Makefile

###
## This Makefile is only here to make sure Task is installable
## Usage: `make` or `make TASK_VERSION=<version>`
###

ifneq ($(wildcard .env.dist),)
include .env.dist
endif
ifneq ($(wildcard .env),)
include .env
endif

.DEFAULT_GOAL:=install

OS?=$(eval OS:=$$(shell uname -s | tr '[:upper:]' '[:lower:]'))$(OS)
MACH?=$(eval MACH:=$$(shell uname -m))$(MACH)
ARCH?=$(eval ARCH:=$$(if $$(filter $$(MACH),x86_64),amd64)$$(if $$(filter $$(MACH),x86 i686 i386),386))$(ARCH)

DESTDIR?=.
PREFIX?=
BIN_DIR?=$(patsubst %/,%,$(DESTDIR))$(patsubst %/,%,$(PREFIX))/bin
CACHE_DIR?=$(patsubst %/,%,$(DESTDIR))$(patsubst %/,%,$(PREFIX))/.cache

TASK_VERSION?=

TASK_GITHUB_OWNER?=go-task
TASK_GITHUB_REPOSITORY?=task
TASK_GITHUB_TARBALL_FILENAME?=task_$(OS)_$(ARCH).tar.gz
TASK_GITHUB_CHECKSUM_FILENAME?=task_checksums.txt

TASK_GITHUB_RELEASES_BASE_URL?=https://github.com/$(TASK_GITHUB_OWNER)/$(TASK_GITHUB_REPOSITORY)/releases
TASK_GITHUB_DOWNLOAD_BASE_URL?=$(patsubst %/,%,$(TASK_GITHUB_RELEASES_BASE_URL))/download

TASK_GITHUB_TAG=$(eval TASK_GITHUB_TAG:=$$(or $$(filter-out latest,$$(TASK_VERSION)),$$(notdir $$(shell curl -Ls -o /dev/null -w %{url_effective} $$(patsubst %/,%,$$(TASK_GITHUB_RELEASES_BASE_URL))/latest))))$(TASK_GITHUB_TAG)

# $1 is the command
is_command=command -v "$(1)" >/dev/null

# $1 is the url, $2 is the local filename
download=\
	if $(call is_command,curl); then \
		curl -sSL "$(1)" -o "$(2)"; \
	elif $(call is_command,wget); then \
		wget -q -O "$(2)" "$(1)"; \
	else \
		exit 1; \
	fi

# $1 is filename, returns hash
generate_sha256_hash=\
	if $(call is_command,gsha256sum); then \
		HASH=$$(gsha256sum "$(1)") || exit 1; \
	elif $(call is_command,sha256sum); then \
		HASH=$$(sha256sum "$(1)") || exit 1; \
	elif $(call is_command,shasum); then \
		HASH=$$(shasum -a 256 "$(1)" 2>/dev/null) || exit 1; \
	elif $(call is_command,openssl); then \
		HASH=$$(openssl dgst -sha256 -r "$(1)") || exit 1; \
	else \
		exit 1; \
	fi; \
	echo "$${HASH}" | cut -d ' ' -f 1

#. Check for non-POSIX dependencies - @see https://pubs.opengroup.org/onlinepubs/9699919799/idx/utilities.html
define check-extra-dependency
ifeq ($$(shell command -v $(1) || which $(1) 2>/dev/null),)
$$(error Please provide the command "$(1)")
endif
endef
$(foreach command,tar,$(eval $(call check-extra-dependency,$(command))))

###
## Directories
###

$(BIN_DIR) $(CACHE_DIR):
	if test ! -d "$(@)"; then mkdir -p "$(@)"; fi

###
## Binaries
###

$(CACHE_DIR)/task/%/$(TASK_GITHUB_CHECKSUM_FILENAME): | $(CACHE_DIR)
	if test ! -d "$(dir $(@))"; then mkdir -p "$(dir $(@))"; fi
	$(call download,$(patsubst %/,%,$(TASK_GITHUB_DOWNLOAD_BASE_URL))/$(TASK_GITHUB_TAG)/$(TASK_GITHUB_CHECKSUM_FILENAME),$(@))
	if test -f "$(@)"; then touch "$(@)"; fi
.PRECIOUS: $(CACHE_DIR)/task/%/$(TASK_GITHUB_CHECKSUM_FILENAME)

$(CACHE_DIR)/task/%/$(TASK_GITHUB_TARBALL_FILENAME): $(CACHE_DIR)/task/%/$(TASK_GITHUB_CHECKSUM_FILENAME) | $(CACHE_DIR)
	if test ! -d "$(dir $(@))"; then mkdir -p "$(dir $(@))"; fi
	$(call download,$(patsubst %/,%,$(TASK_GITHUB_DOWNLOAD_BASE_URL))/$(TASK_GITHUB_TAG)/$(TASK_GITHUB_TARBALL_FILENAME),$(@))
	trap "test \"\$$?\" != \"0\" && rm -f \"$(<)\" && rm -f \"$(@)\" && ( rmdir -p \"$(dir $(@))\" 2>/dev/null )" EXIT; \
		EXPECTED_HASH="$$(cat "$(<)" | grep "$(notdir $(@))" | cut -d ' ' -f 1)"; \
		ACTUAL_HASH="$$($(call generate_sha256_hash,$(@)))"; \
		if test "$${ACTUAL_HASH}" != "$${EXPECTED_HASH}"; then exit 1; fi
	if test -f "$(@)"; then touch "$(@)"; fi
.PRECIOUS: $(CACHE_DIR)/task/%/$(TASK_GITHUB_TARBALL_FILENAME)

$(BIN_DIR)/task-%: $(CACHE_DIR)/task/%/$(TASK_GITHUB_TARBALL_FILENAME) | $(BIN_DIR)
	tar -xvf "$(<)" task -O > "$(@)"
	if test -f "$(@)"; then chmod +x "$(@)"; touch "$(@)"; fi
.PRECIOUS: $(BIN_DIR)/task-%

task: $(BIN_DIR)/task-$(TASK_GITHUB_TAG)
	@true
.PHONY: task

task.remove:
	if test -d "$(CACHE_DIR)/task"; then rm -rf "$(CACHE_DIR)/task"; fi
	if test -d "$(CACHE_DIR)"; then find "$(CACHE_DIR)" -type d -empty -delete; fi
	if test -d "$(BIN_DIR)"; then find "$(BIN_DIR)" -maxdepth 1 -type f -name 'task*' -delete; fi
	if test -d "$(BIN_DIR)"; then find "$(BIN_DIR)" -type d -empty -delete; fi
.PHONY: task.remove

###
## Symlink
###

$(BIN_DIR)/task: $(BIN_DIR)/task-$(TASK_GITHUB_TAG)
	if test -f "$(@)"; then rm -f "$(@)"; fi
	if test -L "$(@)"; then rm -f "$(@)"; fi
	ln -s "$(abspath $(<))" "$(@)"
	$(@) --version
.PRECIOUS: $(BIN_DIR)/task

task-symlink: $(BIN_DIR)/task
	@true
.PHONY: task-symlink

task-symlink.remove:
	if test -f "$(BIN_DIR)/task"; then rm -f "$(BIN_DIR)/task"; fi
	if test -L "$(BIN_DIR)/task"; then rm -f "$(BIN_DIR)/task"; fi
.PHONY: task-symlink.remove

###
## Alias
###

ALIAS_FILE?=

ifneq ($(ALIAS_FILE),)
.PRECIOUS: $(ALIAS_FILE)
endif

task-alias: | task
ifneq ($(ALIAS_FILE),)
	if test ! -f "$(ALIAS_FILE)"; then touch "$(ALIAS_FILE)"; fi
	if ! grep -q "^alias task=" "$(ALIAS_FILE)"; then \
		echo 'alias task="'\''$(abspath $(BIN_DIR)/task-$(TASK_GITHUB_TAG))'\''"' >> "$(ALIAS_FILE)"; \
	else \
		sed -i 's#^alias task=.*$$#alias task="'\''$(abspath $(BIN_DIR)/task-$(TASK_GITHUB_TAG))'\''"#' "$(ALIAS_FILE)"; \
	fi
	grep -q "^alias task=" "$(ALIAS_FILE)"
	. "$(ALIAS_FILE)" && '$(abspath $(BIN_DIR)/task-$(TASK_GITHUB_TAG))' --version
else
	@true
endif
.PHONY: task-alias

task-alias.remove:
	if test -f "$(ALIAS_FILE)" && grep -q "^alias task=" "$(ALIAS_FILE)"; then \
		sed -i '\#^alias task=#d' "$(ALIAS_FILE)"; \
	fi
.PHONY: task-alias.remove

###
## Installation
###

install: | task task-alias task-symlink; @true
.PHONY: install

clean: | task-alias.remove task-symlink.remove task.remove ; @true
.PHONY: clean