/*

 * SSA/ASS common functions

 * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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.

 *

 * FFmpeg 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 FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "avcodec.h"

#include "ass.h"

#include "libavutil/avstring.h"

#include "libavutil/bprint.h"

#include "libavutil/mem.h"

#include "version.h"

int ff_ass_subtitle_header_full(AVCodecContext *avctx,

                                int play_res_x, int play_res_y,

                                const char *font, int font_size,

                                int primary_color, int secondary_color,

                                int outline_color, int back_color,

                                int bold, int italic, int underline,

                                int border_style, int alignment)

{

    avctx->subtitle_header = av_asprintf(

             "[Script Info]\n"

             "; Script generated by FFmpeg/Lavc%s\n"

             "ScriptType: v4.00+\n"

             "PlayResX: %d\n"

             "PlayResY: %d\n"

             "ScaledBorderAndShadow: yes\n"

             "YCbCr Matrix: None\n"

             "\n"

             "[V4+ Styles]\n"

             /* ASS (v4+) header */

             "Format: Name, "

             "Fontname, Fontsize, "

             "PrimaryColour, SecondaryColour, OutlineColour, BackColour, "

             "Bold, Italic, Underline, StrikeOut, "

             "ScaleX, ScaleY, "

             "Spacing, Angle, "

             "BorderStyle, Outline, Shadow, "

             "Alignment, MarginL, MarginR, MarginV, "

             "Encoding\n"

             "Style: "

             "Default,"             /* Name */

             "%s,%d,"               /* Font{name,size} */

             "&H%x,&H%x,&H%x,&H%x," /* {Primary,Secondary,Outline,Back}Colour */

             "%d,%d,%d,0,"          /* Bold, Italic, Underline, StrikeOut */

             "100,100,"             /* Scale{X,Y} */

             "0,0,"                 /* Spacing, Angle */

             "%d,1,0,"              /* BorderStyle, Outline, Shadow */

             "%d,10,10,10,"         /* Alignment, Margin[LRV] */

             "1\n"                  /* Encoding */

             "\n"

             "[Events]\n"

             "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\n",

             !(avctx->flags & AV_CODEC_FLAG_BITEXACT) ? AV_STRINGIFY(LIBAVCODEC_VERSION) : "",

             play_res_x, play_res_y, font, font_size,

             primary_color, secondary_color, outline_color, back_color,

             -bold, -italic, -underline, border_style, alignment);

    if (!avctx->subtitle_header)

        return AVERROR(ENOMEM);

    avctx->subtitle_header_size = strlen(avctx->subtitle_header);

    return 0;

}

int ff_ass_subtitle_header(AVCodecContext *avctx,

                           const char *font, int font_size,

                           int color, int back_color,

                           int bold, int italic, int underline,

                           int border_style, int alignment)

{

    return ff_ass_subtitle_header_full(avctx,

                               ASS_DEFAULT_PLAYRESX, ASS_DEFAULT_PLAYRESY,

                               font, font_size, color, color,

                               back_color, back_color,

                               bold, italic, underline,

                               border_style, alignment);

}

int ff_ass_subtitle_header_default(AVCodecContext *avctx)

{

    return ff_ass_subtitle_header(avctx, ASS_DEFAULT_FONT,

                               ASS_DEFAULT_FONT_SIZE,

                               ASS_DEFAULT_COLOR,

                               ASS_DEFAULT_BACK_COLOR,

                               ASS_DEFAULT_BOLD,

                               ASS_DEFAULT_ITALIC,

                               ASS_DEFAULT_UNDERLINE,

                               ASS_DEFAULT_BORDERSTYLE,

                               ASS_DEFAULT_ALIGNMENT);

}

char *ff_ass_get_dialog(int readorder, int layer, const char *style,

                        const char *speaker, const char *text)

{

    return av_asprintf("%d,%d,%s,%s,0,0,0,,%s",

                       readorder, layer, style ? style : "Default",

                       speaker ? speaker : "", text);

}

int ff_ass_add_rect2(AVSubtitle *sub, const char *dialog,

                    int readorder, int layer, const char *style,

                    const char *speaker, unsigned *nb_rect_allocated)

{

    AVSubtitleRect **rects = sub->rects, *rect;

    char *ass_str;

    uint64_t new_nb = 0;

    if (sub->num_rects >= UINT_MAX)

        return AVERROR(ENOMEM);

    if (nb_rect_allocated && *nb_rect_allocated <= sub->num_rects) {

        if (sub->num_rects < UINT_MAX / 17 * 16) {

            new_nb = sub->num_rects + sub->num_rects/16 + 1;

        } else

            new_nb = UINT_MAX;

    } else if (!nb_rect_allocated)

        new_nb = sub->num_rects + 1;

    if (new_nb) {

        rects = av_realloc_array(rects, new_nb, sizeof(*sub->rects));

        if (!rects)

            return AVERROR(ENOMEM);

        if (nb_rect_allocated)

            *nb_rect_allocated = new_nb;

        sub->rects = rects;

    }

    rect       = av_mallocz(sizeof(*rect));

    if (!rect)

        return AVERROR(ENOMEM);

    rects[sub->num_rects++] = rect;

    rect->type = SUBTITLE_ASS;

    ass_str = ff_ass_get_dialog(readorder, layer, style, speaker, dialog);

    if (!ass_str)

        return AVERROR(ENOMEM);

    rect->ass = ass_str;

    return 0;

}

int ff_ass_add_rect(AVSubtitle *sub, const char *dialog,

                    int readorder, int layer, const char *style,

                    const char *speaker)

{

    return ff_ass_add_rect2(sub, dialog, readorder, layer, style, speaker, NULL);

}

void ff_ass_decoder_flush(AVCodecContext *avctx)

{

    FFASSDecoderContext *s = avctx->priv_data;

    if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))

        s->readorder = 0;

}

void ff_ass_bprint_text_event(AVBPrint *buf, const char *p, int size,

                             const char *linebreaks, int keep_ass_markup)

{

    const char *p_end = p + size;

    for (; p < p_end && *p; p++) {

        /* forced custom line breaks, not accounted as "normal" EOL */

        if (linebreaks && strchr(linebreaks, *p)) {

            av_bprintf(buf, "\\N");

        /* cancel curly brackets to avoid bogus override tag blocks

         * hiding text. Standard ASS has no character escapes,

         * though (only) libass provides \{ and \}.

         * Unpaired closing brackets don't need escaping at all though and

         * to make the situation less bad in standard ASS insert an empty block

         */

        } else if (!keep_ass_markup && *p == '{') {

            av_bprintf(buf, "\\{{}");

        /* append word-joiner U+2060 as UTF-8 to break up sequences like \N */

        } else if (!keep_ass_markup && *p == '\\') {

            if (p_end - p <= 3 || strncmp(p + 1, "\xe2\x81\xa0", 3))

                av_bprintf(buf, "\\\xe2\x81\xa0");

            else

                av_bprintf(buf, "\\");

        /* some packets might end abruptly (no \0 at the end, like for example

         * in some cases of demuxing from a classic video container), some

         * might be terminated with \n or \r\n which we have to remove (for

         * consistency with those who haven't), and we also have to deal with

         * evil cases such as \r at the end of the buffer (and no \0 terminated

         * character) */

        } else if (p[0] == '\n') {

            /* some stuff left so we can insert a line break */

            if (p < p_end - 1)

                av_bprintf(buf, "\\N");

        } else if (p[0] == '\r' && p < p_end - 1 && p[1] == '\n') {

            /* \r followed by a \n, we can skip it. We don't insert the \N yet

             * because we don't know if it is followed by more text */

            continue;

        /* finally, a sane character */

        } else {

            av_bprint_chars(buf, *p, 1);

        }

    }

}