CC ?= cc
PKG_CONFIG ?= pkg-config
PREFIX ?= /usr/local
BINDIR ?= $(PREFIX)/bin
DESTDIR ?=

TARGET := bin/yapssg
SOURCES := src/Main.c $(wildcard src/*/*.c)
OBJECTS := $(patsubst src/%.c,obj/%.o,$(SOURCES))
VERSION_O := obj/Version/Version.o
VERSION_H := obj/Version/version.h

CPPFLAGS += -Isrc $(shell $(PKG_CONFIG) --cflags libxml-2.0 luajit)
CFLAGS ?= -O2 -Wall -Wextra -Werror -std=c99
LDLIBS += $(shell $(PKG_CONFIG) --libs libxml-2.0 luajit)

.PHONY: all clean install FORCE

all: $(TARGET)

$(TARGET): $(OBJECTS) | bin
	$(CC) $(LDFLAGS) $(OBJECTS) $(LDLIBS) -o $@

$(VERSION_O): CPPFLAGS += -Iobj

$(VERSION_O): $(VERSION_H)

$(VERSION_H): FORCE
	@mkdir -p $(@D)
	@if v="$$(git describe --tags --exact-match HEAD 2>/dev/null)" && [ -n "$$v" ]; then \
		:; \
	elif h="$$(git rev-parse --short HEAD 2>/dev/null)" && [ -n "$$h" ]; then \
		d="$$(git log -1 --format='%ad' --date='format:%y.%m.%d' 2>/dev/null)"; \
		b="$$(git rev-parse --abbrev-ref HEAD 2>/dev/null)"; \
		v="$${d}+$${h}_$${b}"; \
	else \
		if [ -f $@ ]; then exit 0; fi; \
		v="$$(date +%y.%m.%d)+unknown"; \
	fi; \
	printf '#define YAPSSG_VERSION "%s"\n' "$$v" > $@.tmp; \
	cmp -s $@ $@.tmp || mv -f $@.tmp $@; \
	rm -f $@.tmp

obj/%.o: src/%.c
	mkdir -p $(@D)
	$(CC) $(CPPFLAGS) $(CFLAGS) -MMD -MP -c $< -o $@

bin:
	mkdir -p $@

clean:
	rm -rf obj bin

install: $(TARGET)
	install -Dm755 $(TARGET) $(DESTDIR)$(BINDIR)/yapssg

-include $(OBJECTS:.o=.d)