/**
    * Copyright 2004-2012 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.kuali.maven.plugin;
  
  import java.io.File;
  import java.io.IOException;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.lang.StringUtils;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.project.MavenProject;
  import org.kuali.maven.common.Extractor;
  
  /**
   * Update the SCM section of a Maven pom so the URL's match the correct SCM URL. The correct SCM URL to use must be
   * provided to the plugin as a property.
   * 
   * @goal updatescm
   */
  public class UpdateScmMojo extends AbstractMojo {
  
      /**
       * The Maven project this plugin runs in.
       * 
       * @parameter expression="${project}"
       * @required
       * @readonly
       */
      private MavenProject project;
  
      /**
       * The property containing the correct SCM URL. This can be a project property, system property, or environment
       * variable.
       * 
       * @parameter expression="${extractor.scmUrlProperty}" default-value="scm.url"
       * @required
       */
      private String scmUrlProperty;
  
      /**
       * The location of the Maven pom to update.
       * 
       * @parameter expression="${extractor.pom}" default-value="${project.basedir}/pom.xml"
       * @required
       */
      private File pom;
  
      @Override
      public void execute() throws MojoExecutionException, MojoFailureException {
          Extractor extractor = new Extractor();
          String pomUrl = extractor.getScmUrl(project.getScm());
          String actualUrl = extractor.getActualUrl(project, scmUrlProperty);
          if (pomUrl.equals(actualUrl)) {
              getLog().info("pom url matches actual url.  Nothing to do!");
              return;
          }
          try {
              String content = FileUtils.readFileToString(pom);
              content = handleConnection(content, "connection", pomUrl, actualUrl);
              content = handleConnection(content, "developerConnection", pomUrl, actualUrl);
              content = handleConnection(content, "url", pomUrl, actualUrl);
              FileUtils.writeStringToFile(pom, content);
          } catch (IOException e) {
              throw new MojoExecutionException("Unexpected IO exception", e);
          }
      }
  
      protected String handleConnection(String content, String tag, String pomUrl, String newUrl) {
          String scm = StringUtils.substringBetween(content, "<scm>", "</scm>");
          getLog().debug("scm=" + scm);
          String open = "<" + tag + ">";
          String close = "</" + tag + ">";
          String oldScm = open + StringUtils.substringBetween(scm, open, close) + close;
          getLog().debug("oldScm=" + oldScm);
          getLog().debug("pomUrl=        " + pomUrl);
          int pos = oldScm.indexOf(pomUrl);
          if (pos == -1) {
              throw new IllegalStateException("Existing SCM information doesn't contain " + pomUrl);
          }
          String newScm = oldScm.replace(pomUrl, newUrl);
          getLog().debug("Old=[" + oldScm + "]");
          getLog().info("Update - " + newScm);
          return content.replace(oldScm, newScm);
      }
 
     public MavenProject getProject() {
         return project;
     }
 
     public String getScmUrlProperty() {
         return scmUrlProperty;
     }
 
     public void setScmUrlProperty(String svnUrlProperty) {
         this.scmUrlProperty = svnUrlProperty;
     }
 }