/*
    * Copyright (C) 2012 Atlassian
    *
    * 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.atlassian.jira.rest.client.internal.async;
  
  import com.atlassian.event.api.EventPublisher;
  import com.atlassian.httpclient.apache.httpcomponents.DefaultHttpClient;
  import com.atlassian.httpclient.api.HttpClient;
  import com.atlassian.httpclient.api.Request;
  import com.atlassian.httpclient.api.factory.HttpClientOptions;
  import com.atlassian.httpclient.spi.ThreadLocalContextManagers;
  import com.atlassian.jira.rest.client.api.AuthenticationHandler;
  import com.atlassian.sal.api.ApplicationProperties;
  import com.atlassian.util.concurrent.Effect;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URI;
  import java.util.Date;
  import java.util.Properties;
  
  /**
   * Factory for asynchronous http clients.
   *
   * @since v2.0
   */
  public class AsynchronousHttpClientFactory {
  
  	@SuppressWarnings("unchecked")
  	public DisposableHttpClient createClient(final URI serverUri, final AuthenticationHandler authenticationHandler) {
  		final HttpClientOptions options = new HttpClientOptions();
  		options.setRequestPreparer(new Effect<Request>() {
  			@Override
  			public void apply(final Request request) {
  				authenticationHandler.configure(request);
  			}
  		});
  		final DefaultHttpClient defaultHttpClient = new DefaultHttpClient(new NoOpEventPublisher(),
  				new RestClientApplicationProperties(serverUri),
  				ThreadLocalContextManagers.noop(), options);
  		return new AtlassianHttpClientDecorator(defaultHttpClient) {
  
  			@Override
  			public void destroy() throws Exception {
  				defaultHttpClient.destroy();
  			}
  		};
  	}
  
  	public DisposableHttpClient createClient(final HttpClient client) {
  		return new AtlassianHttpClientDecorator(client) {
  
  			@Override
  			public void destroy() throws Exception {
  				// This should never be implemented. This is simply creation of a wrapper
  				// for AtlassianHttpClient which is extended by a destroy method.
  				// Destroy method should never be called for AtlassianHttpClient coming from
  				// a client! Imagine you create a RestClient, pass your own HttpClient there
  				// and it gets destroy.
  			}
  		};
  	}
  
  	private static class NoOpEventPublisher implements EventPublisher {
  		@Override
  		public void publish(Object o) {
  		}
  
  		@Override
  		public void register(Object o) {
  		}
  
  		@Override
  		public void unregister(Object o) {
  		}
  
  		@Override
  		public void unregisterAll() {
  		}
  	}
  
  	/**
  	 * These properties are used to present JRJC as a User-Agent during http requests.
  	 */
 	@SuppressWarnings("deprecation")
 	private static class RestClientApplicationProperties implements ApplicationProperties {
 
 		private final String baseUrl;
 
 		private RestClientApplicationProperties(URI jiraURI) {
 			this.baseUrl = jiraURI.getPath();
 		}
 
 		@Override
 		public String getBaseUrl() {
 			return baseUrl;
 		}
 
 		@Override
 		public String getDisplayName() {
 			return "Atlassian JIRA Rest Java Client";
 		}
 
 		@Override
 		public String getVersion() {
 			return MavenUtils.getVersion("com.atlassian.jira", "jira-rest-java-com.atlassian.jira.rest.client");
 		}
 
 		@Override
 		public Date getBuildDate() {
 			// TODO implement using MavenUtils, JRJC-123
 			throw new UnsupportedOperationException();
 		}
 
 		@Override
 		public String getBuildNumber() {
 			// TODO implement using MavenUtils, JRJC-123
 			return String.valueOf(0);
 		}
 
 		@Override
 		public File getHomeDirectory() {
 			return new File(".");
 		}
 
 		@Override
 		public String getPropertyValue(final String s) {
 			throw new UnsupportedOperationException("Not implemented");
 		}
 	}
 
 	private static final class MavenUtils {
 		private static final Logger logger = LoggerFactory.getLogger(MavenUtils.class);
 
 		private static final String UNKNOWN_VERSION = "unknown";
 
 		static String getVersion(String groupId, String artifactId) {
 			final Properties props = new Properties();
 			InputStream resourceAsStream = null;
 			try {
 				resourceAsStream = MavenUtils.class.getResourceAsStream(String
 						.format("/META-INF/maven/%s/%s/pom.properties", groupId, artifactId));
 				props.load(resourceAsStream);
 				return props.getProperty("version", UNKNOWN_VERSION);
 			} catch (Exception e) {
 				logger.debug("Could not find version for maven artifact {}:{}", groupId, artifactId);
 				logger.debug("Got the following exception", e);
 				return UNKNOWN_VERSION;
 			} finally {
 				if (resourceAsStream != null) {
 					try {
 						resourceAsStream.close();
 					} catch (IOException ioe) {
 						// ignore
 					}
 				}
 			}
 		}
 	}
 
 }