#### Notes ####################################################################
# This build process is done in three stages (out-of-source build):
# 1. copy source files to the local build directory.
# 2. build dir: replace the string "{{ INSTALL_PREFIX }}" with the value of $PREFIX
# 3. install files from the build directory to the target directory.
#
# Why this dance?
# * To fully support that a user can install this project to a custom path e.g.
#   $(PREFIX=/usr/local make install), we need to modify the files that refer
#   to other files on disk. We do this by having a placeholder
#   "{{ INSTALL_PREFIX }}"  that is substituted with the value of $PREFIX when
#   installed.
# * We don't want to modify the files that are controlled by git, thus let's
#   copy them to a build directory and then modify.

#### Non-file targets #########################################################
.PHONY: help clean uninstall \
	install-systemd install-cron \
	install-targets-script install-targets-conf install-targets-systemd \
	install-targets-cron install-targets-launchagent \
	install-targets-schedtask uninstall-targets-schedtask \
	activate-launchagent-backup deactivate-launchagent-backup \
	activate-launchagent-chec deactivate-launchagent-check

#### Macros ###################################################################
NOW := $(shell date +%Y-%m-%d_%H:%M:%S)

# GNU and macOS install have incompatible command line arguments.
GNU_INSTALL := $(shell install --version 2>/dev/null | \
			   grep -q GNU && echo true || echo false)
ifeq ($(GNU_INSTALL),true)
    BAK_SUFFIX = --suffix=.$(NOW).bak
else
    BAK_SUFFIX = -B .$(NOW).bak
endif


# Source: https://stackoverflow.com/a/14777895/265508
ifeq ($(OS),Windows_NT)
    CUR_OS := Windows
else
    CUR_OS := $(shell uname)
endif


# Create parent directories of a file, if not existing.
# Reference: https://stackoverflow.com/a/25574592/265508
MKDIR_PARENTS=sh -c '\
	     dir=$$(dirname $$1); \
	     test -d $$dir || mkdir -p $$dir \
	     ' MKDIR_PARENTS

# LaunchAgent names.
UID					:= $(shell id -u)
LAUNCHAGENT_BACKUP			= com.github.erikw.restic-backup
LAUNCHAGENT_CHECK			= com.github.erikw.restic-check
LAUNCHAGENT_TARGET_BACKUP	= gui/$(UID)/$(LAUNCHAGENT_BACKUP)
LAUNCHAGENT_TARGET_CHECK	= gui/$(UID)/$(LAUNCHAGENT_CHECK)

# What to substitute {{ INSTALL_PREFIX }} in sources to.
# This can be useful to set to empty on commandline when building e.g. an AUR
# package in a separate build directory (PREFIX).
INSTALL_PREFIX := $(PREFIX)

# Where to install persistent configuration files. Used by Homebrew.
SYSCONFDIR := $(PREFIX)

# Where to install LaunchAgent. Used by Homebrew.
LAUNCHAGENTDIR := $(HOME)

# ScheduledTask powershell scripts.
SCHEDTASK_INSTALL	= install.ps1
SCHEDTASK_UNINSTALL = uninstall.ps1

# Source directories.
DIR_SCRIPT		= bin
DIR_CONF		= etc/restic
DIR_SYSTEMD		= usr/lib/systemd/system
DIR_CRON		= etc/cron.d
DIR_LAUNCHAGENT	= Library/LaunchAgents
DIR_SCHEDTASK	= ScheduledTask

# Source files.
SRCS_SCRIPT		= $(filter-out \
						%cron_mail \
						%systemd-email \
						%nm-unmetered-connection.sh \
					, $(wildcard $(DIR_SCRIPT)/*))
SRCS_CONF		= $(wildcard $(DIR_CONF)/*)
SRCS_SYSTEMD	= $(filter-out \
						%status-email-user@.service \
						%nm-unmetered-connection.service \
					, $(wildcard $(DIR_SYSTEMD)/*))
SRCS_CRON		= $(wildcard $(DIR_CRON)/*)
SRCS_LAUNCHAGENT= $(wildcard $(DIR_LAUNCHAGENT)/*)
SRCS_SCHEDTASK	= $(wildcard $(DIR_SCHEDTASK)/*)

# Local build directory. Sources will be copied here,
# modified and then installed from this directory.
BUILD_DIR				= build
BUILD_DIR_SCRIPT		= $(BUILD_DIR)/$(DIR_SCRIPT)
BUILD_DIR_CONF			= $(BUILD_DIR)/$(DIR_CONF)
BUILD_DIR_SYSTEMD		= $(BUILD_DIR)/$(DIR_SYSTEMD)
BUILD_DIR_CRON			= $(BUILD_DIR)/$(DIR_CRON)
BUILD_DIR_LAUNCHAGENT	= $(BUILD_DIR)/$(DIR_LAUNCHAGENT)
BUILD_DIR_SCHEDTASK		= $(BUILD_DIR)/$(DIR_SCHEDTASK)

# Sources copied to build directory.
BUILD_SRCS_SCRIPT		= $(addprefix $(BUILD_DIR)/, $(SRCS_SCRIPT))
BUILD_SRCS_CONF			= $(addprefix $(BUILD_DIR)/, $(SRCS_CONF))
BUILD_SRCS_SYSTEMD		= $(addprefix $(BUILD_DIR)/, $(SRCS_SYSTEMD))
BUILD_SRCS_CRON			= $(addprefix $(BUILD_DIR)/, $(SRCS_CRON))
BUILD_SRCS_LAUNCHAGENT	= $(addprefix $(BUILD_DIR)/, $(SRCS_LAUNCHAGENT))
BUILD_SRCS_SCHEDTASK	= $(addprefix $(BUILD_DIR)/, $(SRCS_SCHEDTASK))

# Destination directories
DEST_DIR_SCRIPT		= $(PREFIX)/$(DIR_SCRIPT)
DEST_DIR_CONF		= $(SYSCONFDIR)/$(DIR_CONF)
DEST_DIR_SYSTEMD	= $(PREFIX)/$(DIR_SYSTEMD)
DEST_DIR_CRON		= $(PREFIX)/$(DIR_CRON)
DEST_DIR_LAUNCHAGENT= $(LAUNCHAGENTDIR)/$(DIR_LAUNCHAGENT)
DEST_DIR_MAC_LOG	= $(HOME)/Library/Logs/restic

# Destination file targets.
DEST_TARGS_SCRIPT		= $(addprefix $(PREFIX)/, $(SRCS_SCRIPT))
DEST_TARGS_CONF			= $(addprefix $(SYSCONFDIR)/, $(SRCS_CONF))
DEST_TARGS_SYSTEMD		= $(addprefix $(PREFIX)/, $(SRCS_SYSTEMD))
DEST_TARGS_CRON			= $(addprefix $(PREFIX)/, $(SRCS_CRON))
DEST_TARGS_LAUNCHAGENT	= $(addprefix $(LAUNCHAGENTDIR)/, $(SRCS_LAUNCHAGENT))

DEST_LAUNCHAGENT_BACKUP = $(DEST_DIR_LAUNCHAGENT)/$(LAUNCHAGENT_BACKUP).plist
DEST_LAUNCHAGENT_CHECK = $(DEST_DIR_LAUNCHAGENT)/$(LAUNCHAGENT_CHECK).plist

INSTALLED_FILES = $(DEST_TARGS_SCRIPT) $(DEST_TARGS_CONF) \
				  $(DEST_TARGS_SYSTEMD) $(DEST_TARGS_CRON) \
				  $(DEST_TARGS_LAUNCHAGENT)


#### Targets ##################################################################
# target: help - Default target; displays all targets.
help:
	@egrep "#\starget:" [Mm]akefile | cut -d " " -f3- | sort -d

# target: clean - Remove build files.
clean:
	$(RM) -r $(BUILD_DIR)

# target: uninstall - Uninstall ALL installed (including config) files.
uninstall: uninstall-schedtask
	@for file in $(INSTALLED_FILES); do \
			echo $(RM) $$file; \
			$(RM) $$file; \
	done

# To change the installation root path,
# set the PREFIX variable in your shell's environment, like:
# $ PREFIX=/usr/local make install-systemd
# $ PREFIX=/tmp/test make install-systemd
# target: install-systemd - Install systemd setup.
install-systemd: install-targets-script install-targets-conf \
					install-targets-systemd

# target: install-cron - Install cron setup.
install-cron: install-targets-script install-targets-conf install-targets-cron

# target: install-launchagent - Install backup LaunchAgent setup.
install-launchagent: install-targets-script install-targets-conf \
						install-targets-launchagent

# target: install-launchagent-check - Install check LaunchAgent setup.
# Intended to be run after install-launchagent, thus not requiring scripts/conf
#install-launchagent: install-targets-launchagent

# target: install-schedtask - Install Windows ScheduledTasks
install-schedtask: install-targets-script install-targets-conf \
						install-targets-schedtask

# target: uninstall-schedtask - Uninstall Windows ScheduledTasks
uninstall-schedtask: uninstall-targets-schedtask

# Install targets. Prereq build sources as well,
# so that build dir is re-created if deleted.
install-targets-script: $(DEST_TARGS_SCRIPT) $(BUILD_SRCS_SCRIPT)
install-targets-conf: $(DEST_TARGS_CONF) $(BUILD_SRCS_CONF)
install-targets-systemd: $(DEST_TARGS_SYSTEMD) $(BUILD_SRCS_SYSTEMD)
install-targets-cron: $(DEST_TARGS_CRON) $(BUILD_SRCS_CRON)
install-targets-launchagent: $(DEST_TARGS_LAUNCHAGENT) \
	$(BUILD_SRCS_LAUNCHAGENT) $(DEST_DIR_MAC_LOG)
install-targets-schedtask: $(BUILD_DIR_SCHEDTASK)/$(SCHEDTASK_INSTALL)
	test $(CUR_OS) != Windows || ./$<

uninstall-targets-schedtask: $(BUILD_DIR_SCHEDTASK)/$(SCHEDTASK_UNINSTALL)
	test $(CUR_OS) != Windows || ./$<

# Copies sources to build directory & replace "{{ INSTALL_PREFIX }}".
$(BUILD_DIR)/% : %
	@${MKDIR_PARENTS} $@
	cp $< $@
	sed -i.bak -e 's|{{ INSTALL_PREFIX }}|$(INSTALL_PREFIX)|g' $@; rm $@.bak

# Install destination script files.
$(DEST_DIR_SCRIPT)/%: $(BUILD_DIR_SCRIPT)/%
	@${MKDIR_PARENTS} $@
	install -m 0555 $< $@

# Install destination conf files. Additionally backup existing files.
$(DEST_DIR_CONF)/%: $(BUILD_DIR_CONF)/%
	@${MKDIR_PARENTS} $@
	install -m 0600 -b $(BAK_SUFFIX) $< $@

# Install destination systemd files.
$(DEST_DIR_SYSTEMD)/%: $(BUILD_DIR_SYSTEMD)/%
	@${MKDIR_PARENTS} $@
	install -m 0644 $< $@

# Install destination cron files.
$(DEST_DIR_CRON)/%: $(BUILD_DIR_CRON)/%
	@${MKDIR_PARENTS} $@
	install -m 0644 $< $@

# Install destination launchagent files.
$(DEST_DIR_LAUNCHAGENT)/%: $(BUILD_DIR_LAUNCHAGENT)/%
	@${MKDIR_PARENTS} $@
	install -m 0444 $< $@

# Install destination mac log dir.
$(DEST_DIR_MAC_LOG):
	mkdir -p $@

# target: activate-launchagent-backup - Activate the backup LaunchAgent.
activate-launchagent-backup:
	launchctl bootstrap gui/$(UID) $(DEST_LAUNCHAGENT_BACKUP)
	launchctl enable $(LAUNCHAGENT_TARGET_BACKUP)
	launchctl kickstart -p $(LAUNCHAGENT_TARGET_BACKUP)

# target: activate-launchagent-check - Activate the check LaunchAgent.
activate-launchagent-check:
	launchctl bootstrap gui/$(UID) $(DEST_LAUNCHAGENT_CHECK)
	launchctl enable $(LAUNCHAGENT_TARGET_CHECK)
	launchctl kickstart -p $(LAUNCHAGENT_TARGET_CHECK)

# target: deactivate-launchagent-backup - Remove the backup LaunchAgent.
deactivate-launchagent-backup:
	launchctl bootout $(LAUNCHAGENT_TARGET_BACKUP)

# target: deactivate-launchagent-check - Remove the check LaunchAgent.
deactivate-launchagent-check:
	launchctl bootout $(LAUNCHAGENT_TARGET_CHECK)