prefix = /usr/local
bindir = $(prefix)/bin
libdir = $(prefix)/lib
systemddir = $(libdir)/systemd

GOPATH := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))

CFLAGS = -std=c99 -Wall -Wextra -Werror -pedantic
CGO_CFLAGS = $(CFLAGS) -Wno-unused-parameter
export CGO_ENABLED = 1

cgo_variables = CGO_ENABLED CGO_CFLAGS CGO_CPPFLAGS CGO_CXXFLAGS CGO_LDFLAGS CC CXX

deps = gopkg.in/yaml.v2
subdirs = src/nslcd_proto

all: build

include $(addsuffix /Makefile,$(subdirs))

secondary += 
download += $(addprefix src/,$(deps))
generate +=
build += bin/nshd nshd.service
install += $(addprefix $(DESTDIR),$(bindir)/nshd $(systemddir)/system/nshd.socket $(systemddir)/system/nshd.service)

download: $(download)
generate: $(generate)
build: $(build)
install: $(install)
.PHONY: download generate build install

clean:
	rm -rf -- pkg bin src/*.*/
	rm -f -- $(generate) $(build) $(secondary)
.PHONY: clean

uninstall:
	rm -f -- $(install)
	rmdir -p -- $(sort $(dir $(install))) 2>/dev/null || true
.PHONY: uninstall

$(foreach d,$(deps),$(eval src/$d: NET; GOPATH='$(GOPATH)' go get -d -u $d))
.PHONY: NET

bin/nshd: $(download) $(generate) $(shell find src -name .git -prune -o -print) $(addprefix .Makefile.var.,$(cgo_variables))
	@true $(foreach f,$(filter .Makefile.var.%,$^), && test $@ -nt $f ) || rm -rf -- bin pkg
	GOPATH='$(GOPATH)' CGO_CFLAGS='$(CGO_CFLAGS)' go install nshd

nshd.service: nshd.service.in .Makefile.var.bindir
	< $< sed 's|@bindir@|$(bindir)|g' > $@

$(DESTDIR)$(bindir)/%: bin/%
	install -Dm755 $< $@
$(DESTDIR)$(systemddir)/system/%.socket: %.socket
	install -Dm644 $< $@
$(DESTDIR)$(systemddir)/system/%.service: %.service
	install -Dm644 $< $@

.Makefile.var.%: FORCE
	@printf '%s' '$($*)' > .tmp$@ && { cmp -s .tmp$@ $@ && rm -f -- .tmp$@ || mv -Tf .tmp$@ $@; } || { rm -f -- .tmp$@; false; }
.PHONY: FORCE

.SECONDARY:
.DELETE_ON_ERROR: