#include "application.h"

#include <assert.h>
#include <iostream>

#include "command_line.h"
#include "imgui_impl_sdl3.h"
#include "imgui_internal.h"
#include "filesystem/stb_image.h"
#include "rhi/texture.h"
#include "spdlog/async.h"
#include "spdlog/spdlog.h"
#include "spdlog/sinks/basic_file_sink.h"

#if WIN32
#include "rhi/windows/dx11/renderer_dx11.h"
#endif

bool g_is_running = true;
bool g_exit_requested = false;

application::~application()
{
    application::shutdown();
}

void application::init(window_params in_window_params, int argc, char** argv)
{
    try 
    {
        auto async_file = spdlog::basic_logger_mt<spdlog::async_factory>("async_file_logger", "logs/log.txt");
    }
    catch (const spdlog::spdlog_ex &ex)
    {
        std::cout << "Log init failed: " << ex.what() << std::endl;
    }
    
    command_line::instance().init(argc, argv);
    SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER);
    
    // Setup Dear ImGui context
    IMGUI_CHECKVERSION();
    init_imgui(ImGui::CreateContext());
    ImGuiIO& io = ImGui::GetIO();
    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
    ImGui::StyleColorsDark();
    //ImGui::StyleColorsLight();
    
    unsigned int window_flags = 0;

#if WIN32
    bool use_dx11 = false;
    bool use_dx12 = false;
    bool use_vulkan = false;
#else
    bool use_vulkan = true;
#endif

#if WIN32
    command_line::instance().get_arg("dx11", use_dx11);
    command_line::instance().get_arg("dx12", use_dx12);
    command_line::instance().get_arg("vulkan", use_vulkan);
    // only one renderer can be used at a time
    const int renderer_count = use_dx11 + use_dx12 + use_vulkan;
    assert(renderer_count <= 1);
    
    // if no renderer is specified, use dx11
    if (!(use_dx11 || use_dx12 || use_vulkan))
    {
        use_dx11 = true;
    }
    
    if (use_dx11)
    {
        renderer_ = new renderer_dx11();
    }
    // if (use_dx12)
    // {
    //     renderer_ = new renderer_dx12();
    // }
    // if (use_vulkan)
    // {
    //     renderer_ = new renderer_vulkan();
    //     window_flags |= SDL_WINDOW_VULKAN;
    // }
#else
    if (use_vulkan)
    {
        renderer_ = new renderer_vulkan();
        window_flags |= SDL_WINDOW_VULKAN;
    }
#endif
    
    // if (!renderer_)
    //     renderer_ = new renderer_null();

    if (in_window_params.fullscreen)
        window_flags |= SDL_WINDOW_FULLSCREEN;
    if (in_window_params.borderless)
        window_flags |= SDL_WINDOW_BORDERLESS;
    if (in_window_params.resizable)
        window_flags |= SDL_WINDOW_RESIZABLE;
    if (in_window_params.minimized)
        window_flags |= SDL_WINDOW_MINIMIZED;
    if (in_window_params.maximized)
        window_flags |= SDL_WINDOW_MAXIMIZED;
    if (in_window_params.hi_dpi)
        window_flags |= SDL_WINDOW_HIGH_PIXEL_DENSITY;
    if (in_window_params.always_on_top)
        window_flags |= SDL_WINDOW_ALWAYS_ON_TOP;
    
    // new SDL window
    window_ = SDL_CreateWindow(in_window_params.title.c_str(), in_window_params.width, in_window_params.height, window_flags);
    if (!window_)
    {
        spdlog::error("Failed to create SDL window: {}", SDL_GetError());
        return;
    }
    SDL_SetWindowPosition(window_, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
    SDL_ShowWindow(window_);

    renderer_->init(window_);
    renderer_->resize(in_window_params.width, in_window_params.height);
    g_is_running = true;
}

int application::run()
{
    while (!g_exit_requested)
    {
        SDL_Event event;
        while (SDL_PollEvent(&event))
        {
            ImGui_ImplSDL3_ProcessEvent(&event);
            if (event.type == SDL_EVENT_QUIT)
                g_exit_requested = true;
            if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window_))
                g_exit_requested = true;
            if (event.type == SDL_EVENT_WINDOW_RESIZED)
            {
                const int width = event.window.data1;
                const int height = event.window.data2;
                renderer_->resize(width, height);
            }
        }
        if (g_exit_requested)
            break;
        
        renderer_->new_frame();
        draw_gui();
        renderer_->end_frame();
    }
    return 0;
}

void application::shutdown()
{
    renderer_->shutdown();
    ImGui::DestroyContext();

    delete renderer_;
}

texture* application::load_texture(const std::string& path) const
{
    int width = 0;
    int height = 0;
    unsigned char* image_data = stbi_load(path.c_str(), &width, &height, nullptr, 4);
    if (!image_data)
    {
        spdlog::error("Failed to load texture: {}", path.c_str());
        return nullptr;
    }
    const auto texture = renderer_->create_texture(image_data, width, height);
    stbi_image_free(image_data);
    return texture;
}

texture* application::create_texture(const unsigned char* data, const int width, const int height) const
{
    return renderer_->create_texture(data, width, height);
}