/*
  * SSA/ASS spliting 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_split.h"
 
 typedef enum {
     ASS_STR,
     ASS_INT,
     ASS_FLT,
     ASS_COLOR,
     ASS_TIMESTAMP,
     ASS_ALGN,
 } ASSFieldType;
 
 typedef struct {
     const char *name;
     int type;
     int offset;
 } ASSFields;
 
 typedef struct {
     const char *section;
     const char *format_header;
     const char *fields_header;
     int         size;
     int         offset;
     int         offset_count;
     ASSFields   fields[10];
 } ASSSection;
 
 static const ASSSection ass_sections[] = {
     { .section       = "Script Info",
       .offset        = offsetof(ASS, script_info),
       .fields = {{"ScriptType", ASS_STR, offsetof(ASSScriptInfo, script_type)},
                  {"Collisions", ASS_STR, offsetof(ASSScriptInfo, collisions) },
                  {"PlayResX",   ASS_INT, offsetof(ASSScriptInfo, play_res_x) },
                  {"PlayResY",   ASS_INT, offsetof(ASSScriptInfo, play_res_y) },
                  {"Timer",      ASS_FLT, offsetof(ASSScriptInfo, timer)      },
                  {0},
         }
     },
     { .section       = "V4+ Styles",
       .format_header = "Format",
       .fields_header = "Style",
       .size          = sizeof(ASSStyle),
       .offset        = offsetof(ASS, styles),
       .offset_count  = offsetof(ASS, styles_count),
       .fields = {{"Name",         ASS_STR,  offsetof(ASSStyle, name)         },
                  {"Fontname",     ASS_STR,  offsetof(ASSStyle, font_name)    },
                  {"Fontsize",     ASS_INT,  offsetof(ASSStyle, font_size)    },
                  {"PrimaryColour",ASS_COLOR,offsetof(ASSStyle, primary_color)},
                  {"BackColour",   ASS_COLOR,offsetof(ASSStyle, back_color)   },
                  {"Bold",         ASS_INT,  offsetof(ASSStyle, bold)         },
                  {"Italic",       ASS_INT,  offsetof(ASSStyle, italic)       },
                  {"Underline",    ASS_INT,  offsetof(ASSStyle, underline)    },
                  {"Alignment",    ASS_INT,  offsetof(ASSStyle, alignment)    },
                  {0},
         }
     },
     { .section       = "V4 Styles",
       .format_header = "Format",
       .fields_header = "Style",
       .size          = sizeof(ASSStyle),
       .offset        = offsetof(ASS, styles),
       .offset_count  = offsetof(ASS, styles_count),
       .fields = {{"Name",         ASS_STR,  offsetof(ASSStyle, name)         },
                  {"Fontname",     ASS_STR,  offsetof(ASSStyle, font_name)    },
                  {"Fontsize",     ASS_INT,  offsetof(ASSStyle, font_size)    },
                  {"PrimaryColour",ASS_COLOR,offsetof(ASSStyle, primary_color)},
                  {"BackColour",   ASS_COLOR,offsetof(ASSStyle, back_color)   },
                  {"Bold",         ASS_INT,  offsetof(ASSStyle, bold)         },
                  {"Italic",       ASS_INT,  offsetof(ASSStyle, italic)       },
                  {"Alignment",    ASS_ALGN, offsetof(ASSStyle, alignment)    },
                  {0},
         }
     },
     { .section       = "Events",
       .format_header = "Format",
       .fields_header = "Dialogue",
       .size          = sizeof(ASSDialog),
       .offset        = offsetof(ASS, dialogs),
       .offset_count  = offsetof(ASS, dialogs_count),
       .fields = {{"Layer",  ASS_INT,        offsetof(ASSDialog, layer)       },
                  {"Start",  ASS_TIMESTAMP,  offsetof(ASSDialog, start)       },
                  {"End",    ASS_TIMESTAMP,  offsetof(ASSDialog, end)         },
                  {"Style",  ASS_STR,        offsetof(ASSDialog, style)       },
                  {"Text",   ASS_STR,        offsetof(ASSDialog, text)        },
                  {0},
         }
     },
 };
 
 
 typedef int (*ASSConvertFunc)(void *dest, const char *buf, int len);
 
 static int convert_str(void *dest, const char *buf, int len)
 {
     char *str = av_malloc(len + 1);
     if (str) {
         memcpy(str, buf, len);
         str[len] = 0;
         if (*(void **)dest)
             av_free(*(void **)dest);
         *(char **)dest = str;
     }
     return !str;
 }
 static int convert_int(void *dest, const char *buf, int len)
 {
     return sscanf(buf, "%d", (int *)dest) == 1;
 }
 static int convert_flt(void *dest, const char *buf, int len)
 {
     return sscanf(buf, "%f", (float *)dest) == 1;
 }
 static int convert_color(void *dest, const char *buf, int len)
 {
     return sscanf(buf, "&H%8x", (int *)dest) == 1 ||
            sscanf(buf, "%d",    (int *)dest) == 1;
 }
 static int convert_timestamp(void *dest, const char *buf, int len)
 {
     int c, h, m, s, cs;
     if ((c = sscanf(buf, "%d:%02d:%02d.%02d", &h, &m, &s, &cs)) == 4)
         *(int *)dest = 360000*h + 6000*m + 100*s + cs;
     return c == 4;
 }
 static int convert_alignment(void *dest, const char *buf, int len)
 {
     int a;
     if (sscanf(buf, "%d", &a) == 1) {
         /* convert V4 Style alignment to V4+ Style */
         *(int *)dest = a + ((a&4) >> 1) - 5*!!(a&8);
         return 1;
     }
     return 0;
 }
 
 static const ASSConvertFunc convert_func[] = {
     [ASS_STR]       = convert_str,
     [ASS_INT]       = convert_int,
     [ASS_FLT]       = convert_flt,
     [ASS_COLOR]     = convert_color,
     [ASS_TIMESTAMP] = convert_timestamp,
     [ASS_ALGN]      = convert_alignment,
 };
 
 
 struct ASSSplitContext {
     ASS ass;
     int current_section;
     int field_number[FF_ARRAY_ELEMS(ass_sections)];
     int *field_order[FF_ARRAY_ELEMS(ass_sections)];
 };
 
 
 static uint8_t *realloc_section_array(ASSSplitContext *ctx)
 {
     const ASSSection *section = &ass_sections[ctx->current_section];
     int *count = (int *)((uint8_t *)&ctx->ass + section->offset_count);
     void **section_ptr = (void **)((uint8_t *)&ctx->ass + section->offset);
     uint8_t *tmp = av_realloc(*section_ptr, (*count+1)*section->size);
     if (!tmp)
         return NULL;
     *section_ptr = tmp;
     tmp += *count * section->size;
     memset(tmp, 0, section->size);
     (*count)++;
     return tmp;
 }
 
 static inline int is_eol(char buf)
 {
     return buf == '\r' || buf == '\n' || buf == 0;
 }
 
 static inline const char *skip_space(const char *buf)
 {
     while (*buf == ' ')
         buf++;
     return buf;
 }
 
 static const char *ass_split_section(ASSSplitContext *ctx, const char *buf)
 {
     const ASSSection *section = &ass_sections[ctx->current_section];
     int *number = &ctx->field_number[ctx->current_section];
     int *order = ctx->field_order[ctx->current_section];
     int *tmp, i, len;
 
     while (buf && *buf) {
         if (buf[0] == '[') {
             ctx->current_section = -1;
             break;
         }
         if (buf[0] == ';' || (buf[0] == '!' && buf[1] == ':')) {
             /* skip comments */
         } else if (section->format_header && !order) {
             len = strlen(section->format_header);
             if (strncmp(buf, section->format_header, len) || buf[len] != ':')
                 return NULL;
             buf += len + 1;
             while (!is_eol(*buf)) {
                 buf = skip_space(buf);
                 len = strcspn(buf, ", \r\n");
                 if (!(tmp = av_realloc(order, (*number + 1) * sizeof(*order))))
                     return NULL;
                 order = tmp;
                 order[*number] = -1;
                 for (i=0; section->fields[i].name; i++)
                     if (!strncmp(buf, section->fields[i].name, len)) {
                         order[*number] = i;
                         break;
                     }
                 (*number)++;

                 buf = skip_space(buf + len + (buf[len] == ','));

             }
             ctx->field_order[ctx->current_section] = order;
         } else if (section->fields_header) {
             len = strlen(section->fields_header);
             if (!strncmp(buf, section->fields_header, len) && buf[len] == ':') {
                 uint8_t *ptr, *struct_ptr = realloc_section_array(ctx);
                 if (!struct_ptr)  return NULL;
                 buf += len + 1;
                 for (i=0; !is_eol(*buf) && i < *number; i++) {
                     int last = i == *number - 1;
                     buf = skip_space(buf);
                     len = strcspn(buf, last ? "\r\n" : ",\r\n");
                     if (order[i] >= 0) {
                         ASSFieldType type = section->fields[order[i]].type;
                         ptr = struct_ptr + section->fields[order[i]].offset;
                         convert_func[type](ptr, buf, len);
                     }

                     buf += len;
                     if (!last && *buf) buf++;
                     buf = skip_space(buf);

                 }
             }
         } else {
             len = strcspn(buf, ":\r\n");
             if (buf[len] == ':') {
                 for (i=0; section->fields[i].name; i++)
                     if (!strncmp(buf, section->fields[i].name, len)) {
                         ASSFieldType type = section->fields[i].type;
                         uint8_t *ptr = (uint8_t *)&ctx->ass + section->offset;
                         ptr += section->fields[i].offset;
                         buf = skip_space(buf + len + 1);
                         convert_func[type](ptr, buf, strcspn(buf, "\r\n"));
                         break;
                     }
             }
         }

         buf += strcspn(buf, "\n");
         buf += !!*buf;

     }
     return buf;
 }
 
 static int ass_split(ASSSplitContext *ctx, const char *buf)
 {
     char c, section[16];
     int i;
 
     if (ctx->current_section >= 0)
         buf = ass_split_section(ctx, buf);
 
     while (buf && *buf) {
         if (sscanf(buf, "[%15[0-9A-Za-z+ ]]%c", section, &c) == 2) {

             buf += strcspn(buf, "\n");
             buf += !!*buf;

             for (i=0; i<FF_ARRAY_ELEMS(ass_sections); i++)
                 if (!strcmp(section, ass_sections[i].section)) {
                     ctx->current_section = i;
                     buf = ass_split_section(ctx, buf);
                 }

         } else {
             buf += strcspn(buf, "\n");
             buf += !!*buf;
         }

     }
     return buf ? 0 : AVERROR_INVALIDDATA;
 }
 
 ASSSplitContext *ff_ass_split(const char *buf)
 {
     ASSSplitContext *ctx = av_mallocz(sizeof(*ctx));
     ctx->current_section = -1;
     if (ass_split(ctx, buf) < 0) {
         ff_ass_split_free(ctx);
         return NULL;
     }
     return ctx;
 }
 
 static void free_section(ASSSplitContext *ctx, const ASSSection *section)
 {
     uint8_t *ptr = (uint8_t *)&ctx->ass + section->offset;
     int i, j, *count, c = 1;
 
     if (section->format_header) {
         ptr   = *(void **)ptr;
         count = (int *)((uint8_t *)&ctx->ass + section->offset_count);
     } else
         count = &c;
 
     if (ptr)
         for (i=0; i<*count; i++, ptr += section->size)
             for (j=0; section->fields[j].name; j++) {
                 const ASSFields *field = &section->fields[j];
                 if (field->type == ASS_STR)
                     av_freep(ptr + field->offset);
             }
     *count = 0;
 
     if (section->format_header)
         av_freep((uint8_t *)&ctx->ass + section->offset);
 }
 
 ASSDialog *ff_ass_split_dialog(ASSSplitContext *ctx, const char *buf,
                                int cache, int *number)
 {
     ASSDialog *dialog = NULL;
     int i, count;
     if (!cache)
         for (i=0; i<FF_ARRAY_ELEMS(ass_sections); i++)
             if (!strcmp(ass_sections[i].section, "Events")) {
                 free_section(ctx, &ass_sections[i]);
                 break;
             }
     count = ctx->ass.dialogs_count;
     if (ass_split(ctx, buf) == 0)
         dialog = ctx->ass.dialogs + count;
     if (number)
         *number = ctx->ass.dialogs_count - count;
     return dialog;
 }
 
 void ff_ass_split_free(ASSSplitContext *ctx)
 {
     if (ctx) {
         int i;

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

             free_section(ctx, &ass_sections[i]);

             av_freep(&(ctx->field_order[i]));
         }

         av_free(ctx);
     }
 }
 
 
 int ff_ass_split_override_codes(const ASSCodesCallbacks *callbacks, void *priv,
                                 const char *buf)
 {
     const char *text = NULL;
     char new_line[2];
     int text_len = 0;
 

     while (buf && *buf) {

         if (text && callbacks->text &&
             (sscanf(buf, "\\%1[nN]", new_line) == 1 ||
              !strncmp(buf, "{\\", 2))) {
             callbacks->text(priv, text, text_len);
             text = NULL;
         }
         if (sscanf(buf, "\\%1[nN]", new_line) == 1) {
             if (callbacks->new_line)
                 callbacks->new_line(priv, new_line[0] == 'N');
             buf += 2;
         } else if (!strncmp(buf, "{\\", 2)) {
             buf++;
             while (*buf == '\\') {
                 char style[2], c[2], sep[2], c_num[2] = "0", tmp[128] = {0};
                 unsigned int color = 0xFFFFFFFF;
                 int len, size = -1, an = -1, alpha = -1;
                 int x1, y1, x2, y2, t1 = -1, t2 = -1;
                 if (sscanf(buf, "\\%1[bisu]%1[01\\}]%n", style, c, &len) > 1) {
                     int close = c[0] == '0' ? 1 : c[0] == '1' ? 0 : -1;
                     len += close != -1;
                     if (callbacks->style)
                         callbacks->style(priv, style[0], close);
                 } else if (sscanf(buf, "\\c%1[\\}]%n", sep, &len) > 0 ||
                            sscanf(buf, "\\c&H%X&%1[\\}]%n", &color, sep, &len) > 1 ||
                            sscanf(buf, "\\%1[1234]c%1[\\}]%n", c_num, sep, &len) > 1 ||
                            sscanf(buf, "\\%1[1234]c&H%X&%1[\\}]%n", c_num, &color, sep, &len) > 2) {
                     if (callbacks->color)
                         callbacks->color(priv, color, c_num[0] - '0');
                 } else if (sscanf(buf, "\\alpha%1[\\}]%n", sep, &len) > 0 ||
                            sscanf(buf, "\\alpha&H%2X&%1[\\}]%n", &alpha, sep, &len) > 1 ||
                            sscanf(buf, "\\%1[1234]a%1[\\}]%n", c_num, sep, &len) > 1 ||
                            sscanf(buf, "\\%1[1234]a&H%2X&%1[\\}]%n", c_num, &alpha, sep, &len) > 2) {
                     if (callbacks->alpha)
                         callbacks->alpha(priv, alpha, c_num[0] - '0');
                 } else if (sscanf(buf, "\\fn%1[\\}]%n", sep, &len) > 0 ||
                            sscanf(buf, "\\fn%127[^\\}]%1[\\}]%n", tmp, sep, &len) > 1) {
                     if (callbacks->font_name)
                         callbacks->font_name(priv, tmp[0] ? tmp : NULL);
                 } else if (sscanf(buf, "\\fs%1[\\}]%n", sep, &len) > 0 ||
                            sscanf(buf, "\\fs%u%1[\\}]%n", &size, sep, &len) > 1) {
                     if (callbacks->font_size)
                         callbacks->font_size(priv, size);
                 } else if (sscanf(buf, "\\a%1[\\}]%n", sep, &len) > 0 ||
                            sscanf(buf, "\\a%2u%1[\\}]%n", &an, sep, &len) > 1 ||
                            sscanf(buf, "\\an%1[\\}]%n", sep, &len) > 0 ||
                            sscanf(buf, "\\an%1u%1[\\}]%n", &an, sep, &len) > 1) {
                     if (an != -1 && buf[2] != 'n')
                         an = (an&3) + (an&4 ? 6 : an&8 ? 3 : 0);
                     if (callbacks->alignment)
                         callbacks->alignment(priv, an);
                 } else if (sscanf(buf, "\\r%1[\\}]%n", sep, &len) > 0 ||
                            sscanf(buf, "\\r%127[^\\}]%1[\\}]%n", tmp, sep, &len) > 1) {
                     if (callbacks->cancel_overrides)
                         callbacks->cancel_overrides(priv, tmp);
                 } else if (sscanf(buf, "\\move(%d,%d,%d,%d)%1[\\}]%n", &x1, &y1, &x2, &y2, sep, &len) > 4 ||
                            sscanf(buf, "\\move(%d,%d,%d,%d,%d,%d)%1[\\}]%n", &x1, &y1, &x2, &y2, &t1, &t2, sep, &len) > 6) {
                     if (callbacks->move)
                         callbacks->move(priv, x1, y1, x2, y2, t1, t2);
                 } else if (sscanf(buf, "\\pos(%d,%d)%1[\\}]%n", &x1, &y1, sep, &len) > 2) {
                     if (callbacks->move)
                         callbacks->move(priv, x1, y1, x1, y1, -1, -1);
                 } else if (sscanf(buf, "\\org(%d,%d)%1[\\}]%n", &x1, &y1, sep, &len) > 2) {
                     if (callbacks->origin)
                         callbacks->origin(priv, x1, y1);
                 } else {
                     len = strcspn(buf+1, "\\}") + 2;  /* skip unknown code */
                 }
                 buf += len - 1;
             }
             if (*buf++ != '}')
                 return AVERROR_INVALIDDATA;
         } else {
             if (!text) {
                 text = buf;
                 text_len = 1;
             } else
                 text_len++;
             buf++;
         }
     }
     if (text && callbacks->text)
         callbacks->text(priv, text, text_len);
     if (callbacks->end)
         callbacks->end(priv);
     return 0;
 }
 

 ASSStyle *ff_ass_style_get(ASSSplitContext *ctx, const char *style)

 {
     ASS *ass = &ctx->ass;
     int i;
 
     if (!style || !*style)
         style = "Default";
     for (i=0; i<ass->styles_count; i++)
         if (!strcmp(ass->styles[i].name, style))
             return ass->styles + i;
     return NULL;
 }