#include <glad/glad.h> // Include GLAD before GLFW
#include <GLFW/glfw3.h>
#include <iostream>

// ImGui includes
#include "imgui/imgui.h"
#include "imgui/imgui_impl_glfw.h"
#include "imgui/imgui_impl_opengl3.h"

// Callback to resize the viewport when the window is resized
void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
	(void)window; // Unused parameter
	glViewport(0, 0, width, height);
}

int main() {
	// 1. Initialize GLFW
	glfwInit();
    // Set OpenGL version to 3.3 Core Profile - For MacOS, you may need to uncomment the next line
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

#ifdef __APPLE__
    const char* glsl_version = "#version 330";
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // Required on Mac
#endif

	// 2. Create the Window
	GLFWwindow *window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
	if (window == NULL) {
		std::cout << "Failed to create GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

	// 3. Initialize GLAD (Load function pointers)
	if (!gladLoadGLLoader(reinterpret_cast<GLADloadproc>(glfwGetProcAddress))) {
		std::cout << "Failed to initialize GLAD" << std::endl;
		return -1;
	}

	// --- ImGui Setup Start ---
	IMGUI_CHECKVERSION();
	ImGui::CreateContext();
	ImGuiIO &io = ImGui::GetIO();
	(void)io;

	// Setup Dear ImGui style
	ImGui::StyleColorsDark();
	// ImGui::StyleColorsLight();

	// Setup Platform/Renderer backends
	ImGui_ImplGlfw_InitForOpenGL(window, true);
	ImGui_ImplOpenGL3_Init(glsl_version);

	// 4. The Render Loop
	while (!glfwWindowShouldClose(window)) {
		// Input
		if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
			glfwSetWindowShouldClose(window, true);

        // --- ImGui Frame Start ---
        ImGui_ImplOpenGL3_NewFrame();
        ImGui_ImplGlfw_NewFrame();
        ImGui::NewFrame();

        // Create a simple window
        ImGui::Begin("Settings");
        ImGui::Text("Hello from Dear ImGui!");
        ImGui::End();
        // --- ImGui Frame End ---

		// Rendering commands here
		glClearColor(0.01f, 0.01f, 0.01f, 1.0f); // Set clear color (Dark Gray)
		glClear(GL_COLOR_BUFFER_BIT);         // Clear the screen

        ImGui::Render();
        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

		// Swap buffers and poll IO events
		glfwSwapBuffers(window);
		glfwPollEvents();
	}

	// 5. Clean up

    ImGui_ImplOpenGL3_Shutdown();
    ImGui_ImplGlfw_Shutdown();
    ImGui::DestroyContext();
	glfwTerminate();
	return 0;
}