CC ?= cc
CXX ?= c++
PKG_CONFIG ?= pkg-config
BUILD_DIR ?= build
PREFIX ?= /usr/local

CFLAGS ?= -O2 -g
CFLAGS += -std=c99 -Wall -Wextra -Wpedantic -Wconversion -Wshadow -Iinclude
CXXFLAGS ?= -O2 -g
CXXFLAGS += -std=c++17 -Wall -Wextra -Wpedantic -Iinclude
LDFLAGS ?=

CORE_SOURCES := src/core/xtlite.c src/graph/graph.c src/dsp/gain.c src/engine/offline_engine.c
CORE_OBJECTS := $(CORE_SOURCES:%.c=$(BUILD_DIR)/%.o)
TEST_OBJECT := $(BUILD_DIR)/tests/unit/test_core.o
GUI_AVAILABLE := $(shell $(PKG_CONFIG) --exists fltk 2>/dev/null && echo yes)

.PHONY: all clean test gui install
all: $(BUILD_DIR)/libxtlite.a

$(BUILD_DIR)/libxtlite.a: $(CORE_OBJECTS)
	@mkdir -p $(@D)
	$(AR) rcs $@ $^

$(BUILD_DIR)/%.o: %.c
	@mkdir -p $(@D)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/%.o: %.cpp
	@mkdir -p $(@D)
	$(CXX) $(CXXFLAGS) $(shell $(PKG_CONFIG) --cflags fltk 2>/dev/null) -c $< -o $@

$(TEST_OBJECT): tests/unit/test_core.c
	@mkdir -p $(@D)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/test_core: $(TEST_OBJECT) $(BUILD_DIR)/libxtlite.a
	$(CC) $(LDFLAGS) -o $@ $(TEST_OBJECT) $(BUILD_DIR)/libxtlite.a -lm

test: $(BUILD_DIR)/test_core
	./$(BUILD_DIR)/test_core

ifeq ($(GUI_AVAILABLE),yes)
gui: $(BUILD_DIR)/xtlite

$(BUILD_DIR)/xtlite: $(BUILD_DIR)/src/gui/main.o $(BUILD_DIR)/src/gui/main_window.o $(BUILD_DIR)/libxtlite.a
	$(CXX) $(LDFLAGS) -o $@ $^ $(shell $(PKG_CONFIG) --libs fltk) -lm
else
gui:
	@echo "FLTK was not found by pkg-config. Install FLTK development files to build the GUI."
	@exit 1
endif

install: all
	install -d "$(DESTDIR)$(PREFIX)/include/xtlite" "$(DESTDIR)$(PREFIX)/lib"
	install -m 0644 include/xtlite/*.h "$(DESTDIR)$(PREFIX)/include/xtlite/"
	install -m 0644 "$(BUILD_DIR)/libxtlite.a" "$(DESTDIR)$(PREFIX)/lib/"

clean:
	rm -rf "$(BUILD_DIR)"