package com.aragost.javahg;

 import java.io.IOException;

 import java.util.List;

 import com.aragost.javahg.commands.AddCommand;

 import com.aragost.javahg.commands.BranchCommand;

 import com.aragost.javahg.commands.MergeCommand;

 import com.aragost.javahg.commands.ParentsCommand;

 import com.aragost.javahg.commands.RemoveCommand;

 import com.aragost.javahg.commands.StatusCommand;

 import com.aragost.javahg.commands.StatusResult;

 import com.aragost.javahg.merge.MergeContext;

 /**

  * Represents working copy for a Repository.

  * <p>

  * Warning: The instance cache the information and will not see

  * changes to the working copy. Create a new instance if you need the

  * most current state.

  * 

  */

 public class WorkingCopy {

     private Repository repository;

     private boolean parentsRetrieved = false;

     private Changeset parent1;

     private Changeset parent2;

     private String branchName;

     WorkingCopy(Repository repository) {

         this.repository = repository;

     }

     public Changeset getParent1() {

         ensureParentsRetrieved();

         return this.parent1;

     }

     public Changeset getParent2() {

         ensureParentsRetrieved();

         return this.parent2;

     }

     /**

      * @return branch name for working copy

      */

     public synchronized String getBranchName() {

         if (this.branchName == null) {

             this.branchName = BranchCommand.on(this.repository).get();

         }

         return this.branchName;

     }

     /**

      * Set the branch name of working copy

      * 

      * @param branchName

      */

     public synchronized void setBranchName(String branchName) {

         BranchCommand.on(this.repository).set(branchName);

         this.branchName = branchName;

     }

     public void remove(String... files) {

         RemoveCommand.on(this.repository).execute(files);

     }

     public void add(String... files) {

         AddCommand.on(this.repository).execute(files);

     }

     /**

      * Merge the working copy with the specified changeset

      * 

      * @param remote

      * @return a MergeContext

      * @throws IOException

      */

     public MergeContext merge(Changeset remote) throws IOException {

         return MergeCommand.on(this.repository).rev(remote.getNode()).execute();

     }

     /**

      * 

      * @return status for working copy relative to first parent

      */

     public StatusResult status() {

         return StatusCommand.on(this.repository).execute();

     }

     /**

      * 

      * @return status for working copy relative to second parent

      */

     public StatusResult parent2Status() {

         if (getParent2() == null) {

             return null;

         }

         return StatusCommand.on(this.repository).rev(getParent2().getNode()).execute();

     }

     private synchronized void ensureParentsRetrieved() {

         if (!this.parentsRetrieved) {

             retrieveParents();

             this.parentsRetrieved = true;

         }

     }

     private void retrieveParents() {

         List<Changeset> parents = ParentsCommand.on(this.repository).execute();

         switch (parents.size()) {

         // Fall though on purpose

         case 2:

             this.parent2 = parents.get(1);

         case 1:

             this.parent1 = parents.get(0);

         case 0:

             break;

         default:

             throw new RuntimeException("More that 2 parents from parents command");

         }

     }

 }