OPTIMIZE ?= -O3
DEBUG ?= -g

AR ?= ar
CXX ?= g++
IWYU ?= iwyu
CHRONIC ?= chronic

PKGS := fmt
PKG_FLAGS := $(shell pkg-config --cflags ${PKGS})
PKG_LIBS := -Wl,--push-state,--as-needed $(shell pkg-config --libs ${PKGS}) -Wl,--pop-state

CXXFLAGS := -Wall -Werror -std=c++20 -fPIC -iquote . ${PKG_FLAGS} ${OPTIMIZE} ${DEBUG}

.DEFAULT_GOAL := all

VERSION := $(shell git describe --always --dirty --long --tags 2> /dev/null)
ifndef VERSION
VERSION := unknown
endif
$(info Version ${VERSION})

define GITTAGCPP =
#include <string>

std::string GIT_TAG = "$(subst ",\",${VERSION})";
endef
export GITTAGCPP

ifneq ($(shell which ${IWYU}),)
iwyu = ${CHRONIC} ${IWYU} -Xiwyu --error -Xiwyu --mapping_file=tools/iwyu.imp ${CXXFLAGS} $(1)
else
$(warning Not using IWYU)
iwyu =
endif

libname = $(shell realpath --canonicalize-missing --relative-to . build/$(dir $(1))/lib$(notdir $(1)))

define mklib =

ifneq ($(wildcard $(1)/*.cpp),)

$(call libname,$(1).a): $(patsubst %.cpp,build/%.o,$(wildcard $(1)/*.cpp))
	@mkdir -p $$(dir $$@)
	$${AR} cr $$@ $$+

$(call libname,$(1).so): $(patsubst %.cpp,build/%.o,$(wildcard $(1)/*.cpp))
	@mkdir -p $$(dir $$@)
	$${CXX} $${CXXFLAGS} -shared -o $$@ $$+ ${PKG_LIBS}

PARTARS += $(call libname,$(1).a)
PARTSOS += $(call libname,$(1).so)

endif

ifdef iwyu

build/$(1)/iwyu.cpp:
	@mkdir -p $$(dir $$@)
	@tools/iwyu-header $$(wildcard $(1)/*.h) > $$@
	@$$(call iwyu,$$@)
.PHONY: build/$(1)/iwyu.cpp

IWYU_CPPS += build/$(1)/iwyu.cpp

endif

endef

PARTS := $(patsubst ./%,%,$(shell find -mindepth 1 -type d -\( -name .\* -prune -o -name build -prune -o -name tools -prune -o -print -\)))

PARTARS :=
PARTSOS :=
IWYU_CPPS :=

$(foreach part,${PARTS},$(eval $(call mklib,${part})))

MAINOBJS := $(patsubst %.cpp,build/%.o,$(wildcard *.cpp))
MAINOBJS += build/git-tag.o

$(info )

all: ${IWYU_CPPS} issim issim-static

issim: build/issim-dynamic
	@ln -sf $< $@
.PHONY: issim

issim-static: build/issim-static
	@ln -sf $< $@
.PHONY: issim-static

build/issim-dynamic: ${MAINOBJS} ${PARTSOS}
	@mkdir -p $(dir $@)
	${CXX} ${CXXFLAGS} -o $@ $+ ${PKG_LIBS}

build/issim-static: ${MAINOBJS} ${PARTARS}
	@mkdir -p $(dir $@)
	${CXX} ${CXXFLAGS} -o $@ $+ ${PKG_LIBS}

clean:
	rm -rf build issim issim-static
.PHONY: clean

build/git-tag.cpp:
	@mkdir -p $(dir $@)
	@echo "$$GITTAGCPP" > $@
.PHONY: build/git-tag.cpp

include $(shell find -type f -name \*.d)

build/%.o: %.cpp
	@mkdir -p $(dir $@)
	@$(call iwyu,$<)
	${CXX} ${CXXFLAGS} -MMD -c -o $@ $<

build/%.o: build/%.cpp
	@mkdir -p $(dir $@)
	${CXX} ${CXXFLAGS} -MMD -c -o $@ $<

.SUFFIXES:
.SECONDARY: