#include <@APP_INCLUDE@>
#include <engine.hpp>
#include <chrono>

#include "gfx_vulkan.hpp"
#include "platform.hpp"
#include <string_utils.hpp>

#include <SDL.h>
#include <SDL_vulkan.h>

#ifdef PLATFORM_WINDOWS
#include <winrt/Windows.UI.ViewManagement.h>
#pragma comment(lib, "windowsapp")
#endif

@APP_CLASS@* app = nullptr;
GFX* gfx_interface = nullptr;

struct Window {
    int identifier = 0;
    SDL_Window* window = nullptr;

    bool operator==(const Window& b) {
        return identifier == b.identifier && window == b.window;
    }
};

std::vector<Window> windows;

Window* get_window(const int index) {
    for(auto& window : windows) {
        if(window.identifier == index)
            return &window;
    }

    return nullptr;
}

Window* get_window_by_sdl_id(const Uint32 id) {
    for(auto& window : windows) {
        if(SDL_GetWindowID(window.window) == id)
            return &window;
    }

    return nullptr;
}

static std::map<InputButton, int> inputToKeyCode = { {
    {InputButton::C, SDL_SCANCODE_C},
    {InputButton::V, SDL_SCANCODE_V},
    {InputButton::X, SDL_SCANCODE_X},
    {InputButton::Y, SDL_SCANCODE_Y},
    {InputButton::Z, SDL_SCANCODE_Z},
    {InputButton::Backspace, SDL_SCANCODE_BACKSPACE},
    {InputButton::Enter, SDL_SCANCODE_RETURN},
    {InputButton::W, SDL_SCANCODE_W},
    {InputButton::A, SDL_SCANCODE_A},
    {InputButton::S, SDL_SCANCODE_S},
    {InputButton::D, SDL_SCANCODE_D},
    {InputButton::Q, SDL_SCANCODE_Q},
    {InputButton::Shift, SDL_SCANCODE_LSHIFT},
    {InputButton::Alt, SDL_SCANCODE_LALT},
    {InputButton::Super, SDL_SCANCODE_APPLICATION},
    {InputButton::Escape, SDL_SCANCODE_ESCAPE},
    {InputButton::Tab, SDL_SCANCODE_TAB},
    {InputButton::Ctrl, SDL_SCANCODE_LCTRL},
    {InputButton::Space, SDL_SCANCODE_SPACE},
    {InputButton::LeftArrow, SDL_SCANCODE_LEFT},
    {InputButton::RightArrow, SDL_SCANCODE_RIGHT}
}};

/*
 * Platform functions"
 */

const char* platform::get_name() {
    return SDL_GetPlatform();
}

bool platform::supports_feature(const PlatformFeature feature) {
    if(feature == PlatformFeature::Windowing)
        return true;

    return false;
}

int platform::open_window(const std::string_view title, const prism::Rectangle rect, const WindowFlags flags) {
    auto& win = windows.emplace_back();
    win.identifier = windows.size() - 1;

    int sdl_flags = SDL_WINDOW_VULKAN;
    if(flags == WindowFlags::Borderless)
        sdl_flags |= SDL_WINDOW_BORDERLESS;
    if(flags == WindowFlags::Resizable)
        sdl_flags |= SDL_WINDOW_RESIZABLE;

    int real_x = rect.offset.x;
    int real_y = rect.offset.y;
    if(rect.offset.x == -1 && rect.offset.y == -1) {
        real_x = SDL_WINDOWPOS_CENTERED;
        real_y = SDL_WINDOWPOS_CENTERED;
    }

    win.window = SDL_CreateWindow(title.data(), real_x, real_y, rect.extent.width, rect.extent.height, sdl_flags);

    engine->add_window((void*)&win, win.identifier, rect.extent);
    app->initialize_render();

    return win.identifier;
}

void platform::close_window(const int index) {
    auto window = get_window(index);

    engine->remove_window(window->identifier);

    SDL_DestroyWindow(window->window);

    utility::erase(windows, *window);
}

void platform::force_quit() {
    SDL_Quit();
}

float platform::get_window_dpi(const int index) {
    return 1.0;
}

float platform::get_monitor_dpi() {
    return 1.0;
}

prism::Rectangle platform::get_monitor_resolution() {
    SDL_DisplayMode DM;
    SDL_GetCurrentDisplayMode(0, &DM);

    return {0, 0, (uint32_t)DM.w, (uint32_t)DM.h};
}

prism::Rectangle platform::get_monitor_work_area() {
    return platform::get_monitor_resolution();
}

prism::Offset platform::get_window_position(const int index) {
    auto window = get_window(index);

    int x, y;
    SDL_GetWindowPosition(window->window, &x, &y);

    return {(int32_t)x, (int32_t)y};
}

prism::Extent platform::get_window_size(const int index) {
    auto window = get_window(index);

    int width, height;
    SDL_GetWindowSize(window->window, &width, &height);

    return {(uint32_t)width, (uint32_t)height};
}

prism::Extent platform::get_window_drawable_size(const int index) {
    auto window = get_window(index);

    int width, height;
    SDL_GetWindowSize(window->window, &width, &height);

    return {(uint32_t)width, (uint32_t)height};
}

bool platform::is_window_focused(const int index) {
    auto window = get_window(index);
    return (SDL_GetWindowFlags(window->window) & SDL_WINDOW_INPUT_FOCUS) != 0;
}

void platform::set_window_focused(const int index) {
    auto window = get_window(index);
    SDL_RaiseWindow(window->window);
}

void platform::set_window_position(const int index, const prism::Offset offset) {
    auto window = get_window(index);

    SDL_SetWindowPosition(window->window, offset.x, offset.y);
}

void platform::set_window_size(const int index, const prism::Extent extent) {
    auto window = get_window(index);

    SDL_SetWindowSize(window->window, extent.width, extent.height);
}

void platform::set_window_title(const int index, const std::string_view title) {
    auto window = get_window(index);

    SDL_SetWindowTitle(window->window, title.data());
}

bool platform::get_key_down(const InputButton key) {
    const Uint8 *state = SDL_GetKeyboardState(NULL);

    return state[inputToKeyCode[key]] && state[SDL_SCANCODE_DOWN];
}

int platform::get_keycode(const InputButton key) {
    return inputToKeyCode[key];
}

prism::Offset platform::get_cursor_position() {
    int x, y;
    SDL_GetMouseState(&x, &y);

    return {(int32_t)x, (int32_t)y};
}

prism::Offset platform::get_screen_cursor_position() {
    int x, y;
    SDL_GetGlobalMouseState(&x, &y);

    return {(int32_t)x, (int32_t)y};
}

bool platform::get_mouse_button_down(const int button) {
    Uint8 sdl_button = SDL_BUTTON_LEFT;
    switch(button) {
        case 0:
            sdl_button = SDL_BUTTON_LEFT;
            break;
        case 1:
            sdl_button = SDL_BUTTON_RIGHT;
            break;
        case 2:
            sdl_button = SDL_BUTTON_MIDDLE;
            break;
    }

    return (SDL_GetMouseState(NULL, NULL) & SDL_BUTTON(sdl_button)) != 0;
}

float mouse_wheel_x, mouse_wheel_y;

std::tuple<float, float> platform::get_wheel_delta() {
    return {mouse_wheel_x, mouse_wheel_y};
}

std::tuple<float, float> platform::get_right_stick_position() {
    return {0.0f, 0.0f};
}

std::tuple<float, float> platform::get_left_stick_position() {
    return {0.0f, 0.0f};
}

void platform::capture_mouse(const bool capture) {
    SDL_CaptureMouse((SDL_bool)capture);
}

char* platform::translate_keycode(const unsigned int keycode) {
    return const_cast<char*>(SDL_GetKeyName(SDL_GetKeyFromScancode((SDL_Scancode)keycode)));
}

void platform::begin_text_input() {
    SDL_StartTextInput();
}

void platform::end_text_input() {
    SDL_StopTextInput();
}

void platform::mute_output() {}

void platform::unmute_output() {}

int main(int argc, char* argv[]) {
    SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER);

    engine = new prism::engine(argc, argv);

    app = new @APP_CLASS@();
    engine->set_app(app);

    GFXCreateInfo info = {};

    gfx_interface = new GFXVulkan();
    if(gfx_interface->initialize(info)) {
        engine->set_gfx(gfx_interface);
    } else {
        return -1;
    }

    app_main(engine);

    auto end = std::chrono::high_resolution_clock::now();

    while(!engine->is_quitting()) {
         SDL_Event event = {};
         while(SDL_PollEvent(&event)) {
             switch(event.type) {
                 case SDL_QUIT:
                     engine->quit();
                     break;
                 case SDL_MOUSEWHEEL: {
                     mouse_wheel_x = event.wheel.x;
                     mouse_wheel_y = event.wheel.y;
                 }
                     break;
                 case SDL_MOUSEBUTTONDOWN:
                 {
                     int engine_button = 0;
                     if(event.button.button == SDL_BUTTON_RIGHT)
                         engine_button = 1;
                     else if(event.button.button == SDL_BUTTON_MIDDLE)
                         engine_button = 2;

                     engine->process_mouse_down(engine_button, {0, 0});
                 }
                    break;
                 case SDL_KEYDOWN:
                 {
                     engine->process_key_down(event.key.keysym.scancode);
                 }
                    break;
                 case SDL_KEYUP:
                 {
                     engine->process_key_up(event.key.keysym.scancode);
                 }
                    break;
                 case SDL_WINDOWEVENT:
                 {
                     if (event.window.event == SDL_WINDOWEVENT_RESIZED) {
                         auto window = get_window_by_sdl_id(event.window.windowID);
                         if(window != nullptr)
                            engine->resize(window->identifier, {static_cast<uint32_t>(event.window.data1), static_cast<uint32_t>(event.window.data2)});
                     } else if(event.window.event == SDL_WINDOWEVENT_CLOSE) {
                         engine->quit();
                     }
                 }
                     break;
                 case SDL_TEXTINPUT:
                 {
                    engine->process_text_input(event.text.text);
                 }
                    break;
             }
         }

         if(engine->is_quitting())
             break;

        auto begin = std::chrono::high_resolution_clock::now();

        float deltatime = (float)std::chrono::duration_cast<std::chrono::nanoseconds>(begin - end).count() / 1000000000ULL;
        end = begin;

        engine->update(deltatime);
        engine->begin_frame(deltatime);

        for(auto window : windows)
            engine->render(window.identifier);

        engine->end_frame();
     }

    engine->prepare_quit();

    return 0;
}

#ifdef PLATFORM_WINDOWS
PlatformTheme platform::get_theme() {
	using namespace winrt::Windows::UI::ViewManagement;

	// TODO: figure out if this works pre-anniversary update/other windows other than 10
	UISettings settings;
	auto background = settings.GetColorValue(UIColorType::Background);
	auto foreground = settings.GetColorValue(UIColorType::Foreground);

	if (background == winrt::Windows::UI::Colors::White())
		return PlatformTheme::Light;
	else
		return PlatformTheme::Dark;
}
#else
PlatformTheme platform::get_theme() {
    return PlatformTheme::Light;
}
#endif

void* platform::create_native_surface(int index, void* instance) {
    auto window = get_window(index);

    VkSurfaceKHR surface;

    SDL_Vulkan_CreateSurface(window->window, (VkInstance)instance, &surface);

    return surface;
}

std::vector<const char*> platform::get_native_surface_extension() {
    // dummy window
    auto dummy = SDL_CreateWindow("", 0, 0, 1, 1, SDL_WINDOW_VULKAN);

    unsigned int count = 0;
    SDL_Vulkan_GetInstanceExtensions(dummy, &count, nullptr);

    std::vector<const char*> extensions(count);
    SDL_Vulkan_GetInstanceExtensions(dummy, &count, extensions.data());

    SDL_DestroyWindow(dummy);

    return extensions;
}