#include "imgui.h"
#include "imgui_impl_glfw.h"
#include "imgui_impl_opengl3.h"
#include <GLFW/glfw3.h>

static void glfw_error_callback(int error, const char* description)
{
    fprintf(stderr, "Glfw Error %d: %s\n", error, description);
}

int main(int, char**)
{
    // Setup window
    glfwSetErrorCallback(glfw_error_callback);
    if (!glfwInit())
        return -1;

    const char* glsl_version = "#version 130";
    GLFWwindow* window = glfwCreateWindow(1280, 720, "Login Form", NULL, NULL);
    if (window == NULL)
        return -1;
    glfwMakeContextCurrent(window);
    glfwSwapInterval(1); // Enable vsync

    // Initialize OpenGL loader (GLAD in this case)
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        fprintf(stderr, "Failed to initialize OpenGL loader!\n");
        return -1;
    }

    // Setup Dear ImGui context
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;
    
    // Setup Dear ImGui style
    ImGui::StyleColorsDark();

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

    char email[128] = "";
    char password[128] = "";
    bool show_login_window = true;

    while (!glfwWindowShouldClose(window))
    {
        // Poll and handle events
        glfwPollEvents();

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

        if (show_login_window)
        {
            ImGui::Begin("Sign In", &show_login_window, ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove);
            ImGui::SetWindowSize(ImVec2(400, 200));
            ImGui::SetWindowPos(ImVec2((1280 - 400) / 2, (720 - 200) / 2));

            ImGui::Text("Email");
            ImGui::InputText("##email", email, IM_ARRAYSIZE(email));
            ImGui::Text("Password");
            ImGui::InputText("##password", password, IM_ARRAYSIZE(password), ImGuiInputTextFlags_Password);

            if (ImGui::Button("Sign in"))
            {
                // Handle sign in
            }

            ImGui::End();
        }

        // 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());

        glfwSwapBuffers(window);
    }

    // Cleanup
    ImGui_ImplOpenGL3_Shutdown();
    ImGui_ImplGlfw_Shutdown();
    ImGui::DestroyContext();

    glfwDestroyWindow(window);
    glfwTerminate();

    return 0;
}