#include "mpvwidget.h"
#include <stdexcept>
#include <QtGui/QOpenGLContext>
#include <QtCore/QMetaObject>
#include "application.h"

static void wakeup(void *ctx)
{
    QMetaObject::invokeMethod((MpvWidget *)ctx, "on_mpv_events", Qt::QueuedConnection);
}

static void *get_proc_address(void *ctx, const char *name)
{
    Q_UNUSED(ctx);
    QOpenGLContext *glctx = QOpenGLContext::currentContext();
    if (!glctx)
        return nullptr;
    return reinterpret_cast<void *>(glctx->getProcAddress(QByteArray(name)));
}

MpvWidget::MpvWidget(QWidget *parent, Qt::WindowFlags f)
    : QOpenGLWidget(parent, f)
{
    setAttribute(Qt::WA_TranslucentBackground);
    mpv = mpv_create();
    if (!mpv)
        throw std::runtime_error("could not create mpv context");

    mpv_set_option_string(mpv, "terminal", "yes");
    mpv_set_option_string(mpv, "msg-level", "all=v");
    if (mpv_initialize(mpv) < 0)
        throw std::runtime_error("could not initialize mpv context");

    // Request hw decoding, just for testing.
    mpv::qt::set_option_variant(mpv, "hwdec", "auto");

    mpv_observe_property(mpv, 0, "duration", MPV_FORMAT_DOUBLE);
    mpv_observe_property(mpv, 0, "time-pos", MPV_FORMAT_DOUBLE);
    mpv_set_wakeup_callback(mpv, wakeup, this);
}

MpvWidget::~MpvWidget()
{
    makeCurrent();
    if (mpv_gl)
        mpv_render_context_free(mpv_gl);
    mpv_terminate_destroy(mpv);
}

void MpvWidget::command(const QVariant &params)
{
    mpv::qt::command_variant(mpv, params);
}

void MpvWidget::setProperty(const QString &name, const QVariant &value)
{
    mpv::qt::set_property_variant(mpv, name, value);
}

QVariant MpvWidget::getProperty(const QString &name) const
{
    return mpv::qt::get_property_variant(mpv, name);
}

void MpvWidget::initializeGL()
{
    mpv_opengl_init_params gl_init_params{get_proc_address, nullptr, nullptr};
    mpv_render_param params[] {
        {MPV_RENDER_PARAM_API_TYPE, const_cast<char *>(MPV_RENDER_API_TYPE_OPENGL)},
        {MPV_RENDER_PARAM_OPENGL_INIT_PARAMS, &gl_init_params},
        {MPV_RENDER_PARAM_INVALID, nullptr}
    };

    if (mpv_render_context_create(&mpv_gl, mpv, params) < 0)
        throw std::runtime_error("failed to initialize mpv GL context");
    mpv_render_context_set_update_callback(mpv_gl, MpvWidget::on_update, reinterpret_cast<void *>(this));
}
#include <QDateTime>
void MpvWidget::paintGL()
{
    int iwidth = width();
    double dwidth = iwidth * devicePixelRatioF();
    int iheight = height();
    double dheight = iheight * devicePixelRatioF();
    int deviceiwidth = dwidth;
    int deviceiheight = dheight;
    mpv_opengl_fbo mpfbo{static_cast<int>(defaultFramebufferObject()), deviceiwidth, deviceiheight, 0};
    int flip_y{1};

    mpv_render_param params[] = {
        {MPV_RENDER_PARAM_OPENGL_FBO, &mpfbo},
        {MPV_RENDER_PARAM_FLIP_Y, &flip_y},
        {MPV_RENDER_PARAM_INVALID, nullptr}
    };
    // See render_gl.h on what OpenGL environment mpv expects, and
    // other API details.
    mpv_render_context_render(mpv_gl, params);

    if (dApp->m_cuurentMode == IdCopyScreen && dApp->m_currentScreenNum > 1) {
        QPixmap pix = QPixmap::fromImage(grabFramebuffer());
        emit dApp->refreshPix(pix);
    }
}

void MpvWidget::on_mpv_events()
{
    // Process all events, until the event queue is empty.
    while (mpv) {
        mpv_event *event = mpv_wait_event(mpv, 0);
        if (event->event_id == MPV_EVENT_NONE) {
            break;
        }
        handle_mpv_event(event);
    }
}

void MpvWidget::handle_mpv_event(mpv_event *event)
{
    switch (event->event_id) {
    case MPV_EVENT_PROPERTY_CHANGE: {
        mpv_event_property *prop = (mpv_event_property *)event->data;
        if (strcmp(prop->name, "time-pos") == 0) {
            if (prop->format == MPV_FORMAT_DOUBLE) {
                double time = *(double *)prop->data;
                Q_EMIT positionChanged(time);
            }
        } else if (strcmp(prop->name, "duration") == 0) {
            if (prop->format == MPV_FORMAT_DOUBLE) {
                double time = *(double *)prop->data;
                Q_EMIT durationChanged(time);
            }
        }
        break;
    }
    default: ;
        // Ignore uninteresting or unknown events.
    }
}

// Make Qt invoke mpv_render_context_render() to draw a new/updated video frame.
void MpvWidget::maybeUpdate()
{
    // If the Qt window is not visible, Qt's update() will just skip rendering.
    // This confuses mpv's render API, and may lead to small occasional
    // freezes due to video rendering timing out.
    // Handle this by manually redrawing.
    // Note: Qt doesn't seem to provide a way to query whether update() will
    //       be skipped, and the following code still fails when e.g. switching
    //       to a different workspace with a reparenting window manager.
    if (window()->isMinimized()) {
        makeCurrent();
        paintGL();
        context()->swapBuffers(context()->surface());
        doneCurrent();
    } else {
        update();
    }
}

void MpvWidget::on_update(void *ctx)
{
    QMetaObject::invokeMethod((MpvWidget *)ctx, "maybeUpdate");
}