#include "videoplayer.hpp"

//#ifdef OPENMW_USE_FFMPEG

#include <OgreMaterialManager.h>
#include <OgreSceneManager.h>
#include <OgreMaterial.h>
#include <OgreHardwarePixelBuffer.h>


extern "C"
{
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libswscale/swscale.h>
}

#include "../mwbase/windowmanager.hpp"
#include "../mwbase/environment.hpp"


#define MIN_QUEUED_PACKETS 30


namespace MWRender
{

    int OgreResource_Read(void *opaque, uint8_t *buf, int buf_size)
    {
        Ogre::DataStreamPtr stream = *((Ogre::DataStreamPtr*)opaque);

        int num_read = stream->size() - stream->tell();

        if (num_read > buf_size)
            num_read = buf_size;

        stream->read(buf, num_read);
        return num_read;
    }

    int OgreResource_Write(void *opaque, uint8_t *buf, int buf_size)
    {
        Ogre::DataStreamPtr stream = *((Ogre::DataStreamPtr*)opaque);

        int num_write = stream->size() - stream->tell();

        if (num_write > buf_size)
            num_write = buf_size;

        stream->write (buf, num_write);
        return num_write;
    }

    int64_t OgreResource_Seek(void *opaque, int64_t offset, int whence)
    {
        Ogre::DataStreamPtr stream = *((Ogre::DataStreamPtr*)opaque);

        switch (whence)
        {
        case SEEK_SET:
            stream->seek(offset);
        case SEEK_CUR:
            stream->seek(stream->tell() + offset);
        case SEEK_END:
            stream->seek(stream->size() + offset);
        case AVSEEK_SIZE:
            return stream->size();
        default:
            return -1;
        }

        return stream->tell();
    }

    //-------------------------------------------------------------------------------------------

    AVPacketQueue::AVPacketQueue():
    mFirstPacket(NULL), mLastPacket(NULL), mNumPackets(0), mSize(0)

    {
    }

    int AVPacketQueue::put(AVPacket* pkt)
    {
        if(av_dup_packet(pkt) < 0)
        {
            return -1;
        }

        AVPacketList* pkt1;
        pkt1 = (AVPacketList*)av_malloc(sizeof(AVPacketList));
        if (pkt1 == NULL) return -1;
        pkt1->pkt = *pkt;
        pkt1->next = NULL;

        if (mLastPacket == NULL) mFirstPacket = pkt1;
        else mLastPacket->next = pkt1;

        mLastPacket = pkt1;
        mNumPackets++;
        mSize += pkt1->pkt.size;

        return 0;
    }

    int AVPacketQueue::get(AVPacket* pkt, int block)
    {
        AVPacketList* pkt1;

        while (true)
        {
            pkt1 = mFirstPacket;
            if (pkt1 != NULL)
            {
                mFirstPacket = pkt1->next;

                if (mFirstPacket == NULL) mLastPacket = NULL;

                mNumPackets--;
                mSize -= pkt1->pkt.size;
                *pkt = pkt1->pkt;
                av_free(pkt1);
                return 1;
            }
            else if (block == 0)
            {
                return 0;
            }
            else
            {
                return -1;
            }
        }
    }

    //-------------------------------------------------------------------------------------------

    VideoPlayer::VideoPlayer(Ogre::SceneManager *sceneMgr)
        : mAvContext(NULL)
        , mVideoStreamId(-1)
        , mAudioStreamId(-1)
        , mVideoClock(0)
        , mAudioClock(0)
        , mClock(0)
    {
        Ogre::MaterialPtr videoMaterial = Ogre::MaterialManager::getSingleton ().create("VideoMaterial", "General");
        videoMaterial->getTechnique(0)->getPass(0)->setDepthWriteEnabled(false);
        videoMaterial->getTechnique(0)->getPass(0)->setDepthCheckEnabled(false);
        videoMaterial->getTechnique(0)->getPass(0)->setLightingEnabled(false);
        mTextureUnit = videoMaterial->getTechnique(0)->getPass(0)->createTextureUnitState();

        mRectangle = new Ogre::Rectangle2D(true);
        mRectangle->setCorners(-1.0, 1.0, 1.0, -1.0);
        mRectangle->setMaterial("VideoMaterial");
        mRectangle->setRenderQueueGroup(Ogre::RENDER_QUEUE_OVERLAY+1);
        // Use infinite AAB to always stay visible
        Ogre::AxisAlignedBox aabInf;
        aabInf.setInfinite();
        mRectangle->setBoundingBox(aabInf);
        // Attach background to the scene
        Ogre::SceneNode* node = sceneMgr->getRootSceneNode()->createChildSceneNode();
        node->attachObject(mRectangle);
        mRectangle->setVisible(false);
        mRectangle->setVisibilityFlags (0x1);
    }

    VideoPlayer::~VideoPlayer()
    {
        if (mAvContext)
            deleteContext();

        delete mRectangle;
    }

    void VideoPlayer::play (const std::string& resourceName)
    {
        mStream = Ogre::ResourceGroupManager::getSingleton ().openResource (resourceName);


        mVideoStreamId = -1;
        mAudioStreamId = -1;
        mAudioStream = NULL;
        mVideoStream = NULL;
        mVideoClock = 0;
        mAudioClock = 0;
        mClock = 0;

        // if something is already playing, close it
        if (mAvContext)
            close();

        mRectangle->setVisible(true);

        MWBase::Environment::get().getWindowManager ()->pushGuiMode (MWGui::GM_Video);


        // BASIC INITIALIZATION

        // Load all the decoders
        av_register_all();

        AVIOContext	 *ioContext = 0;

        int err = 0;

        mAvContext = avformat_alloc_context();
        if (!mAvContext)
            throwError(0);

        ioContext = avio_alloc_context(NULL, 0, 0, &mStream, OgreResource_Read, OgreResource_Write, OgreResource_Seek);
        if (!ioContext)
            throwError(0);

        mAvContext->pb = ioContext;

        err = avformat_open_input(&mAvContext, resourceName.c_str(), NULL, NULL);
        if (err != 0)
            throwError(err);

        err = avformat_find_stream_info(mAvContext, 0);
        if (err < 0)
            throwError(err);




        // Find the video stream among the different streams
        for (unsigned int i = 0; i < mAvContext->nb_streams; i++)
        {
            if (mAvContext->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
            {
                mVideoStreamId = i;
                mVideoStream = mAvContext->streams[i];
                break;
            }
        }

        if (mVideoStreamId < 0)
            throw std::runtime_error("No video stream found in the video");

        // Get the video decoder
        mVideoCodec = avcodec_find_decoder(mVideoStream->codec->codec_id);
        if (NULL == mVideoCodec)
            throw std::runtime_error("No video decoder found");

        // Load the video codec
        err = avcodec_open2(mVideoStream->codec, mVideoCodec, 0);
        if (err < 0)
            throwError (err);



        // Find the audio stream among the different streams
        for (unsigned int i = 0; i < mAvContext->nb_streams; i++)
        {
            if (mAvContext->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
            {
                mAudioStreamId = i;
                mAudioStream = mAvContext->streams[i];
                break;
            }
        }

        if (mAudioStreamId >= 0)
        {
            // Get the audio decoder
            mAudioCodec = avcodec_find_decoder(mAudioStream->codec->codec_id);
            if (mAudioCodec == NULL)
            {
                throw std::runtime_error("Stream doesn't have an audio codec");
            }

            // Load the audio codec
            err = avcodec_open2(mAudioStream->codec, mAudioCodec, 0);
            if (err < 0)
                throwError (err);
        }



        // Create the frame buffers
        mRawFrame = avcodec_alloc_frame();
        mRGBAFrame = avcodec_alloc_frame();
        if (!mRawFrame || !mRGBAFrame)
        {
            throw std::runtime_error("Can't allocate video frames");
        }


        avpicture_alloc ((AVPicture *)mRGBAFrame, PIX_FMT_RGBA, mVideoStream->codec->width, mVideoStream->codec->height);


        // Setup the image scaler
        // All this does is convert from YUV to RGB - note it would be faster to do this in a shader,
        // but i'm not worried about performance just yet
        mSwsContext = sws_getContext(mVideoStream->codec->width, mVideoStream->codec->height,
            mVideoStream->codec->pix_fmt,
            mVideoStream->codec->width, mVideoStream->codec->height,
            PIX_FMT_RGBA,
            SWS_BICUBIC, NULL, NULL, NULL);
        if (!mSwsContext)
            throw std::runtime_error("Can't create SWS Context");

        mTextureUnit->setTextureName ("");

        if (!Ogre::TextureManager::getSingleton ().getByName("VideoTexture").isNull())
            Ogre::TextureManager::getSingleton().remove("VideoTexture");

        mVideoTexture = Ogre::TextureManager::getSingleton().createManual(
                    "VideoTexture",
            Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
            Ogre::TEX_TYPE_2D,
            mVideoStream->codec->width, mVideoStream->codec->height,
            0,
            Ogre::PF_BYTE_RGBA,
            Ogre::TU_DYNAMIC_WRITE_ONLY_DISCARDABLE);

        // initialize to (0, 0, 0, 1)
        std::vector<Ogre::uint32> buffer;
        buffer.resize(mVideoStream->codec->width * mVideoStream->codec->height);
        for (int p=0; p<mVideoStream->codec->width * mVideoStream->codec->height; ++p)
        {
            buffer[p] = (255 << 24);
        }
        memcpy(mVideoTexture->getBuffer()->lock(Ogre::HardwareBuffer::HBL_DISCARD), &buffer[0], mVideoStream->codec->width*mVideoStream->codec->height*4);
        mVideoTexture->getBuffer()->unlock();

        mTextureUnit->setTextureName ("VideoTexture");


        // Queue up some packets
        while(
            mVideoPacketQueue.getNumPackets()<MIN_QUEUED_PACKETS ||
            (mAudioStream && mAudioPacketQueue.getNumPackets()<MIN_QUEUED_PACKETS)
            )
        {
            //Keep adding until we have 30 video and audio packets.
            bool addedPacket = addToBuffer();
            if(!addedPacket)
            {
                //No more packets
                break;
            }
        }

        mTimer.reset();
    }

    void VideoPlayer::throwError(int error)
    {
        char buffer[4096] = {0};

        if (0 == av_strerror(error, buffer, sizeof(buffer)))
        {
            std::stringstream msg;
            msg << "FFMPEG error: ";
            msg << buffer << std::endl;
            throw std::runtime_error(msg.str());
        }
        else
            throw std::runtime_error("Unknown FFMPEG error");
    }

    void VideoPlayer::update()
    {
        if (!mAvContext)
            return;

        double dt = mTimer.getMilliseconds () / 1000.f;
        mTimer.reset ();

        //UpdateAudio(fTime);
        //std::cout << "num packets: " << mVideoPacketQueue.getNumPackets() << " clocks: " << mVideoClock << " , " << mClock << std::endl;
        while (!mVideoPacketQueue.isEmpty() && mVideoClock < mClock)
        {
            while(
                mVideoPacketQueue.getNumPackets()<MIN_QUEUED_PACKETS ||
                (mAudioStream && mAudioPacketQueue.getNumPackets()<MIN_QUEUED_PACKETS)
                )
            {
                //Keep adding until we have 30 video and audio packets.
                bool addedPacket = addToBuffer();

                if(!addedPacket)
                {
                    //No more packets
                    break;
                }
            }

            if (mVideoPacketQueue.getNumPackets ())
                decodeNextVideoFrame();
        }

        mClock += dt;

        //curTime += fTime;

        if(mVideoPacketQueue.getNumPackets()==0 /* && mAudioPacketQueue.getNumPackets()==0 */)
            close();
    }

    void VideoPlayer::decodeNextVideoFrame ()
    {
        // Make sure there is something to decode
        assert (mVideoPacketQueue.getNumPackets ());

        // Get the front frame and decode it
        AVPacket packet;
        mVideoPacketQueue.get(&packet, 1);

        int res;
        int didDecodeFrame = 0;
        res = avcodec_decode_video2(mVideoStream->codec, mRawFrame, &didDecodeFrame, &packet);

        if (res < 0 || !didDecodeFrame)
            throw std::runtime_error ("an error occured while decoding the video frame");

        // Set video clock to the PTS of this packet (presentation timestamp)
        double pts = 0;
        if (packet.pts != -1.0)  pts = packet.pts;
        pts *= av_q2d(mVideoStream->time_base);
        mVideoClock = pts;

        // Convert the frame to RGB
        sws_scale(mSwsContext,
            mRawFrame->data, mRawFrame->linesize,
            0, mVideoStream->codec->height,
            mRGBAFrame->data, mRGBAFrame->linesize);


        Ogre::HardwarePixelBufferSharedPtr pixelBuffer = mVideoTexture->getBuffer();
        Ogre::PixelBox pb(mVideoStream->codec->width, mVideoStream->codec->height, 1, Ogre::PF_BYTE_RGBA, mRGBAFrame->data[0]);
        pixelBuffer->blitFromMemory(pb);

        if (packet.data != NULL) av_free_packet(&packet);
    }

    void VideoPlayer::close ()
    {
        mRectangle->setVisible (false);
        MWBase::Environment::get().getWindowManager ()->removeGuiMode (MWGui::GM_Video);
        deleteContext();
    }

    void VideoPlayer::deleteContext()
    {
        while (mVideoPacketQueue.getNumPackets ())
        {
            AVPacket packet;
            mVideoPacketQueue.get(&packet, 1);
            if (packet.data != NULL) av_free_packet(&packet);
        }
        while (mAudioPacketQueue.getNumPackets ())
        {
            AVPacket packet;
            mAudioPacketQueue.get(&packet, 1);
            if (packet.data != NULL) av_free_packet(&packet);
        }

        if (mVideoStream && mVideoStream->codec != NULL) avcodec_close(mVideoStream->codec);
        if (mAudioStream && mAudioStream->codec != NULL) avcodec_close(mAudioStream->codec);

        avpicture_free((AVPicture *)mRGBAFrame);

        if (mRawFrame)
            av_free(mRawFrame);
        if (mRGBAFrame)
            av_free(mRGBAFrame);

        sws_freeContext(mSwsContext);

        avformat_close_input(&mAvContext);

        mAvContext = NULL;
    }



    bool VideoPlayer::addToBuffer()
    {
        if(mAvContext)
        {
            AVPacket packet;
            if (av_read_frame(mAvContext, &packet) >= 0)
            {
                if (packet.stream_index == mVideoStreamId)
                {
                    // I don't believe this is necessary.
                    /*
                    if(mClock==0)
                    {
                        mClock = packet.dts;
                        mClock *= av_q2d(mVideoStream->time_base);
                        std::cout << "Initializing clock to: " << mClock << std::endl;
                    }
                    */

                    mVideoPacketQueue.put(&packet);

                    return true;
                }
                else if (packet.stream_index == mAudioStreamId && mAudioStream)
                {
                    mAudioPacketQueue.put(&packet);
                    return true;
                }
                else
                {
                    av_free_packet(&packet);
                    return false;
                }
            }
        }

        return false;
    }
}

//#endif