# --- minimal linux makefile ------------------------------------------------- #
# This makefile works on linux with options to crosscompile by changing the    #
# TARGET option. By default, compile the defined application for the native    #
# platform.                                                                    #
#                                                                              #
# Before use, make sure to adapt the parameters in the following sections      #
# 	- project architecture : general folder layout                             #
# 	- toolchain configuration : compiler to use and other little things        #
# 	- defines settings : list of defines to pass to the compiler			   #
# 	- general settings : include control and release options				   #
# ---------------------------------------------------------------------------- #

# --- project architecture
# program name
EXE_PREFIX=main
# project folder architecture
SRC=src
BIN=bin
INC=
OBJ=$(BIN)/obj

# --- toolchain configuration
TARGET=
CC=$(TARGET)gcc
AS=$(TARGET)gcc -x assembler-with-cpp -c

# --- defines settings
#list all C defines here with -D before the name
C_DEFS=
#list all ASM defines here with -D before the name
A_DEFS=
#list all linker flags here with -l before the name
LDFLAGS=-lavcodec -lavformat -lavutil -lavdevice -lv4l2

# --- general settings
# RELEASE=0 -> disable optimisation, then enable debug
# RELEASE=1 -> enable optimisation, then disable debug
RELEASE=0

#-------------------------------------------------------------------------------
# files discovery and paths solving
# down here is black magic, you probably don't want to modify anything

#list all directories, sort them and remove duplicates
DIRS:=$(sort $(shell find . -type d))
#find paths to src files from directory list
SRC_PATHS=$(foreach DIR, $(SRC), $(filter ./$(DIR)%, $(DIRS)))

#list c files
C_FILES=$(foreach PATH, . $(SRC_PATHS), $(wildcard $(PATH)/*.c))
#filter useless STmcube files
ifeq ($(strip $(FILTER)), 1)
    C_FILES:=$(filter-out %template.c, $(C_FILES))
endif

#list h files
#H_FILES=$(foreach PATH, $(INC_PATHS), $(wildcard $(PATH)/*.h))
#list asm files
ASM_FILES=$(foreach PATH, . $(SRC_PATHS), $(wildcard $(PATH)/*.s))

#separate main c file from other c files
MAIN_C_FILES:=$(filter %$(EXE_PREFIX).c, $(C_FILES))
C_FILES:=$(filter-out %$(EXE_PREFIX).c, $(C_FILES))

#create new paths to store o files
MAIN_OBJ_FILES=$(patsubst ./%.c, ./$(OBJ)/%.o, $(MAIN_C_FILES))
OBJ_FILES=$(patsubst ./%.c, ./$(OBJ)/%.o, $(C_FILES)) \
		  $(patsubst ./%.s, ./$(OBJ)/%.o, $(ASM_FILES))
DEPEND_FILES=$(MAIN_OBJ_FILES:%.o,%.d)$(OBJ_FILES:%.o,%.d)

#-------------------------------------------------------------------------------
# makefile incantation

# --- include path flag management
ifneq ($(strip $(INC)),)
    INCLUDE=-I$(INC)
else
    INCLUDE=
endif

# --- release flag management
ifeq ($(strip $(RELEASE)), 0)
    CFLAGS=-g3 -Os
    LDFLAGS+=-g3 -Os
else
    CFLAGS=-O2
endif

# --- flags definition
#merge all c compiler options
CFLAGS+=$(CPUFLAGS) -std=c23 -Wall -Wextra -Warray-bounds \
		-Wno-unused-parameter -fomit-frame-pointer $(C_DEFS)
#merge all asm compiler options
ASFLAG=-Wa,--gdwarf2 -D__ASSEMBLY__ $(C_DEFS) $(A_DEFS)
#merge all linker options
LDFLAGS+=-lc -lgcc -lgcov -lm -Wl,-Map=$@.map,--gc-sections

# --- folder creation
DIR_GUARD=@mkdir -p $(@D)

#-------------------------------------------------------------------------------
# makefile rules

# --- main rule
all: $(BIN)/$(EXE_PREFIX)

# --- rules configuration
rebuild : clean all

.SUFFIXES:
.SECONDARY:
#define rules name
.PHONY: all clean rebuild

# --- secondary rules
#exec file compilation
$(BIN)/$(EXE_PREFIX) : $(MAIN_OBJ_FILES) $(OBJ_FILES)
	@echo
	@printf '\e[1;32m==== linking $@ ====\e[0m'
	@echo
	$(DIR_GUARD)
	$(CC) $(LIBRARIES) $(LDFLAGS) $(CFLAGS) -o $@ $^
	@$(SKIP_LINE)

#c files compilation
$(OBJ)/%.o : %.c
	@echo
	@printf '\e[1;34m==== compiling [opt=$(opt)] $< ====\e[0m'
	@echo
	$(DIR_GUARD)
	$(CC) $(INCLUDE) -c $(CFLAGS) $< -o $@ $(LIBRARIES)
	@$(SKIP_LINE)

$(BIN)/%.o : %.c
	@echo
	@printf '\e[1;34m==== compiling [opt=$(opt)] $< ====\e[0m'
	@echo
	$(DIR_GUARD)
	$(CC) $(INCLUDE) -c $(CFLAGS) $< -o $@ $(LIBRARIES)
	@$(SKIP_LINE)

#asm files compilation
$(OBJ)/%.o : %.s
	@echo
	@printf '\e[1;35m==== compiling [opt=$(opt)] $^ $@ $(LIBRARIES)====\e[0m'
	@echo
	$(DIR_GUARD)
	$(AS) $(ASFLAGS) $< -o $@ $(LIBRARIES)
	@$(SKIP_LINE)

$(BIN)/%.o : %.s
	@echo
	@printf '\e[1;35m==== compiling [opt=$(opt)] $^ $@ $(LIBRARIES)====\e[0m'
	@echo
	$(DIR_GUARD)
	$(AS) $(ASFLAGS) $< -o $@ $(LIBRARIES)
	@$(SKIP_LINE)

# --- remove generated files
clean:
	-rm -rf $(BIN)/*

-include $(DEPEND_FILES)