/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * 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 jetbrains.buildServer.buildTriggers.url;

import org.apache.commons.io.FileUtils;
import org.jetbrains.annotations.NotNull;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;

/**
 * User: Victory.Bedrosova
 * Date: 9/28/12
 * Time: 5:29 PM
 */
final class FileResourceHashProvider implements ResourceHashProvider {

  @NotNull
  public String getResourceHash(@NotNull TriggerParameters triggerParameters) throws ResourceHashProviderException {
    try {
      return getResourceHash(triggerParameters.getURL());
    } catch (Throwable e) {
      throw new ResourceHashProviderException("URL " + triggerParameters.getURL() + ": " + e.getMessage(), e);
    }
  }

  @NotNull
  String getResourceHash(@NotNull String url) throws MalformedURLException {
    final File file = getFile(url);
    return file.exists() ? getExistingFileHash(file) : UrlBuildTriggerUtil.UNEXITING_RESOURCE_HASH;
  }

  @NotNull
  private File getFile(@NotNull String urlStr) throws MalformedURLException {
    final URL url = new URL(urlStr);
    try {
      return new File(url.toURI());
    } catch(URISyntaxException e) {
      return new File(url.getPath());
    }
  }

  @NotNull
  private String getExistingFileHash(@NotNull File file) {
    return UrlBuildTriggerUtil.getResourceHash(file.lastModified(), FileUtils.sizeOf(file));
  }
}