// Copyright (C) 2004-2026 Artifex Software, Inc.

//

// This file is part of MuPDF.

//

// MuPDF is free software: you can redistribute it and/or modify it under the

// terms of the GNU Affero General Public License as published by the Free

// Software Foundation, either version 3 of the License, or (at your option)

// any later version.

//

// MuPDF 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 Affero General Public License for more

// details.

//

// You should have received a copy of the GNU Affero General Public License

// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>

//

// Alternative licensing terms are available from the licensor.

// For commercial licensing, see <https://www.artifex.com/> or contact

// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,

// CA 94129, USA, for further information.

#include "mupdf/fitz.h"

#include "html-imp.h"

#include <string.h>

#include <math.h>

enum { T, R, B, L };

typedef struct

{

  fz_document super;

  fz_archive *zip;

  fz_html_font_set *set;

  fz_html *html;

  fz_outline *outline;

  const fz_htdoc_format_t *format;

} html_document;

typedef struct

{

  fz_page super;

  html_document *doc;

  int number;

} html_page;

static void

htdoc_drop_document(fz_context *ctx, fz_document *doc_)

{

  html_document *doc = (html_document*)doc_;

  fz_drop_archive(ctx, doc->zip);

  fz_drop_html(ctx, doc->html);

  fz_drop_html_font_set(ctx, doc->set);

  fz_drop_outline(ctx, doc->outline);

}

static fz_link_dest

htdoc_resolve_link(fz_context *ctx, fz_document *doc_, const char *dest)

{

  html_document *doc = (html_document*)doc_;

  const char *s = strchr(dest, '#');

  if (s && s[1] != 0)

  {

    float y = fz_find_html_target(ctx, doc->html, s+1);

    if (y >= 0)

    {

      int page = y / doc->html->page_h;

      return fz_make_link_dest_xyz(0, page, 0, y - page * doc->html->page_h, 0);

    }

  }

  return fz_make_link_dest_none();

}

static int

htdoc_count_pages(fz_context *ctx, fz_document *doc_, int chapter)

{

  html_document *doc = (html_document*)doc_;

  if (doc->html->tree.root->s.layout.b > 0)

    return ceilf(doc->html->tree.root->s.layout.b / doc->html->page_h);

  return 1;

}

static void

htdoc_update_outline(fz_context *ctx, fz_document *doc, fz_outline *node)

{

  while (node)

  {

    fz_link_dest dest = htdoc_resolve_link(ctx, doc, node->uri);

    node->page = dest.loc;

    node->x = dest.x;

    node->y = dest.y;

    htdoc_update_outline(ctx, doc, node->down);

    node = node->next;

  }

}

static void

htdoc_layout(fz_context *ctx, fz_document *doc_, float w, float h, float em)

{

  html_document *doc = (html_document*)doc_;

  fz_layout_html(ctx, doc->html, w, h, em);

  htdoc_update_outline(ctx, doc_, doc->outline);

}

static void

htdoc_drop_page(fz_context *ctx, fz_page *page_)

{

}

static fz_rect

htdoc_bound_page(fz_context *ctx, fz_page *page_, fz_box_type box)

{

  html_page *page = (html_page*)page_;

  html_document *doc = page->doc;

  fz_rect bbox;

  bbox.x0 = 0;

  bbox.y0 = 0;

  bbox.x1 = doc->html->page_w + doc->html->page_margin[L] + doc->html->page_margin[R];

  bbox.y1 = doc->html->page_h + doc->html->page_margin[T] + doc->html->page_margin[B];

  return bbox;

}

static void

htdoc_run_page(fz_context *ctx, fz_page *page_, fz_device *dev, fz_matrix ctm, fz_cookie *cookie)

{

  html_page *page = (html_page*)page_;

  html_document *doc = page->doc;

  fz_draw_html(ctx, dev, ctm, doc->html, page->number);

}

static fz_link *

htdoc_load_links(fz_context *ctx, fz_page *page_)

{

  html_page *page = (html_page*)page_;

  html_document *doc = page->doc;

  return fz_load_html_links(ctx, doc->html, page->number, "");

}

static fz_bookmark

htdoc_make_bookmark(fz_context *ctx, fz_document *doc_, fz_location loc)

{

  html_document *doc = (html_document*)doc_;

  return fz_make_html_bookmark(ctx, doc->html, loc.page);

}

static fz_location

htdoc_lookup_bookmark(fz_context *ctx, fz_document *doc_, fz_bookmark mark)

{

  html_document *doc = (html_document*)doc_;

  return fz_make_location(0, fz_lookup_html_bookmark(ctx, doc->html, mark));

}

static fz_page *

htdoc_load_page(fz_context *ctx, fz_document *doc_, int chapter, int number)

{

  html_document *doc = (html_document*)doc_;

  html_page *page = fz_new_derived_page(ctx, html_page, doc_);

  page->super.bound_page = htdoc_bound_page;

  page->super.run_page_contents = htdoc_run_page;

  page->super.load_links = htdoc_load_links;

  page->super.drop_page = htdoc_drop_page;

  page->doc = doc;

  page->number = number;

  return (fz_page*)page;

}

static fz_outline *

htdoc_load_outline(fz_context *ctx, fz_document *doc_)

{

  html_document *doc = (html_document*)doc_;

  return fz_keep_outline(ctx, doc->outline);

}

static int

htdoc_lookup_metadata(fz_context *ctx, fz_document *doc_, const char *key, char *buf, size_t size)

{

  html_document *doc = (html_document *)doc_;

  if (!strcmp(key, FZ_META_FORMAT))

    return 1 + (int)fz_strlcpy(buf, doc->format->format_name, size);

  if (!strcmp(key, FZ_META_INFO_TITLE) && doc->html->title)

    return 1 + (int)fz_strlcpy(buf, doc->html->title, size);

  return -1;

}

static fz_html *

generic_parse(fz_context *ctx, fz_html_font_set *set, fz_archive *zip, const char *base_uri, fz_buffer *buffer_in, const char *user_css, const fz_htdoc_format_t *format)

{

  fz_buffer *buffer_html = NULL;

  fz_html *html = NULL;

  fz_var(buffer_html);

  fz_try(ctx)

  {

    if (format->convert_to_html)

      buffer_html = format->convert_to_html(ctx, set, buffer_in, zip, user_css);

    else

      buffer_html = fz_keep_buffer(ctx, buffer_in);

    html = fz_parse_html(ctx, set, zip, base_uri, buffer_html, user_css, format->try_xml, format->try_html5, format->patch_mobi);

  }

  fz_always(ctx)

  {

    fz_drop_buffer(ctx, buffer_html);

  }

  fz_catch(ctx)

  {

    fz_drop_html(ctx, html);

    fz_rethrow(ctx);

  }

  return html;

}

fz_document *

fz_htdoc_open_document_with_buffer(fz_context *ctx, fz_archive *dir, fz_buffer *buf, const fz_htdoc_format_t *format)

{

  html_document *doc = NULL;

  fz_var(doc);

  fz_var(dir);

  fz_try(ctx)

  {

    doc = fz_new_derived_document(ctx, html_document);

    doc->super.drop_document = htdoc_drop_document;

    doc->super.layout = htdoc_layout;

    doc->super.load_outline = htdoc_load_outline;

    doc->super.resolve_link_dest = htdoc_resolve_link;

    doc->super.make_bookmark = htdoc_make_bookmark;

    doc->super.lookup_bookmark = htdoc_lookup_bookmark;

    doc->super.count_pages = htdoc_count_pages;

    doc->super.load_page = htdoc_load_page;

    doc->super.lookup_metadata = htdoc_lookup_metadata;

    doc->super.is_reflowable = 1;

    doc->zip = fz_keep_archive(ctx, dir);

    doc->format = format;

    doc->set = fz_new_html_font_set(ctx);

    doc->html = generic_parse(ctx, doc->set, doc->zip, ".", buf, fz_user_css(ctx), format);

    doc->outline = fz_load_html_outline(ctx, doc->html);

  }

  fz_always(ctx)

    fz_drop_buffer(ctx, buf);

  fz_catch(ctx)

  {

    fz_drop_document(ctx, &doc->super);

    fz_rethrow(ctx);

  }

  return (fz_document*)doc;

}

fz_document *

fz_htdoc_open_document_with_stream_and_dir(fz_context *ctx, fz_stream *stm, fz_archive *dir, const fz_htdoc_format_t *format)

{

  fz_buffer *buf = NULL;

  if (stm)

    buf = fz_read_all(ctx, stm, 0);

  return fz_htdoc_open_document_with_buffer(ctx, dir, buf, format);

}

/* Variant specific functions */

/* Generic HTML document handler */

static int isws(int c)

{

  return c == 32 || c == 9 || c == 10 || c == 13 || c == 12;

}

static int recognize_html_content(fz_context *ctx, const fz_document_handler *handler, fz_stream *stream, fz_archive *dir, void **hstate, fz_document_recognize_state_free_fn **free_state, int xhtml)

{

  uint8_t buffer[4096];

  size_t i, n, m;

  enum {

    state_top,

    state_open,

    state_pling,

    state_query,

    state_maybe_doctype,

    state_maybe_doctype_ws,

    state_maybe_doctype_html,

    state_maybe_doctype_html_xhtml,

    state_maybe_comment,

    state_maybe_html,

    state_maybe_html_xhtml,

    state_comment

  };

  int state = state_top;

  int type = 0;

  if (hstate)

    *hstate = NULL;

  if (free_state)

    *free_state = NULL;

  if (stream == NULL)

    return 0;

  /* Simple state machine. Search for "<!doctype html" or "<html" in the first

   * 4K of the file, allowing for comments and whitespace and case insensitivity. */

  n = fz_read(ctx, stream, buffer, sizeof(buffer));

  fz_seek(ctx, stream, 0, SEEK_SET);

  if (n == 0)

    return 0;

  i = 0;

  if (n >= 3 && buffer[0] == 0xEF && buffer[1] == 0xBB && buffer[2] == 0xBF)

  {

    /* UTF-8 encoded BOM. Just skip it. */

    i = 3;

  }

  else if (n >= 2 && buffer[0] == 0xFE && buffer[1] == 0xFF)

  {

    /* UTF-16, big endian. */

    type = 1;

    i = 2;

    n &= ~1;

  }

  else if (n >= 2 && buffer[0] == 0xFF && buffer[1] == 0xFE)

  {

    /* UTF-16, little endian. */

    i = 2;

    type = 2;

    n &= ~1;

  }

  while (i < n)

  {

    int c;

    switch (type)

    {

    case 0: /* UTF-8 */

      c = buffer[i++];

      break;

    case 1: /* UTF-16 - big endian */

      c = buffer[i++] << 8;

      c |= buffer[i++];

      break;

    case 2: /* UTF-16 - little endian */

      c = buffer[i++];

      c |= buffer[i++] << 8;

      break;

    }

    switch (state)

    {

    case state_top:

      if (isws(c))

        continue; /* whitespace */

      if (c == '<')

        state = state_open;

      else

        return 0; /* Non whitespace found at the top level prior to a known tag. Fail. */

      break;

    case state_open:

      if (isws(c))

        continue; /* whitespace */

      if (c == '!')

        state = state_pling;

      else if (c == '?')

        state = state_query;

      else if (c == 'h' || c == 'H')

        state = state_maybe_html;

      else

        return 0; /* Not an acceptable opening tag. */

      m = 0;

      break;

    case state_query:

      if (c == '>')

        state = state_top;

      break;

    case state_pling:

      if (isws(c))

        continue; /* whitespace */

      else if (c == '-')

        state = state_maybe_comment;

      else if (c == 'd' || c == 'D')

        state = state_maybe_doctype;

      else

        return 0; /* Not an acceptable opening tag. */

      break;

    case state_maybe_comment:

      if (c == '-')

        state = state_comment;

      else

        return 0; /* Not an acceptable opening tag. */

      break;

    case state_comment:

      if (c == '-')

      {

        m++;

      }

      else if (c == '>' && m >= 2)

      {

        state = state_top;

      }

      else

        m = 0;

      break;

    case state_maybe_doctype:

      if (c == "octype"[m] || c == "OCTYPE"[m])

      {

        m++;

        if (m == 6)

        {

          state = state_maybe_doctype_ws;

          m = 0;

        }

      }

      else

        return 0; /* Not an acceptable opening tag. */

      break;

    case state_maybe_doctype_ws:

      if (isws(c))

        m++;

      else if (m > 0 && (c == 'h' || c == 'H'))

      {

        state = state_maybe_doctype_html;

        m = 0;

      }

      else

        return 0; /* Not an acceptable opening tag. */

      break;

    case state_maybe_doctype_html:

      if (c == "tml"[m] || c == "TML"[m])

      {

        m++;

        if (m == 3)

        {

          state = state_maybe_doctype_html_xhtml;

          m = 0;

        }

      }

      else

        return 0; /* Not an acceptable opening tag. */

      break;

    case state_maybe_doctype_html_xhtml:

      if (c == '>')

      {

        /* Not xhtml - the xhtml agent can handle this at a pinch (so 25),

         * but we'd rather the html one did (75). */

        return xhtml ? 25 : 75;

      }

      if (c >= 'A'  && c <= 'Z')

        c += 'a'-'A';

      if (c == "xhtml"[m])

      {

        m++;

        if (m == 5)

        {

          /* xhtml - the xhtml agent would be better (75) than the html

           * agent (25). */

          return xhtml ? 75 : 25;

        }

      }

      else

        m = 0;

      break;

    case state_maybe_html:

      if (c == "tml"[m] || c == "TML"[m])

      {

        m++;

        if (m == 3)

        {

          state = state_maybe_html_xhtml;

          m = 0;

        }

      }

      else

        return 0; /* Not an acceptable opening tag. */

      break;

    case state_maybe_html_xhtml:

      if (c == '>')

      {

        /* Not xhtml - the xhtml agent can handle this at a pinch (so 25),

         * but we'd rather the html one did (75). */

        return xhtml ? 25 : 75;

      }

      if (c >= 'A'  && c <= 'Z')

        c += 'a'-'A';

      if (c == "xhtml"[m])

      {

        m++;

        if (m == 5)

        {

          /* xhtml - the xhtml agent would be better (75) than the html

           * agent (25). */

          return xhtml ? 75 : 25;

        }

      }

      else

        m = 0;

      break;

    }

  }

  return 0;

}

int htdoc_recognize_html_content(fz_context *ctx, const fz_document_handler *handler, fz_stream *stream, fz_archive *dir, void **hstate, fz_document_recognize_state_free_fn **free_state)

{

  return recognize_html_content(ctx, handler, stream, dir, hstate, free_state, 0);

}

static const fz_htdoc_format_t fz_htdoc_html5 =

{

  "HTML5",

  NULL,

  0, 1, 0

};

static fz_document *

htdoc_open_document(fz_context *ctx, const fz_document_handler *handler, fz_stream *file, fz_stream *accel, fz_archive *dir, void *state)

{

  return fz_htdoc_open_document_with_stream_and_dir(ctx, file, dir, &fz_htdoc_html5);

}

static const char *htdoc_extensions[] =

{

  "htm",

  "html",

  NULL

};

static const char *htdoc_mimetypes[] =

{

  "text/html",

  NULL

};

fz_document_handler html_document_handler =

{

  NULL,

  htdoc_open_document,

  htdoc_extensions,

  htdoc_mimetypes,

  htdoc_recognize_html_content,

  1

};

/* XHTML document handler */

static const fz_htdoc_format_t fz_htdoc_xhtml =

{

  "XHTML",

  NULL,

  1, 1, 0

};

static fz_document *

xhtdoc_open_document(fz_context *ctx, const fz_document_handler *handler, fz_stream *file, fz_stream *accel, fz_archive *dir, void *state)

{

  return fz_htdoc_open_document_with_stream_and_dir(ctx, file, dir, &fz_htdoc_xhtml);

}

int xhtdoc_recognize_xhtml_content(fz_context *ctx, const fz_document_handler *handler, fz_stream *stream, fz_archive *dir, void **hstate, fz_document_recognize_state_free_fn **free_state)

{

  return recognize_html_content(ctx, handler, stream, dir, hstate, free_state, 1);

}

static const char *xhtdoc_extensions[] =

{

  "xhtml",

  NULL

};

static const char *xhtdoc_mimetypes[] =

{

  "application/xhtml+xml",

  NULL

};

fz_document_handler xhtml_document_handler =

{

  NULL,

  xhtdoc_open_document,

  xhtdoc_extensions,

  xhtdoc_mimetypes,

  xhtdoc_recognize_xhtml_content,

  1

};

/* FB2 document handler */

static const fz_htdoc_format_t fz_htdoc_fb2 =

{

  "FictionBook2",

  NULL,

  1, 0, 0

};

static fz_document *

fb2doc_open_document(fz_context *ctx, const fz_document_handler *handler, fz_stream *file, fz_stream *accel, fz_archive *dir, void *state)

{

  return fz_htdoc_open_document_with_stream_and_dir(ctx, file, dir, &fz_htdoc_fb2);

}

static int

fb2doc_recognize_content(fz_context *ctx, const fz_document_handler *handler, fz_stream *stream, fz_archive *dir, void **state, fz_document_recognize_state_free_fn **free_state)

{

  const char *match = "<FictionBook";

  int pos = 0;

  int n = 4096;

  int c;

  if (state)

    *state = NULL;

  if (free_state)

    *free_state = NULL;

  if (stream == NULL)

    return 0;

  do

  {

    c = fz_read_byte(ctx, stream);

    if (c == EOF)

      return 0;

    if (c == match[pos])

    {

      pos++;

      if (pos == 12)

        return 100;

    }

    else

    {

      /* Restart matching, but recheck c against the start. */

      pos = (c == match[0]);

    }

  }

  while (--n > 0);

  return 0;

}

static const char *fb2doc_extensions[] =

{

  "fb2",

  "xml",

  NULL

};

static const char *fb2doc_mimetypes[] =

{

  "application/x-fictionbook",

  "application/xml",

  "text/xml",

  NULL

};

fz_document_handler fb2_document_handler =

{

  NULL,

  fb2doc_open_document,

  fb2doc_extensions,

  fb2doc_mimetypes,

  fb2doc_recognize_content

};

/* Mobi document handler */

static const fz_htdoc_format_t fz_htdoc_mobi =

{

  "MOBI",

  NULL,

  1, 1, 1

};

static fz_document *

mobi_open_document_with_buffer(fz_context *ctx, fz_buffer *mobi)

{

  fz_archive *dir = NULL;

  fz_buffer *html;

  fz_document *doc;

  fz_var(dir);

  fz_try(ctx)

  {

    dir = fz_extract_html_from_mobi(ctx, mobi);

    html = fz_read_archive_entry(ctx, dir, "index.html");

    doc = fz_htdoc_open_document_with_buffer(ctx, dir, html, &fz_htdoc_mobi);

  }

  fz_always(ctx)

  {

    fz_drop_buffer(ctx, mobi);

    fz_drop_archive(ctx, dir);

  }

  fz_catch(ctx)

  {

    fz_rethrow(ctx);

  }

  return doc;

}

static int

mobi_recognize_content(fz_context *ctx, const fz_document_handler *handler, fz_stream *stream, fz_archive *dir, void **state, fz_document_recognize_state_free_fn **free_state)

{

  char text[8];

  if (state)

    *state = NULL;

  if (free_state)

    *free_state = NULL;

  if (stream == NULL)

    return 0;

  fz_seek(ctx, stream, 32 + 28, SEEK_SET);

  if (fz_read(ctx, stream, (unsigned char *)text, 8) != 8)

    return 0;

  if (memcmp(text, "BOOKMOBI", 8) == 0)

    return 100;

  if (memcmp(text, "TEXtREAd", 8) == 0)

    return 100;

  return 0;

}

static fz_document *

mobi_open_document(fz_context *ctx, const fz_document_handler *handler, fz_stream *file, fz_stream *accel, fz_archive *dir, void *state)

{

  return mobi_open_document_with_buffer(ctx, fz_read_all(ctx, file, 0));

}

static const char *mobi_extensions[] =

{

  "mobi",

  "prc",

  "pdb",

  NULL

};

static const char *mobi_mimetypes[] =

{

  "application/x-mobipocket-ebook",

  NULL

};

fz_document_handler mobi_document_handler =

{

  NULL,

  mobi_open_document,

  mobi_extensions,

  mobi_mimetypes,

  mobi_recognize_content

};