/*

 * 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 <assert.h>

#include "mpv_talloc.h"

#include "misc/bstr.h"

#include "common/msg.h"

#include "codecs.h"

void mp_add_decoder(struct mp_decoder_list *list, const char *codec,

                    const char *decoder, const char *desc)

{

    struct mp_decoder_entry entry = {

        .codec = talloc_strdup(list, codec),

        .decoder = talloc_strdup(list, decoder),

        .desc = talloc_strdup(list, desc),

    };

    MP_TARRAY_APPEND(list, list->entries, list->num_entries, entry);

}

// Add entry, but only if it's not yet on the list, and if the codec matches.

// If codec == NULL, don't compare codecs.

static void add_new(struct mp_decoder_list *to, struct mp_decoder_entry *entry,

                    const char *codec)

{

    if (!entry || (codec && strcmp(entry->codec, codec) != 0))

        return;

    mp_add_decoder(to, entry->codec, entry->decoder, entry->desc);

}

// Select a decoder from the given list for the given codec. The selection

// can be influenced by the selection string, which can specify a priority

// list of preferred decoders.

// This returns a list of decoders to try, with the preferred decoders first.

// The selection string corresponds to --vd/--ad directly, and has the

// following syntax:

//   selection = [<entry> ("," <entry>)*]

//       entry = <decoder>       // prefer decoder

//       entry = "-" <decoder>   // exclude a decoder

//       entry = "-"                            // don't add fallback decoders

// Forcing a decoder means it's added even if the codec mismatches.

struct mp_decoder_list *mp_select_decoders(struct mp_log *log,

                                           struct mp_decoder_list *all,

                                           const char *codec,

                                           const char *selection)

{

    struct mp_decoder_list *list = talloc_zero(NULL, struct mp_decoder_list);

    if (!codec)

        codec = "unknown";

    bool stop = false;

    bstr sel = bstr0(selection);

    while (sel.len) {

        bstr entry;

        bstr_split_tok(sel, ",", &entry, &sel);

        if (bstr_equals0(entry, "-")) {

            mp_warn(log, "Excluding codecs is deprecated.\n");

            stop = true;

            break;

        }

        for (int n = 0; n < all->num_entries; n++) {

            struct mp_decoder_entry *cur = &all->entries[n];

            if (bstr_equals0(entry, cur->decoder))

                add_new(list, cur, codec);

        }

    }

    if (!stop) {

        // Add the remaining codecs which haven't been added yet

        for (int n = 0; n < all->num_entries; n++)

            add_new(list, &all->entries[n], codec);

    }

    return list;

}

void mp_append_decoders(struct mp_decoder_list *list, struct mp_decoder_list *a)

{

    for (int n = 0; n < a->num_entries; n++)

        add_new(list, &a->entries[n], NULL);

}

void mp_print_decoders(struct mp_log *log, int msgl, const char *header,

                       struct mp_decoder_list *list)

{

    mp_msg(log, msgl, "%s\n", header);

    for (int n = 0; n < list->num_entries; n++) {

        struct mp_decoder_entry *entry = &list->entries[n];

        mp_msg(log, msgl, "    %s", entry->decoder);

        if (strcmp(entry->decoder, entry->codec) != 0)

            mp_msg(log, msgl, " (%s)", entry->codec);

        mp_msg(log, msgl, " - %s\n", entry->desc);

    }

    if (list->num_entries == 0)

        mp_msg(log, msgl, "    (no decoders)\n");

}