/*
    * Copyright 2012 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.maven.issue.util;
  
  import org.apache.maven.artifact.versioning.ArtifactVersion;
  import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
  import org.apache.maven.project.MavenProject;
  
  /**
   * Utility class to handle versions.
   */
  public final class VersionHelper
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * Signals to increment the major version number, setting minor and micro to
     * zero.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String MAJOR = "MAJOR";
  
    /**
     * Signals to increment the minor version number, setting micro to zero.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String MINOR = "MINOR";
  
    /**
     * Signals to increment the micro version number.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String MICRO = "MICRO";
  
    /**
     * Signals to use the current version (without SNAPSHOT).
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String CURRENT = "CURRENT";
  
    /**
     * Signals to use the current version (inclusive if present SNAPSHOT).
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    public static final String SNAPSHOT = "SNAPSHOT";
  
    // --- members --------------------------------------------------------------
  
    /**
     * The Mave project.
     */
    private final MavenProject project;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param project the Mave project.
     */
    public VersionHelper(final MavenProject project)
    {
      this.project = project;
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
 
   // --- business -------------------------------------------------------------
 
   /**
    * Calculates the next version.
    *
    * @param version the version to analyze.
    * @return the version if it is neither {@link #MAJOR}, {@link #MINOR}, or
    *         {@link #MICRO}.
    */
   public String calculateNextVersion(final String version)
   {
     final String nextVersion;
     if (MAJOR.equals(version))
     {
       nextVersion = calcMajor();
     }
     else if (MINOR.equals(version))
     {
       nextVersion = calcMinor();
     }
     else if (MICRO.equals(version))
     {
       nextVersion = calcMicro();
     }
     else if (CURRENT.equals(version))
     {
       nextVersion = getVersionStrippedFromSnapshotSuffix(project.getVersion());
     }
     else if (SNAPSHOT.equals(version))
     {
       nextVersion = project.getVersion();
     }
     else
     {
       nextVersion = version;
     }
 
     return nextVersion;
   }
 
   /**
    * Returns the given version without the <code>-SNAPSHOT</code> suffix.
    *
    * @param version the version to strip.
    * @return the stripped version or (if no suffix was present) the
    *         {@code version}.
    */
   public static String getVersionStrippedFromSnapshotSuffix(final String version)
   {
     if (version.endsWith("-SNAPSHOT"))
     {
       return version.substring(0, version.length() - 9);
     }
     return version;
   }
 
   private String calcMajor()
   {
     final String nextVersion;
     final ArtifactVersion artifactVersion = createArtifactVersion();
     if (artifactVersion == null)
     {
       return null;
     }
     final int next = artifactVersion.getMajorVersion() + 1;
     nextVersion = next + ".0.0";
     return nextVersion;
   }
 
   private String calcMinor()
   {
     final String nextVersion;
     final ArtifactVersion artifactVersion = createArtifactVersion();
     if (artifactVersion == null)
     {
       return null;
     }
     final int next = artifactVersion.getMinorVersion() + 1;
     nextVersion =
         String.valueOf(artifactVersion.getMajorVersion()) + '.' + next + ".0";
     return nextVersion;
   }
 
   private String calcMicro()
   {
     final String nextVersion;
     final ArtifactVersion artifactVersion = createArtifactVersion();
     if (artifactVersion == null)
     {
       return null;
     }
     final int next = artifactVersion.getIncrementalVersion() + 1;
     nextVersion =
         String.valueOf(artifactVersion.getMajorVersion()) + '.'
             + artifactVersion.getMinorVersion() + '.' + next;
     return nextVersion;
   }
 
   private ArtifactVersion createArtifactVersion()
   {
     final String version = project.getVersion();
     final ArtifactVersion artifactVersion = new DefaultArtifactVersion(version);
     if (notRecognized(artifactVersion))
     {
       return null;
     }
     return artifactVersion;
   }
 
   private static boolean notRecognized(final ArtifactVersion artifactVersion)
   {
     return (artifactVersion.getMajorVersion() == 0
             && artifactVersion.getMinorVersion() == 0 && artifactVersion
         .getIncrementalVersion() == 0);
   }
 
   // --- object basics --------------------------------------------------------
 
 }