#include "ffcpp/Player.h"
#include <memory>
#include <SDL.h>
#include <SDL_thread.h>
#include <iostream>

#include <future>

namespace ff = ffcpp;

#define WINDOW_WIDTH    1280
#define WINDOW_HEIGHT   720

class SDLWindow: public ff::IVideoSink, public ff::IAudioSink {
private:
    template<typename T> using SDLUniquePtr = std::unique_ptr<T, void(*)(T*)>;
    using SDLWindowPtr = SDLUniquePtr<SDL_Window>;
    using SDLRendererPtr = SDLUniquePtr<SDL_Renderer>;
    using SDLTexturePtr = SDLUniquePtr<SDL_Texture>;

private:
    SDLWindowPtr _wnd;
    SDLRendererPtr _renderer;
    SDLTexturePtr _texture;
    SDL_AudioSpec _audioSpec;
    SDL_AudioDeviceID _aDevId;

    std::packaged_task<void()> _renderTask;
    ff::IAudioSource* _audioSrc;

public:
    SDLWindow(): _wnd(nullptr, SDL_DestroyWindow), _renderer(nullptr, SDL_DestroyRenderer), _texture(nullptr, SDL_DestroyTexture), _audioSrc(nullptr) {
        int res = SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER);
        if(res < 0) throw std::runtime_error("Error initializing SDL");

        _wnd.reset(SDL_CreateWindow("ffPlayer", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, WINDOW_WIDTH, WINDOW_HEIGHT, SDL_WINDOW_OPENGL));
        if(!_wnd) throw std::runtime_error("Error creating SDL window");

        _renderer.reset(SDL_CreateRenderer(_wnd.get(), -1, 0));
        if(!_renderer) throw std::runtime_error("Error creating SDL renderer");

        _texture.reset(SDL_CreateTexture(_renderer.get(), SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, WINDOW_WIDTH, WINDOW_HEIGHT));
        if(!_texture) throw std::runtime_error("Error creating SDL texture");

        SDL_AudioSpec want;
        SDL_zero(want);
        want.freq = 44100;
        want.format = AUDIO_F32;
        want.channels = 2;
        want.samples = 8192;
        want.callback = SDLWindow::audioCallback;
        want.userdata = this;

        _aDevId = SDL_OpenAudioDevice(nullptr, 0, &want, &_audioSpec, SDL_AUDIO_ALLOW_ANY_CHANGE);
        if(_aDevId == 0) throw std::runtime_error("Error opening audio device");

        SDL_PauseAudioDevice(_aDevId, 0);
    }

    void handleEvents() {
        SDL_Event event;

        while(true) {
            SDL_WaitEvent(&event);
            switch(event.type) {
                case SDL_QUIT:
                    return;
                case SDL_USEREVENT: {
                    _renderTask();
                    break;
                }
            }
        }
    }

private:
    static void audioCallback(void* userdata, Uint8* stream, int len) {
        ff::IAudioSource* src = static_cast<SDLWindow*>(userdata)->_audioSrc;

        if(src) {
            //std::cout << "fill sample buffer" << std::endl;
            src->fillSampleBuffer(stream, len);
        }
    }

    AVSampleFormat sdlToFFMpeg(SDL_AudioFormat format) {
        switch (format) {
            case AUDIO_S16: return AV_SAMPLE_FMT_S16;
            case AUDIO_S32: return AV_SAMPLE_FMT_S32;
            case AUDIO_F32: return AV_SAMPLE_FMT_FLT;
            default:
                throw std::runtime_error("unknown audio sample format: " + std::to_string(format));
        }
    }

    // IVideoSink implementation
private:
    virtual AVPixelFormat getPixelFormat() const noexcept override {
        return AV_PIX_FMT_YUV420P;
    }

    virtual void drawFrame(void* pixelsData, int pitch) override {
        std::cout << "drawing frame" << std::endl;
        SDL_UpdateTexture(_texture.get(), nullptr, pixelsData, pitch);
        SDL_RenderClear(_renderer.get());
        SDL_RenderCopy(_renderer.get(), _texture.get(), nullptr, nullptr);
        SDL_RenderPresent(_renderer.get());
    }

    virtual void drawPlanarYUVFrame(const void *yPlane, const void *uPlane, const void *vPlane, int yPitch, int uPitch, int vPitch) override {
        _renderTask = std::packaged_task<void()>([=]{
            SDL_UpdateYUVTexture(_texture.get(), nullptr, (const uint8_t*)yPlane, yPitch, (const uint8_t*)uPlane, uPitch, (const uint8_t*)vPlane, vPitch);
            SDL_RenderClear(_renderer.get());
            SDL_RenderCopy(_renderer.get(), _texture.get(), nullptr, nullptr);
            SDL_RenderPresent(_renderer.get());
        });
        auto future = _renderTask.get_future();

        SDL_Event event;
        event.type = SDL_USEREVENT;
        int res = SDL_PushEvent(&event);

        future.get();
    }

    // IAudioSink implementation
private:
    void setAudioSource(ff::IAudioSource* audioSrc) override {
        std::cout << "set audio source" << std::endl;
        _audioSrc = audioSrc;
    }

    AVSampleFormat getSampleFormat() override {
        return sdlToFFMpeg(_audioSpec.format);
    }

    int getChannelsCount() override {
        return _audioSpec.channels;
    }

    int getSampleRate() override {
        return _audioSpec.freq;
    }
};

int main(int argc, char** argv) {
    try {
        auto wnd = std::make_shared<SDLWindow>();

        ff::Player player(wnd, wnd);
        player.setMedia(argv[1]);
        player.setVideoSize(WINDOW_WIDTH, WINDOW_HEIGHT);
        player.play();

        wnd->handleEvents();
    } catch (...) {
        std::cout << "exception" << std::endl;
        return 0;
    }

    return 0;
}