#  Copyright (c) 2016, 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.


PKGCONFIG =  	$(shell which pkg-config)
GIT 	  = 	$(shell which git)
TAR 	  = 	$(shell which tar)
MKDIR     = 	$(shell which mkdir)
TOUCH 	  = 	$(shell which touch)
CP        = 	$(shell which cp)
RM 	  = 	$(shell which rm)
LN        =     $(shell which ln)
FIND 	  = 	$(shell which find)
INSTALL   = 	$(shell which install)
MKTEMP    = 	$(shell which mktemp)
STRIP     = 	$(shell which strip)
PANDOC    =	$(shell which pandoc)
SED       =     $(shell which sed)
GZIP      =     $(shell which gzip)
RPMBUILD  =     $(shell which rpmbuild)
GIT2DEBCL =     ./tools/git2debcl
CPPFIND   =     ./tools/cppfind

ifeq ($(PKGCONFIG),"")
$(error "pkg-config not installed")
endif

ifeq ($(PANDOC),"")
$(warning "pandoc does not appear available: manpage won't be buildable")
endif

XATTR_AVAILABLE = $(shell test ! -e /usr/include/attr/xattr.h; echo $$?)

FUSE_AVAILABLE = $(shell ! pkg-config --exists fuse; echo $$?)

ifeq ($(FUSE_AVAILABLE),0)
FUSE_AVAILABLE = $(shell test ! -e /usr/include/fuse.h; echo $$?)
endif

ifeq ($(FUSE_AVAILABLE),0)
$(error "FUSE development package doesn't appear available")
endif

FLAG_NOPATH = $(shell $(CPPFIND) "flag_nopath")
FLAG_UTIME  = $(shell $(CPPFIND) "flag_utime_omit_ok")
FALLOCATE   = $(shell $(CPPFIND) "fuse_fs_fallocate")
FLOCK       = $(shell $(CPPFIND) "fuse_fs_flock")
READ_BUF    = $(shell $(CPPFIND) "fuse_fs_read_buf")
WRITE_BUF   = $(shell $(CPPFIND) "fuse_fs_write_buf")

UGID_USE_RWLOCK = 0

OPTS 	    = -O2
SRC	    = $(wildcard src/*.cpp)
OBJ         = $(SRC:src/%.cpp=obj/%.o)
DEPS        = $(OBJ:obj/%.o=obj/%.d)
TARGET      = mergerfs
MANPAGE     = $(TARGET).1
FUSE_CFLAGS = $(shell $(PKGCONFIG) --cflags fuse)
CFLAGS      = -g -Wall \
	      $(OPTS) \
	      -Wno-unused-result \
              $(FUSE_CFLAGS) \
              -DFUSE_USE_VERSION=29 \
              -MMD \
	      -DFLAG_NOPATH=$(FLAG_NOPATH) \
	      -DFLAG_UTIME=$(FLAG_UTIME) \
	      -DFALLOCATE=$(FALLOCATE) \
              -DFLOCK=$(FLOCK) \
	      -DREAD_BUF=$(READ_BUF) \
              -DWRITE_BUF=$(WRITE_BUF) \
	      -DUGID_USE_RWLOCK=$(UGID_USE_RWLOCK)
LDFLAGS       = $(shell $(PKGCONFIG) fuse --libs)

PREFIX        = /usr/local
EXEC_PREFIX   = $(PREFIX)
DATAROOTDIR   = $(PREFIX)/share
DATADIR       = $(DATAROOTDIR)
BINDIR        = $(EXEC_PREFIX)/bin
SBINDIR       = $(EXEC_PREFIX)/sbin
MANDIR        = $(DATAROOTDIR)/man
MAN1DIR       = $(MANDIR)/man1

INSTALLBINDIR  = $(DESTDIR)$(BINDIR)
INSTALLSBINDIR = $(DESTDIR)$(SBINDIR)
INSTALLMAN1DIR = $(DESTDIR)$(MAN1DIR)

ifeq ($(XATTR_AVAILABLE),0)
$(warning "xattr not available: disabling")
CFLAGS += -DWITHOUT_XATTR
endif

all: $(TARGET)

help:
	@echo "usage: make"
	@echo "make XATTR_AVAILABLE=0 - to build program without xattrs functionality (auto discovered otherwise)"

$(TARGET): src/version.hpp obj/obj-stamp $(OBJ)
	$(CXX) $(CFLAGS) $(OBJ) -o $@ $(LDFLAGS)

mount.mergerfs: $(TARGET)
	$(LN) -fs "$<" "$@"

changelog:
	$(GIT2DEBCL) --name $(TARGET) > ChangeLog

authors:
	$(GIT) log --format='%aN <%aE>' | sort -f | uniq > AUTHORS

src/version.hpp:
	$(eval VERSION := $(shell $(GIT) describe --always --tags --dirty))
	@echo "#ifndef _VERSION_HPP" > src/version.hpp
	@echo "#define _VERSION_HPP" >> src/version.hpp
	@echo "static const char MERGERFS_VERSION[] = \"$(VERSION)\";" >> src/version.hpp
	@echo "#endif" >> src/version.hpp

obj/obj-stamp:
	$(MKDIR) -p obj
	$(TOUCH) $@

obj/%.o: src/%.cpp
	$(CXX) $(CFLAGS) -c $< -o $@

clean: rpm-clean
ifneq ($(GIT),)
ifeq  ($(shell test -e .git; echo $$?),0)
	$(RM) -f src/version.hpp
endif
endif
	$(RM) -rf obj
	$(RM) -f "$(TARGET)" mount.mergerfs
	$(FIND) . -name "*~" -delete

distclean: clean
	$(GIT) clean -fd

install: install-base install-mount.mergerfs install-man

install-base: $(TARGET)
	$(MKDIR) -p "$(INSTALLBINDIR)"
	$(INSTALL) -v -m 0755 "$(TARGET)" "$(INSTALLBINDIR)/$(TARGET)"

install-mount.mergerfs: mount.mergerfs
	$(MKDIR) -p "$(INSTALLBINDIR)"
	$(CP) -a "$<" "$(INSTALLBINDIR)/$<"

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

install-strip: install-base
	$(STRIP) "$(INSTALLBINDIR)/$(TARGET)"

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

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

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

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

$(MANPAGE): README.md
ifneq (,$(PANDOC))
	$(PANDOC) -s -t man -o "man/$(MANPAGE)" README.md
endif

man: $(MANPAGE)

tarball: clean man changelog authors src/version.hpp
	$(eval VERSION := $(shell $(GIT) describe --always --tags --dirty))
	$(eval VERSION := $(subst -,_,$(VERSION)))
	$(eval FILENAME := $(TARGET)-$(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)

debian-changelog:
	$(GIT2DEBCL) --name $(TARGET) > debian/changelog

signed-deb: debian-changelog
	dpkg-buildpackage

deb: debian-changelog
	dpkg-buildpackage -uc -us

rpm-clean:
	$(RM) -rf rpmbuild

rpm: tarball
	$(eval VERSION := $(shell $(GIT) describe --always --tags --dirty))
	$(eval VERSION := $(subst -,_,$(VERSION)))
	$(MKDIR) -p rpmbuild/BUILD rpmbuild/RPMS rpmbuild/SOURCES
	$(SED) 's/__VERSION__/$(VERSION)/g' $(TARGET).spec > \
		rpmbuild/SOURCES/$(TARGET).spec
	cp -ar $(TARGET)-$(VERSION).tar.gz rpmbuild/SOURCES
	$(RPMBUILD) -ba rpmbuild/SOURCES/$(TARGET).spec \
		--define "_topdir $(CURDIR)/rpmbuild"

.PHONY: all clean install help

include $(wildcard obj/*.d)