#include "videosplitthread.h"
#include <QImage>
#include <QPainter>
#include <QDebug>
extern "C"{
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libswscale/swscale.h>
}
VideoSplitThread::VideoSplitThread(int sw, int sh, int dw, int dh, int cnt, QPointF pos, QByteArray file) : sw(sw), sh(sh), dw(dw), dh(dh), cnt(cnt), pos(pos), file(file) {
    connect(this, &QThread::finished, this, &QThread::deleteLater);
}

void VideoSplitThread::run() {
    AVFormatContext *in_fmt = avformat_alloc_context(), *out_fmt = 0;
    AVCodecContext *de_ctx = 0, *en_ctx = 0;
    QString err;
    char buf[AV_ERROR_MAX_STRING_SIZE];
    int ret;
    {
        if((ret = avformat_open_input(&in_fmt, file.constData(), nullptr, nullptr)) < 0) {
            err = QString("Couldn't open input stream. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
            goto free;
        }
        if((ret = avformat_find_stream_info(in_fmt, nullptr)) < 0) {
            err = QString("Couldn't find stream information. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
            goto free;
        }
        auto outfile = file+"-square.mp4";
        if((ret = avformat_alloc_output_context2(&out_fmt, 0, "mp4", outfile.constData())) < 0) {
            err = QString("avformat_alloc_output_context2 fail. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
            goto free;
        }
        int vi_idx = -1;
        AVStream *out_vi_stream;
        for(uint ss=0; ss<in_fmt->nb_streams; ss++) {
            AVStream *stream = in_fmt->streams[ss];
            qDebug()<<"codec_type"<<av_get_media_type_string(stream->codecpar->codec_type);
            if(stream->codecpar->codec_type == AVMEDIA_TYPE_DATA) continue;
            AVStream *out_stream = avformat_new_stream(out_fmt, 0);
            if(vi_idx == -1 && stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
                vi_idx = ss;
                out_vi_stream = out_stream;
            } else {
                if((ret = avcodec_parameters_copy(out_stream->codecpar, stream->codecpar)) < 0) {
                    err = QString("avcodec_parameters_copy fail. ") + av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
                    goto free;
                }
            }
            out_stream->time_base = stream->time_base;
            out_stream->start_time = stream->start_time;
            out_stream->duration = stream->duration;
        }
        if(vi_idx == -1) {
            err = "Didn't find a Video Stream";
            goto free;
        }

        auto codecpar = in_fmt->streams[vi_idx]->codecpar;

        auto decoder = avcodec_find_decoder(codecpar->codec_id);
        if(decoder==0) {
            err = "Could not found Video Decoder";
            goto free;
        }
        de_ctx = avcodec_alloc_context3(decoder);
        de_ctx->thread_count = 4;
        avcodec_parameters_to_context(de_ctx, codecpar);
        if(avcodec_open2(de_ctx, decoder, 0) < 0) {
            err = "Could not open Video decode Ctx";
            goto free;
        }

        auto out_codecpar = out_vi_stream->codecpar;
        out_codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
        out_codecpar->codec_id = AV_CODEC_ID_H264;
        out_codecpar->format = AV_PIX_FMT_YUV420P;
        out_codecpar->width = dw;
        out_codecpar->height = dh;

        auto encoder = avcodec_find_encoder(out_codecpar->codec_id);
        if(encoder==0) {
            fprintf(stderr, "Codec not found\n");
            goto free;
        }
        en_ctx = avcodec_alloc_context3(encoder);
        en_ctx->thread_count = 4;
        avcodec_parameters_to_context(en_ctx, out_codecpar);
        en_ctx->bit_rate = dw*dh*6;
        en_ctx->gop_size = de_ctx->gop_size;
        en_ctx->max_b_frames = 3;
        en_ctx->time_base = out_vi_stream->time_base;

        if((ret = avcodec_open2(en_ctx, encoder, 0)) < 0) {
            err = QString("Open video encode ctx failed. ") + av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
            goto free;
        }
        if(out_fmt->flags & AVFMT_NOFILE) qDebug()<<"AVFMT_NOFILE";
        else if((ret = avio_open(&out_fmt->pb, outfile.constData(), AVIO_FLAG_WRITE)) < 0) {
            err = QString("avio_open fail. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
            goto free;
        }
        qDebug()<<"oformat"<<out_fmt->oformat;
        if((ret = avformat_write_header(out_fmt, 0)) < 0) {
            err = QString("avformat_write_header fail. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
            goto free;
        }
        auto sws_ctx = sws_getContext(de_ctx->width, de_ctx->height, de_ctx->pix_fmt, sw, sh, AV_PIX_FMT_0RGB, SWS_FAST_BILINEAR, 0, 0, 0);
        auto out_sws_ctx = sws_getContext(dw, dh, AV_PIX_FMT_0RGB, dw, dh, AV_PIX_FMT_YUV420P, SWS_FAST_BILINEAR, 0, 0, 0);
        auto packet = av_packet_alloc();
        auto frm = av_frame_alloc();
        QImage img(sw, sh, QImage::Format_RGB32);
        uint8_t *img_data[4]{img.bits(), 0, 0, 0};
        int img_linesize[4]{img.bytesPerLine(), 0, 0, 0};
        QImage out_img(dw, dh, QImage::Format_RGB32);
        uint8_t *out_img_data[4]{out_img.bits(), 0, 0, 0};
        int out_img_linesize[4]{out_img.bytesPerLine(), 0, 0, 0};
        QPainter painter(&out_img);
        while(1) {
            if((ret = av_read_frame(in_fmt, packet)) < 0) {
                if(ret!=AVERROR_EOF) {
                    err = QString("Read packet fail: ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
                    break;
                }
                ret = avcodec_send_packet(de_ctx, 0);
            } else {
                if(packet->stream_index != vi_idx) {
                    av_interleaved_write_frame(out_fmt, packet);
                    continue;
                }
                ret = avcodec_send_packet(de_ctx, packet);
            }
            if(ret < 0) {
                err = QString("avcodec_send_packet fail. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
                break;
            }
            while((ret = avcodec_receive_frame(de_ctx, frm)) != AVERROR(EAGAIN)) {
                if(ret < 0) {
                    if(ret!=AVERROR_EOF) {
                        err = QString("Receive frame fail: ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
                        goto free2;
                    }
                    ret = avcodec_send_frame(en_ctx, 0);
                } else {
                    sws_scale(sws_ctx, frm->data, frm->linesize, 0, de_ctx->height, img_data, img_linesize);
                    painter.drawImage(pos, img);
                    auto apos = pos;
                    for(int i=1; i<cnt; i++) {
                        apos.rx() -= dw;
                        apos.ry() += dh/cnt;
                        painter.drawImage(apos, img);
                    }
                    auto pts = frm->pts;
                    auto dur = frm->pkt_duration;
                    av_frame_unref(frm);
                    frm->pts = pts;
                    frm->pkt_duration = dur;
                    frm->format = AV_PIX_FMT_YUV420P;
                    frm->width = dw;
                    frm->height = dh;
                    if((ret = av_frame_get_buffer(frm, 0)) < 0) {
                        err = QString("av_frame_get_buffer fail. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
                        goto free2;
                    }
                    sws_scale(out_sws_ctx, out_img_data, out_img_linesize, 0, dh, frm->data, frm->linesize);
                    ret = avcodec_send_frame(en_ctx, frm);
                    int pro = frm->pts*100/out_vi_stream->duration;
                    if(pro > lastPro) {
                        lastPro = pro;
                        emit emProgress(pro);
                    }
                }
                if(ret < 0) {
                    err = QString("avcodec_send_frame fail. ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
                    goto free2;
                }
                while((ret = avcodec_receive_packet(en_ctx, packet)) != AVERROR(EAGAIN)) {
                    if(ret < 0) {
                        if(ret!=AVERROR_EOF) err = QString("Receive frame fail: ")+av_make_error_string(buf, AV_ERROR_MAX_STRING_SIZE, ret);
                        else {
                            av_interleaved_write_frame(out_fmt, 0);
                            av_write_trailer(out_fmt);
                            emit emProgress(100);
                        }
                        goto free2;
                    } else {
                        av_interleaved_write_frame(out_fmt, packet);
                    }
                }
            }
        }
        free2:
        av_frame_free(&frm);
        av_packet_free(&packet);
        sws_freeContext(sws_ctx);
        sws_freeContext(out_sws_ctx);
    }
    free:
    avcodec_free_context(&de_ctx);
    avcodec_free_context(&en_ctx);
    avformat_close_input(&in_fmt);
    avio_closep(&out_fmt->pb);
    if(out_fmt) avformat_free_context(out_fmt);
    emit emErr(err);
}