/**
 * Copyright 2011 Google Inc.
 *
 *  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 org.waveprotocol.box.server.robots.operations;

import com.google.wave.api.ParticipantProfile;

import org.apache.commons.codec.digest.DigestUtils;
import org.waveprotocol.box.server.robots.operations.FetchProfilesService.ProfilesFetcher;

/**
 * A {@link ProfilesFetcher} implementation that assigns a Gravatar identicon
 * image URL for the user avatar. Users can change the avatar image by going to
 * gravatar.com and adding their wave address to the main profile. It is
 * impossible to create a main profile with wave address since gravatar requires
 * email address verification.
 * 
 * @author yurize@apache.org (Yuri Zelikov)
 */
public class GravatarProfilesFetcher implements ProfilesFetcher {

  private static final String GRAVATAR_URL = "http://www.gravatar.com/avatar/";

  public static GravatarProfilesFetcher create() {
    return new GravatarProfilesFetcher();
  }

  private GravatarProfilesFetcher() {

  }

  /**
   * Returns the Gravatar identicon URL for the given email address.
   */
  public String getImageUrl(String email) {
    // Hexadecimal MD5 hash of the requested user's lowercased email address
    // with all whitespace trimmed.
    String emailHash = DigestUtils.md5Hex(email.toLowerCase().trim());
    return GRAVATAR_URL + emailHash + ".jpg?s=100&d=identicon";
  }

  @Override
  public ParticipantProfile fetchProfile(String email) {
    ParticipantProfile pTemp = null;
    pTemp = ProfilesFetcher.SIMPLE_PROFILES_FETCHER.fetchProfile(email);
    ParticipantProfile profile =
        new ParticipantProfile(email, pTemp.getName(), getImageUrl(email), pTemp.getProfileUrl());
    return profile;
  }
}