/**
    * Copyright 2010-2013 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.common.util.project;
  
  import java.nio.charset.Charset;
  import java.util.Properties;
  
  import org.kuali.common.util.Assert;
  import org.kuali.common.util.PropertyUtils;
  import org.kuali.common.util.Str;
  import org.kuali.common.util.cache.Cache;
  import org.kuali.common.util.cache.SimpleCache;
  import org.kuali.common.util.maven.MavenConstants;
  import org.kuali.common.util.project.model.ImmutableProject;
  import org.kuali.common.util.project.model.Project;
  import org.kuali.common.util.project.model.ProjectIdentifier;
  import org.kuali.common.util.property.Constants;
  import org.kuali.common.util.spring.env.EnvironmentService;
  import org.springframework.util.PropertyPlaceholderHelper;
  
  public class DefaultProjectService implements ProjectService {
  
  	private static final Cache<String, Project> CACHE = new SimpleCache<String, Project>();
  	private static final PropertyPlaceholderHelper PPH = Constants.DEFAULT_PROPERTY_PLACEHOLDER_HELPER;
  	private static final String PROPERTIES_ENCODING_KEY = "project.properties.encoding";
  	private static final String PROPERTIES_ENCODING_DEFAULT = Charset.defaultCharset().toString();
  
  	private final EnvironmentService env;
  
  	public DefaultProjectService(EnvironmentService env) {
  		Assert.noNulls(env);
  		this.env = env;
  	}
  
  	/**
  	 * @deprecated Use ProjectUtils.getProject(properties) instead
  	 */
  	@Deprecated
  	@Override
  	public Project getProject(Properties properties) {
  		String groupId = properties.getProperty(MavenConstants.GROUP_ID_KEY);
  		String artifactId = properties.getProperty(MavenConstants.ARTIFACT_ID_KEY);
  		String version = properties.getProperty(MavenConstants.VERSION_KEY);
  		return new ImmutableProject(groupId, artifactId, version, properties);
  	}
  
  	@Override
  	public Project getProject(ProjectIdentifier identifier) {
  		return getProject(identifier.getGroupId(), identifier.getArtifactId());
  	}
  
  	@Override
  	public Project getProject(String groupId, String artifactId) {
  
  		// Both of these are required
  		Assert.noBlanks("groupId and artifactId are required", groupId, artifactId);
  
  		// Construct the cache key
  		String cacheKey = groupId + ":" + artifactId;
  
  		// Check the cache
  		Project project = CACHE.get(cacheKey);
  		if (project == null) {
  			// Construct a project object from project.properties
  			project = load(groupId, artifactId);
  			// Cache it
  			CACHE.put(cacheKey, project);
  		}
  		return project;
  	}
  
  	protected void clearCache() {
  		CACHE.clear();
  	}
  
  	protected Project load(String groupId, String artifactId) {
  
  		// Get the unique path to the project.properties file
  		String location = getPropertiesFileLocation(groupId, artifactId);
  
  		// If that location doesn't exist, we have issues
  		Assert.exists(location, "[" + location + "] does not exist");
  
  		// Use platform default encoding to load project.properties
  		// Set the system property "project.properties.encoding" or the environment variable "PROJECT_PROPERTIES_ENCODING" to override
  		String encoding = env.getString(PROPERTIES_ENCODING_KEY, PROPERTIES_ENCODING_DEFAULT);
 
 		// Load the properties from disk
 		Properties properties = PropertyUtils.load(location, encoding);
 
 		// Convert the properties into a project
 		return getProject(properties);
 	}
 
 	protected String getPropertiesFileLocation(String groupId, String artifactId) {
 		Properties properties = new Properties();
 		properties.setProperty(Constants.GROUP_ID_PATH_KEY, Str.getPath(groupId));
 		properties.setProperty(Constants.ARTIFACT_ID_KEY, artifactId);
 		return PPH.replacePlaceholders(Constants.PROJECT_PROPERTIES_LOCATION, properties);
 	}
 
 	public EnvironmentService getEnv() {
 		return env;
 	}
 
 }