/*

 * Copyright (c) 2012 Clément Bœsch

 *

 * 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

 */

/**

 * @file

 * JACOsub subtitle decoder

 * @see http://unicorn.us.com/jacosub/jscripts.html

 */

#include <time.h>

#include "ass.h"

#include "codec_internal.h"

#include "jacosub.h"

#include "libavutil/avstring.h"

#include "libavutil/bprint.h"

#include "libavutil/time_internal.h"

static int insert_text(AVBPrint *dst, const char *in, const char *arg)

{

    av_bprintf(dst, "%s", arg);

    return 0;

}

static int insert_datetime(AVBPrint *dst, const char *in, const char *arg)

{

    char buf[16] = {0};

    time_t now = time(0);

    struct tm ltime;

    localtime_r(&now, &ltime);

    if (strftime(buf, sizeof(buf), arg, &ltime))

        av_bprintf(dst, "%s", buf);

    return 0;

}

static int insert_color(AVBPrint *dst, const char *in, const char *arg)

{

    return 1; // skip id

}

static int insert_font(AVBPrint *dst, const char *in, const char *arg)

{

    return 1; // skip id

}

static const struct {

    const char *from;

    const char *arg;

    int (*func)(AVBPrint *dst, const char *in, const char *arg);

} ass_codes_map[] = {

    {"\\~", "~",        insert_text},       // tilde doesn't need escaping

    {"~",   "{\\h}",    insert_text},       // hard space

    {"\\n", "\\N",      insert_text},       // newline

    {"\\D", "%d %b %Y", insert_datetime},   // current date

    {"\\T", "%H:%M",    insert_datetime},   // current time

    {"\\N", "{\\r}",    insert_text},       // reset to default style

    {"\\I", "{\\i1}",   insert_text},       // italic on

    {"\\i", "{\\i0}",   insert_text},       // italic off

    {"\\B", "{\\b1}",   insert_text},       // bold on

    {"\\b", "{\\b0}",   insert_text},       // bold off

    {"\\U", "{\\u1}",   insert_text},       // underline on

    {"\\u", "{\\u0}",   insert_text},       // underline off

    {"\\C", "",         insert_color},      // TODO: color

    {"\\F", "",         insert_font},       // TODO: font

};

enum {

    ALIGN_VB = 1<<0, // vertical bottom, default

    ALIGN_VM = 1<<1, // vertical middle

    ALIGN_VT = 1<<2, // vertical top

    ALIGN_JC = 1<<3, // justify center, default

    ALIGN_JL = 1<<4, // justify left

    ALIGN_JR = 1<<5, // justify right

};

static void jacosub_to_ass(AVCodecContext *avctx, AVBPrint *dst, const char *src)

{

    int i, valign = 0, halign = 0;

    char c = av_toupper(*src);

    char directives[128] = {0};

    /* extract the optional directives */

    if ((c >= 'A' && c <= 'Z') || c == '[') {

        char *p    = directives;

        char *pend = directives + sizeof(directives) - 1;

        do *p++ = av_toupper(*src++);

        while (*src && !jss_whitespace(*src) && p < pend);

        *p = 0;

        src = jss_skip_whitespace(src);

    }

    /* handle directives (TODO: handle more of them, and more reliably) */

    if      (strstr(directives, "VB")) valign = ALIGN_VB;

    else if (strstr(directives, "VM")) valign = ALIGN_VM;

    else if (strstr(directives, "VT")) valign = ALIGN_VT;

    if      (strstr(directives, "JC")) halign = ALIGN_JC;

    else if (strstr(directives, "JL")) halign = ALIGN_JL;

    else if (strstr(directives, "JR")) halign = ALIGN_JR;

    if (valign || halign) {

        if (!valign) valign = ALIGN_VB;

        if (!halign) halign = ALIGN_JC;

        switch (valign | halign) {

        case ALIGN_VB | ALIGN_JL: av_bprintf(dst, "{\\an1}"); break; // bottom left

        case ALIGN_VB | ALIGN_JC: av_bprintf(dst, "{\\an2}"); break; // bottom center

        case ALIGN_VB | ALIGN_JR: av_bprintf(dst, "{\\an3}"); break; // bottom right

        case ALIGN_VM | ALIGN_JL: av_bprintf(dst, "{\\an4}"); break; // middle left

        case ALIGN_VM | ALIGN_JC: av_bprintf(dst, "{\\an5}"); break; // middle center

        case ALIGN_VM | ALIGN_JR: av_bprintf(dst, "{\\an6}"); break; // middle right

        case ALIGN_VT | ALIGN_JL: av_bprintf(dst, "{\\an7}"); break; // top left

        case ALIGN_VT | ALIGN_JC: av_bprintf(dst, "{\\an8}"); break; // top center

        case ALIGN_VT | ALIGN_JR: av_bprintf(dst, "{\\an9}"); break; // top right

        }

    }

    /* process timed line */

    while (*src && *src != '\n') {

        /* text continue on the next line */

        if (src[0] == '\\' && src[1] == '\n') {

            src += 2;

            while (jss_whitespace(*src))

                src++;

            continue;

        }

        /* special character codes */

        for (i = 0; i < FF_ARRAY_ELEMS(ass_codes_map); i++) {

            const char *from = ass_codes_map[i].from;

            const char *arg  = ass_codes_map[i].arg;

            size_t codemap_len = strlen(from);

            if (!strncmp(src, from, codemap_len)) {

                src += codemap_len;

                src += ass_codes_map[i].func(dst, src, arg);

                break;

            }

        }

        /* simple char copy */

        if (i == FF_ARRAY_ELEMS(ass_codes_map))

            av_bprintf(dst, "%c", *src++);

    }

}

static int jacosub_decode_frame(AVCodecContext *avctx, AVSubtitle *sub,

                                int *got_sub_ptr, const AVPacket *avpkt)

{

    int ret;

    const char *ptr = avpkt->data;

    FFASSDecoderContext *s = avctx->priv_data;

    if (avpkt->size <= 0)

        goto end;

    if (*ptr) {

        AVBPrint buffer;

        // skip timers

        ptr = jss_skip_whitespace(ptr);

        ptr = strchr(ptr, ' '); if (!ptr) goto end; ptr++;

        ptr = strchr(ptr, ' '); if (!ptr) goto end; ptr++;

        av_bprint_init(&buffer, JSS_MAX_LINESIZE, JSS_MAX_LINESIZE);

        jacosub_to_ass(avctx, &buffer, ptr);

        ret = ff_ass_add_rect(sub, buffer.str, s->readorder++, 0, NULL, NULL);

        av_bprint_finalize(&buffer, NULL);

        if (ret < 0)

            return ret;

    }

end:

    *got_sub_ptr = sub->num_rects > 0;

    return avpkt->size;

}

const FFCodec ff_jacosub_decoder = {

    .p.name         = "jacosub",

    CODEC_LONG_NAME("JACOsub subtitle"),

    .p.type         = AVMEDIA_TYPE_SUBTITLE,

    .p.id           = AV_CODEC_ID_JACOSUB,

    .init           = ff_ass_subtitle_header_default,

    FF_CODEC_DECODE_SUB_CB(jacosub_decode_frame),

    .flush          = ff_ass_decoder_flush,

    .priv_data_size = sizeof(FFASSDecoderContext),

};