1; i < monthsLength + 1; i++) {
+        let monthGroup: TimelineYearMonth | undefined;
+        let monthGroupHeight = 0;
+        if (i === -1) {
+          // lead-in
+          monthGroupHeight = timelineManager.topSectionHeight;
+        } else if (i === monthsLength) {
+          // lead-out
+          monthGroupHeight = bottomSectionHeight;
+        } else {
+          monthGroup = timelineManager.months[i].yearMonth;
+          monthGroupHeight = timelineManager.months[i].height;
+        }
+
+        let next = top - monthGroupHeight * maxScrollPercent;
+        // instead of checking for < 0, add a little wiggle room for subpixel resolution
+        if (next < -1 && monthGroup) {
+          viewportTopMonth = monthGroup;
+
+          // allowing next to be at least 1 may cause percent to go negative, so ensure positive percentage
+          viewportTopMonthScrollPercent = Math.max(0, top / (monthGroupHeight * maxScrollPercent));
+
+          // compensate for lost precision/rounding errors advance to the next bucket, if present
+          if (viewportTopMonthScrollPercent > 0.9999 && i + 1 < monthsLength - 1) {
+            viewportTopMonth = timelineManager.months[i + 1].yearMonth;
+            viewportTopMonthScrollPercent = 0;
+          }
+
+          found = true;
+          break;
+        }
+        top = next;
+      }
+      if (!found) {
+        isInLeadOutSection = true;
+        viewportTopMonth = undefined;
+        viewportTopMonthScrollPercent = 0;
+        timelineScrollPercent = 1;
+      }
+    }
+  };
+
+  const handleSelectAsset = (asset: TimelineAsset) => {
+    if (!timelineManager.albumAssets.has(asset.id)) {
+      assetInteraction.selectAsset(asset);
+    }
+  };
+
+  let lastAssetMouseEvent: TimelineAsset | null = $state(null);
+
+  let shiftKeyIsDown = $state(false);
+
+  const onKeyDown = (event: KeyboardEvent) => {
+    if (event.key === 'Shift') {
+      event.preventDefault();
+      shiftKeyIsDown = true;
+    }
+  };
+
+  const onKeyUp = (event: KeyboardEvent) => {
+    if (event.key === 'Shift') {
+      event.preventDefault();
+      shiftKeyIsDown = false;
+    }
+  };
+  const handleSelectAssetCandidates = (asset: TimelineAsset | null) => {
+    if (asset) {
+      void selectAssetCandidates(asset);
+    }
+    lastAssetMouseEvent = asset;
+  };
+
+  const handleGroupSelect = (dayGroup: DayGroup, assets: TimelineAsset[]) => {
+    const group = dayGroup.groupTitle;
+    if (assetInteraction.selectedGroup.has(group)) {
+      assetInteraction.removeGroupFromMultiselectGroup(group);
+      for (const asset of assets) {
+        assetInteraction.removeAssetFromMultiselectGroup(asset.id);
+      }
+    } else {
+      assetInteraction.addGroupToMultiselectGroup(group);
+      for (const asset of assets) {
+        handleSelectAsset(asset);
+      }
+    }
+
+    if (timelineManager.assetCount == assetInteraction.selectedAssets.length) {
+      isSelectingAllAssets.set(true);
+    } else {
+      isSelectingAllAssets.set(false);
+    }
+  };
+
+  const onSelectAssets = async (asset: TimelineAsset) => {
+    if (!asset) {
+      return;
+    }
+    onSelect(asset);
+
+    if (singleSelect) {
+      scrollTop(0);
+      return;
+    }
+
+    const rangeSelection = assetInteraction.assetSelectionCandidates.length > 0;
+    const deselect = assetInteraction.hasSelectedAsset(asset.id);
+
+    // Select/deselect already loaded assets
+    if (deselect) {
+      for (const candidate of assetInteraction.assetSelectionCandidates) {
+        assetInteraction.removeAssetFromMultiselectGroup(candidate.id);
+      }
+      assetInteraction.removeAssetFromMultiselectGroup(asset.id);
+    } else {
+      for (const candidate of assetInteraction.assetSelectionCandidates) {
+        handleSelectAsset(candidate);
+      }
+      handleSelectAsset(asset);
+    }
+
+    assetInteraction.clearAssetSelectionCandidates();
+
+    if (assetInteraction.assetSelectionStart && rangeSelection) {
+      let startBucket = timelineManager.getMonthGroupByAssetId(assetInteraction.assetSelectionStart.id);
+      let endBucket = timelineManager.getMonthGroupByAssetId(asset.id);
+
+      if (startBucket === null || endBucket === null) {
+        return;
+      }
+
+      // Select/deselect assets in range (start,end)
+      let started = false;
+      for (const monthGroup of timelineManager.months) {
+        if (monthGroup === endBucket) {
+          break;
+        }
+        if (started) {
+          await timelineManager.loadSegment(monthGroup.identifier);
+          for (const asset of monthGroup.assetsIterator()) {
+            if (deselect) {
+              assetInteraction.removeAssetFromMultiselectGroup(asset.id);
+            } else {
+              handleSelectAsset(asset);
+            }
+          }
+        }
+        if (monthGroup === startBucket) {
+          started = true;
+        }
+      }
+
+      // Update date group selection in range [start,end]
+      started = false;
+      for (const monthGroup of timelineManager.months) {
+        if (monthGroup === startBucket) {
+          started = true;
+        }
+        if (started) {
+          // Split month group into day groups and check each group
+          for (const dayGroup of monthGroup.dayGroups) {
+            const dayGroupTitle = dayGroup.groupTitle;
+            if (dayGroup.getAssets().every((a) => assetInteraction.hasSelectedAsset(a.id))) {
+              assetInteraction.addGroupToMultiselectGroup(dayGroupTitle);
+            } else {
+              assetInteraction.removeGroupFromMultiselectGroup(dayGroupTitle);
+            }
+          }
+        }
+        if (monthGroup === endBucket) {
+          break;
+        }
+      }
+    }
+
+    assetInteraction.setAssetSelectionStart(deselect ? null : asset);
+  };
+
+  const selectAssetCandidates = async (endAsset: TimelineAsset) => {
+    if (!shiftKeyIsDown) {
+      return;
+    }
+
+    const startAsset = assetInteraction.assetSelectionStart;
+    if (!startAsset) {
+      return;
+    }
+
+    const assets = assetsSnapshot(await timelineManager.retrieveRange(startAsset, endAsset));
+    assetInteraction.setAssetSelectionCandidates(assets);
+  };
+
+  $effect(() => {
+    if (!lastAssetMouseEvent) {
+      assetInteraction.clearAssetSelectionCandidates();
+    }
+  });
+
+  $effect(() => {
+    if (!shiftKeyIsDown) {
+      assetInteraction.clearAssetSelectionCandidates();
+    }
+  });
+
+  $effect(() => {
+    if (shiftKeyIsDown && lastAssetMouseEvent) {
+      void selectAssetCandidates(lastAssetMouseEvent);
+    }
+  });
+
  $effect(() => {
    if ($showAssetViewer) {
      const { localDateTime } = getTimes($viewingAsset.fileCreatedAt, DateTime.local().offset / 60);
      void timelineManager.loadSegment(getSegmentIdentifier({ year: localDateTime.year, month: localDateTime.month }));
    }
  });
+
+  const assetSelectHandler = (
+    timelineManager: TimelineManager,
+    asset: TimelineAsset,
+    assetsInDayGroup: TimelineAsset[],
+    groupTitle: string,
+  ) => {
+    void onSelectAssets(asset);
+
+    // Check if all assets are selected in a group to toggle the group selection's icon
+    let selectedAssetsInGroupCount = assetsInDayGroup.filter((asset) =>
+      assetInteraction.hasSelectedAsset(asset.id),
+    ).length;
+
+    // if all assets are selected in a group, add the group to selected group
+    if (selectedAssetsInGroupCount == assetsInDayGroup.length) {
+      assetInteraction.addGroupToMultiselectGroup(groupTitle);
+    } else {
+      assetInteraction.removeGroupFromMultiselectGroup(groupTitle);
+    }
+
+    if (timelineManager.assetCount == assetInteraction.selectedAssets.length) {
+      isSelectingAllAssets.set(true);
+    } else {
+      isSelectingAllAssets.set(false);
+    }
+  };
+
+  const _onClick = (
+    timelineManager: TimelineManager,
+    assets: TimelineAsset[],
+    groupTitle: string,
+    asset: TimelineAsset,
+  ) => {
+    if (isSelectionMode || assetInteraction.selectionActive) {
+      assetSelectHandler(timelineManager, asset, assets, groupTitle);
+      return;
+    }
+    void navigate({ targetRoute: 'current', assetId: asset.id });
+  };
 </script>

+<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} />
+
+<HotModuleReload onAfterUpdate={handleAfterUpdate} onBeforeUpdate={handleBeforeUpdate} />
+
 <TimelineKeyboardActions
-  scrollToAsset={async (asset) => (await viewer?.scrollToAsset(asset)) ?? Promise.resolve(false)}
+  scrollToAsset={(asset) => scrollToAsset(asset) ?? false}
  {timelineManager}
  {assetInteraction}
  bind:isShowDeleteConfirmation
  {onEscape}
 />

-<PhotostreamWithScrubber
-  bind:this={viewer}
-  {enableRouting}
-  {timelineManager}
-  {isShowDeleteConfirmation}
-  {showSkeleton}
-  {children}
-  {empty}
+{#if timelineManager.months.length > 0}
+  <Scrubber
+    {timelineManager}
+    height={timelineManager.viewportHeight}
+    timelineTopOffset={timelineManager.topSectionHeight}
+    timelineBottomOffset={bottomSectionHeight}
+    {isInLeadOutSection}
+    {timelineScrollPercent}
+    {viewportTopMonthScrollPercent}
+    {viewportTopMonth}
+    {onScrub}
+    bind:scrubberWidth
+    onScrubKeyDown={(evt) => {
+      evt.preventDefault();
+      let amount = 50;
+      if (shiftKeyIsDown) {
+        amount = 500;
+      }
+      if (evt.key === 'ArrowUp') {
+        amount = -amount;
+        if (shiftKeyIsDown) {
+          element?.scrollBy({ top: amount, behavior: 'smooth' });
+        }
+      } else if (evt.key === 'ArrowDown') {
+        element?.scrollBy({ top: amount, behavior: 'smooth' });
+      }
+    }}
+  />
+{/if}
+
+<!-- Right margin MUST be equal to the width of scrubber -->
+<section
+  id="asset-grid"
+  class={['scrollbar-hidden h-full overflow-y-auto outline-none', { 'm-0': isEmpty }, { 'ms-0': !isEmpty }]}
+  style:margin-right={(usingMobileDevice ? 0 : scrubberWidth) + 'px'}
+  tabindex="-1"
+  bind:clientHeight={timelineManager.viewportHeight}
+  bind:clientWidth={null, (v: number) => ((timelineManager.viewportWidth = v), updateSlidingWindow())}
+  bind:this={element}
+  onscroll={() => (handleTimelineScroll(), updateSlidingWindow(), updateIsScrolling())}
 >
-  {#snippet skeleton({ segment })}
-    <Skeleton
-      height={segment.height - segment.timelineManager.headerHeight}
-      title={(segment as MonthGroup).monthGroupTitle}
-    />
-  {/snippet}
-  {#snippet segment({ segment, onScrollCompensationMonthInDOM })}
-    <SelectableSegment
-      {segment}
-      {onScrollCompensationMonthInDOM}
-      {timelineManager}
-      {assetInteraction}
-      {isSelectionMode}
-      {singleSelect}
-      {onAssetOpen}
-      {onAssetSelect}
+  <section
+    bind:this={timelineElement}
+    id="virtual-timeline"
+    class:invisible={showSkeleton}
+    style:height={timelineManager.timelineHeight + 'px'}
+  >
+    <section
+      use:resizeObserver={topSectionResizeObserver}
+      class:invisible={showSkeleton}
+      style:position="absolute"
+      style:left="0"
+      style:right="0"
    >
-      {#snippet content({ onAssetOpen, onAssetSelect, onAssetHover })}
-        <SelectableDay {assetInteraction} {onAssetSelect}>
-          {#snippet content({ onDayGroupSelect, onDayGroupAssetSelect })}
-            <MonthSegment
-              {assetInteraction}
-              {customThumbnailLayout}
-              {singleSelect}
-              monthGroup={segment as MonthGroup}
-              {timelineManager}
-              {onDayGroupSelect}
-            >
-              {#snippet thumbnail({ asset, position, dayGroup, groupIndex })}
-                {@const isAssetSelectionCandidate = assetInteraction.hasSelectionCandidate(asset.id)}
-                {@const isAssetSelected =
-                  assetInteraction.hasSelectedAsset(asset.id) || timelineManager.albumAssets.has(asset.id)}
-                {@const isAssetDisabled = timelineManager.albumAssets.has(asset.id)}
-                <Thumbnail
-                  showStackedIcon={withStacked}
-                  {showArchiveIcon}
-                  {asset}
-                  {groupIndex}
-                  onClick={() => onAssetOpen(asset)}
-                  onSelect={() => onDayGroupAssetSelect(dayGroup, asset)}
-                  onMouseEvent={(isMouseOver) => {
-                    if (isMouseOver) {
-                      onAssetHover(asset);
-                    } else {
-                      onAssetHover(null);
-                    }
-                  }}
-                  selected={isAssetSelected}
-                  selectionCandidate={isAssetSelectionCandidate}
-                  disabled={isAssetDisabled}
-                  thumbnailWidth={position.width}
-                  thumbnailHeight={position.height}
-                />
-              {/snippet}
-            </MonthSegment>
-          {/snippet}
-        </SelectableDay>
-      {/snippet}
-    </SelectableSegment>
-  {/snippet}
-</PhotostreamWithScrubber>
+      {@render children?.()}
+      {#if isEmpty}
+        <!-- (optional) empty placeholder -->
+        {@render empty?.()}
+      {/if}
+    </section>
+
+    {#each timelineManager.months as monthGroup (monthGroup.viewId)}
+      {@const display = monthGroup.intersecting}
+      {@const absoluteHeight = monthGroup.top}
+
+      {#if !monthGroup.isLoaded}
+        <div
+          style:height={monthGroup.height + 'px'}
+          style:position="absolute"
+          style:transform={`translate3d(0,${absoluteHeight}px,0)`}
+          style:width="100%"
+        >
+          <Skeleton
+            height={monthGroup.height - monthGroup.timelineManager.headerHeight}
+            title={monthGroup.monthGroupTitle}
+          />
+        </div>
+      {:else if display}
+        <div
+          class="month-group"
+          style:height={monthGroup.height + 'px'}
+          style:position="absolute"
+          style:transform={`translate3d(0,${absoluteHeight}px,0)`}
+          style:width="100%"
+        >
+          <MonthSegment
+            {assetInteraction}
+            {customThumbnailLayout}
+            {singleSelect}
+            {monthGroup}
+            {timelineManager}
+            onDayGroupSelect={handleGroupSelect}
+          >
+            {#snippet thumbnail({ asset, position, dayGroup, groupIndex })}
+              {@const isAssetSelectionCandidate = assetInteraction.hasSelectionCandidate(asset.id)}
+              {@const isAssetSelected =
+                assetInteraction.hasSelectedAsset(asset.id) || timelineManager.albumAssets.has(asset.id)}
+              {@const isAssetDisabled = timelineManager.albumAssets.has(asset.id)}
+              <Thumbnail
+                showStackedIcon={withStacked}
+                {showArchiveIcon}
+                {asset}
+                {groupIndex}
+                onClick={(asset) => {
+                  if (typeof onThumbnailClick === 'function') {
+                    onThumbnailClick(asset, timelineManager, dayGroup, _onClick);
+                  } else {
+                    _onClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
+                  }
+                }}
+                onSelect={() => {
+                  if (isSelectionMode || assetInteraction.selectionActive) {
+                    assetSelectHandler(timelineManager, asset, dayGroup.getAssets(), dayGroup.groupTitle);
+                    return;
+                  }
+                  void onSelectAssets(asset);
+                }}
+                onMouseEvent={() => handleSelectAssetCandidates(asset)}
+                selected={isAssetSelected}
+                selectionCandidate={isAssetSelectionCandidate}
+                disabled={isAssetDisabled}
+                thumbnailWidth={position.width}
+                thumbnailHeight={position.height}
+              />
+            {/snippet}
+          </MonthSegment>
+        </div>
+      {/if}
+    {/each}
+    <!-- spacer for leadout -->
+    <div
+      class="h-[60px]"
+      style:position="absolute"
+      style:left="0"
+      style:right="0"
+      style:transform={`translate3d(0,${timelineManager.timelineHeight}px,0)`}
+    ></div>
+  </section>
+</section>

 <Portal target="body">
  {#if $showAssetViewer}
-    <TimelineAssetViewer {timelineManager} {removeAction} {withStacked} {isShared} {album} {person} {onViewerClose} />
+    <TimelineAssetViewer bind:showSkeleton {timelineManager} {removeAction} {withStacked} {isShared} {album} {person} />
  {/if}
 </Portal>
+
+<style>
+  #asset-grid {
+    contain: strict;
+    scrollbar-width: none;
+  }
+
+  .month-group {
+    contain: layout size paint;
+    transform-style: flat;
+    backface-visibility: hidden;
+    transform-origin: center center;
+  }
+</style>
--- a/web/src/lib/components/timeline/TimelineAssetViewer.svelte
+++ b/web/src/lib/components/timeline/TimelineAssetViewer.svelte
@@ -9,16 +9,15 @@
  import { toTimelineAsset } from '$lib/utils/timeline-util';
  import { getAssetInfo, type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';

-  let { asset: viewingAsset, mutex, preloadAssets } = assetViewingStore;
+  let { asset: viewingAsset, gridScrollTarget, mutex, preloadAssets } = assetViewingStore;

  interface Props {
    timelineManager: TimelineManager;
-
+    showSkeleton: boolean;
    withStacked?: boolean;
    isShared?: boolean;
    album?: AlbumResponseDto | null;
    person?: PersonResponseDto | null;
-    onViewerClose?: (asset: { id: string }) => Promise<void>;

    removeAction?:
      | AssetAction.UNARCHIVE
@@ -31,12 +30,12 @@

  let {
    timelineManager,
+    showSkeleton = $bindable(false),
    removeAction,
    withStacked = false,
    isShared = false,
    album = null,
    person = null,
-    onViewerClose = () => Promise.resolve(void 0),
  }: Props = $props();

  const handlePrevious = async () => {
@@ -80,6 +79,13 @@
    }
  };

+  const handleClose = async (asset: { id: string }) => {
+    assetViewingStore.showAssetViewer(false);
+    showSkeleton = true;
+    $gridScrollTarget = { at: asset.id };
+    await navigate({ targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget });
+  };
+
  const handlePreAction = async (action: Action) => {
    switch (action.type) {
      case removeAction:
@@ -91,7 +97,7 @@
      case AssetAction.SET_VISIBILITY_TIMELINE: {
        // find the next asset to show or close the viewer
        // eslint-disable-next-line @typescript-eslint/no-unused-expressions
-        (await handleNext()) || (await handlePrevious()) || (await onViewerClose?.(action.asset));
+        (await handleNext()) || (await handlePrevious()) || (await handleClose(action.asset));

        // delete after find the next one
        timelineManager.removeAssets([action.asset.id]);
@@ -105,12 +111,12 @@
      case AssetAction.UNARCHIVE:
      case AssetAction.FAVORITE:
      case AssetAction.UNFAVORITE: {
-        timelineManager.updateAssets([action.asset]);
+        timelineManager.upsertAssets([action.asset]);
        break;
      }

      case AssetAction.ADD: {
-        timelineManager.addAssets([action.asset]);
+        timelineManager.upsertAssets([action.asset]);
        break;
      }

@@ -119,7 +125,7 @@
        break;
      }
      case AssetAction.REMOVE_ASSET_FROM_STACK: {
-        timelineManager.addAssets([toTimelineAsset(action.asset)]);
+        timelineManager.upsertAssets([toTimelineAsset(action.asset)]);
        if (action.stack) {
          //Have to unstack then restack assets in timeline in order to update the stack count in the timeline.
          updateUnstackedAssetInTimeline(
@@ -166,6 +172,6 @@
    onPrevious={handlePrevious}
    onNext={handleNext}
    onRandom={handleRandom}
-    onClose={onViewerClose}
+    onClose={handleClose}
  />
 {/await}
--- a/web/src/lib/components/timeline/actions/ArchiveAction.svelte
+++ b/web/src/lib/components/timeline/actions/ArchiveAction.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
  import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
  import type { OnArchive } from '$lib/utils/actions';
  import { archiveAssets } from '$lib/utils/asset-utils';
  import { AssetVisibility } from '@immich/sdk';
@@ -12,9 +13,10 @@
    onArchive?: OnArchive;
    menuItem?: boolean;
    unarchive?: boolean;
+    manager?: PhotostreamManager;
  }

-  let { onArchive, menuItem = false, unarchive = false }: Props = $props();
+  let { onArchive, menuItem = false, unarchive = false, manager }: Props = $props();

  let text = $derived(unarchive ? $t('unarchive') : $t('to_archive'));
  let icon = $derived(unarchive ? mdiArchiveArrowUpOutline : mdiArchiveArrowDownOutline);
@@ -24,12 +26,13 @@
  const { clearSelect, getOwnedAssets } = getAssetControlContext();

  const handleArchive = async () => {
-    const isArchived = unarchive ? AssetVisibility.Timeline : AssetVisibility.Archive;
-    const assets = [...getOwnedAssets()].filter((asset) => asset.visibility !== isArchived);
+    const visibility = unarchive ? AssetVisibility.Timeline : AssetVisibility.Archive;
+    const assets = [...getOwnedAssets()].filter((asset) => asset.visibility !== visibility);
    loading = true;
-    const ids = await archiveAssets(assets, isArchived as AssetVisibility);
+    const ids = await archiveAssets(assets, visibility as AssetVisibility);
    if (ids) {
-      onArchive?.(ids, isArchived ? AssetVisibility.Archive : AssetVisibility.Timeline);
+      manager?.updateAssetOperation(ids, (asset) => ((asset.visibility = visibility), void 0));
+      onArchive?.(ids, visibility ? AssetVisibility.Archive : AssetVisibility.Timeline);
      clearSelect();
    }
    loading = false;
--- a/web/src/lib/components/timeline/actions/DeleteAssetsAction.svelte
+++ b/web/src/lib/components/timeline/actions/DeleteAssetsAction.svelte
@@ -1,6 +1,8 @@
 <script lang="ts">
  import DeleteAssetDialog from '$lib/components/photos-page/delete-asset-dialog.svelte';
  import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
  import { featureFlags } from '$lib/stores/server-config.store';
  import { type OnDelete, type OnUndoDelete, deleteAssets } from '$lib/utils/actions';
  import { IconButton } from '@immich/ui';
@@ -9,13 +11,14 @@
  import MenuOption from '../../shared-components/context-menu/menu-option.svelte';

  interface Props {
-    onAssetDelete: OnDelete;
-    onUndoDelete?: OnUndoDelete | undefined;
+    onAssetDelete?: OnDelete;
+    onUndoDelete?: OnUndoDelete;
    menuItem?: boolean;
    force?: boolean;
+    manager?: PhotostreamManager;
  }

-  let { onAssetDelete, onUndoDelete = undefined, menuItem = false, force = !$featureFlags.trash }: Props = $props();
+  let { onAssetDelete, onUndoDelete, menuItem = false, force = !$featureFlags.trash, manager }: Props = $props();

  const { clearSelect, getOwnedAssets } = getAssetControlContext();

@@ -36,7 +39,12 @@
  const handleDelete = async () => {
    loading = true;
    const assets = [...getOwnedAssets()];
-    await deleteAssets(force, onAssetDelete, assets, onUndoDelete);
+    const undo = (assets: TimelineAsset[]) => {
+      manager?.upsertAssets(assets);
+      onUndoDelete?.(assets);
+    };
+    await deleteAssets(force, onAssetDelete, assets, undo);
+    manager?.removeAssets(assets.map((asset) => asset.id));
    clearSelect();
    isShowConfirmation = false;
    loading = false;
--- a/web/src/lib/components/timeline/actions/FavoriteAction.svelte
+++ b/web/src/lib/components/timeline/actions/FavoriteAction.svelte
@@ -5,6 +5,7 @@
    notificationController,
  } from '$lib/components/shared-components/notification/notification';
  import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
  import type { OnFavorite } from '$lib/utils/actions';
  import { handleError } from '$lib/utils/handle-error';
  import { updateAssets } from '@immich/sdk';
@@ -16,9 +17,10 @@
    onFavorite?: OnFavorite;
    menuItem?: boolean;
    removeFavorite: boolean;
+    manager?: PhotostreamManager;
  }

-  let { onFavorite, menuItem = false, removeFavorite }: Props = $props();
+  let { onFavorite, menuItem = false, removeFavorite, manager }: Props = $props();

  let text = $derived(removeFavorite ? $t('remove_from_favorites') : $t('to_favorite'));
  let icon = $derived(removeFavorite ? mdiHeartMinusOutline : mdiHeartOutline);
@@ -39,11 +41,7 @@
      if (ids.length > 0) {
        await updateAssets({ assetBulkUpdateDto: { ids, isFavorite } });
      }
-
-      for (const asset of assets) {
-        asset.isFavorite = isFavorite;
-      }
-
+      manager?.updateAssetOperation(ids, (asset) => ((asset.isFavorite = isFavorite), void 0));
      onFavorite?.(ids, isFavorite);

      notificationController.show({
--- a/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte
+++ b/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte
@@ -7,10 +7,8 @@
    type RelativeResult,
  } from '$lib/components/shared-components/change-date.svelte';
  import {
-    setFocusToAsset as setFocusAssetUtil,
-    setFocusTo as setFocusToUtil,
-    type FocusDirection,
-    type FocusInterval,
+    setFocusToAsset as setFocusAssetInit,
+    setFocusTo as setFocusToInit,
  } from '$lib/components/timeline/actions/focus-actions';
  import { AppRoute } from '$lib/constants';
  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
@@ -34,7 +32,7 @@
    assetInteraction: AssetInteraction;
    isShowDeleteConfirmation: boolean;
    onEscape?: () => void;
-    scrollToAsset: (asset: TimelineAsset) => Promise<boolean>;
+    scrollToAsset: (asset: TimelineAsset) => boolean;
  }

  let {
@@ -53,7 +51,7 @@
      !(isTrashEnabled && !force),
      (assetIds) => timelineManager.removeAssets(assetIds),
      assetInteraction.selectedAssets,
-      !isTrashEnabled || force ? undefined : (assets) => timelineManager.addAssets(assets),
+      !isTrashEnabled || force ? undefined : (assets) => timelineManager.upsertAssets(assets),
    );
    assetInteraction.clearMultiselect();
  };
@@ -149,10 +147,8 @@
    }
  });

-  const setFocusTo = (direction: FocusDirection, interval: FocusInterval) =>
-    setFocusToUtil(scrollToAsset, timelineManager, direction, interval);
-
-  const setFocusAsset = (asset: TimelineAsset) => setFocusAssetUtil(scrollToAsset, asset);
+  const setFocusTo = setFocusToInit.bind(undefined, scrollToAsset, timelineManager);
+  const setFocusAsset = setFocusAssetInit.bind(undefined, scrollToAsset);

  let shortcutList = $derived(
    (() => {
@@ -216,7 +212,7 @@
          (DateTime.fromISO(dateString.date) as DateTime<true>).toObject(),
        );
        if (asset) {
-          void setFocusAsset(asset);
+          setFocusAsset(asset);
        }
      }
    }}
--- a/web/src/lib/components/timeline/actions/focus-actions.ts
+++ b/web/src/lib/components/timeline/actions/focus-actions.ts
@@ -21,26 +21,19 @@ export const focusPreviousAsset = () =>

 const queryHTMLElement = (query: string) => document.querySelector(query) as HTMLElement;

-export const setFocusToAsset = async (
-  scrollToAsset: (asset: TimelineAsset) => Promise<boolean>,
-  asset: TimelineAsset,
-) => {
-  const scrolled = await scrollToAsset(asset);
+export const setFocusToAsset = (scrollToAsset: (asset: TimelineAsset) => boolean, asset: TimelineAsset) => {
+  const scrolled = scrollToAsset(asset);
  if (scrolled) {
    const element = queryHTMLElement(`[data-thumbnail-focus-container][data-asset="${asset.id}"]`);
    element?.focus();
  }
 };

-export type FocusDirection = 'earlier' | 'later';
-
-export type FocusInterval = 'day' | 'month' | 'year' | 'asset';
-
 export const setFocusTo = async (
-  scrollToAsset: (asset: TimelineAsset) => Promise<boolean>,
+  scrollToAsset: (asset: TimelineAsset) => boolean,
  store: TimelineManager,
-  direction: FocusDirection,
-  interval: FocusInterval,
+  direction: 'earlier' | 'later',
+  interval: 'day' | 'month' | 'year' | 'asset',
 ) => {
  if (tracker.isActive()) {
    // there are unfinished running invocations, so return early
@@ -72,10 +65,7 @@ export const setFocusTo = async (
    return;
  }

-  const scrolled = await scrollToAsset(asset);
-  if (!invocation.isStillValid()) {
-    return;
-  }
+  const scrolled = scrollToAsset(asset);
  if (scrolled) {
    await tick();
    if (!invocation.isStillValid()) {
--- a/web/src/lib/managers/photostream-manager/PhotostreamManager.svelte.ts
+++ b/web/src/lib/managers/photostream-manager/PhotostreamManager.svelte.ts
@@ -3,16 +3,21 @@ import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-s
 import { CancellableTask } from '$lib/utils/cancellable-task';
 import { clamp, debounce } from 'lodash-es';

-import type {
+import {
  PhotostreamSegment,
-  SegmentIdentifier,
+  type SegmentIdentifier,
 } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
+
+import { updateObject } from '$lib/managers/timeline-manager/internal/utils.svelte';
 import type {
  AssetDescriptor,
+  AssetOperation,
+  MoveAsset,
  TimelineAsset,
  TimelineManagerLayoutOptions,
  Viewport,
 } from '$lib/managers/timeline-manager/types';
+import { setDifference } from '$lib/utils/timeline-util';

 export abstract class PhotostreamManager {
  isInitialized = $state(false);
@@ -269,14 +274,13 @@ export abstract class PhotostreamManager {
    return this.months.find((segment) => identifier.matches(segment));
  }

-  findSegmentForAssetId(assetId: string): Promise<PhotostreamSegment | undefined> {
+  getSegmentForAssetId(assetId: string) {
    for (const month of this.months) {
      const asset = month.assets.find((asset) => asset.id === assetId);
      if (asset) {
-        return Promise.resolve(month);
+        return month;
      }
    }
-    return Promise.resolve(void 0);
  }

  refreshLayout() {
@@ -295,15 +299,11 @@ export abstract class PhotostreamManager {
    return this.topSectionHeight + this.bottomSectionHeight + (this.timelineHeight - this.viewportHeight);
  }

-  retrieveLoadedRange(start: AssetDescriptor, end: AssetDescriptor): TimelineAsset[] {
+  retrieveRange(start: AssetDescriptor, end: AssetDescriptor): Promise<TimelineAsset[]> {
    const range: TimelineAsset[] = [];
    let collecting = false;

    for (const month of this.months) {
-      if (collecting && !month.isLoaded) {
-        // if there are any unloaded months in the range, return empty []
-        return [];
-      }
      for (const asset of month.assets) {
        if (asset.id === start.id) {
          collecting = true;
@@ -312,14 +312,112 @@ export abstract class PhotostreamManager {
          range.push(asset);
        }
        if (asset.id === end.id) {
-          return range;
+          return Promise.resolve(range);
        }
      }
    }
-    return range;
+    return Promise.resolve(range);
  }

-  retrieveRange(start: AssetDescriptor, end: AssetDescriptor): Promise<TimelineAsset[]> {
-    return Promise.resolve(this.retrieveLoadedRange(start, end));
+  updateAssetOperation(ids: string[], operation: AssetOperation) {
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    return this.#runAssetOperation(new Set(ids), operation);
+  }
+
+  upsertAssets(assets: TimelineAsset[]) {
+    const notExcluded = assets.filter((asset) => !this.isExcluded(asset));
+    const notUpdated = this.#updateAssets(notExcluded);
+    this.addAssetsToSegments([...notUpdated]);
+  }
+
+  #updateAssets(assets: TimelineAsset[]) {
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const lookup = new Map<string, TimelineAsset>(assets.map((asset) => [asset.id, asset]));
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const { unprocessedIds } = this.#runAssetOperation(new Set(lookup.keys()), (asset) =>
+      updateObject(asset, lookup.get(asset.id)),
+    );
+    const result: TimelineAsset[] = [];
+    for (const id of unprocessedIds.values()) {
+      result.push(lookup.get(id)!);
+    }
+    return result;
+  }
+
+  removeAssets(ids: string[]) {
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const { unprocessedIds } = this.#runAssetOperation(new Set(ids), () => ({ remove: true }));
+    return [...unprocessedIds];
+  }
+
+  isExcluded(_: TimelineAsset) {
+    return false;
+  }
+
+  protected createUpsertContext(): unknown {
+    return;
+  }
+
+  protected abstract upsertAssetIntoSegment(asset: TimelineAsset, context: unknown): void;
+
+  protected postCreateSegments(): void {}
+
+  protected postUpsert(_: unknown): void {}
+
+  protected addAssetsToSegments(assets: TimelineAsset[]) {
+    if (assets.length === 0) {
+      return;
+    }
+    const context = this.createUpsertContext();
+    const monthCount = this.months.length;
+    for (const asset of assets) {
+      this.upsertAssetIntoSegment(asset, context);
+    }
+    if (this.months.length !== monthCount) {
+      this.postCreateSegments();
+    }
+    this.postUpsert(context);
+    this.updateIntersections();
+  }
+
+  #runAssetOperation(ids: Set<string>, operation: AssetOperation) {
+    if (ids.size === 0) {
+      // eslint-disable-next-line svelte/prefer-svelte-reactivity
+      return { processedIds: new Set(), unprocessedIds: ids, changedGeometry: false };
+    }
+
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const changedMonthGroups = new Set<PhotostreamSegment>();
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    let idsToProcess = new Set(ids);
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const idsProcessed = new Set<string>();
+    const combinedMoveAssets: MoveAsset[][] = [];
+    for (const month of this.months) {
+      if (idsToProcess.size > 0) {
+        const { moveAssets, processedIds, changedGeometry } = month.runAssetOperation(idsToProcess, operation);
+        if (moveAssets.length > 0) {
+          combinedMoveAssets.push(moveAssets);
+        }
+        idsToProcess = setDifference(idsToProcess, processedIds);
+        for (const id of processedIds) {
+          idsProcessed.add(id);
+        }
+        if (changedGeometry) {
+          changedMonthGroups.add(month);
+        }
+      }
+    }
+    if (combinedMoveAssets.length > 0) {
+      this.addAssetsToSegments(combinedMoveAssets.flat().map((a) => a.asset));
+    }
+    const changedGeometry = changedMonthGroups.size > 0;
+    for (const month of changedMonthGroups) {
+      updateGeometry(this, month, { invalidateHeight: true });
+    }
+    if (changedGeometry) {
+      this.updateIntersections();
+    }
+    return { unprocessedIds: idsToProcess, processedIds: idsProcessed, changedGeometry };
  }
 }
--- a/web/src/lib/managers/photostream-manager/PhotostreamSegment.svelte.ts
+++ b/web/src/lib/managers/photostream-manager/PhotostreamSegment.svelte.ts
@@ -4,7 +4,7 @@ import { t } from 'svelte-i18n';
 import { get } from 'svelte/store';

 import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
-import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+import type { AssetOperation, MoveAsset, TimelineAsset } from '$lib/managers/timeline-manager/types';
 import type { ViewerAsset } from '$lib/managers/timeline-manager/viewer-asset.svelte';

 export type SegmentIdentifier = {
@@ -147,4 +147,49 @@ export abstract class PhotostreamSegment {
  }

  abstract findAssetAbsolutePosition(assetId: string): number;
+
+  runAssetOperation(ids: Set<string>, operation: AssetOperation) {
+    if (ids.size === 0) {
+      return {
+        moveAssets: [] as MoveAsset[],
+        // eslint-disable-next-line svelte/prefer-svelte-reactivity
+        processedIds: new Set<string>(),
+        unprocessedIds: ids,
+        changedGeometry: false,
+      };
+    }
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const unprocessedIds = new Set<string>(ids);
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const processedIds = new Set<string>();
+    const moveAssets: MoveAsset[] = [];
+    let changedGeometry = false;
+    for (const assetId of unprocessedIds) {
+      const index = this.viewerAssets.findIndex((viewAsset) => viewAsset.id == assetId);
+      if (index === -1) {
+        continue;
+      }
+
+      const asset = this.viewerAssets[index].asset!;
+      const oldTime = { ...asset.localDateTime };
+      const opResult = operation(asset);
+      let remove = false;
+      if (opResult) {
+        remove = (opResult as { remove: boolean }).remove ?? false;
+      }
+      const newTime = asset.localDateTime;
+      if (oldTime.year !== newTime.year || oldTime.month !== newTime.month || oldTime.day !== newTime.day) {
+        const { year, month, day } = newTime;
+        remove = true;
+        moveAssets.push({ asset, date: { year, month, day } });
+      }
+      unprocessedIds.delete(assetId);
+      processedIds.add(assetId);
+      if (remove || this.timelineManager.isExcluded(asset)) {
+        this.viewerAssets.splice(index, 1);
+        changedGeometry = true;
+      }
+    }
+    return { moveAssets, processedIds, unprocessedIds, changedGeometry };
+  }
 }
--- a/web/src/lib/managers/timeline-manager/day-group.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/day-group.svelte.ts
@@ -129,7 +129,11 @@ export class DayGroup {

      const asset = this.viewerAssets[index].asset!;
      const oldTime = { ...asset.localDateTime };
-      let { remove } = operation(asset);
+      const opResult = operation(asset);
+      let remove = false;
+      if (opResult) {
+        remove = (opResult as { remove: boolean }).remove ?? false;
+      }
      const newTime = asset.localDateTime;
      if (oldTime.year !== newTime.year || oldTime.month !== newTime.month || oldTime.day !== newTime.day) {
        const { year, month, day } = newTime;
--- a/web/src/lib/managers/timeline-manager/internal/operations-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/operations-support.svelte.ts
@@ -1,103 +0,0 @@
-import { setDifference, type TimelineDate } from '$lib/utils/timeline-util';
-import { AssetOrder } from '@immich/sdk';
-
-import { SvelteSet } from 'svelte/reactivity';
-import { GroupInsertionCache } from '../group-insertion-cache.svelte';
-import { MonthGroup } from '../month-group.svelte';
-import type { TimelineManager } from '../timeline-manager.svelte';
-import type { AssetOperation, TimelineAsset } from '../types';
-import { updateGeometry } from './layout-support.svelte';
-import { getMonthGroupByDate } from './search-support.svelte';
-
-export function addAssetsToMonthGroups(
-  timelineManager: TimelineManager,
-  assets: TimelineAsset[],
-  options: { order: AssetOrder },
-) {
-  if (assets.length === 0) {
-    return;
-  }
-
-  const addContext = new GroupInsertionCache();
-  const updatedMonthGroups = new SvelteSet<MonthGroup>();
-  const monthCount = timelineManager.months.length;
-  for (const asset of assets) {
-    let month = getMonthGroupByDate(timelineManager, asset.localDateTime);
-
-    if (!month) {
-      month = new MonthGroup(timelineManager, asset.localDateTime, 1, true, options.order);
-      timelineManager.months.push(month);
-    }
-
-    month.addTimelineAsset(asset, addContext);
-    updatedMonthGroups.add(month);
-  }
-
-  if (timelineManager.months.length !== monthCount) {
-    timelineManager.months.sort((a, b) => {
-      return a.yearMonth.year === b.yearMonth.year
-        ? b.yearMonth.month - a.yearMonth.month
-        : b.yearMonth.year - a.yearMonth.year;
-    });
-  }
-
-  for (const group of addContext.existingDayGroups) {
-    group.sortAssets(options.order);
-  }
-
-  for (const monthGroup of addContext.bucketsWithNewDayGroups) {
-    monthGroup.sortDayGroups();
-  }
-
-  for (const month of addContext.updatedBuckets) {
-    month.sortDayGroups();
-    updateGeometry(timelineManager, month, { invalidateHeight: true });
-  }
-  timelineManager.updateIntersections();
-}
-
-export function runAssetOperation(
-  timelineManager: TimelineManager,
-  ids: Set<string>,
-  operation: AssetOperation,
-  options: { order: AssetOrder },
-) {
-  if (ids.size === 0) {
-    return { processedIds: new SvelteSet(), unprocessedIds: ids, changedGeometry: false };
-  }
-
-  const changedMonthGroups = new SvelteSet<MonthGroup>();
-  let idsToProcess = new SvelteSet(ids);
-  const idsProcessed = new SvelteSet<string>();
-  const combinedMoveAssets: { asset: TimelineAsset; date: TimelineDate }[][] = [];
-  for (const month of timelineManager.months) {
-    if (idsToProcess.size > 0) {
-      const { moveAssets, processedIds, changedGeometry } = month.runAssetOperation(idsToProcess, operation);
-      if (moveAssets.length > 0) {
-        combinedMoveAssets.push(moveAssets);
-      }
-      idsToProcess = setDifference(idsToProcess, processedIds);
-      for (const id of processedIds) {
-        idsProcessed.add(id);
-      }
-      if (changedGeometry) {
-        changedMonthGroups.add(month);
-      }
-    }
-  }
-  if (combinedMoveAssets.length > 0) {
-    addAssetsToMonthGroups(
-      timelineManager,
-      combinedMoveAssets.flat().map((a) => a.asset),
-      options,
-    );
-  }
-  const changedGeometry = changedMonthGroups.size > 0;
-  for (const month of changedMonthGroups) {
-    updateGeometry(timelineManager, month, { invalidateHeight: true });
-  }
-  if (changedGeometry) {
-    timelineManager.updateIntersections();
-  }
-  return { unprocessedIds: idsToProcess, processedIds: idsProcessed, changedGeometry };
-}
--- a/web/src/lib/managers/timeline-manager/internal/search-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/search-support.svelte.ts
@@ -143,79 +143,3 @@ export function findMonthGroupForDate(timelineManager: TimelineManager, targetYe
    }
  }
 }
-
-export interface MonthGroupForSearch {
-  yearMonth: TimelineYearMonth;
-  top: number;
-  height: number;
-}
-
-export interface BinarySearchResult {
-  month: TimelineYearMonth;
-  monthScrollPercent: number;
-}
-
-export function findMonthAtScrollPosition(
-  months: MonthGroupForSearch[],
-  scrollPosition: number,
-  maxScrollPercent: number,
-): BinarySearchResult | null {
-  const SUBPIXEL_TOLERANCE = -1; // Tolerance for scroll position checks
-  const NEAR_END_THRESHOLD = 0.9999; // Threshold for detecting near-end of month
-
-  if (months.length === 0) {
-    return null;
-  }
-
-  // Check if we're before the first month
-  const firstMonthTop = months[0].top * maxScrollPercent;
-  if (scrollPosition < firstMonthTop - SUBPIXEL_TOLERANCE) {
-    return null;
-  }
-
-  // Check if we're after the last month
-  const lastMonth = months.at(-1)!;
-  const lastMonthBottom = (lastMonth.top + lastMonth.height) * maxScrollPercent;
-  if (scrollPosition >= lastMonthBottom - SUBPIXEL_TOLERANCE) {
-    return null;
-  }
-
-  // Binary search to find the month containing the scroll position
-  let left = 0;
-  let right = months.length - 1;
-
-  while (left <= right) {
-    const mid = Math.floor((left + right) / 2);
-    const month = months[mid];
-    const monthTop = month.top * maxScrollPercent;
-    const monthBottom = monthTop + month.height * maxScrollPercent;
-
-    if (scrollPosition >= monthTop - SUBPIXEL_TOLERANCE && scrollPosition < monthBottom - SUBPIXEL_TOLERANCE) {
-      // Found the month containing the scroll position
-      const distanceIntoMonth = scrollPosition - monthTop;
-      const monthScrollPercent = Math.max(0, distanceIntoMonth / (month.height * maxScrollPercent));
-
-      // Handle month boundary edge case
-      if (monthScrollPercent > NEAR_END_THRESHOLD && mid < months.length - 1) {
-        return {
-          month: months[mid + 1].yearMonth,
-          monthScrollPercent: 0,
-        };
-      }
-
-      return {
-        month: month.yearMonth,
-        monthScrollPercent,
-      };
-    }
-
-    if (scrollPosition < monthTop) {
-      right = mid - 1;
-    } else {
-      left = mid + 1;
-    }
-  }
-
-  // Shouldn't reach here, but return null if we do
-  return null;
-}
--- a/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts
@@ -13,10 +13,10 @@ export class WebsocketSupport {
  #processPendingChanges = throttle(() => {
    const { add, update, remove } = this.#getPendingChangeBatches();
    if (add.length > 0) {
-      this.#timelineManager.addAssets(add);
+      this.#timelineManager.upsertAssets(add);
    }
    if (update.length > 0) {
-      this.#timelineManager.updateAssets(update);
+      this.#timelineManager.upsertAssets(update);
    }
    if (remove.length > 0) {
      this.#timelineManager.removeAssets(remove);
--- a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts
+++ b/web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts
@@ -1,8 +1,5 @@
 import { sdkMock } from '$lib/__mocks__/sdk.mock';
-import {
-  findMonthGroupForAsset,
-  getMonthGroupByDate,
-} from '$lib/managers/timeline-manager/internal/search-support.svelte';
+import { getMonthGroupByDate } from '$lib/managers/timeline-manager/internal/search-support.svelte';
 import { AbortError } from '$lib/utils';
 import { fromISODateTimeUTCToObject, getSegmentIdentifier } from '$lib/utils/timeline-util';
 import { type AssetResponseDto, type TimeBucketAssetResponseDto } from '@immich/sdk';
@@ -176,7 +173,7 @@ describe('TimelineManager', () => {
    });
  });

-  describe('addAssets', () => {
+  describe('upsertAssets', () => {
    let timelineManager: TimelineManager;

    beforeEach(async () => {
@@ -197,7 +194,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);

      expect(timelineManager.months.length).toEqual(1);
      expect(timelineManager.assetCount).toEqual(1);
@@ -213,8 +210,8 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        })
        .map((asset) => deriveLocalDateTimeFromFileCreatedAt(asset));
-      timelineManager.addAssets([assetOne]);
-      timelineManager.addAssets([assetTwo]);
+      timelineManager.upsertAssets([assetOne]);
+      timelineManager.upsertAssets([assetTwo]);

      expect(timelineManager.months.length).toEqual(1);
      expect(timelineManager.assetCount).toEqual(2);
@@ -239,7 +236,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-16T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo, assetThree]);
+      timelineManager.upsertAssets([assetOne, assetTwo, assetThree]);

      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 });
      expect(month).not.toBeNull();
@@ -265,7 +262,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2023-01-20T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo, assetThree]);
+      timelineManager.upsertAssets([assetOne, assetTwo, assetThree]);

      expect(timelineManager.months.length).toEqual(3);
      expect(timelineManager.months[0].yearMonth.year).toEqual(2024);
@@ -279,11 +276,11 @@ describe('TimelineManager', () => {
    });

    it('updates existing asset', () => {
-      const updateAssetsSpy = vi.spyOn(timelineManager, 'updateAssets');
+      const updateAssetsSpy = vi.spyOn(timelineManager, 'upsertAssets');
      const asset = deriveLocalDateTimeFromFileCreatedAt(timelineAssetFactory.build());
-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);

-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);
      expect(updateAssetsSpy).toBeCalledWith([asset]);
      expect(timelineManager.assetCount).toEqual(1);
    });
@@ -295,7 +292,7 @@ describe('TimelineManager', () => {

      const timelineManager = new TimelineManager();
      await timelineManager.updateOptions({ isTrashed: true });
-      timelineManager.addAssets([asset, trashedAsset]);
+      timelineManager.upsertAssets([asset, trashedAsset]);
      expect(await getAssets(timelineManager)).toEqual([trashedAsset]);
    });
  });
@@ -310,22 +307,15 @@ describe('TimelineManager', () => {
      await timelineManager.updateViewport({ width: 1588, height: 1000 });
    });

-    it('ignores non-existing assets', () => {
-      timelineManager.updateAssets([deriveLocalDateTimeFromFileCreatedAt(timelineAssetFactory.build())]);
-
-      expect(timelineManager.months.length).toEqual(0);
-      expect(timelineManager.assetCount).toEqual(0);
-    });
-
    it('updates an asset', () => {
      const asset = deriveLocalDateTimeFromFileCreatedAt(timelineAssetFactory.build({ isFavorite: false }));
      const updatedAsset = { ...asset, isFavorite: true };

-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);
      expect(timelineManager.assetCount).toEqual(1);
      expect(timelineManager.months[0].getFirstAsset().isFavorite).toEqual(false);

-      timelineManager.updateAssets([updatedAsset]);
+      timelineManager.upsertAssets([updatedAsset]);
      expect(timelineManager.assetCount).toEqual(1);
      expect(timelineManager.months[0].getFirstAsset().isFavorite).toEqual(true);
    });
@@ -341,12 +331,12 @@ describe('TimelineManager', () => {
        fileCreatedAt: fromISODateTimeUTCToObject('2024-03-20T12:00:00.000Z'),
      });

-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);
      expect(timelineManager.months.length).toEqual(1);
      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(1);

-      timelineManager.updateAssets([updatedAsset]);
+      timelineManager.upsertAssets([updatedAsset]);
      expect(timelineManager.months.length).toEqual(2);
      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(0);
@@ -366,7 +356,7 @@ describe('TimelineManager', () => {
    });

    it('ignores invalid IDs', () => {
-      timelineManager.addAssets(
+      timelineManager.upsertAssets(
        timelineAssetFactory
          .buildList(2, {
            fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
@@ -386,7 +376,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        })
        .map((asset) => deriveLocalDateTimeFromFileCreatedAt(asset));
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);
      timelineManager.removeAssets([assetOne.id]);

      expect(timelineManager.assetCount).toEqual(1);
@@ -400,7 +390,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        })
        .map((asset) => deriveLocalDateTimeFromFileCreatedAt(asset));
-      timelineManager.addAssets(assets);
+      timelineManager.upsertAssets(assets);
      timelineManager.removeAssets(assets.map((asset) => asset.id));

      expect(timelineManager.assetCount).toEqual(0);
@@ -432,7 +422,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-15T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);
      expect(timelineManager.getFirstAsset()).toEqual(assetOne);
    });
  });
@@ -557,12 +547,12 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-02-15T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);

-      expect(findMonthGroupForAsset(timelineManager, assetTwo.id)?.monthGroup.yearMonth.year).toEqual(2024);
-      expect(findMonthGroupForAsset(timelineManager, assetTwo.id)?.monthGroup.yearMonth.month).toEqual(2);
-      expect(findMonthGroupForAsset(timelineManager, assetOne.id)?.monthGroup.yearMonth.year).toEqual(2024);
-      expect(findMonthGroupForAsset(timelineManager, assetOne.id)?.monthGroup.yearMonth.month).toEqual(1);
+      expect(timelineManager.getMonthGroupByAssetId(assetTwo.id)?.yearMonth.year).toEqual(2024);
+      expect(timelineManager.getMonthGroupByAssetId(assetTwo.id)?.yearMonth.month).toEqual(2);
+      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.year).toEqual(2024);
+      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.month).toEqual(1);
    });

    it('ignores removed months', () => {
@@ -576,11 +566,11 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-02-15T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);

      timelineManager.removeAssets([assetTwo.id]);
-      expect(findMonthGroupForAsset(timelineManager, assetOne.id)?.monthGroup.yearMonth.year).toEqual(2024);
-      expect(findMonthGroupForAsset(timelineManager, assetOne.id)?.monthGroup.yearMonth.month).toEqual(1);
+      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.year).toEqual(2024);
+      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.month).toEqual(1);
    });
  });
 });
--- a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts
@@ -11,14 +11,11 @@ import {
 } from '$lib/utils/timeline-util';

 import { isEqual } from 'lodash-es';
-import { SvelteDate, SvelteMap, SvelteSet } from 'svelte/reactivity';
+import { SvelteDate, SvelteSet } from 'svelte/reactivity';

 import { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import { GroupInsertionCache } from '$lib/managers/timeline-manager/group-insertion-cache.svelte';
 import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
-import {
-  addAssetsToMonthGroups,
-  runAssetOperation,
-} from '$lib/managers/timeline-manager/internal/operations-support.svelte';
 import {
  findMonthGroupForAsset as findMonthGroupForAssetUtil,
  findMonthGroupForDate,
@@ -28,16 +25,9 @@ import {
 } from '$lib/managers/timeline-manager/internal/search-support.svelte';
 import { WebsocketSupport } from '$lib/managers/timeline-manager/internal/websocket-support.svelte';
 import { DayGroup } from './day-group.svelte';
-import { isMismatched, updateObject } from './internal/utils.svelte';
+import { isMismatched } from './internal/utils.svelte';
 import { MonthGroup } from './month-group.svelte';
-import type {
-  AssetDescriptor,
-  AssetOperation,
-  Direction,
-  ScrubberMonth,
-  TimelineAsset,
-  TimelineManagerOptions,
-} from './types';
+import type { AssetDescriptor, Direction, ScrubberMonth, TimelineAsset, TimelineManagerOptions } from './types';

 export class TimelineManager extends PhotostreamManager {
  albumAssets: Set<string> = new SvelteSet();
@@ -181,13 +171,7 @@ export class TimelineManager extends PhotostreamManager {
    this.scrubberTimelineHeight = this.timelineHeight;
  }

-  addAssets(assets: TimelineAsset[]) {
-    const assetsToUpdate = assets.filter((asset) => !this.isExcluded(asset));
-    const notUpdated = this.updateAssets(assetsToUpdate);
-    addAssetsToMonthGroups(this, [...notUpdated], { order: this.#options.order ?? AssetOrder.Desc });
-  }
-
-  async findSegmentForAssetId(id: string) {
+  async findMonthGroupForAsset(id: string) {
    if (!this.isInitialized) {
      await this.initTask.waitUntilCompletion();
    }
@@ -218,6 +202,11 @@ export class TimelineManager extends PhotostreamManager {
    return getMonthGroupByDate(this, yearMonth);
  }

+  getMonthGroupByAssetId(assetId: string) {
+    const monthGroupInfo = findMonthGroupForAssetUtil(this, assetId);
+    return monthGroupInfo?.monthGroup;
+  }
+
  async getRandomMonthGroup() {
    const random = Math.floor(Math.random() * this.months.length);
    const month = this.months[random];
@@ -230,40 +219,6 @@ export class TimelineManager extends PhotostreamManager {
    return month?.getRandomAsset();
  }

-  updateAssetOperation(ids: string[], operation: AssetOperation) {
-    runAssetOperation(this, new SvelteSet(ids), operation, { order: this.#options.order ?? AssetOrder.Desc });
-  }
-
-  updateAssets(assets: TimelineAsset[]) {
-    const lookup = new SvelteMap<string, TimelineAsset>(assets.map((asset) => [asset.id, asset]));
-    const { unprocessedIds } = runAssetOperation(
-      this,
-      new SvelteSet(lookup.keys()),
-      (asset) => {
-        updateObject(asset, lookup.get(asset.id));
-        return { remove: false };
-      },
-      { order: this.#options.order ?? AssetOrder.Desc },
-    );
-    const result: TimelineAsset[] = [];
-    for (const id of unprocessedIds.values()) {
-      result.push(lookup.get(id)!);
-    }
-    return result;
-  }
-
-  removeAssets(ids: string[]) {
-    const { unprocessedIds } = runAssetOperation(
-      this,
-      new SvelteSet(ids),
-      () => {
-        return { remove: true };
-      },
-      { order: this.#options.order ?? AssetOrder.Desc },
-    );
-    return [...unprocessedIds];
-  }
-
  refreshLayout() {
    for (const month of this.months) {
      updateGeometry(this, month, { invalidateHeight: true });
@@ -319,4 +274,42 @@ export class TimelineManager extends PhotostreamManager {
  getAssetOrder() {
    return this.#options.order ?? AssetOrder.Desc;
  }
+
+  protected createUpsertContext(): unknown {
+    return new GroupInsertionCache();
+  }
+
+  protected upsertAssetIntoSegment(asset: TimelineAsset, context: GroupInsertionCache): void {
+    let month = getMonthGroupByDate(this, asset.localDateTime);
+
+    if (!month) {
+      month = new MonthGroup(this, asset.localDateTime, 1, true, this.#options.order);
+      this.months.push(month);
+    }
+
+    month.addTimelineAsset(asset, context);
+  }
+
+  protected postCreateSegments(): void {
+    this.months.sort((a, b) => {
+      return a.yearMonth.year === b.yearMonth.year
+        ? b.yearMonth.month - a.yearMonth.month
+        : b.yearMonth.year - a.yearMonth.year;
+    });
+  }
+
+  protected postUpsert(context: GroupInsertionCache): void {
+    for (const group of context.existingDayGroups) {
+      group.sortAssets(this.#options.order);
+    }
+
+    for (const monthGroup of context.bucketsWithNewDayGroups) {
+      monthGroup.sortDayGroups();
+    }
+
+    for (const month of context.updatedBuckets) {
+      month.sortDayGroups();
+      updateGeometry(this, month, { invalidateHeight: true });
+    }
+  }
 }
--- a/web/src/lib/managers/timeline-manager/types.ts
+++ b/web/src/lib/managers/timeline-manager/types.ts
@@ -35,7 +35,7 @@ export type TimelineAsset = {
  longitude?: number | null;
 };

-export type AssetOperation = (asset: TimelineAsset) => { remove: boolean };
+export type AssetOperation = (asset: TimelineAsset) => { remove: boolean } | unknown;

 export type MoveAsset = { asset: TimelineAsset; date: TimelineDate };

--- a/web/src/lib/utils/actions.ts
+++ b/web/src/lib/utils/actions.ts
@@ -21,15 +21,15 @@ export type OnSetVisibility = (ids: string[]) => void;

 export const deleteAssets = async (
  force: boolean,
-  onAssetDelete: OnDelete,
+  onAssetDelete: OnDelete | undefined,
  assets: TimelineAsset[],
-  onUndoDelete: OnUndoDelete | undefined = undefined,
+  onUndoDelete: OnUndoDelete | undefined,
 ) => {
  const $t = get(t);
  try {
    const ids = assets.map((a) => a.id);
    await deleteBulk({ assetBulkDeleteDto: { ids, force } });
-    onAssetDelete(ids);
+    onAssetDelete?.(ids);

    notificationController.show({
      message: force
@@ -98,5 +98,5 @@ export function updateUnstackedAssetInTimeline(timelineManager: TimelineManager,
    },
  );

-  timelineManager.addAssets(assets);
+  timelineManager.upsertAssets(assets);
 }
--- a/web/src/lib/utils/timeline-util.ts
+++ b/web/src/lib/utils/timeline-util.ts
@@ -24,19 +24,11 @@ export type TimelineDateTime = TimelineDate & {
  millisecond: number;
 };

-export type ScrubberData = {
+export type ScrubberListener = (scrubberData: {
  scrubberMonth: { year: number; month: number };
  overallScrollPercent: number;
  scrubberMonthScrollPercent: number;
-};
-
-export type ScrubberListener = (scrubberData: ScrubberData) => void | Promise<void>;
-
-export type ScrubberDataWithScrollTo = ScrubberData & {
-  scrollToFunction: (top: number) => void;
-};
-
-export type ScrubberListenerWithScrollTo = (scrubberData: ScrubberDataWithScrollTo) => void | Promise<void>;
+}) => void | Promise<void>;

 // used for AssetResponseDto.dateTimeOriginal, amongst others
 export const fromISODateTime = (isoDateTime: string, timeZone: string): DateTime<true> =>
--- a/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -34,7 +34,6 @@
  import { AlbumPageViewMode, AppRoute } from '$lib/constants';
  import { activityManager } from '$lib/managers/activity-manager.svelte';
  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
-  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
  import AlbumOptionsModal from '$lib/modals/AlbumOptionsModal.svelte';
  import AlbumShareModal from '$lib/modals/AlbumShareModal.svelte';
  import AlbumUsersModal from '$lib/modals/AlbumUsersModal.svelte';
@@ -262,18 +261,15 @@
    }
  };

-  const handleSetVisibility = (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
+  const handleSetVisibility = () => {
    assetInteraction.clearMultiselect();
  };

-  const handleRemoveAssets = async (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
+  const handleRemoveAssets = async () => {
    await refreshAlbum();
  };

-  const handleUndoRemoveAssets = async (assets: TimelineAsset[]) => {
-    timelineManager.addAssets(assets);
+  const handleUndoRemoveAssets = async () => {
    await refreshAlbum();
  };

@@ -452,7 +448,7 @@
        {isSelectionMode}
        {singleSelect}
        {showArchiveIcon}
-        onAssetSelect={onSelect}
+        {onSelect}
        onEscape={handleEscape}
      >
        {#if viewMode !== AlbumPageViewMode.SELECT_ASSETS}
@@ -572,14 +568,7 @@
          <AddToAlbum shared />
        </ButtonContextMenu>
        {#if assetInteraction.isAllUserOwned}
-          <FavoriteAction
-            removeFavorite={assetInteraction.isAllFavorite}
-            onFavorite={(ids, isFavorite) =>
-              timelineManager.updateAssetOperation(ids, (asset) => {
-                asset.isFavorite = isFavorite;
-                return { remove: false };
-              })}
-          ></FavoriteAction>
+          <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager}></FavoriteAction>
        {/if}
        <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')} offset={{ x: 175, y: 25 }}>
          <DownloadAction menuItem filename="{album.albumName}.zip" />
@@ -594,7 +583,7 @@
                onClick={() => updateThumbnailUsingCurrentSelection()}
              />
            {/if}
-            <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} />
+            <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
            <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
          {/if}

@@ -606,7 +595,12 @@
            <RemoveFromAlbum menuItem bind:album onRemove={handleRemoveAssets} />
          {/if}
          {#if assetInteraction.isAllUserOwned}
-            <DeleteAssets menuItem onAssetDelete={handleRemoveAssets} onUndoDelete={handleUndoRemoveAssets} />
+            <DeleteAssets
+              menuItem
+              onAssetDelete={handleRemoveAssets}
+              onUndoDelete={handleUndoRemoveAssets}
+              manager={timelineManager}
+            />
          {/if}
        </ButtonContextMenu>
      </AssetSelectControlBar>
--- a/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -65,32 +65,18 @@
    assets={assetInteraction.selectedAssets}
    clearSelect={() => assetInteraction.clearMultiselect()}
  >
-    <ArchiveAction
-      unarchive
-      onArchive={(ids, visibility) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.visibility = visibility;
-          return { remove: false };
-        })}
-    />
+    <ArchiveAction unarchive manager={timelineManager} />
    <CreateSharedLink />
    <SelectAllAssets {timelineManager} {assetInteraction} />
    <ButtonContextMenu icon={mdiPlus} title={$t('add_to')}>
      <AddToAlbum />
      <AddToAlbum shared />
    </ButtonContextMenu>
-    <FavoriteAction
-      removeFavorite={assetInteraction.isAllFavorite}
-      onFavorite={(ids, isFavorite) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.isFavorite = isFavorite;
-          return { remove: false };
-        })}
-    />
+    <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager} />
    <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
      <DownloadAction menuItem />
      <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
-      <DeleteAssets menuItem onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)} />
+      <DeleteAssets menuItem manager={timelineManager} />
    </ButtonContextMenu>
  </AssetSelectControlBar>
 {/if}
--- a/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -71,7 +71,7 @@
    assets={assetInteraction.selectedAssets}
    clearSelect={() => assetInteraction.clearMultiselect()}
  >
-    <FavoriteAction removeFavorite onFavorite={(assetIds) => timelineManager.removeAssets(assetIds)} />
+    <FavoriteAction removeFavorite manager={timelineManager} />
    <CreateSharedLink />
    <SelectAllAssets {timelineManager} {assetInteraction} />
    <ButtonContextMenu icon={mdiPlus} title={$t('add_to')}>
@@ -83,20 +83,12 @@
      <ChangeDate menuItem />
      <ChangeDescription menuItem />
      <ChangeLocation menuItem />
-      <ArchiveAction
-        menuItem
-        unarchive={assetInteraction.isAllArchived}
-        onArchive={(assetIds) => timelineManager.removeAssets(assetIds)}
-      />
+      <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
      {#if $preferences.tags.enabled}
        <TagAction menuItem />
      {/if}
      <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
-      <DeleteAssets
-        menuItem
-        onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)}
-        onUndoDelete={(assets) => timelineManager.addAssets(assets)}
-      />
+      <DeleteAssets menuItem manager={timelineManager} />
    </ButtonContextMenu>
  </AssetSelectControlBar>
 {/if}
--- a/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -349,15 +349,8 @@
    }
  };

-  const handleDeleteAssets = async (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
-    await updateAssetCount();
-  };
-
-  const handleUndoDeleteAssets = async (assets: TimelineAsset[]) => {
-    timelineManager.addAssets(assets);
-    await updateAssetCount();
-  };
+  const handleDeleteAssets = async () => await updateAssetCount();
+  const handleUndoDeleteAssets = async () => await updateAssetCount();

  let person = $derived(data.person);

@@ -392,7 +385,7 @@
      {assetInteraction}
      isSelectionMode={viewMode === PersonPageViewMode.SELECT_PERSON}
      singleSelect={viewMode === PersonPageViewMode.SELECT_PERSON}
-      onAssetSelect={handleSelectFeaturePhoto}
+      onSelect={handleSelectFeaturePhoto}
      onEscape={handleEscape}
    >
      {#if viewMode === PersonPageViewMode.VIEW_ASSETS}
@@ -511,14 +504,7 @@
        <AddToAlbum />
        <AddToAlbum shared />
      </ButtonContextMenu>
-      <FavoriteAction
-        removeFavorite={assetInteraction.isAllFavorite}
-        onFavorite={(ids, isFavorite) =>
-          timelineManager.updateAssetOperation(ids, (asset) => {
-            asset.isFavorite = isFavorite;
-            return { remove: false };
-          })}
-      />
+      <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager} />
      <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
        <DownloadAction menuItem filename="{person.name || 'immich'}.zip" />
        <MenuOption
@@ -529,19 +515,16 @@
        <ChangeDate menuItem />
        <ChangeDescription menuItem />
        <ChangeLocation menuItem />
-        <ArchiveAction
-          menuItem
-          unarchive={assetInteraction.isAllArchived}
-          onArchive={(assetIds) => timelineManager.removeAssets(assetIds)}
-        />
+        <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
        {#if $preferences.tags.enabled && assetInteraction.isAllUserOwned}
          <TagAction menuItem />
        {/if}
        <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
        <DeleteAssets
          menuItem
-          onAssetDelete={(assetIds) => handleDeleteAssets(assetIds)}
-          onUndoDelete={(assets) => handleUndoDeleteAssets(assets)}
+          manager={timelineManager}
+          onAssetDelete={handleDeleteAssets}
+          onUndoDelete={handleUndoDeleteAssets}
        />
      </ButtonContextMenu>
    </AssetSelectControlBar>
--- a/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte
@@ -70,12 +70,12 @@

  const handleLink: OnLink = ({ still, motion }) => {
    timelineManager.removeAssets([motion.id]);
-    timelineManager.updateAssets([still]);
+    timelineManager.upsertAssets([still]);
  };

  const handleUnlink: OnUnlink = ({ still, motion }) => {
-    timelineManager.addAssets([motion]);
-    timelineManager.updateAssets([still]);
+    timelineManager.upsertAssets([motion]);
+    timelineManager.upsertAssets([still]);
  };

  const handleSetVisibility = (assetIds: string[]) => {
@@ -118,14 +118,7 @@
      <AddToAlbum />
      <AddToAlbum shared />
    </ButtonContextMenu>
-    <FavoriteAction
-      removeFavorite={assetInteraction.isAllFavorite}
-      onFavorite={(ids, isFavorite) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.isFavorite = isFavorite;
-          return { remove: false };
-        })}
-    ></FavoriteAction>
+    <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager}></FavoriteAction>
    <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
      <DownloadAction menuItem />
      {#if assetInteraction.selectedAssets.length > 1 || isAssetStackSelected}
@@ -146,15 +139,11 @@
      <ChangeDate menuItem />
      <ChangeDescription menuItem />
      <ChangeLocation menuItem />
-      <ArchiveAction menuItem onArchive={(assetIds) => timelineManager.removeAssets(assetIds)} />
+      <ArchiveAction menuItem manager={timelineManager} />
      {#if $preferences.tags.enabled}
        <TagAction menuItem />
      {/if}
-      <DeleteAssets
-        menuItem
-        onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)}
-        onUndoDelete={(assets) => timelineManager.addAssets(assets)}
-      />
+      <DeleteAssets menuItem manager={timelineManager} />
      <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
      <hr />
      <AssetJobActions />
--- a/web/src/routes/(user)/utilities/geolocation/+page.svelte
+++ b/web/src/routes/(user)/utilities/geolocation/+page.svelte
@@ -5,6 +5,7 @@
  import Timeline from '$lib/components/timeline/Timeline.svelte';
  import { AssetAction } from '$lib/constants';
  import { authManager } from '$lib/managers/auth-manager.svelte';
+  import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
  import GeolocationUpdateConfirmModal from '$lib/modals/GeolocationUpdateConfirmModal.svelte';
@@ -62,7 +63,7 @@
      }),
    );

-    timelineManager.updateAssets(updatedAssets);
+    timelineManager.upsertAssets(updatedAssets);

    handleDeselectAll();
  };
@@ -109,7 +110,17 @@
    return !!asset.latitude && !!asset.longitude;
  };

-  const handleAssetOpen = (asset: TimelineAsset, defaultAssetOpen: () => void) => {
+  const handleThumbnailClick = (
+    asset: TimelineAsset,
+    timelineManager: TimelineManager,
+    dayGroup: DayGroup,
+    onClick: (
+      timelineManager: TimelineManager,
+      assets: TimelineAsset[],
+      groupTitle: string,
+      asset: TimelineAsset,
+    ) => void,
+  ) => {
    if (hasGps(asset)) {
      locationUpdated = true;
      setTimeout(() => {
@@ -117,9 +128,9 @@
      }, 1500);
      location = { latitude: asset.latitude!, longitude: asset.longitude! };
      void setQueryValue('at', asset.id);
-      return;
+    } else {
+      onClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
    }
-    defaultAssetOpen();
  };
 </script>

@@ -182,7 +193,7 @@
    removeAction={AssetAction.ARCHIVE}
    onEscape={handleEscape}
    withStacked
-    onAssetOpen={handleAssetOpen}
+    onThumbnailClick={handleThumbnailClick}
  >
    {#snippet customThumbnailLayout(asset: TimelineAsset)}
      {#if hasGps(asset)}