// Copyright 2012 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gitiles;

import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.base.Function;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import javax.servlet.http.HttpServletRequest;

/** Interface for URLs displayed on source browsing pages. */
public interface GitilesUrls {
  /**
   * Escapes repository or path names to be safely embedded into a URL.
   * <p>
   * This escape implementation escapes a repository or path name such as
   * "foo/bar&lt;/child" to appear as "foo/bar%3C/child". Spaces are escaped as
   * "%20". Its purpose is to escape a repository name to be safe for inclusion
   * in the path component of the URL, where "/" is a valid character that
   * should not be encoded, while almost any other non-alpha, non-numeric
   * character will be encoded using URL style encoding.
   */
  public static final Function<String, String> NAME_ESCAPER =
      new Function<String, String>() {
        @Override
        public String apply(String s) {
          try {
            return URLEncoder.encode(s, UTF_8.name())
                .replace("%2F", "/")
                .replace("%2f", "/")
                .replace("+", "%20")
                .replace("%2B", "+")
                .replace("%2b", "+");
          } catch (UnsupportedEncodingException e) {
            throw new IllegalStateException(e);
          }
        }
      };

  /**
   * Return the name of the host from the request.
   *
   * Used in various user-visible text, like "MyHost Git Repositories".
   *
   * @param req request.
   * @return host name; may be null.
   */
  public String getHostName(HttpServletRequest req);

  /**
   * Return the base URL for git repositories on this host.
   *
   * @param req request.
   * @return base URL for git repositories.
   */
  public String getBaseGitUrl(HttpServletRequest req);

  /**
   * Return the base URL for Gerrit projects on this host.
   *
   * @param req request.
   * @return base URL for Gerrit Code Review, or null if Gerrit is not
   *     configured.
   */
  public String getBaseGerritUrl(HttpServletRequest req);
}