#include "playback.h"
#include "SDL_mixer.h"
#include "playback_backend.hpp"
#include <SDL_audio.h>
#include <chrono>
extern "C" {
#include <vgmstream.h>
#include <util.h>
#include <plugins.h>
}
#include <climits>
#include <SDL.h>
#include <exception>
#include <thread>
#include <cmath>
#ifdef __linux__
#include <pthread.h>
#endif
#include "log.hpp"
#include <filesystem>
#include "dbus.hpp"
#include <string.h>
#include "util.hpp"
#include "file_backend.hpp"
using namespace std::chrono;

size_t CalculateBufSize(SDL_AudioSpec *obtained, double seconds, double max_seconds, size_t samples_override = 0) {
    return ((((samples_override == 0) ? obtained->samples : samples_override) * std::min(seconds, max_seconds)) + 1) * sizeof(SAMPLETYPE) * obtained->channels;
}
void PlaybackInstance::SDLCallbackInner(Uint8 *stream, int len) {
    SDL_memset((void*)stream, 0, len);
    if (!playback_ready.load()) return;
    if (process == nullptr) return;
    if (st == nullptr) return;
	size_t unit = sizeof(SAMPLETYPE) * spec.channels;
	size_t bytes_per_iter = (bufsize / unit) * unit;
	while (st->numSamples() * unit <= (size_t)len) {
		if (process == nullptr) {
			return;
		}
        Uint8 *new_buf;
        int new_bufsize;
        new_buf = buf;
        bytes_per_iter = backend_spec.size;
        if (bytes_per_iter > bufsize) {
        	bytes_per_iter = bufsize;
        }
        new_bufsize = bytes_per_iter;
        if (this->process != nullptr) {
            size_t new_bytes = this->process->render(buf, bytes_per_iter);
            if (SDL_AudioStreamPut(sdl_stream, buf, new_bytes) < 0) {
                ERROR.writefln("SDL_AudioStreamPut: %s", SDL_GetError());
                DEBUG.writefln("Current audio backend: %s", process->get_backend_id().c_str());
                DEBUG.writefln("SDL_AudioStream *sdl_stream = %0lx", (size_t)sdl_stream);
                return;
            }
            do {
	            new_bufsize = SDL_AudioStreamGet(sdl_stream, buf, std::min((size_t)backend_spec.samples, bufsize / unit) * unit);
	            if (new_bufsize < 0) {
	                ERROR.writefln("SDL_AudioStreamGet: %s", SDL_GetError());
	                DEBUG.writefln("Current audio backend: %s", process->get_backend_id().c_str());
	                return;
	            }
	            SAMPLETYPE *sbuf = (SAMPLETYPE*)buf;
	            for (size_t i = 0; i < (new_bufsize / unit) * spec.channels; i++) {
	                sbuf[i] *= real_volume;
	            }
                st->putSamples(sbuf, new_bufsize / unit);
            } while (new_bufsize > 0);
        } else {
        	return;
        }
	}
    st->receiveSamples((SAMPLETYPE*)stream, len / unit);
}
#ifdef __ANDROID__
oboe::DataCallbackResult PlaybackInstance::onAudioReady(
        oboe::AudioStream *audioStream,
        void *audioData,
        int32_t numFrames) {
    audio_playback_mutex.lock();
    if (!audio_playback_paused.load()) {
    	SDLCallbackInner((Uint8*)audioData, numFrames * audioStream->getBytesPerFrame());
    } else {
    	memset(audioData, 0, numFrames * audioStream->getBytesPerFrame());
    }
    audio_playback_mutex.unlock();
    return oboe::DataCallbackResult::Continue;
}
#endif
void PlaybackInstance::LockAudioDevice() {
#ifdef USE_SDL
	SDL_LockAudioDevice(device);
#else
	audio_playback_mutex.lock();
#endif
}
void PlaybackInstance::UnlockAudioDevice() {
#ifdef USE_SDL
	SDL_UnlockAudioDevice(device);
#else
	audio_playback_mutex.unlock();
#endif
}
void PlaybackInstance::SDLCallback(void *userdata, Uint8 *stream, int len) {
    ((PlaybackInstance*)userdata)->SDLCallbackInner(stream, len);
}
void PlaybackInstance::Load(const char *file, int idx) {
    LockAudioDevice();
    load_finished.store(false);
    playback_ready.store(false);
    if (process != nullptr) delete process;
    try {
    	process = new PlaybackProcess(file, idx);
    } catch (std::exception e) {
    	ERROR.writefln("Exception caught when creating process: %s", e.what());
     	process = nullptr;
    }
    length = 0.0;
    if (process != nullptr && process->process_running()) {
        length = process->get_length();
        auto backend_spec_proxy = process->get_audio_spec();
        memset(&backend_spec, 0, sizeof(backend_spec));
        backend_spec.channels = backend_spec_proxy->channel_count();
        audio_data_t sample_fmt;
        sample_fmt.size = backend_spec_proxy->bits() / 8;
        sample_fmt.endian = backend_spec_proxy->endian() == EndianID::BIG;
        sample_fmt.is_float = backend_spec_proxy->format_type() == FormatType::FLOAT;
        sample_fmt.is_signed = backend_spec_proxy->format_type() != FormatType::UNSIGNED;
        backend_spec.format = sample_spec_to_sdl(sample_fmt);
        backend_spec.freq = backend_spec_proxy->sample_rate();
        backend_spec.samples = backend_spec_proxy->has_max_samples() ? backend_spec_proxy->max_samples() : backend_spec_proxy->has_min_samples() ? backend_spec_proxy->min_samples() : 0;
        if (backend_spec.samples == 0) backend_spec.samples = 100;
        DEBUG.writeln("Backend audio specification:");
        DEBUG.writefln("\tFormat: %s", sdl_to_str(backend_spec.format).c_str());
        DEBUG.writefln("\tChannels: %d", backend_spec.channels);
        DEBUG.writefln("\tSample rate: %d", backend_spec.freq);
        DEBUG.writefln("\tSamples: %d", backend_spec.samples);
        if (sdl_stream != nullptr) {
            SDL_FreeAudioStream(sdl_stream);
        }
        sdl_stream = SDL_NewAudioStream(backend_spec.format, backend_spec.channels, backend_spec.freq, spec.format, spec.channels, spec.freq);
        if (sdl_stream == nullptr) {
            ERROR.writefln("SDL_NewAudioStream: %s", SDL_GetError());
            DEBUG.writefln("format: AUDIO_%s%d%s", sample_fmt.is_float ? "F" : sample_fmt.is_signed ? "S" : "U", sample_fmt.size * 8, sample_fmt.endian ? "MSB" : "LSB");
            set_error("Failed to create SDL audio stream");
            set_signal(PlaybackSignalErrorOccurred);
        }
        size_t required_size = sample_fmt.size * backend_spec.samples;
        st->setChannels(spec.channels);
        st->setRate(spec.freq);
        st->flush();
        backend_spec.size = required_size;
        bufsize = backend_spec.size;
        buf = (Uint8*)malloc(bufsize);
        if (buf == nullptr) {
            ERROR.writeln("Failed to allocate memory for playback!");
            set_error("Failed to allocate memory for playback!");
            set_signal(PlaybackSignalErrorOccurred);
            bufsize = 0;
        }
        delete backend_spec_proxy;
        playback_ready.store(true);
    } else {
        set_error("Failed to create playback backend.");
        set_signal(PlaybackSignalErrorOccurred);
        delete process;
        process = nullptr;
    }
    UnlockAudioDevice();
    load_finished.store(true);
    flag_mutex.lock();
    stopped.store(false);
    paused = false;
    just_started.store(true);
    flag_mutex.unlock();
}
void PlaybackInstance::Unload() {
    if (process == nullptr) return;
    LockAudioDevice();
    delete process;
    process = nullptr;
    SDL_FreeAudioStream(sdl_stream);
    sdl_stream = nullptr;
    if (buf) free(buf);
    buf = nullptr;
    UnlockAudioDevice();
}
void PlaybackInstance::UpdateST() {
    bool any_changed = false;
    if (speed > 0.0f && speed_changed.exchange(false)) {
        any_changed = true;
        st->setRate(speed);
        set_signal(PlaybackSignalSpeedChanged);
    }
    if (tempo > 0.0f && tempo_changed.exchange(false)) {
        any_changed = true;
        st->setTempo(tempo);
        set_signal(PlaybackSignalTempoChanged);
    }
    if (pitch > 0.0f && pitch_changed.exchange(false)) {
        any_changed = true;
        st->setPitch(pitch);
        set_signal(PlaybackSignalPitchChanged);
    }
    if (any_changed && process != nullptr) {
    	process->set_rate(st->getInputOutputSampleRatio());
    }
}
double PlaybackInstance::GetMaxSeconds() {
    return std::max((double)(MaxSpeed * MaxTempo), st->getInputOutputSampleRatio());
}
void PlaybackInstance::InitLoopFunction() {
    bool reload = false;
    init_audio_data();
    speed_changed.store(true);
    tempo_changed.store(true);
    pitch_changed.store(true);
    playback_ready.store(false);
    if (!SDL_WasInit(SDL_INIT_AUDIO)) {
        if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
            ERROR.writefln("Error initializing SDL: '%s'", SDL_GetError());
            set_error("Failed to initialize SDL!");
            return;
        }
    }
    SDL_AudioSpec obtained;
    SDL_AudioSpec desired;
    desired.format = SDL_SAMPLE_FMT;
    desired.freq = 48000;
    desired.samples = 400;
    desired.channels = 2;
    desired.callback = PlaybackInstance::SDLCallback;
    desired.userdata = this;
    st = new SoundTouch();
#ifdef USE_SDL
    if ((device = SDL_OpenAudioDevice(nullptr, 0, &desired, &obtained, SDL_AUDIO_ALLOW_CHANNELS_CHANGE|SDL_AUDIO_ALLOW_FREQUENCY_CHANGE|SDL_AUDIO_ALLOW_SAMPLES_CHANGE)) == 0) {
        ERROR.writefln("Error opening audio device: '%s'", SDL_GetError());
        set_error("Failed to open audio device!");
        running = false;
        loop_started = false;
        return;
    }
    SDL_PauseAudioDevice(device, 0);
#elif defined(USE_OBOE)
    oboe::AudioStreamBuilder builder;
    builder.setDirection(oboe::Direction::Output);
    builder.setSharingMode(oboe::SharingMode::Shared);
    builder.setPerformanceMode(oboe::PerformanceMode::PowerSaving);
    builder.setFormat(SAMPLE_FMT);
    builder.setDataCallback(this);
    auto res = builder.openStream(ostream);
    if (res != oboe::Result::OK) {
        ERROR.writefln("Error opening audio device.");
        set_error("Failed to open audio device!");
        running = false;
        loop_started = false;
        return;
    }
    obtained = desired;
    obtained.channels = ostream->getChannelCount();
    obtained.freq = ostream->getSampleRate();
    auto bufferFrames = ostream->getBufferSizeInFrames();
    auto bytesPerFrame = ostream->getBytesPerFrame();
    auto bytesPerSample = ostream->getBytesPerSample();
    obtained.size = bufferFrames * bytesPerFrame;
    obtained.samples = obtained.size / bytesPerSample;
    oboe::AudioFormat format = ostream->getFormat();
    DEBUG.writefln("About to start audio stream.\n\
Format: %s\n\
Channel count: %u\n\
Sample rate: %u\n\
Buffer size (frames): %u\n\
Bytes per frame: %u\n\
Total bytes: %u\n\
Bytes per sample: %u\n\
Total samples: %u"
         , oboe::convertToText(format)
         , obtained.channels
         , obtained.freq
         , bufferFrames
         , bytesPerFrame
         , obtained.size
         , bytesPerSample
         , obtained.samples
    );
    ostream->requestStart();
#else
#error Invalid configuration detected.
#endif
    spec = obtained;
    st->setSampleRate(spec.freq);
    st->setChannels(spec.channels);
    UpdateST();

    reload = false;
    playback_ready.store(false);
    flag_mutex.lock();
    this->position = 0.0;
    seeking.store(false);
    paused = true;
    flag_mutex.unlock();
    playback_ready.store(false);
    length = 0.0;
    memset(&backend_spec, 0, sizeof(backend_spec));
    if (sdl_stream) SDL_FreeAudioStream(sdl_stream);
    sdl_stream = nullptr;
    bufsize = 0;
    if (buf) free((void*)buf);
    buf = nullptr;
    if (process) delete process;
    process = nullptr;
    stream_changed.store(false);
    file_changed.store(false);
    load_requested.store(false);
    current_file = {};
    current_stream = -1;
    current_title = {};
    seeking.store(false);
    pause_changed.store(false);
    just_stopped.store(true);
    just_started.store(false);
    stopped.store(true);
    set_signal(PlaybackSignalStarted);
    load_finished.store(true);
}
void PlaybackInstance::LoopFunction() {
    if (file_changed.exchange(false) || load_requested.exchange(false)) {
        Unload();
        Load(filePath.c_str(), 0);
        if (process && process->process_running()) {
            playback_ready.store(true);
        } else {
            playback_ready.store(false);
        }
        load_finished.store(true);
        just_started.store(true);
    }
    if (stream_changed.exchange(false)) {
        current_file_mutex.lock();
        if (current_file.has_value()) {
            std::string file = current_file.value();
            if (current_stream >= streams.size() || current_stream < 0 ||
            streams[current_stream].name == "" || streams[current_stream].length <= 0) {
                if (stream != nullptr) {
                    current_stream = stream->stream_index;
                } else {
                    current_stream = 0;
                }
            } else {
                LockAudioDevice();
                if (process && process->process_running()) process->set_stream_idx(current_stream);
                UnlockAudioDevice();
            }
            if (process && process->process_running()) {
                playback_ready.store(true);
            } else {
                playback_ready.store(false);
            }
        }
        current_file_mutex.unlock();
    }
    if (flag_mutex.try_lock()) {
        if (seeking.exchange(false)) {
            if (process && process->process_running()) process->set_position(this->position);
            set_signal(PlaybackSignalSeeked);
        }
        if (pause_changed.exchange(false) || just_stopped.exchange(false) || just_started.exchange(false)) {
        	audio_playback_paused.store(stopped.load() || paused);
#ifdef USE_SDL
            SDL_PauseAudioDevice(device, (audio_playback_paused.load()) ? 1 : 0);
#endif
            if (paused) {
                set_signal(PlaybackSignalPaused);
            } else {
                set_signal(PlaybackSignalResumed);
            }
        }
        if (update.exchange(false)) {
            LockAudioDevice();
            real_volume = volume / 100.0;
            UpdateST();
            UnlockAudioDevice();
        }
        flag_mutex.unlock();
    }
    if (process) {
        position = process->get_position();
    } else {
        position = 0.0;
    }

}
void PlaybackInstance::DeinitLoopFunction() {
    playback_ready.store(false);
    // ====
    Unload();
#ifdef USE_SDL
    SDL_CloseAudioDevice(device);
#elif defined(USE_OBOE)
    if (ostream && ostream->getState() != oboe::StreamState::Closed) {
        ostream->stop();
        ostream->close();
    }
    ostream.reset();
#endif
    SDL_QuitSubSystem(SDL_INIT_AUDIO);
    delete st;
    st = nullptr;
    if (buf) free(buf);
    current_file_mutex.lock();
    current_file = {};
    current_file_mutex.unlock();
    set_signal(PlaybackSignalStopped);
}
void PlaybackInstance::ThreadFunc() {
    #ifdef __linux__
    pthread_setname_np(pthread_self(), "Playback control thread");
    #endif
    start_loop();
    while (running && loop_started) {
        LoopHook();
        std::this_thread::sleep_for(20ms);
    }
    stop_loop();
}

PlaybackInstance::PlaybackInstance() {
    running = false;
    paused = true;
    position = 0;
    sdl_stream = nullptr;
    length = 0;
    volume = 100.0;
    real_volume = 1.0;
    speed = 1.0;
    pitch = 1.0;
    tempo = 1.0;
    prev_speed = -1.0;
    prev_pitch = -1.0;
    prev_tempo = -1.0;
    buf = nullptr;
    tempo_changed.store(true);
    speed_changed.store(true);
    pitch_changed.store(true);
    current_file = {};
    playback_ready = false;
    bufsize = 0;
    process = nullptr;
    running.store(true);
#ifdef NO_THREADS
    start_loop();
#else
    thread = std::thread(&PlaybackInstance::ThreadFunc, this);
    loop_started = true;
#endif
    while (loop_started && !load_finished.exchange(false)) {
#ifdef NO_THREADS
        LoopHook();
#endif
        std::this_thread::sleep_for(20ms);
    }
    load_finished.store(false);

}
std::optional<std::string> PlaybackInstance::get_current_file() {
    current_file_mutex.lock();
    std::optional<std::string> output = current_file;
    current_file_mutex.unlock();
    return output;
}
std::optional<std::string> PlaybackInstance::get_current_title() {
    current_file_mutex.lock();
    std::optional<std::string> output = current_title;
    current_file_mutex.unlock();
    return output;
}
PlaybackInstance::~PlaybackInstance() {
    Stop();
    running.store(false);
    #ifdef NO_THREADS
    stop_loop();
    #else
    thread.join();
    #endif
}
void PlaybackInstance::Load(std::string filePath) {
    load_finished.store(false);
    this->filePath = filePath;
    INFO.writefln("Loading %s...", filePath.c_str());
    flag_mutex.lock();
    this->position = 0.0;
    seeking.store(true);
    paused = true;
    Update();
    flag_mutex.unlock();
    file_changed.store(true);
    wait([this]() {
        return load_finished.load();
    });
}
void PlaybackInstance::Start(std::string filePath, int streamIdx) {
    load_finished.store(false);
    Load(filePath);
    INFO.writefln("Playing %s...", filePath.c_str());
    flag_mutex.lock();
    this->position = 0.0;
    seeking.store(true);
    paused = false;
    current_stream = streamIdx;
    stream_changed.store(true);
    Update();
    flag_mutex.unlock();
    wait([this]() {
        return load_finished.load();
    });
}
void PlaybackInstance::play_stream(int idx) {
    flag_mutex.lock();
    this->position = 0.0;
    seeking.store(true);
    paused = false;
    current_stream = idx;
    stream_changed.store(true);
    Update();
    just_started.store(true);
    flag_mutex.unlock();
}
double PlaybackInstance::GetPosition() {
    return position;
}
double PlaybackInstance::GetLength() {
    return length;
}

void PlaybackInstance::Seek(double position) {
    flag_mutex.lock();
    this->position = position;
    seeking.store(true);
    flag_mutex.unlock();
}

void PlaybackInstance::Pause() {
    flag_mutex.lock();
    paused = !paused;
    pause_changed.store(true);
    flag_mutex.unlock();
}

bool PlaybackInstance::IsPaused() {
    return paused;
}

void PlaybackInstance::Stop() {
    flag_mutex.lock();
    stopped.store(true);
    just_started.store(false);
    just_stopped.store(true);
    flag_mutex.unlock();
}
void PlaybackInstance::Update() {
    if (prev_pitch != pitch) {
        pitch_changed.store(true);
    }
    if (prev_speed != speed) {
        speed_changed.store(true);
    }
    if (prev_tempo != tempo) {
        tempo_changed.store(true);
    }
    update.store(true);
}

bool PlaybackInstance::IsStopped() {
    return !running;
}
void Playback::set_signal(uint16_t signal) {
    signal_mutex.lock();
    for (auto &kv : signals_occurred) {
        kv.second |= signal;
    }
    signal_mutex.unlock();
}
uint16_t Playback::handle_signals(uint16_t signals, void *handle) {
    if (signal_mutex.try_lock()) {
        if (!signals_occurred.contains(handle)) {
            signals_occurred[handle] = PlaybackSignalNone;
        }
        uint16_t output = signals_occurred[handle];
        signals_occurred[handle] &= ~output;
        signal_mutex.unlock();
        return output;
    } else {
        return PlaybackSignalNone;
    }
}
void Playback::register_handle(void *handle) {
    signal_mutex.lock();
    if (!signals_occurred.contains(handle)) {
        signals_occurred[handle] = PlaybackSignalNone;
    }
    signal_mutex.unlock();
    error_mutex.lock();
    if (!errors_occurred.contains(handle)) {
        std::deque<std::string> new_value;
        for (size_t i = 0; i < errors.size(); i++) {
            new_value.push_back(errors[i]);
        }
        errors_occurred[handle] = new_value;
    }
    error_mutex.unlock();
}

void Playback::unregister_handle(void *handle) {
    signal_mutex.lock();
    if (signals_occurred.contains(handle)) {
        signals_occurred.erase(handle);
    }
    signal_mutex.unlock();
    error_mutex.lock();
    if (errors_occurred.contains(handle)) {
        errors_occurred.erase(handle);
    }
    error_mutex.unlock();
}
void PlaybackInstance::SetTempo(float tempo) {
    this->tempo = tempo;
    Update();
}
void PlaybackInstance::SetPitch(float pitch) {
    this->pitch = pitch;
    Update();
}
void PlaybackInstance::SetSpeed(float speed) {
    this->speed = speed;
    Update();
}
void PlaybackInstance::SetVolume(float volume) {
    this->volume = volume;
    Update();
}
float PlaybackInstance::GetTempo() {
    return tempo;
}
float PlaybackInstance::GetPitch() {
    return pitch;
}
float PlaybackInstance::GetSpeed() {
    return speed;
}
float PlaybackInstance::GetVolume() {
    return volume;
}
void Playback::set_error(std::string desc) {
    error_mutex.lock();
    errors.push_back(desc);
    for (auto &kv : errors_occurred) {
        kv.second.push_front(desc);
    }
    error_mutex.unlock();
    set_signal(PlaybackSignalErrorOccurred);
}
Playback *Playback::Create(bool *daemon_found, bool daemon) {
#ifdef DBUS_ENABLED
    auto *dbus_proxy = DBusAPISender::Create();
    if (dbus_proxy != nullptr) {
        if (daemon_found != nullptr) {
            *daemon_found = dbus_proxy->IsDaemon();
        }
        DEBUG.writefln("DBus proxy daemon found: %s", *daemon_found ? "true" : "false");
        if (daemon) {
            delete dbus_proxy;
            return nullptr;
        } else {
            return dbus_proxy;
        }
    }
    if (daemon_found != nullptr) {
        *daemon_found = false;
    }
#endif
    DEBUG.writeln("Creating new playback instance.");
    return new PlaybackInstance();
}
std::vector<PlaybackStream> PlaybackInstance::get_streams() {
    std::vector<PlaybackStream> output;
    for (auto stream : streams) {
        output.push_back(stream);
    }
    return output;
}
int PlaybackInstance::get_current_stream() {
    return current_stream;
}

void PlaybackInstance::set_property(std::string path, google::protobuf::Any value) {
	if (this->process != nullptr) {
		this->process->set_property(path, value);
	}
}
std::optional<google::protobuf::Any> PlaybackInstance::get_property(std::string path) {
	if (this->process != nullptr) {
		return this->process->get_property(path);
	}
	return {};
}
std::optional<google::protobuf::Any> PlaybackInstance::reset_property(std::string path) {
	return {};
}
std::vector<Property> PlaybackInstance::get_property_list() {
	if (process == nullptr) return {};
	return process->get_property_list();
}