#include <glad/glad.h>  // Use GLAD instead of GLEW
#include <GLFW/glfw3.h>
#include "imgui.h"
#include "imgui_impl_glfw.h"
#include "imgui_impl_opengl3.h"
//#include <glm/glm.hpp>
#include <iostream>

#define NOMINMAX
#include <windows.h>

// GLFW error callback function
void glfw_error_callback(int error, const char* description) {
    std::cerr << "GLFW Error " << error << ": " << description << std::endl;
}

int main();

int CALLBACK WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
    return main();
}

int main() {
    // Setup window
    glfwSetErrorCallback(glfw_error_callback);

    if (!glfwInit()) {
        std::cerr << "Failed to initialize GLFW" << std::endl;
        return -1;
    }

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
    glfwWindowHint(GLFW_RESIZABLE, GL_TRUE);
    glfwWindowHint(GLFW_VISIBLE, GL_TRUE);
    glfwWindowHint(GLFW_MAXIMIZED, GL_TRUE);
    glfwWindowHint(GLFW_DEPTH_BITS, 0);
    glfwWindowHint(GLFW_STENCIL_BITS, 0);

    // Create a windowed mode window and its OpenGL context
    GLFWwindow* window = glfwCreateWindow(1280, 720, "ImGui + GLFW + GLAD Example", nullptr, nullptr);
    if (!window) {
        std::cerr << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }

    glfwMakeContextCurrent(window);
    glfwSwapInterval(0); // Enable vsync

    // Initialize GLAD
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
        std::cerr << "Failed to initialize GLAD" << std::endl;
        return -1;
    }

    // Setup Dear ImGui context
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); //(void)io;
    // io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18);
    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;


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

    // Setup Platform/Renderer bindings
    ImGui_ImplGlfw_InitForOpenGL(window, true);
    ImGui_ImplOpenGL3_Init("#version 130");

    // Main loop
    while (!glfwWindowShouldClose(window)) {
        // Poll and handle events (inputs, window resize, etc.)
        //glfwPollEvents();
        glfwWaitEventsTimeout(0.1);

        // Start the ImGui frame
        ImGui_ImplOpenGL3_NewFrame();
        ImGui_ImplGlfw_NewFrame();
        ImGui::NewFrame();

        ImGui::DockSpaceOverViewport();

        // Create a simple ImGui window
        {
            ImGui::Begin("Hello, world!");   // Create a window called "Hello, world!"
            ImGui::Text("This is a simple window using ImGui and GLFW.");
            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
            ImGui::End();
        }

        ImGui::ShowDemoWindow();

        // Rendering
        ImGui::Render();
        int display_w, display_h;
        glfwGetFramebufferSize(window, &display_w, &display_h);
        glViewport(0, 0, display_w, display_h);
        glClearColor(0.45f, 0.55f, 0.60f, 1.00f);
        glClear(GL_COLOR_BUFFER_BIT);
        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

        // Swap buffers
        glfwSwapBuffers(window);
    }

    // Cleanup
    ImGui_ImplOpenGL3_Shutdown();
    ImGui_ImplGlfw_Shutdown();
    ImGui::DestroyContext();
    glfwDestroyWindow(window);
    glfwTerminate();

    return 0;
}