CROSS_COMPILE ?=

TARGET_FILE ?= test

CC = $(CROSS_COMPILE)gcc
CPP = $(CROSS_COMPILE)cpp

SRC_DIR = src
OBJ_DIR = obj
BIN_DIR = bin

INCLUDES := inc

#Alpine Linux ftdi include path
INCLUDES += /usr/include/libftdi1

DISTRO=$(head -1 /etc/issue)
ifeq "$(findstring Alpine,$(DISTRO))" ""
LIBS := ftdi
else
LIBS := ftdi1
endif

LD_FLAGS :=
C_FLAGS := -O0 -g
CPP_FLAGS := $(addprefix -I, $(INCLUDES))

C_SRCS = $(wildcard $(SRC_DIR)/*.c)
C_OBJS = $(patsubst $(SRC_DIR)%,$(OBJ_DIR)%,$(patsubst %.c,%.o,$(C_SRCS)))

OBJS = $(C_OBJS)

TARGET = $(BIN_DIR)/$(TARGET_FILE)
THIS_MAKEFILE := $(lastword $(MAKEFILE_LIST))

.PHONY: all
all: $(TARGET)

$(TARGET): $(OBJS) $(THIS_MAKEFILE)
	head -1 /etc/issue
	echo "$(LIBS)"
	echo "$(DISTRO)"
	echo "$(findstring Alpine,$(DISTRO))"
	@mkdir -p $(BIN_DIR)
	$(CC) $(C_FLAGS) $(LD_FLAGS) $(OBJS) $(addprefix -l,$(LIBS)) -o $@

.PRECIOUS: $(OBJ_DIR)/%.d
$(OBJ_DIR)/%.d: $(SRC_DIR)/%.c
	@mkdir -p $(OBJ_DIR)
	$(CPP) -MM -MF $@ -MP -MT $(patsubst %.d,%.o,$@) $(CPP_FLAGS) $(patsubst $(OBJ_DIR)/%.d,$(SRC_DIR)/%.c,$@)

$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c $(OBJ_DIR)/%.d
	@mkdir -p $(OBJ_DIR)
	$(CC) -c $(CPP_FLAGS) $(C_FLAGS) $< -o $@

.PHONY: clean
clean:
	rm -rf $(OBJS) $(patsubst %.o,%.d,$(OBJS)) $(TARGET)

ifneq ($(MAKECMDGOALS),clean)
-include $(patsubst %.o,%.d,$(OBJS))
endif