// Copyright (C) 2004-2024 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 "svg-imp.h"

typedef struct

{

  fz_page super;

  svg_document *doc;

} svg_page;

static void

svg_drop_document(fz_context *ctx, fz_document *doc_)

{

  svg_document *doc = (svg_document*)doc_;

  fz_drop_tree(ctx, doc->idmap, NULL);

  fz_drop_xml(ctx, doc->xml);

}

static int

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

{

  return 1;

}

static fz_rect

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

{

  svg_page *page = (svg_page*)page_;

  svg_document *doc = page->doc;

  svg_parse_document_bounds(ctx, doc, doc->root);

  return fz_make_rect(0, 0, doc->width, doc->height);

}

static void

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

{

  svg_page *page = (svg_page*)page_;

  svg_document *doc = page->doc;

  svg_run_document(ctx, doc, doc->root, dev, ctm);

}

static void

svg_drop_page(fz_context *ctx, fz_page *page_)

{

  /* nothing */

}

static fz_page *

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

{

  svg_document *doc = (svg_document*)doc_;

  svg_page *page;

  if (number != 0)

    fz_throw(ctx, FZ_ERROR_ARGUMENT, "cannot find page %d", number);

  page = fz_new_derived_page(ctx, svg_page, doc_);

  page->super.bound_page = svg_bound_page;

  page->super.run_page_contents = svg_run_page;

  page->super.drop_page = svg_drop_page;

  page->doc = doc;

  return (fz_page*)page;

}

static void

svg_build_id_map(fz_context *ctx, svg_document *doc, fz_xml *root)

{

  fz_xml *node;

  char *id_att = fz_xml_att(root, "id");

  if (id_att)

    doc->idmap = fz_tree_insert(ctx, doc->idmap, id_att, root);

  for (node = fz_xml_down(root); node; node = fz_xml_next(node))

    svg_build_id_map(ctx, doc, node);

}

static int

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

{

  if (!strcmp(key, FZ_META_FORMAT))

    return 1 + (int)fz_strlcpy(buf, "SVG", size);

  return -1;

}

static fz_document *

svg_open_document_with_xml(fz_context *ctx, fz_xml_doc *xmldoc, fz_xml *xml, const char *base_uri, fz_archive *zip)

{

  svg_document *doc;

  doc = fz_new_derived_document(ctx, svg_document);

  doc->super.drop_document = svg_drop_document;

  doc->super.count_pages = svg_count_pages;

  doc->super.load_page = svg_load_page;

  doc->super.lookup_metadata = svg_lookup_metadata;

  doc->idmap = NULL;

  if (base_uri)

    fz_strlcpy(doc->base_uri, base_uri, sizeof doc->base_uri);

  doc->xml = NULL;

  doc->root = xml;

  doc->zip = zip;

  fz_try(ctx)

  {

    if (xmldoc)

      svg_build_id_map(ctx, doc, fz_xml_root(xmldoc));

    else

      svg_build_id_map(ctx, doc, doc->root);

  }

  fz_catch(ctx)

  {

    fz_drop_document(ctx, &doc->super);

    fz_rethrow(ctx);

  }

  return (fz_document*)doc;

}

static fz_document *

svg_open_document_with_buffer(fz_context *ctx, fz_buffer *buf, const char *base_uri, fz_archive *zip)

{

  svg_document *doc;

  doc = fz_new_derived_document(ctx, svg_document);

  doc->super.drop_document = svg_drop_document;

  doc->super.count_pages = svg_count_pages;

  doc->super.load_page = svg_load_page;

  doc->super.lookup_metadata = svg_lookup_metadata;

  doc->idmap = NULL;

  if (base_uri)

    fz_strlcpy(doc->base_uri, base_uri, sizeof doc->base_uri);

  doc->zip = zip;

  fz_try(ctx)

  {

    doc->xml = fz_parse_xml(ctx, buf, 0);

    doc->root = fz_xml_root(doc->xml);

    svg_build_id_map(ctx, doc, doc->root);

  }

  fz_catch(ctx)

  {

    fz_drop_document(ctx, &doc->super);

    fz_rethrow(ctx);

  }

  return (fz_document*)doc;

}

static fz_document *

svg_open_document(fz_context *ctx, const fz_document_handler *handler, fz_stream *file, fz_stream *accel, fz_archive *zip, void *state)

{

  fz_buffer *buf = fz_read_all(ctx, file, 0);

  fz_document *doc = NULL;

  fz_try(ctx)

    doc = svg_open_document_with_buffer(ctx, buf, NULL, NULL);

  fz_always(ctx)

    fz_drop_buffer(ctx, buf);

  fz_catch(ctx)

    fz_rethrow(ctx);

  return doc;

}

fz_display_list *

fz_new_display_list_from_svg(fz_context *ctx, fz_buffer *buf, const char *base_uri, fz_archive *zip, float *w, float *h)

{

  fz_document *doc;

  fz_display_list *list = NULL;

  doc = svg_open_document_with_buffer(ctx, buf, base_uri, zip);

  fz_try(ctx)

  {

    list = fz_new_display_list_from_page_number(ctx, doc, 0);

    *w = ((svg_document*)doc)->width;

    *h = ((svg_document*)doc)->height;

  }

  fz_always(ctx)

    fz_drop_document(ctx, doc);

  fz_catch(ctx)

    fz_rethrow(ctx);

  return list;

}

fz_display_list *

fz_new_display_list_from_svg_xml(fz_context *ctx, fz_xml_doc *xmldoc, fz_xml *xml, const char *base_uri, fz_archive *zip, float *w, float *h)

{

  fz_document *doc;

  fz_display_list *list = NULL;

  doc = svg_open_document_with_xml(ctx, xmldoc, xml, base_uri, zip);

  fz_try(ctx)

  {

    list = fz_new_display_list_from_page_number(ctx, doc, 0);

    *w = ((svg_document*)doc)->width;

    *h = ((svg_document*)doc)->height;

  }

  fz_always(ctx)

    fz_drop_document(ctx, doc);

  fz_catch(ctx)

    fz_rethrow(ctx);

  return list;

}

fz_image *

fz_new_image_from_svg(fz_context *ctx, fz_buffer *buf, const char *base_uri, fz_archive *zip)

{

  fz_display_list *list;

  fz_image *image = NULL;

  float w, h;

  list = fz_new_display_list_from_svg(ctx, buf, base_uri, zip, &w, &h);

  fz_try(ctx)

    image = fz_new_image_from_display_list(ctx, w, h, list);

  fz_always(ctx)

    fz_drop_display_list(ctx, list);

  fz_catch(ctx)

    fz_rethrow(ctx);

  return image;

}

fz_image *

fz_new_image_from_svg_xml(fz_context *ctx, fz_xml_doc *xmldoc, fz_xml *xml, const char *base_uri, fz_archive *zip)

{

  fz_display_list *list;

  fz_image *image = NULL;

  float w, h;

  list = fz_new_display_list_from_svg_xml(ctx, xmldoc, xml, base_uri, zip, &w, &h);

  fz_try(ctx)

    image = fz_new_image_from_display_list(ctx, w, h, list);

  fz_always(ctx)

    fz_drop_display_list(ctx, list);

  fz_catch(ctx)

    fz_rethrow(ctx);

  return image;

}

static const char *svg_extensions[] =

{

  "svg",

  NULL

};

static const char *svg_mimetypes[] =

{

  "image/svg+xml",

  NULL

};

static int

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

{

  // A standalone SVG document is an XML document with an <svg> root element.

  //

  // Assume the document is ASCII or UTF-8.

  //

  // Parse the start of the file using a simplified XML parser, skipping

  // processing instructions and comments, and stopping at the first

  // element.

  //

  // Return failure on anything unexpected, or if the first element is not SVG.

  int c;

  if (state)

    *state = NULL;

  if (free_state)

    *free_state = NULL;

  if (stm == NULL)

    return 0;

parse_text:

  // Skip whitespace until "<"

  c = fz_read_byte(ctx, stm);

  while (c == ' ' || c == '\r' || c == '\n' || c == '\t')

    c = fz_read_byte(ctx, stm);

  if (c == '<')

    goto parse_element;

  return 0;

parse_element:

  // Either "<?...>" or "<!...>" or "<svg" or not an SVG document.

  c = fz_read_byte(ctx, stm);

  if (c == '!' || c == '?')

    goto parse_comment;

  if (c != 's')

    return 0;

  c = fz_read_byte(ctx, stm);

  if (c != 'v')

    return 0;

  c = fz_read_byte(ctx, stm);

  if (c != 'g')

    return 0;

  return 100;

parse_comment:

  // Skip everything after "<?" or "<!" until ">"

  c = fz_read_byte(ctx, stm);

  while (c != EOF && c != '>')

    c = fz_read_byte(ctx, stm);

  if (c == '>')

    goto parse_text;

  return 0;

}

fz_document_handler svg_document_handler =

{

  NULL,

  svg_open_document,

  svg_extensions,

  svg_mimetypes,

  svg_recognize_doc_content

};