/***************************************************************************
 *                                                                         *
 *   This file is part of the Fotowall project,                            *
 *       http://www.enricoros.com/opensource/fotowall                      *
 *                                                                         *
 *   Copyright (C) 2009 by Enrico Ros <enrico.ros@gmail.com>               *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include "VideoProvider.h"
#include <QDirIterator>
#include <QPixmap>
#include <QTimer>
#if defined(HAS_VIDEOCAPTURE)
#include "3rdparty/videocapture/VideoDevice.h"
#endif

// the global video provider instance
Q_GLOBAL_STATIC(VideoProvider, s_providerInstance)
VideoProvider * VideoProvider::instance()
{
    return s_providerInstance();
}

VideoProvider::VideoProvider()
    : QObject()
    , m_snapTimer(0)
{
    // defer video initialization, to offload gui on startup...
    if (!Disable)
        QTimer::singleShot(500, this, SLOT(initDevices()));
}

VideoProvider::~VideoProvider()
{
    delete m_snapTimer;
    qDeleteAll(m_inputs);
}

int VideoProvider::inputCount() const
{
    return m_inputs.size();
}

bool VideoProvider::connectInput(int iIdx, QObject * receiver, const char * method)
{
    // safety check
    if (iIdx < 0 || iIdx >= m_inputs.size() || !receiver || !method) {
        qWarning("VideoProvider::connectInput: fail");
        return false;
    }

    // start the video if we're the first
    VideoInput * input = m_inputs[iIdx];
    if (!input->active) {
#if defined(HAS_VIDEOCAPTURE)
        // try to start the video
        if (!input->device->setCaptureSize(input->device->maxSize()))
            qWarning("VideoProvider::connectInput: can't set the capture size. trying anyways..");
        if (!input->device->startCapturing()) {
            qWarning("VideoProvider::connectInput: can't start capture, stopping");
            return false;
        }
#endif

        // mark as active
        input->active = true;
    }

    // connect input
    if (!connect(input, SIGNAL(newPixmap(QPixmap)), receiver, method)) {
        qWarning("VideoProvider::connectInput: error connecting input %d to %s", iIdx, method);
        return false;
    }

    // add it to the receivers list (for ref. counting only)
    input->receivers.append(receiver);

    // start the capture timer if needed
    if (!m_snapTimer) {
        m_snapTimer = new QTimer(this);
        connect(m_snapTimer, SIGNAL(timeout()), this, SLOT(slotCaptureFromDevices()));
        m_snapTimer->start(50);
    }

    // tell that everything went good
    return true;
}

void VideoProvider::disconnectReceiver(QObject * receiver)
{
    if (!receiver)
        return;

    // remove the receiver from each input
    int activeInputs = 0;
    foreach (VideoInput * input, m_inputs) {

        // perform the disconnection
        disconnect(input, 0, receiver, 0);

        // remove the receiver, if any
        input->receivers.removeAll(receiver);

        // stop video if cleared all receivers
        if (input->receivers.isEmpty() && input->active) {

            // stop capturing
#if defined(HAS_VIDEOCAPTURE)
            input->device->stopCapturing();
#else
            // TODO
#endif

            // mark as inactive
            input->active = false;
        }

        // if active, increment active input count
        if (input->active)
            activeInputs++;
    }

    // stop the timer too if not needed
    if (!activeInputs && m_snapTimer) {
        delete m_snapTimer;
        m_snapTimer = 0;
    }
}

void VideoProvider::setSwapped(int iIdx, bool swapped)
{
    if (iIdx >= 0 && iIdx < m_inputs.size())
        m_inputs[iIdx]->swapped = swapped;
}

bool VideoProvider::swapped(int iIdx) const
{
    if (iIdx >= 0 && iIdx < m_inputs.size())
        return m_inputs[iIdx]->swapped;
    return false;
}

void VideoProvider::initDevices()
{
#if defined(HAS_VIDEOCAPTURE)
    foreach (const VideoCapture::DeviceInfo & info, VideoCapture::VideoDevice::scanDevices()) {
        // create a new capture device and initialize it
        VideoCapture::VideoDevice * capture = new VideoCapture::VideoDevice(info);
        if (!capture->open() || capture->inputCount() < 1) {
            delete capture;
            return;
        }
        //capture->close();         // leave capture open...

        // setup input
        capture->setCurrentInput(0);

        // add the internal reference
        VideoInput * input = new VideoInput();
        input->channels = capture->inputCount();
        input->device = capture;
        m_inputs.append(input);

        // update status
        emit inputCountChanged(m_inputs.size());
    }
#endif
}

void VideoProvider::slotCaptureFromDevices()
{
    // capture from every input to every receiver
    foreach (VideoInput * input, m_inputs) {

        // skip inactive inputs
        if (!input->active)
            continue;

#if defined(HAS_VIDEOCAPTURE)
        // get frame (and check correctness)
        if (!input->device->captureFrame())
            continue;

        // get the qimage from the frame
        QImage frameImage;
        bool captured = input->device->getLastFrame(&frameImage);
        if (!captured) {
            // display the invalid (blue) image anyways
            //continue;
        }

        // apply mirror, if requested
        if (captured && input->swapped)
            frameImage = frameImage.mirrored(true, false);

        // set the pixmap
        emit input->newPixmap(QPixmap::fromImage(frameImage));
#else
        //TODO
#endif
    }
}

VideoInput::VideoInput()
  : channels(1)
  , active(false)
  , swapped(false)
{
}

VideoInput::~VideoInput()
{
#if defined(HAS_VIDEOCAPTURE)
    if (active)
        device->stopCapturing();
    device->close();
    delete device;
#endif
}