/*

 * Copyright (c) 2013 Tim Ruehsen

 * Copyright (c) 2015-2024 Free Software Foundation, Inc.

 *

 * This file is part of libwget.

 *

 * Libwget 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 3 of the License, or

 * (at your option) any later version.

 *

 * Libwget 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 libwget.  If not, see <https://www.gnu.org/licenses/>.

 *

 *

 * Higher level CSS parsing routines

 *

 * Changelog

 * 15.01.2013  Tim Ruehsen  created

 *

 */

#include <config.h>

#include <unistd.h>

#include <stdlib.h>

#include <string.h>

#include <assert.h>

#include <wget.h>

#include "private.h"

typedef struct {

  const char

    **encoding;

  wget_vector

    *uris;

} css_context;

static void url_free(void *url)

{

  wget_css_parsed_url *u = url;

  xfree(u->url);

  xfree(u->abs_url);

  xfree(u);

}

// Callback function, called from CSS parser for each @charset found.

static void get_encoding(void *context, const char *encoding, size_t len)

{

  css_context *ctx = context;

  // take only the first @charset rule

  if (!*ctx->encoding) {

    *ctx->encoding = wget_strmemdup(encoding, len);

    debug_printf("URI content encoding = '%s'\n", *ctx->encoding);

  }

}

// Callback function, called from CSS parser for each URI found.

static void get_url(void *context, const char *url, size_t len, size_t pos)

{

  css_context *ctx = context;

  wget_css_parsed_url *parsed_url;

  if (!(parsed_url = wget_calloc(1, sizeof(wget_css_parsed_url))))

    return;

  if (!(parsed_url->url = wget_strmemdup(url, len))) {

    xfree(parsed_url);

    return;

  }

  parsed_url->len = len;

  parsed_url->pos = pos;

  if (!ctx->uris) {

    ctx->uris = wget_vector_create(16, NULL);

    wget_vector_set_destructor(ctx->uris, url_free);

  }

  wget_vector_add(ctx->uris, parsed_url);

}

static void urls_to_absolute(wget_vector *urls, wget_iri *base)

{

  if (base && urls) {

    wget_buffer buf;

    wget_buffer_init(&buf, NULL, 1024);

    for (int it = 0; it < wget_vector_size(urls); it++) {

      wget_css_parsed_url *url = wget_vector_get(urls, it);

      assert(url != NULL);

      if (wget_iri_relative_to_abs(base, url->url, url->len, &buf))

        url->abs_url = wget_strmemdup(buf.data, buf.length);

      else

        error_printf(_("Cannot resolve relative URI '%s'\n"), url->url);

    }

    wget_buffer_deinit(&buf);

  }

}

wget_vector *wget_css_get_urls(const char *css, size_t len, wget_iri *base, const char **encoding)

{

  css_context context = { .encoding = encoding };

  wget_css_parse_buffer(css, len, get_url, encoding ? get_encoding : NULL, &context);

  urls_to_absolute(context.uris, base);

  return context.uris;

}

wget_vector *wget_css_get_urls_from_localfile(const char *fname, wget_iri *base, const char **encoding)

{

  css_context context = { .encoding = encoding };

  wget_css_parse_file(fname, get_url, encoding ? get_encoding : NULL, &context);

  urls_to_absolute(context.uris, base);

  return context.uris;

}