/*
 * This file is part of MPlayer.
 *
 * MPlayer 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.
 *
 * MPlayer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <stddef.h>
#include <stdbool.h>
#include <inttypes.h>
#include <math.h>
#include <assert.h>

#include "config.h"
#include "talloc.h"

#include "mpvcore/mp_msg.h"
#include "mpvcore/options.h"
#include "mpvcore/mp_common.h"
#include "mpvcore/encode.h"
#include "mpvcore/m_property.h"

#include "audio/out/ao.h"
#include "demux/demux.h"
#include "stream/stream.h"
#include "sub/sub.h"
#include "video/hwdec.h"
#include "video/filter/vf.h"
#include "video/decode/dec_video.h"
#include "video/out/vo.h"

#include "mp_core.h"
#include "command.h"

void update_fps(struct MPContext *mpctx)
{
#if HAVE_ENCODING
    struct dec_video *d_video = mpctx->d_video;
    if (mpctx->encode_lavc_ctx && d_video)
        encode_lavc_set_video_fps(mpctx->encode_lavc_ctx, d_video->header->video->fps);
#endif
}

static void recreate_video_filters(struct MPContext *mpctx)
{
    struct MPOpts *opts = mpctx->opts;
    struct dec_video *d_video = mpctx->d_video;
    assert(d_video);

    vf_uninit_filter_chain(d_video->vfilter);

    char *vf_arg[] = {
        "_oldargs_", (char *)mpctx->video_out, NULL
    };
    d_video->vfilter = vf_open_filter(opts, NULL, "vo", vf_arg);

    d_video->vfilter = append_filters(d_video->vfilter, opts->vf_settings);

    struct vf_instance *vf = d_video->vfilter;
    mpctx->osd->render_subs_in_filter
        = vf->control(vf, VFCTRL_INIT_OSD, NULL) == VO_TRUE;
}

int reinit_video_filters(struct MPContext *mpctx)
{
    struct dec_video *d_video = mpctx->d_video;

    if (!d_video)
        return -2;

    recreate_video_filters(mpctx);
    video_reinit_vo(d_video);

    return d_video->vf_initialized > 0 ? 0 : -1;
}

int reinit_video_chain(struct MPContext *mpctx)
{
    struct MPOpts *opts = mpctx->opts;
    assert(!(mpctx->initialized_flags & INITIALIZED_VCODEC));
    assert(!mpctx->d_video);
    init_demux_stream(mpctx, STREAM_VIDEO);
    struct sh_stream *sh = mpctx->sh[STREAM_VIDEO];
    if (!sh)
        goto no_video;

    MP_VERBOSE(mpctx, "[V] fourcc:0x%X  size:%dx%d  fps:%5.3f\n",
               sh->format,
               sh->video->disp_w, sh->video->disp_h,
               sh->video->fps);
    if (opts->force_fps)
        sh->video->fps = opts->force_fps;
    update_fps(mpctx);

    if (!sh->video->fps && !opts->force_fps && !opts->correct_pts) {
        MP_ERR(mpctx, "FPS not specified in the "
               "header or invalid, use the -fps option.\n");
    }

    double ar = -1.0;
    //================== Init VIDEO (codec & libvo) ==========================
    if (!opts->fixed_vo || !(mpctx->initialized_flags & INITIALIZED_VO)) {
        mpctx->video_out = init_best_video_out(mpctx->global, mpctx->input,
                                               mpctx->encode_lavc_ctx);
        if (!mpctx->video_out) {
            MP_FATAL(mpctx, "Error opening/initializing "
                    "the selected video_out (-vo) device.\n");
            goto err_out;
        }
        mpctx->mouse_cursor_visible = true;
        mpctx->initialized_flags |= INITIALIZED_VO;
    }

    update_window_title(mpctx, true);

    struct dec_video *d_video = talloc_zero(NULL, struct dec_video);
    mpctx->d_video = d_video;
    d_video->last_pts = MP_NOPTS_VALUE;
    d_video->opts = mpctx->opts;
    d_video->header = sh;
    mpctx->initialized_flags |= INITIALIZED_VCODEC;

    // dynamic allocation only to make stheader.h lighter
    talloc_free(d_video->hwdec_info);
    d_video->hwdec_info = talloc_zero(d_video, struct mp_hwdec_info);
    vo_control(mpctx->video_out, VOCTRL_GET_HWDEC_INFO, d_video->hwdec_info);

    if (stream_control(sh->demuxer->stream, STREAM_CTRL_GET_ASPECT_RATIO, &ar)
            != STREAM_UNSUPPORTED)
        d_video->stream_aspect = ar;

    recreate_video_filters(mpctx);

    video_init_best_codec(d_video, opts->video_decoders);

    if (!d_video->initialized)
        goto err_out;

    bool saver_state = opts->pause || !opts->stop_screensaver;
    vo_control(mpctx->video_out, saver_state ? VOCTRL_RESTORE_SCREENSAVER
                                             : VOCTRL_KILL_SCREENSAVER, NULL);

    vo_control(mpctx->video_out, mpctx->paused ? VOCTRL_PAUSE
                                               : VOCTRL_RESUME, NULL);

    mpctx->last_vf_reconfig_count = 0;
    mpctx->restart_playback = true;
    mpctx->sync_audio_to_video = !sh->attached_picture;
    mpctx->delay = 0;
    mpctx->vo_pts_history_seek_ts++;

    vo_seek_reset(mpctx->video_out);
    reset_subtitles(mpctx);

    return 1;

err_out:
no_video:
    uninit_player(mpctx, INITIALIZED_VCODEC | (opts->force_vo ? 0 : INITIALIZED_VO));
    cleanup_demux_stream(mpctx, STREAM_VIDEO);
    mpctx->current_track[STREAM_VIDEO] = NULL;
    handle_force_window(mpctx, true);
    MP_INFO(mpctx, "Video: no video\n");
    return 0;
}

// Try to refresh the video by doing a precise seek to the currently displayed
// frame. This can go wrong in all sorts of ways, so use sparingly.
void mp_force_video_refresh(struct MPContext *mpctx)
{
    struct MPOpts *opts = mpctx->opts;

    // If not paused, the next frame should come soon enough.
    if (opts->pause && mpctx->last_vo_pts != MP_NOPTS_VALUE)
        queue_seek(mpctx, MPSEEK_ABSOLUTE, mpctx->last_vo_pts, 1);
}

static bool filter_output_queued_frame(struct MPContext *mpctx)
{
    struct dec_video *d_video = mpctx->d_video;
    struct vo *video_out = mpctx->video_out;

    struct mp_image *img = vf_chain_output_queued_frame(d_video->vfilter);
    if (img)
        vo_queue_image(video_out, img);
    talloc_free(img);

    return !!img;
}

static bool load_next_vo_frame(struct MPContext *mpctx, bool eof)
{
    if (vo_get_buffered_frame(mpctx->video_out, eof) >= 0)
        return true;
    if (filter_output_queued_frame(mpctx))
        return true;
    return false;
}

static void init_filter_params(struct MPContext *mpctx)
{
    struct MPOpts *opts = mpctx->opts;
    struct dec_video *d_video = mpctx->d_video;

    // Note that the video decoder already initializes the filter chain. This
    // might recreate the chain a second time, which is not very elegant, but
    // allows us to test whether enabling deinterlacing works with the current
    // video format and other filters.
    if (d_video->vf_initialized != 1)
        return;

    if (d_video->vf_reconfig_count <= mpctx->last_vf_reconfig_count) {
        if (opts->deinterlace >= 0) {
            mp_property_do("deinterlace", M_PROPERTY_SET, &opts->deinterlace,
                           mpctx);
        }
    }
    // Setting filter params has to be "stable" (no change if params already
    // set) - checking the reconfig count is just an optimization.
    mpctx->last_vf_reconfig_count = d_video->vf_reconfig_count;
}

static void filter_video(struct MPContext *mpctx, struct mp_image *frame)
{
    struct dec_video *d_video = mpctx->d_video;

    init_filter_params(mpctx);

    frame->pts = d_video->pts;
    mp_image_set_params(frame, d_video->vf_input);
    vf_filter_frame(d_video->vfilter, frame);
    filter_output_queued_frame(mpctx);
}

static int check_framedrop(struct MPContext *mpctx, double frame_time)
{
    struct MPOpts *opts = mpctx->opts;
    // check for frame-drop:
    if (mpctx->d_audio && !mpctx->ao->untimed &&
        !demux_stream_eof(mpctx->sh[STREAM_AUDIO]))
    {
        float delay = opts->playback_speed * ao_get_delay(mpctx->ao);
        float d = delay - mpctx->delay;
        float fps = mpctx->d_video->header->video->fps;
        if (frame_time < 0)
            frame_time = fps > 0 ? 1.0 / fps : 0;
        // we should avoid dropping too many frames in sequence unless we
        // are too late. and we allow 100ms A-V delay here:
        if (d < -mpctx->dropped_frames * frame_time - 0.100 && !mpctx->paused
            && !mpctx->restart_playback) {
            mpctx->drop_frame_cnt++;
            mpctx->dropped_frames++;
            return mpctx->opts->frame_dropping;
        } else
            mpctx->dropped_frames = 0;
    }
    return 0;
}

static struct demux_packet *video_read_frame(struct MPContext *mpctx)
{
    struct dec_video *d_video = mpctx->d_video;
    sh_video_t *sh_video = d_video->header->video;
    demuxer_t *demuxer = d_video->header->demuxer;
    float pts1 = d_video->last_pts;

    struct demux_packet *pkt = demux_read_packet(d_video->header);
    if (!pkt)
        return NULL; // EOF

    if (pkt->pts != MP_NOPTS_VALUE)
        d_video->last_pts = pkt->pts;

    float frame_time = sh_video->fps > 0 ? 1.0f / sh_video->fps : 0;

    // override frame_time for variable/unknown FPS formats:
    if (!mpctx->opts->force_fps) {
        double next_pts = demux_get_next_pts(d_video->header);
        double d = next_pts == MP_NOPTS_VALUE ? d_video->last_pts - pts1
                                              : next_pts - d_video->last_pts;
        if (d >= 0) {
            if (demuxer->type == DEMUXER_TYPE_TV) {
                if (d > 0)
                    sh_video->fps = 1.0f / d;
                frame_time = d;
            } else {
                if ((int)sh_video->fps <= 1)
                    frame_time = d;
            }
        }
    }

    d_video->pts = d_video->last_pts;
    d_video->next_frame_time = frame_time;
    return pkt;
}

static double update_video_nocorrect_pts(struct MPContext *mpctx)
{
    struct dec_video *d_video = mpctx->d_video;
    double frame_time = 0;
    while (1) {
        // In nocorrect-pts mode there is no way to properly time these frames
        if (load_next_vo_frame(mpctx, false))
            break;
        frame_time = d_video->next_frame_time;
        if (mpctx->restart_playback)
            frame_time = 0;
        struct demux_packet *pkt = video_read_frame(mpctx);
        if (!pkt)
            return -1;
        if (mpctx->d_audio)
            mpctx->delay -= frame_time;
        // video_read_frame can change fps (e.g. for ASF video)
        update_fps(mpctx);
        int framedrop_type = check_framedrop(mpctx, frame_time);

        void *decoded_frame = video_decode(d_video, pkt, framedrop_type,
                                           d_video->pts);
        talloc_free(pkt);
        if (decoded_frame) {
            filter_video(mpctx, decoded_frame);
        }
        break;
    }
    return frame_time;
}

static double update_video_attached_pic(struct MPContext *mpctx)
{
    struct dec_video *d_video = mpctx->d_video;

    // Try to decode the picture multiple times, until it is displayed.
    if (mpctx->video_out->hasframe)
        return -1;

    struct mp_image *decoded_frame =
            video_decode(d_video, d_video->header->attached_picture, 0, 0);
    if (decoded_frame)
        filter_video(mpctx, decoded_frame);
    load_next_vo_frame(mpctx, true);
    d_video->pts = MP_NOPTS_VALUE;
    return 0;
}

static void determine_frame_pts(struct MPContext *mpctx)
{
    struct dec_video *d_video = mpctx->d_video;
    struct MPOpts *opts = mpctx->opts;

    if (opts->user_pts_assoc_mode)
        d_video->pts_assoc_mode = opts->user_pts_assoc_mode;
    else if (d_video->pts_assoc_mode == 0) {
        if (d_video->header->demuxer->timestamp_type == TIMESTAMP_TYPE_PTS
            && d_video->codec_reordered_pts != MP_NOPTS_VALUE)
            d_video->pts_assoc_mode = 1;
        else
            d_video->pts_assoc_mode = 2;
    } else {
        int probcount1 = d_video->num_reordered_pts_problems;
        int probcount2 = d_video->num_sorted_pts_problems;
        if (d_video->pts_assoc_mode == 2) {
            int tmp = probcount1;
            probcount1 = probcount2;
            probcount2 = tmp;
        }
        if (probcount1 >= probcount2 * 1.5 + 2) {
            d_video->pts_assoc_mode = 3 - d_video->pts_assoc_mode;
            MP_VERBOSE(mpctx, "Switching to pts association mode "
                       "%d.\n", d_video->pts_assoc_mode);
        }
    }
    d_video->pts = d_video->pts_assoc_mode == 1 ?
                   d_video->codec_reordered_pts : d_video->sorted_pts;
}

double update_video(struct MPContext *mpctx, double endpts)
{
    struct dec_video *d_video = mpctx->d_video;
    struct vo *video_out = mpctx->video_out;
    vf_control(d_video->vfilter, VFCTRL_SET_OSD_OBJ, mpctx->osd); // for vf_sub
    if (!mpctx->opts->correct_pts)
        return update_video_nocorrect_pts(mpctx);

    if (d_video->header->attached_picture)
        return update_video_attached_pic(mpctx);

    double pts;

    while (1) {
        if (load_next_vo_frame(mpctx, false))
            break;
        pts = MP_NOPTS_VALUE;
        struct demux_packet *pkt = NULL;
        while (1) {
            pkt = demux_read_packet(d_video->header);
            if (!pkt || pkt->len)
                break;
            /* Packets with size 0 are assumed to not correspond to frames,
             * but to indicate the absence of a frame in formats like AVI
             * that must have packets at fixed timecode intervals. */
            talloc_free(pkt);
        }
        if (pkt)
            pts = pkt->pts;
        if (pts != MP_NOPTS_VALUE)
            pts += mpctx->video_offset;
        if (pts >= mpctx->hrseek_pts - .005)
            mpctx->hrseek_framedrop = false;
        int framedrop_type = mpctx->hrseek_active && mpctx->hrseek_framedrop ?
                             1 : check_framedrop(mpctx, -1);
        struct mp_image *decoded_frame =
            video_decode(d_video, pkt, framedrop_type, pts);
        talloc_free(pkt);
        if (decoded_frame) {
            determine_frame_pts(mpctx);
            filter_video(mpctx, decoded_frame);
        } else if (!pkt) {
            if (!load_next_vo_frame(mpctx, true))
                return -1;
        }
        break;
    }

    if (!video_out->frame_loaded)
        return 0;

    pts = video_out->next_pts;
    if (pts == MP_NOPTS_VALUE) {
        MP_ERR(mpctx, "Video pts after filters MISSING\n");
        // Try to use decoder pts from before filters
        pts = d_video->pts;
        if (pts == MP_NOPTS_VALUE)
            pts = d_video->last_pts;
    }
    if (endpts == MP_NOPTS_VALUE || pts < endpts)
        add_frame_pts(mpctx, pts);
    if (mpctx->hrseek_active && pts < mpctx->hrseek_pts - .005) {
        vo_skip_frame(video_out);
        return 0;
    }
    mpctx->hrseek_active = false;
    d_video->pts = pts;
    if (d_video->last_pts == MP_NOPTS_VALUE) {
        d_video->last_pts = d_video->pts;
    } else if (d_video->last_pts > d_video->pts) {
        MP_WARN(mpctx, "Decreasing video pts: %f < %f\n",
                d_video->pts, d_video->last_pts);
        /* If the difference in pts is small treat it as jitter around the
         * right value (possibly caused by incorrect timestamp ordering) and
         * just show this frame immediately after the last one.
         * Treat bigger differences as timestamp resets and start counting
         * timing of later frames from the position of this one. */
        if (d_video->last_pts - d_video->pts > 0.5)
            d_video->last_pts = d_video->pts;
        else
            d_video->pts = d_video->last_pts;
    } else if (d_video->pts >= d_video->last_pts + 60) {
        // Assume a PTS difference >= 60 seconds is a discontinuity.
        MP_WARN(mpctx, "Jump in video pts: %f -> %f\n",
                d_video->last_pts, d_video->pts);
        d_video->last_pts = d_video->pts;
    }
    double frame_time = d_video->pts - d_video->last_pts;
    d_video->last_pts = d_video->pts;
    if (mpctx->d_audio)
        mpctx->delay -= frame_time;
    return frame_time;
}