/*
    * 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.DefaultHttpClientFactory;
  import com.atlassian.httpclient.api.HttpClient;
  import com.atlassian.httpclient.api.factory.HttpClientOptions;
  import com.atlassian.jira.rest.client.api.AuthenticationHandler;
  import com.atlassian.sal.api.ApplicationProperties;
  import com.atlassian.sal.api.UrlMode;
  import com.atlassian.sal.api.executor.ThreadLocalContextManager;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.annotation.Nonnull;
  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();
  
          final DefaultHttpClientFactory defaultHttpClientFactory = new DefaultHttpClientFactory(new NoOpEventPublisher(),
                  new RestClientApplicationProperties(serverUri),
                  new ThreadLocalContextManager() {
                      @Override
                      public Object getThreadLocalContext() {
                          return null;
                      }
  
                      @Override
                      public void setThreadLocalContext(Object context) {
                      }
  
                      @Override
                      public void clearThreadLocalContext() {
                      }
                  });
  
          final HttpClient httpClient = defaultHttpClientFactory.create(options);
  
          return new AtlassianHttpClientDecorator(httpClient, authenticationHandler) {
              @Override
              public void destroy() throws Exception {
                  defaultHttpClientFactory.dispose(httpClient);
              }
          };
      }
  
      public DisposableHttpClient createClient(final HttpClient client) {
          return new AtlassianHttpClientDecorator(client, null) {
  
              @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;
         }
 
         /**
          * We'll always have an absolute URL as a client.
          */
         @Nonnull
         @Override
         public String getBaseUrl(UrlMode urlMode) {
             return baseUrl;
         }
 
         @Nonnull
         @Override
         public String getDisplayName() {
             return "Atlassian JIRA Rest Java Client";
         }
 
         @Nonnull
         @Override
         public String getPlatformId() {
             return ApplicationProperties.PLATFORM_JIRA;
         }
 
         @Nonnull
         @Override
         public String getVersion() {
             return MavenUtils.getVersion("com.atlassian.jira", "jira-rest-java-com.atlassian.jira.rest.client");
         }
 
         @Nonnull
         @Override
         public Date getBuildDate() {
             // TODO implement using MavenUtils, JRJC-123
             throw new UnsupportedOperationException();
         }
 
         @Nonnull
         @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
                     }
                 }
             }
         }
     }
 
 }