#  Copyright (c) 2024, Antonio SJ Musumeci <trapexit@spawn.link>
#
#  Permission to use, copy, modify, and/or distribute this software for any
#  purpose with or without fee is hereby granted, provided that the above
#  copyright notice and this permission notice appear in all copies.
#
#  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
#  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
#  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
#  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
#  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
#  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

CP        := cp
FAKEROOT  := fakeroot
FIND 	  := find
GIT 	  := git
GIT2DEBCL := buildtools/git2debcl
INSTALL   := install
LN        := ln
MKDIR     := mkdir
MKTEMP    := mktemp
MV        := mv
RM 	  := rm
SED       := sed
STRIP     := strip
TAR 	  := tar
TOUCH 	  := touch

BUILDDIR := build

ifneq ($(GIT_REPO),0)
ifneq ($(shell $(GIT) --version 2> /dev/null),)
ifeq  ($(shell test -e .git; echo $$?),0)
GIT_REPO = 1
endif
endif
endif

USE_XATTR = 1
UGID_USE_RWLOCK = 0

ifeq ($(NDEBUG),1)
OPT_FLAGS := -O2 -DNDEBUG
else
OPT_FLAGS := -O0 -g -fno-omit-frame-pointer -DDEBUG
endif

ifeq ($(STATIC),1)
STATIC_FLAGS := -static
else
STATIC_FLAGS :=
endif

ifeq ($(LTO),1)
LTO_FLAGS := -flto
else
LTO_FLAGS :=
endif

SRC	    := $(wildcard src/*.cpp)
OBJS        := $(SRC:src/%.cpp=build/.src/%.o)
DEPS        := $(SRC:src/%.cpp=build/.src/%.d)

TESTS       := $(wildcard tests/*.cpp)
TESTS_OBJS  := $(filter-out build/.src/mergerfs.o,$(OBJS))
TESTS_OBJS += $(TESTS:tests/%.cpp=build/.tests/%.o)
TESTS_DEPS  := $(TESTS:tests/%.cpp=build/.tests/%.d)
TESTS_DEPS += $(DEPS)

MANPAGE     := mergerfs.1
CPPFLAGS    += \
		-D_FILE_OFFSET_BITS=64
CFLAGS      := \
		$(OPT_FLAGS) \
		-Wall \
		-Wno-unused-result \
		-pipe \
		-MMD \
		-MP
CXXFLAGS    := \
	        -std=c++17 \
		$(OPT_FLAGS) \
                $(STATIC_FLAGS) \
                $(LTO_FLAGS) \
                -Wall \
                -Wno-unused-result \
		-pipe \
                -MMD \
		-MP
INCLUDE_FLAGS := \
		-Isrc \
		-Ilibfuse/include
MFS_FLAGS  := \
	      -DUSE_XATTR=$(USE_XATTR) \
	      -DUGID_USE_RWLOCK=$(UGID_USE_RWLOCK)
TESTS_FLAGS := \
              -Isrc \
              -DTESTS

LIBFUSE := libfuse/$(BUILDDIR)/libfuse.a
LDFLAGS += \
	-pthread \
	-lrt \
	-lstdc++fs
LDLIBS := $(LIBFUSE)

# https://www.gnu.org/prep/standards/html_node/Directory-Variables.html
DESTDIR       :=
PREFIX        := /usr/local
EXEC_PREFIX   := $(PREFIX)
DATAROOTDIR   := $(PREFIX)/share
DATADIR       := $(DATAROOTDIR)
BINDIR        := $(EXEC_PREFIX)/bin
SBINDIR       := $(EXEC_PREFIX)/sbin
LIBDIR        := $(EXEC_PREFIX)/lib
MANDIR        := $(DATAROOTDIR)/man
MAN1DIR       := $(MANDIR)/man1

INSTALLBINDIR  := $(DESTDIR)$(BINDIR)
INSTALLSBINDIR := $(DESTDIR)$(SBINDIR)
INSTALLLIBDIR  := $(DESTDIR)$(LIBDIR)/mergerfs
INSTALLMAN1DIR := $(DESTDIR)$(MAN1DIR)


.PHONY: all
all: libfuse $(BUILDDIR)/mergerfs $(BUILDDIR)/fsck.mergerfs $(BUILDDIR)/mergerfs.collect-info

.PHONY: help
help:
	@echo "usage: make\n"
	@echo "make USE_XATTR=0      - build program without xattrs functionality"
	@echo "make STATIC=1         - build static binary"
	@echo "make LTO=1            - build with link time optimization"


$(BUILDDIR)/mergerfs: $(LIBFUSE) src/version.hpp $(OBJS)
	$(CXX) $(CXXFLAGS) $(INCLUDE_FLAGS) $(MFS_FLAGS) $(CPPFLAGS) $(OBJS) -o $@ $(LDFLAGS) $(LDLIBS)

$(BUILDDIR)/fsck.mergerfs:
	$(LN) -sf "mergerfs" $@

$(BUILDDIR)/mergerfs.collect-info:
	$(LN) -sf "mergerfs" $@

$(BUILDDIR)/tests: $(BUILDDIR)/mergerfs $(TESTS_OBJS)
	$(CXX) $(CXXFLAGS) $(TESTS_FLAGS) $(INCLUDE_FLAGS) $(MFS_FLAGS) $(CPPFLAGS) $(TESTS_OBJS) -o $@ $(LDFLAGS) $(LDLIBS)

.PHONY: libfuse
$(LIBFUSE):
libfuse:
	$(MAKE) NDEBUG=$(NDEBUG) -C libfuse

tests: $(BUILDDIR)/tests

changelog:
ifeq ($(GIT_REPO),1)
	$(GIT2DEBCL) --name mergerfs > ChangeLog
else
	@echo "WARNING: need git repo to generate ChangeLog"
endif

.PHONY: version
version: src/version.hpp

src/version.hpp:
	./buildtools/update-version

$(BUILDDIR)/stamp:
	$(MKDIR) -p $(BUILDDIR)/.src $(BUILDDIR)/.tests
	$(TOUCH) $@

$(BUILDDIR)/.src/%.o: src/%.cpp $(BUILDDIR)/stamp
	$(CXX) $(CXXFLAGS) $(INCLUDE_FLAGS) $(MFS_FLAGS) $(CPPFLAGS) -c $< -o $@

$(BUILDDIR)/.tests/%.o: tests/%.cpp
	$(CXX) $(CXXFLAGS) $(TESTS_FLAGS) $(INCLUDE_FLAGS) $(MFS_FLAGS) $(CPPFLAGS) -c $< -o $@

$(BUILDDIR)/preload.so: $(BUILDDIR)/stamp tools/preload.c
	$(CC) -shared -fPIC $(CFLAGS) -o $@ tools/preload.c

preload: $(BUILDDIR)/preload.so

.PHONY: clean
clean: rpm-clean
	$(RM) -rf $(BUILDDIR)
	$(FIND) . -name "*~" -delete
	$(MAKE) -C libfuse clean

distclean: clean
ifeq ($(GIT_REPO),1)
	$(GIT) clean -xfd
endif

.PHONY: install
install: install-base install-mount-tools install-preload install-man

.PHONY: install-base
install-base: all
	$(MKDIR) -p "$(INSTALLBINDIR)"
	$(INSTALL) -v -m 0755 "$(BUILDDIR)/mergerfs" "$(INSTALLBINDIR)/mergerfs"
	$(LN) -fs "mergerfs" "${INSTALLBINDIR}/fsck.mergerfs"
	$(LN) -fs "mergerfs" "${INSTALLBINDIR}/mergerfs.collect-info"

.PHONY: install-mount-tools
install-mount-tools: install-base
	$(MKDIR) -p "$(INSTALLBINDIR)"
	$(MAKE) -C libfuse install

.PHONY: install-man
install-man: man/$(MANPAGE)
	$(MKDIR) -p "$(INSTALLMAN1DIR)"
	$(INSTALL) -v -m 0644 "man/$(MANPAGE)" "$(INSTALLMAN1DIR)/$(MANPAGE)"

.PHONY: install-preload
install-preload: preload
	$(MKDIR) -p "$(INSTALLLIBDIR)"
	$(INSTALL) -v -m 444 "$(BUILDDIR)/preload.so" "$(INSTALLLIBDIR)/preload.so"

.PHONY: install-strip
install-strip: install-base
	$(STRIP) "$(INSTALLBINDIR)/mergerfs"

.PHONY: uninstall
uninstall: uninstall-base uninstall-mount.mergerfs uninstall-man

uninstall-base:
	$(RM) -f "$(INSTALLBINDIR)/mergerfs"

uninstall-mount.mergerfs:
	$(RM) -f "$(INSTALLBINDIR)/mount.mergerfs"

uninstall-man:
	$(RM) -f "$(INSTALLMAN1DIR)/$(MANPAGE)"

.PHONY: tarball
tarball: changelog version
	$(eval VERSION := $(shell cat VERSION))
	$(eval VERSION := $(subst -,_,$(VERSION)))
	$(eval FILENAME := mergerfs-$(VERSION))
	$(eval TMPDIR := $(shell $(MKTEMP) --tmpdir -d .$(FILENAME).XXXXXXXX))
	$(MKDIR) $(TMPDIR)/$(FILENAME)
	$(CP) -ar . $(TMPDIR)/$(FILENAME)
	$(TAR) --exclude=.git -cz -C $(TMPDIR) -f $(FILENAME).tar.gz $(FILENAME)
	$(RM) -rf $(TMPDIR)

.PHONY: debian-changelog
debian-changelog:
ifeq ($(GIT_REPO),1)
	$(GIT2DEBCL) --name mergerfs > debian/changelog
else
	$(CP) -v ChangeLog debian/changelog
endif

.PHONY: signed-deb
signed-deb:
	$(MAKE) distclean
	$(MAKE) debian-changelog
	$(FAKEROOT) dpkg-buildpackage -nc

.PHONY: deb
deb:
	$(MAKE) distclean
	$(MAKE) debian-changelog
	$(MAKE) version
	$(FAKEROOT) dpkg-buildpackage -nc -uc -us
	$(MKDIR) -p ./$(BUILDDIR)/pkgs/
	$(MV) -v ../mergerfs*deb ./$(BUILDDIR)/pkgs/

.PHONY: rpm-clean
rpm-clean:
	$(RM) -rf rpmbuild

.PHONY: rpm
rpm: tarball
	$(eval VERSION := $(shell cat VERSION))
	$(eval VERSION := $(subst -,_,$(VERSION)))
	$(MKDIR) -p rpmbuild/BUILD rpmbuild/RPMS rpmbuild/SOURCES
	$(SED) 's/__VERSION__/$(VERSION)/g' mergerfs.spec > \
		rpmbuild/SOURCES/mergerfs.spec
	cp -ar mergerfs-$(VERSION).tar.gz rpmbuild/SOURCES
	rpmbuild -ba rpmbuild/SOURCES/mergerfs.spec \
		--define "_topdir $(CURDIR)/rpmbuild"

.PHONY: install-build-pkgs
install-build-pkgs:
	./buildtools/install-build-pkgs

.PHONY: release
release:
	./buildtools/build-release \
		--target=all \
		--cleanup \
		--branch=$(shell git branch --show-current)

.PHONY: release-sample
release-sample:
	./buildtools/build-release \
		--target=debian.12.amd64 \
		--branch=$(shell git branch --show-current)

.PHONY: release-amd64
release-amd64:
	./buildtools/build-release \
		--target=amd64 \
		--cleanup \
		--branch=$(shell git branch --show-current)

.PHONY: release-arm64
release-arm64:
	./buildtools/build-release \
		--target=arm64 \
		--cleanup \
		--branch=$(shell git branch --show-current)

.PHONY: release-static
release-static:
	./buildtools/build-release \
		--target=static \
		--cleanup \
		--branch=$(shell git branch --show-current)

.PHONY: tags
tags:
	rm -fv TAGS
	find . -name "*.c" -print | etags --append -
	find . -name "*.h" -print | etags --append -
	find . -name "*.cpp" -print | etags --append -
	find . -name "*.hpp" -print | etags --append -


-include $(DEPS)