# Directories
INCLUDE_DIR = include
SRC_DIR = src
BUILD_DIR = build

# ImGui directory (only set if ImGui is used)
IMGUI_DIR = imgui

# Compiler
CXX = g++

# Libs
LIBS = -lGL `pkg-config --libs sdl3`

# Compiler and linker settings
CXXFLAGS = `pkg-config --cflags sdl3` -std=c++17 -I $(INCLUDE_DIR)

# If ImGui directory is set, include its source files
ifdef IMGUI_DIR
CXXFLAGS += -I $(IMGUI_DIR) -I $(IMGUI_DIR)/backends
endif

# Source and object files
SRC = $(wildcard $(SRC_DIR)/*.cpp)

# If ImGui is used, add its source files to the source list
ifdef IMGUI_DIR
SRC += $(IMGUI_DIR)/imgui.cpp $(IMGUI_DIR)/imgui_demo.cpp $(IMGUI_DIR)/imgui_draw.cpp $(IMGUI_DIR)/imgui_tables.cpp $(IMGUI_DIR)/imgui_widgets.cpp
SRC += $(IMGUI_DIR)/backends/imgui_impl_sdl3.cpp $(IMGUI_DIR)/backends/imgui_impl_opengl3.cpp
endif

# Target executable
UNAME := $(shell uname -s)
BUILD_DIR := $(BUILD_DIR)/$(UNAME)
OBJ_DIR := $(BUILD_DIR)/objs
BIN = $(BUILD_DIR)/main

# Object files corresponding to the source files (now in obj directory)
OBJS = $(addprefix $(OBJ_DIR)/, $(addsuffix .o, $(basename $(notdir $(SRC)))))

# development target with debugging
dev: CXXFLAGS += -g -Wall -Wformat
dev: all

# Release target
release: CXXFLAGS += -O3
release: all

# Create directories for build output
dirs:
	@mkdir -p $(BUILD_DIR)
	@mkdir -p $(OBJ_DIR)

# Pattern rule for source files in src directory
$(OBJ_DIR)/%.o: $(SRC_DIR)/%.cpp
	$(CXX) $(CXXFLAGS) -c -o $@ $<

# Pattern rule for ImGui source files
ifdef IMGUI_DIR
$(OBJ_DIR)/%.o: $(IMGUI_DIR)/%.cpp
	$(CXX) $(CXXFLAGS) -c -o $@ $<

$(OBJ_DIR)/%.o: $(IMGUI_DIR)/backends/%.cpp
	$(CXX) $(CXXFLAGS) -c -o $@ $<
endif

all: dirs $(BIN)
	@echo Build complete

$(BIN): $(OBJS)
	$(CXX) -o $@ $^ $(CXXFLAGS) $(LIBS)

clean:
	rm -rf $(BUILD_DIR)