/**
    * 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.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Properties;
  import java.util.Set;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang.StringUtils;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.project.MavenProject;
  import org.kuali.maven.common.PropertiesUtils;
  import org.springframework.core.io.DefaultResourceLoader;
  import org.springframework.core.io.Resource;
  import org.springframework.core.io.ResourceLoader;
  
  /**
   * The read-project-properties goal reads property files and stores the properties as project properties. It serves as
   * an alternate to specifying properties in pom.xml.<br>
   *
   * Properties files handled by this plugin, have their property values resolved using Spring's expression parser. This
   * means anything you can do with Spring property values you can do with property values handled by this plugin. For
   * example, nested properties are supported: eg foo=${a.${b}.c}
   *
   * @author <a href="mailto:zarars@gmail.com">Zarar Siddiqi</a>
   * @author <a href="mailto:Krystian.Nowak@gmail.com">Krystian Nowak</a>
   * @auther Jeff Caddel
   * @version $Id: ReadPropertiesMojo.java 8861 2009-01-21 15:35:38Z pgier $
   * @goal read-project-properties
   */
  public class ReadPropertiesMojo extends AbstractMojo {
      PropertiesUtils utils = new PropertiesUtils();
  
      /**
       * @parameter default-value="${project}"
       * @required
       * @readonly
       */
      private MavenProject project;
  
      /**
       * Locations where properties files can be found. Any url Spring resource loading can understand is valid. eg
       * <code>classpath:myprops.properties</code>. Both, .properties and .xml style properties are supported.
       *
       * @parameter
       * @required
       */
      private String[] locations;
  
      /**
       * If true, the plugin will silently ignore any non-existent properties files, and the build will continue
       *
       * @parameter expression="${properties.quiet}" default-value="false"
       */
      private boolean quiet;
  
      /**
       * If true, the plugin will operate silently without emitting any log messages
       *
       * @parameter expression="${properties.silent}" default-value="false"
       */
      private boolean silent;
  
      /**
       * If true, the plugin will emit more verbose logging messages.
       *
       * @parameter expression="${properties.verbose}" default-value="false"
       */
      private boolean verbose;
  
      /**
       * Comma separated list of property values to ignore
       *
       * @parameter expression="${properties.ignore}"
       */
      private String ignore;
  
      @Override
      public void execute() throws MojoExecutionException {
         // Figure out if there are properties we need to ignore
         List<String> ignoreList = getIgnoreList();
 
         // Update project properties by loading in properties from the locations they've specified
         updateProjectProperties(ignoreList);
 
         // Project + system + env properties
         Properties allProperties = utils.getMavenProperties(project);
         resolveValues(project.getProperties(), allProperties);
 
     }
 
     protected void resolveValues(Properties p1, Properties p2) {
         for (String name : p1.stringPropertyNames()) {
             String originalValue = p1.getProperty(name);
             String resolvedValue = utils.getResolvedValue(originalValue, p2);
             p1.setProperty(name, resolvedValue);
         }
     }
 
     /**
      * Copy properties from p2 into p1, overwriting p1 values as we go.
      *
      * Ignore any properties with a key that appears in the ignore list
      *
      * @param p1
      * @param p2
      * @param ignore
      */
     protected void updateProperties(Properties p1, Properties p2, List<String> ignore) {
         Set<String> names = p2.stringPropertyNames();
         for (String name : names) {
             if (!ignore.contains(name)) {
                 String value = p2.getProperty(name);
                 p1.setProperty(name, value);
             }
         }
     }
 
     protected static final List<String> getListFromCSV(String csv) {
         if (StringUtils.isBlank(csv)) {
             return new ArrayList<String>();
         }
         List<String> list = new ArrayList<String>();
         String[] tokens = StringUtils.split(csv, ",");
         for (String token : tokens) {
             list.add(token.trim());
         }
         return list;
     }
 
     protected String toEmpty(String s) {
         if (StringUtils.isBlank(s)) {
             return "";
         } else {
             return s;
         }
     }
 
     protected boolean exists(String location) {
         if (StringUtils.isBlank(location)) {
             return false;
         }
         File file = new File(location);
         if (file.exists()) {
             return true;
         }
         ResourceLoader loader = new DefaultResourceLoader();
         Resource resource = loader.getResource(location);
         return resource.exists();
     }
 
     protected boolean validate(String location) throws MojoExecutionException {
         boolean exists = exists(location);
         if (exists) {
             return true;
         }
         if (quiet) {
             if (verbose && !silent) {
                 getLog().info("Ignoring non-existent properties file '" + toEmpty(location) + "'");
             }
             return false;
         } else {
             throw new MojoExecutionException("Non-existent properties file '" + location + "'");
         }
     }
 
     protected InputStream getInputStream(String location) throws IOException {
         File file = new File(location);
         if (file.exists()) {
             return new FileInputStream(location);
         }
         ResourceLoader loader = new DefaultResourceLoader();
         Resource resource = loader.getResource(location);
         return resource.getInputStream();
     }
 
     protected Properties getProperties(String location) throws MojoExecutionException {
         InputStream in = null;
         try {
             Properties properties = new Properties();
             in = getInputStream(location);
             if (location.toLowerCase().endsWith(".xml")) {
                 properties.loadFromXML(in);
             } else {
                 properties.load(in);
             }
             return properties;
         } catch (IOException e) {
             throw new MojoExecutionException("Error reading properties file " + location, e);
         } finally {
             IOUtils.closeQuietly(in);
         }
     }
 
     public boolean isQuiet() {
         return quiet;
     }
 
     public void setQuiet(boolean quiet) {
         this.quiet = quiet;
     }
 
     public String getIgnore() {
         return ignore;
     }
 
     public void setIgnore(String ignoreProperties) {
         this.ignore = ignoreProperties;
     }
 
     public MavenProject getProject() {
         return project;
     }
 
     public String[] getLocations() {
         return locations;
     }
 
     public void setLocations(String[] locations) {
         this.locations = locations;
     }
 
     public boolean isVerbose() {
         return verbose;
     }
 
     public void setVerbose(boolean verbose) {
         this.verbose = verbose;
     }
 
     public boolean isSilent() {
         return silent;
     }
 
     public void setSilent(boolean silent) {
         this.silent = silent;
     }
 
     protected List<String> getIgnoreList() {
         List<String> ignoreList = getListFromCSV(ignore);
         if (!silent && verbose && !StringUtils.isBlank(ignore)) {
             getLog().info("Ignoring " + ignore);
         }
         return ignoreList;
     }
 
     protected void updateProjectProperties(List<String> ignoreList) throws MojoExecutionException {
         Properties projectProperties = project.getProperties();
         for (int i = 0; i < locations.length; i++) {
             Properties allProperties = utils.getMavenProperties(project);
             String originalLocation = locations[i];
             String resolvedLocation = utils.getResolvedValue(originalLocation, allProperties);
             getLog().debug("o=" + originalLocation + " r=" + resolvedLocation);
             if (!validate(resolvedLocation)) {
                 continue;
             }
             if (!silent) {
                 getLog().info("Loading " + resolvedLocation);
             }
 
             // Load properties from this location
             Properties p = getProperties(resolvedLocation);
 
             // Update project properties from the properties we just loaded
             updateProperties(projectProperties, p, ignoreList);
         }
     }
 
 }