/**
    * Copyright 2009-2012 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.codehaus.mojo.properties;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Date;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.Set;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.io.IOUtils;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.codehaus.plexus.util.StringUtils;
  import org.springframework.util.PropertyPlaceholderHelper;
  
  /**
   * Write project properties to a file.
   * 
   * @author Jeff Caddel
   * 
   * @goal write-project-properties
   */
  public class WriteProjectProperties extends AbstractWritePropertiesMojo {
  
  	/**
  	 * If true, the plugin will include system properties when writing the properties file. System properties override both environment
  	 * variables and project properties.
  	 * 
  	 * @parameter default-value="false" expression="${properties.includeSystemProperties}"
  	 */
  	private boolean includeSystemProperties;
  
  	/**
  	 * If true, the plugin will include environment variables when writing the properties file. Environment variables are prefixed with
  	 * "env". Environment variables override project properties.
  	 * 
  	 * @parameter default-value="false" expression="${properties.includeEnvironmentVariables}"
  	 */
  	private boolean includeEnvironmentVariables;
  
  	/**
  	 * Comma separated set of properties to exclude when writing the properties file
  	 * 
  	 * @parameter expression="${properties.exclude}"
  	 */
  	private String exclude;
  
  	/**
  	 * Comma separated set of properties to write to the properties file. If provided, only the properties matching those supplied here will
  	 * be written to the properties file.
  	 * 
  	 * @parameter expression="${properties.include}"
  	 */
  	private String include;
  
  	/**
  	 * If true placeholders are resolved before writing properties to the file
  	 * 
  	 * @parameter expression="${properties.resolvePlaceholders}"
  	 */
  	private boolean resolvePlaceholders;
  
  	@Override
  	public void execute() throws MojoExecutionException, MojoFailureException {
  		Properties properties = new Properties();
  		// Add project properties
  		properties.putAll(project.getProperties());
  		if (includeEnvironmentVariables) {
  			// Add environment variables, overriding any existing properties with the same key
  			properties.putAll(getEnvironmentVariables());
  		}
  		if (includeSystemProperties) {
  			// Add system properties, overriding any existing properties with the same key
  			properties.putAll(System.getProperties());
  		}
  
  		// Remove properties as appropriate
  		trim(properties, exclude, include);
  
 		if (resolvePlaceholders) {
 			properties = getResolvedProperties(properties);
 		}
 
 		String comment = "# " + new Date() + "\n";
 		getLog().info("Creating " + outputFile);
 		writeProperties(outputFile, comment, properties);
 	}
 
 	protected Properties getResolvedProperties(Properties props) {
 		PropertyPlaceholderHelper pph = new PropertyPlaceholderHelper("${", "}");
 		List<String> keys = new ArrayList<String>(props.stringPropertyNames());
 		Collections.sort(keys);
 		Properties newProps = new Properties();
 		for (String key : keys) {
 			String originalValue = props.getProperty(key);
 			String resolvedValue = pph.replacePlaceholders(originalValue, props);
 			newProps.setProperty(key, resolvedValue);
 		}
 		return newProps;
 
 	}
 
 	protected static Properties getEnvironmentVariables() {
 		String prefix = "env";
 		Map<String, String> map = System.getenv();
 		Properties props = new Properties();
 		for (String key : map.keySet()) {
 			String newKey = prefix + "." + key;
 			String value = map.get(key);
 			props.setProperty(newKey, value);
 		}
 		return props;
 	}
 
 	protected void trim(Properties properties, String excludeCSV, String includeCSV) {
 		List<String> omitKeys = ReadPropertiesMojo.getListFromCSV(excludeCSV);
 		for (String key : omitKeys) {
 			properties.remove(key);
 		}
 		if (StringUtils.isBlank(includeCSV)) {
 			return;
 		}
 		List<String> includeKeys = ReadPropertiesMojo.getListFromCSV(includeCSV);
 		Set<String> keys = properties.stringPropertyNames();
 		for (String key : keys) {
 			if (!includeKeys.contains(key)) {
 				properties.remove(key);
 			}
 		}
 	}
 
 	protected void writeProperties(File file, String comment, Properties properties) throws MojoExecutionException {
 		SortedProperties sp = new SortedProperties();
 		sp.putAll(properties);
 		OutputStream out = null;
 		try {
 			out = FileUtils.openOutputStream(file);
 			sp.store(out, comment);
 		} catch (IOException e) {
 			throw new MojoExecutionException("Error creating properties file", e);
 		} finally {
 			IOUtils.closeQuietly(out);
 		}
 	}
 
 	public boolean isIncludeSystemProperties() {
 		return includeSystemProperties;
 	}
 
 	public void setIncludeSystemProperties(boolean includeSystemProperties) {
 		this.includeSystemProperties = includeSystemProperties;
 	}
 
 	public boolean isIncludeEnvironmentVariables() {
 		return includeEnvironmentVariables;
 	}
 
 	public void setIncludeEnvironmentVariables(boolean includeEnvironmentVariables) {
 		this.includeEnvironmentVariables = includeEnvironmentVariables;
 	}
 
 	public String getExclude() {
 		return exclude;
 	}
 
 	public void setExclude(String exclude) {
 		this.exclude = exclude;
 	}
 
 	public String getInclude() {
 		return include;
 	}
 
 	public void setInclude(String include) {
 		this.include = include;
 	}
 
 	public boolean isResolvePlaceholders() {
 		return resolvePlaceholders;
 	}
 
 	public void setResolvePlaceholders(boolean resolvePlaceholders) {
 		this.resolvePlaceholders = resolvePlaceholders;
 	}
 }