/*

 * This file is part of mpv.

 *

 * mpv is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * mpv 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 Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <string.h>

#include <math.h>

#include <assert.h>

#include "common/common.h"

#include "common/msg.h"

#include "stream/stream.h"

#include "video/mp_image.h"

#include "demux.h"

#include "stheader.h"

#include "video/csputils.h"

struct priv {

    struct demuxer *slave;

    // streams[slave_stream_index] == our_stream

    struct sh_stream **streams;

    int num_streams;

    // This contains each DVD sub stream, or NULL. Needed because DVD packets

    // can come arbitrarily late in the MPEG stream, so the slave demuxer

    // might add the streams only later.

    struct sh_stream *dvd_subs[32];

    // Used to rewrite the raw MPEG timestamps to playback time.

    double base_time;   // playback display start time of current segment

    double base_dts;    // packet DTS that maps to base_time

    double last_dts;    // DTS of previously demuxed packet

    bool seek_reinit;   // needs reinit after seek

    bool is_dvd, is_cdda;

};

// If the timestamp difference between subsequent packets is this big, assume

// a reset. It should be big enough to account for 1. low video framerates and

// large audio frames, and 2. bad interleaving.

#define DTS_RESET_THRESHOLD 5.0

static void reselect_streams(demuxer_t *demuxer)

{

    struct priv *p = demuxer->priv;

    int num_slave = demux_get_num_stream(p->slave);

    for (int n = 0; n < MPMIN(num_slave, p->num_streams); n++) {

        if (p->streams[n]) {

            demuxer_select_track(p->slave, demux_get_stream(p->slave, n),

                MP_NOPTS_VALUE, demux_stream_is_selected(p->streams[n]));

        }

    }

}

static void get_disc_lang(struct stream *stream, struct sh_stream *sh, bool dvd)

{

    struct stream_lang_req req = {.type = sh->type, .id = sh->demuxer_id};

    if (dvd && sh->type == STREAM_SUB)

        req.id = req.id & 0x1F; // mpeg ID to index

    stream_control(stream, STREAM_CTRL_GET_LANG, &req);

    if (req.name[0])

        sh->lang = talloc_strdup(sh, req.name);

}

static void add_dvd_streams(demuxer_t *demuxer)

{

    struct priv *p = demuxer->priv;

    struct stream *stream = demuxer->stream;

    if (!p->is_dvd)

        return;

    struct stream_dvd_info_req info;

    if (stream_control(stream, STREAM_CTRL_GET_DVD_INFO, &info) > 0) {

        for (int n = 0; n < MPMIN(32, info.num_subs); n++) {

            struct sh_stream *sh = demux_alloc_sh_stream(STREAM_SUB);

            sh->demuxer_id = n + 0x20;

            sh->codec->codec = "dvd_subtitle";

            get_disc_lang(stream, sh, true);

            // p->streams _must_ match with p->slave->streams, so we can't add

            // it yet - it has to be done when the real stream appears, which

            // could be right on start, or any time later.

            p->dvd_subs[n] = sh;

            // emulate the extradata

            struct mp_csp_params csp = MP_CSP_PARAMS_DEFAULTS;

            struct pl_transform3x3 cmatrix;

            mp_get_csp_matrix(&csp, &cmatrix);

            char *s = talloc_strdup(sh, "");

            s = talloc_asprintf_append(s, "palette: ");

            for (int i = 0; i < 16; i++) {

                int color = info.palette[i];

                int y[3] = {(color >> 16) & 0xff, (color >> 8) & 0xff, color & 0xff};

                int c[3];

                mp_map_fixp_color(&cmatrix, 8, y, 8, c);

                color = (c[2] << 16) | (c[1] << 8) | c[0];

                if (i != 0)

                    s = talloc_asprintf_append(s, ", ");

                s = talloc_asprintf_append(s, "%06x", color);

            }

            s = talloc_asprintf_append(s, "\n");

            sh->codec->extradata = s;

            sh->codec->extradata_size = strlen(s);

            demux_add_sh_stream(demuxer, sh);

        }

    }

}

static void add_streams(demuxer_t *demuxer)

{

    struct priv *p = demuxer->priv;

    for (int n = p->num_streams; n < demux_get_num_stream(p->slave); n++) {

        struct sh_stream *src = demux_get_stream(p->slave, n);

        if (src->type == STREAM_SUB) {

            struct sh_stream *sub = NULL;

            if (src->demuxer_id >= 0x20 && src->demuxer_id <= 0x3F)

                sub = p->dvd_subs[src->demuxer_id - 0x20];

            if (sub) {

                mp_assert(p->num_streams == n); // directly mapped

                MP_TARRAY_APPEND(p, p->streams, p->num_streams, sub);

                continue;

            }

        }

        struct sh_stream *sh = demux_alloc_sh_stream(src->type);

        mp_assert(p->num_streams == n); // directly mapped

        MP_TARRAY_APPEND(p, p->streams, p->num_streams, sh);

        // Copy all stream fields that might be relevant

        *sh->codec = *src->codec;

        sh->demuxer_id = src->demuxer_id;

        if (src->type == STREAM_VIDEO) {

            double ar;

            if (stream_control(demuxer->stream, STREAM_CTRL_GET_ASPECT_RATIO, &ar)

                                == STREAM_OK)

            {

                struct mp_image_params f = {.w = src->codec->disp_w,

                                            .h = src->codec->disp_h};

                mp_image_params_set_dsize(&f, 1728 * ar, 1728);

                sh->codec->par_w = f.p_w;

                sh->codec->par_h = f.p_h;

            }

        }

        get_disc_lang(demuxer->stream, sh, p->is_dvd);

        demux_add_sh_stream(demuxer, sh);

    }

    reselect_streams(demuxer);

}

static void d_seek(demuxer_t *demuxer, double seek_pts, int flags)

{

    struct priv *p = demuxer->priv;

    if (p->is_cdda) {

        demux_seek(p->slave, seek_pts, flags);

        return;

    }

    if (flags & SEEK_FACTOR) {

        double tmp = 0;

        stream_control(demuxer->stream, STREAM_CTRL_GET_TIME_LENGTH, &tmp);

        seek_pts *= tmp;

    }

    MP_VERBOSE(demuxer, "seek to: %f\n", seek_pts);

    double seek_arg[] = {seek_pts, flags};

    stream_control(demuxer->stream, STREAM_CTRL_SEEK_TO_TIME, seek_arg);

    if (p->slave->desc->drop_buffers)

        p->slave->desc->drop_buffers(p->slave);

    p->seek_reinit = true;

}

static void reset_pts(demuxer_t *demuxer)

{

    struct priv *p = demuxer->priv;

    double base;

    if (stream_control(demuxer->stream, STREAM_CTRL_GET_CURRENT_TIME, &base) < 1)

        base = 0;

    MP_VERBOSE(demuxer, "reset to time: %f\n", base);

    p->base_dts = p->last_dts = MP_NOPTS_VALUE;

    p->base_time = base;

    p->seek_reinit = false;

}

static bool d_read_packet(struct demuxer *demuxer, struct demux_packet **out_pkt)

{

    struct priv *p = demuxer->priv;

    struct demux_packet *pkt = demux_read_any_packet(p->slave);

    if (!pkt)

        return false;

    demux_update(p->slave, MP_NOPTS_VALUE);

    if (p->seek_reinit)

        reset_pts(demuxer);

    add_streams(demuxer);

    if (pkt->stream >= p->num_streams) { // out of memory?

        talloc_free(pkt);

        return true;

    }

    struct sh_stream *sh = p->streams[pkt->stream];

    if (!demux_stream_is_selected(sh)) {

        talloc_free(pkt);

        return true;

    }

    pkt->stream = sh->index;

    if (p->is_cdda) {

        *out_pkt = pkt;

        return true;

    }

    MP_TRACE(demuxer, "ipts: %d %f %f\n", sh->type, pkt->pts, pkt->dts);

    if (sh->type == STREAM_SUB) {

        if (p->base_dts == MP_NOPTS_VALUE)

            MP_WARN(demuxer, "subtitle packet along PTS reset\n");

    } else if (pkt->dts != MP_NOPTS_VALUE) {

        // Use the very first DTS to rebase the start time of the MPEG stream

        // to the playback time.

        if (p->base_dts == MP_NOPTS_VALUE)

            p->base_dts = pkt->dts;

        if (p->last_dts == MP_NOPTS_VALUE)

            p->last_dts = pkt->dts;

        if (fabs(p->last_dts - pkt->dts) >= DTS_RESET_THRESHOLD) {

            MP_WARN(demuxer, "PTS discontinuity: %f->%f\n", p->last_dts, pkt->dts);

            p->base_time += p->last_dts - p->base_dts;

            p->base_dts = pkt->dts - pkt->duration;

        }

        p->last_dts = pkt->dts;

    }

    if (p->base_dts != MP_NOPTS_VALUE) {

        double delta = -p->base_dts + p->base_time;

        if (pkt->pts != MP_NOPTS_VALUE)

            pkt->pts += delta;

        if (pkt->dts != MP_NOPTS_VALUE)

            pkt->dts += delta;

    }

    MP_TRACE(demuxer, "opts: %d %f %f\n", sh->type, pkt->pts, pkt->dts);

    *out_pkt = pkt;

    return 1;

}

static void add_stream_editions(struct demuxer *demuxer)

{

    unsigned titles = 0;

    if (stream_control(demuxer->stream, STREAM_CTRL_GET_NUM_TITLES, &titles) != STREAM_OK)

        return;

    for (unsigned title = 0; title < titles; ++title) {

        double duration = title;

        if (stream_control(demuxer->stream, STREAM_CTRL_GET_TITLE_LENGTH, &duration) != STREAM_OK)

            continue;

        struct demux_edition new = {

            .demuxer_id = title,

            .default_edition = false,

            .metadata = talloc_zero(demuxer, struct mp_tags),

        };

        MP_TARRAY_APPEND(demuxer, demuxer->editions, demuxer->num_editions, new);

        char *time = mp_format_time(duration, true);

        double playlist = title;

        if (stream_control(demuxer->stream, STREAM_CTRL_GET_TITLE_PLAYLIST, &playlist) == STREAM_OK)

            time = talloc_asprintf_append(time, ") (%05.0f.mpls", playlist);

        mp_tags_set_str(new.metadata, "TITLE",

                        mp_tprintf(42, "title: %u (%s)", title + 1, time));

        talloc_free(time);

    }

}

static void add_stream_chapters(struct demuxer *demuxer)

{

    int num = 0;

    if (stream_control(demuxer->stream, STREAM_CTRL_GET_NUM_CHAPTERS, &num) < 1)

        return;

    for (int n = 0; n < num; n++) {

        double p = n;

        if (stream_control(demuxer->stream, STREAM_CTRL_GET_CHAPTER_TIME, &p) < 1)

            continue;

        demuxer_add_chapter(demuxer, "", p, 0);

    }

}

static int d_open(demuxer_t *demuxer, enum demux_check check)

{

    struct priv *p = demuxer->priv = talloc_zero(demuxer, struct priv);

    if (check != DEMUX_CHECK_FORCE)

        return -1;

    struct demuxer_params params = {

        .force_format = "+lavf",

        .external_stream = demuxer->stream,

        .stream_flags = demuxer->stream_origin,

        .depth = demuxer->depth + 1,

    };

    struct stream *cur = demuxer->stream;

    const char *sname = "";

    if (cur->info)

        sname = cur->info->name;

    p->is_cdda = strcmp(sname, "cdda") == 0;

    p->is_dvd = strcmp(sname, "dvdnav") == 0 ||

                strcmp(sname, "ifo_dvdnav") == 0;

    if (p->is_cdda)

        params.force_format = "+rawaudio";

    char *t = NULL;

    stream_control(demuxer->stream, STREAM_CTRL_GET_DISC_NAME, &t);

    if (t) {

        mp_tags_set_str(demuxer->metadata, "TITLE", t);

        talloc_free(t);

    }

    // Initialize the playback time. We need to read _some_ data to get the

    // correct stream-layer time (at least with libdvdnav).

    stream_read_peek(demuxer->stream, &(char){0}, 1);

    reset_pts(demuxer);

    p->slave = demux_open_url("-", &params, demuxer->cancel, demuxer->global);

    if (!p->slave)

        return -1;

    // Can be seekable even if the stream isn't.

    demuxer->seekable = true;

    add_dvd_streams(demuxer);

    add_streams(demuxer);

    add_stream_chapters(demuxer);

    add_stream_editions(demuxer);

    double len;

    if (stream_control(demuxer->stream, STREAM_CTRL_GET_TIME_LENGTH, &len) >= 1)

        demuxer->duration = len;

    unsigned title;

    if (stream_control(demuxer->stream, STREAM_CTRL_GET_CURRENT_TITLE, &title) >= 1)

        demuxer->edition = title;

    return 0;

}

static void d_close(demuxer_t *demuxer)

{

    struct priv *p = demuxer->priv;

    demux_free(p->slave);

}

const demuxer_desc_t demuxer_desc_disc = {

    .name = "disc",

    .desc = "CD/DVD/BD wrapper",

    .read_packet = d_read_packet,

    .open = d_open,

    .close = d_close,

    .seek = d_seek,

    .switched_tracks = reselect_streams,

};