#include <windows.h>
#include <glad/glad.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "XCEngine/Debug/Logger.h"
#include "XCEngine/Debug/ConsoleLogSink.h"
#include "XCEngine/Containers/String.h"

#pragma comment(lib, "opengl32.lib")

using namespace XCEngine::Debug;
using namespace XCEngine::Containers;

static const int gWidth = 1280;
static const int gHeight = 720;
static HWND gHWND = nullptr;
static HDC gHDC = nullptr;
static HGLRC gHGLRC = nullptr;

void Log(const char* format, ...) {
    char buffer[1024];
    va_list args;
    va_start(args, format);
    vsnprintf(buffer, sizeof(buffer), format, args);
    va_end(args);
    Logger::Get().Debug(LogCategory::Rendering, String(buffer));
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    switch (msg) {
    case WM_CLOSE:
        PostQuitMessage(0);
        break;
    }
    return DefWindowProc(hwnd, msg, wParam, lParam);
}

bool InitOpenGL() {
    gHDC = GetDC(gHWND);
    if (!gHDC) {
        Log("[ERROR] Failed to get DC");
        return false;
    }

    PIXELFORMATDESCRIPTOR pfd = {};
    pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 32;
    pfd.cDepthBits = 24;
    pfd.cStencilBits = 8;
    pfd.iLayerType = PFD_MAIN_PLANE;

    int pixelFormat = ChoosePixelFormat(gHDC, &pfd);
    if (!pixelFormat) {
        Log("[ERROR] Failed to choose pixel format");
        return false;
    }

    if (!SetPixelFormat(gHDC, pixelFormat, &pfd)) {
        Log("[ERROR] Failed to set pixel format");
        return false;
    }

    gHGLRC = wglCreateContext(gHDC);
    if (!gHGLRC) {
        Log("[ERROR] Failed to create GL context");
        return false;
    }

    if (!wglMakeCurrent(gHDC, gHGLRC)) {
        Log("[ERROR] Failed to make GL context current");
        return false;
    }

    if (!gladLoadGL()) {
        Log("[ERROR] Failed to load OpenGL functions");
        return false;
    }

    Log("[INFO] OpenGL initialized: %s", glGetString(GL_RENDERER));
    Log("[INFO] OpenGL Version: %s", glGetString(GL_VERSION));

    glViewport(0, 0, gWidth, gHeight);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);

    return true;
}

void ShutdownOpenGL() {
    if (gHGLRC) {
        wglDeleteContext(gHGLRC);
        gHGLRC = nullptr;
    }
    if (gHDC) {
        ReleaseDC(gHWND, gHDC);
        gHDC = nullptr;
    }
}

void SaveScreenshotPPM(const char* filename) {
    unsigned char* pixels = (unsigned char*)malloc(gWidth * gHeight * 3);
    if (!pixels) {
        Log("[ERROR] Failed to allocate pixel buffer");
        return;
    }

    glPixelStorei(GL_PACK_ALIGNMENT, 1);
    glReadPixels(0, 0, gWidth, gHeight, GL_RGB, GL_UNSIGNED_BYTE, pixels);

    FILE* f = fopen(filename, "wb");
    if (!f) {
        Log("[ERROR] Failed to open file for screenshot: %s", filename);
        free(pixels);
        return;
    }

    fprintf(f, "P6\n%d %d\n255\n", gWidth, gHeight);

    unsigned char* row = (unsigned char*)malloc(gWidth * 3);
    for (int y = gHeight - 1; y >= 0; y--) {
        memcpy(row, pixels + y * gWidth * 3, gWidth * 3);
        fwrite(row, 1, gWidth * 3, f);
    }

    free(row);
    free(pixels);
    fclose(f);

    Log("[INFO] Screenshot saved to %s", filename);
}

void RenderFrame() {
    glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    SwapBuffers(gHDC);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) {
    Logger::Get().Initialize();
    Logger::Get().AddSink(std::make_unique<ConsoleLogSink>());
    Logger::Get().SetMinimumLevel(LogLevel::Debug);

    Log("[INFO] OpenGL Integration Test Starting");

    WNDCLASSEX wc = {};
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.lpszClassName = L"OpenGLTest";

    if (!RegisterClassEx(&wc)) {
        MessageBox(NULL, L"Failed to register window class", L"Error", MB_OK);
        return -1;
    }

    RECT rect = { 0, 0, gWidth, gHeight };
    AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, FALSE);

    gHWND = CreateWindowEx(0, L"OpenGLTest", L"OpenGL Integration Test",
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
        rect.right - rect.left, rect.bottom - rect.top,
        NULL, NULL, hInstance, NULL);

    if (!gHWND) {
        MessageBox(NULL, L"Failed to create window", L"Error", MB_OK);
        return -1;
    }

    if (!InitOpenGL()) {
        MessageBox(NULL, L"Failed to initialize OpenGL", L"Error", MB_OK);
        return -1;
    }

    ShowWindow(gHWND, nShowCmd);
    UpdateWindow(gHWND);

    MSG msg = {};
    int frameCount = 0;
    const int targetFrameCount = 30;

    while (true) {
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
            if (msg.message == WM_QUIT) {
                break;
            }
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        } else {
            RenderFrame();
            frameCount++;

            if (frameCount >= targetFrameCount) {
                Log("[INFO] Reached target frame count %d - taking screenshot!", targetFrameCount);
                SaveScreenshotPPM("minimal.ppm");
                break;
            }
        }
    }

    ShutdownOpenGL();
    Logger::Get().Shutdown();

    Log("[INFO] OpenGL Integration Test Finished");
    return 0;
}