/*

 * Copyright (C) 2010 Collabora Ltd.

 *

 * This library 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.

 *

 * This library 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 this library; if not, write to the Free Software

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

 *

 * Authors: Xavier Claessens <xclaesse@gmail.com>

 */

#include "config.h"

#include "tpaw-string-parser.h"

#include <string.h>

#include "tpaw-utils.h"

#define SCHEMES           "([a-zA-Z\\+]+)"

#define INVALID_CHARS     "\\s\"<>"

#define INVALID_CHARS_EXT INVALID_CHARS "\\[\\](){},;:"

#define INVALID_CHARS_FULL INVALID_CHARS_EXT "?'"

#define BODY              "([^"INVALID_CHARS_FULL"])([^"INVALID_CHARS_EXT"]*)"

#define BODY_END          "([^"INVALID_CHARS"]*)[^"INVALID_CHARS_FULL".]"

#define URI_REGEX         "("SCHEMES"://"BODY_END")" \

                          "|((www|ftp)\\."BODY_END")" \

                          "|((mailto:)?"BODY"@"BODY"\\."BODY_END")"

static GRegex *

uri_regex_dup_singleton (void)

{

  static GRegex *uri_regex = NULL;

  /* We intentionally leak the regex so it's not recomputed */

  if (!uri_regex)

    {

      GError *error = NULL;

      uri_regex = g_regex_new (URI_REGEX, 0, 0, &error);

      if (uri_regex == NULL)

        {

          g_warning ("Failed to create reg exp: %s", error->message);

          g_error_free (error);

          return NULL;

        }

    }

  return g_regex_ref (uri_regex);

}

void

tpaw_string_parser_substr (const gchar *text,

    gssize len,

    TpawStringParser *parsers,

    gpointer user_data)

{

  if (parsers != NULL && parsers[0].match_func != NULL)

    {

      parsers[0].match_func (text, len,

          parsers[0].replace_func, parsers + 1,

          user_data);

    }

}

void

tpaw_string_match_link (const gchar *text,

    gssize len,

    TpawStringReplace replace_func,

    TpawStringParser *sub_parsers,

    gpointer user_data)

{

  GRegex *uri_regex;

  GMatchInfo *match_info;

  gboolean match;

  gint last = 0;

  uri_regex = uri_regex_dup_singleton ();

  if (uri_regex == NULL)

    {

      tpaw_string_parser_substr (text, len, sub_parsers, user_data);

      return;

    }

  match = g_regex_match_full (uri_regex, text, len, 0, 0, &match_info, NULL);

  if (match)

    {

      gint s = 0, e = 0;

      do

        {

          g_match_info_fetch_pos (match_info, 0, &s, &e);

          if (s > last)

            {

              /* Append the text between last link (or the

               * start of the message) and this link */

              tpaw_string_parser_substr (text + last,

                  s - last,

                  sub_parsers,

                  user_data);

            }

          replace_func (text + s, e - s, NULL, user_data);

          last = e;

        } while (g_match_info_next (match_info, NULL));

    }

  tpaw_string_parser_substr (text + last, len - last, sub_parsers, user_data);

  g_match_info_free (match_info);

  g_regex_unref (uri_regex);

}

void

tpaw_string_match_all (const gchar *text,

    gssize len,

    TpawStringReplace replace_func,

    TpawStringParser *sub_parsers,

    gpointer user_data)

{

  replace_func (text, len, NULL, user_data);

}

void

tpaw_string_replace_link (const gchar *text,

    gssize len,

    gpointer match_data,

    gpointer user_data)

{

  GString *string = user_data;

  gchar *real_url;

  gchar *title;

  gchar *markup;

  real_url = tpaw_make_absolute_url_len (text, len);

  /* Need to copy manually, because g_markup_printf_escaped does not work

   * with string precision pitfalls. */

  title = g_strndup (text, len);

  /* Append the link inside  tag */

  markup = g_markup_printf_escaped ("%s", real_url, title);

  g_string_append (string, markup);

  g_free (real_url);

  g_free (title);

  g_free (markup);

}

void

tpaw_string_replace_escaped (const gchar *text,

    gssize len,

    gpointer match_data,

    gpointer user_data)

{

  GString *string = user_data;

  gchar *escaped;

  guint i;

  gsize escaped_len, old_len;

  escaped = g_markup_escape_text (text, len);

  escaped_len = strlen (escaped);

  /* Allocate more space to string (we really need a g_string_extend...) */

  old_len = string->len;

  g_string_set_size (string, old_len + escaped_len);

  g_string_truncate (string, old_len);

  /* Remove '\r' */

  for (i = 0; i < escaped_len; i++)

    {

      if (escaped[i] != '\r')

        g_string_append_c (string, escaped[i]);

    }

  g_free (escaped);

}

gchar *

tpaw_add_link_markup (const gchar *text)

{

  TpawStringParser parsers[] = {

        {tpaw_string_match_link, tpaw_string_replace_link},

        {tpaw_string_match_all, tpaw_string_replace_escaped},

        {NULL, NULL}};

  GString *string;

  g_return_val_if_fail (text != NULL, NULL);

  string = g_string_sized_new (strlen (text));

  tpaw_string_parser_substr (text, -1, parsers, string);

  return g_string_free (string, FALSE);

}