package com.aragost.javahg.merge;
   
   import java.io.IOException;
   
   import com.aragost.javahg.internals.AbstractCommand;
   import com.aragost.javahg.internals.HgInputStream;
   import com.aragost.javahg.internals.UnexpectedCommandOutputException;
   
   public class BackoutConflictResolvingContext extends ConflictResolvingContext {
  
      private static final byte[] MERGING_WITH_CHANGESET = "merging with changeset ".getBytes();
      private static final byte[] BACKS_OUT_CHANGESET = " backs out changeset ".getBytes();
      private static final byte[] CHANGESET = "changeset".getBytes();
      private static final byte[] REVERTING = "reverting".getBytes();
      private static final byte[] CREATED_NEW_HEAD = "created new head".getBytes();
  
      private final boolean merge;
  
      public BackoutConflictResolvingContext(AbstractCommand command, boolean merge) {
          super(command);
          
          this.merge = merge;
      }
  
      /**
       * Example:
       * <pre>
       * $ hg backout --merge 7:7
       * reverting foo.txt
       * created new head
       * changeset 9:664c3e4cbb2b backs out changeset 7:3f5bacea93aa
       * merging with changeset 9:664c3e4cbb2b
       * merging foo.txt
       * warning: conflicts during merge.
       * merging foo.txt incomplete! (edit conflicts, then use 'hg resolve --mark')
       * 0 files updated, 0 files merged, 0 files removed, 1 files unresolved
       * use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
       * </pre>
       * 
       * @see com.aragost.javahg.merge.ConflictResolvingContext#processStream(com.aragost.javahg.internals.HgInputStream,
       *      boolean)
       */
      @Override
      public void processStream(HgInputStream in, boolean whenUnknowReturn)
              throws IOException {
          String createdChangeset = null;
          
          while (!in.isEof()) {
              if (in.match(REVERTING)) {
                  in.upTo('\n');
              } else if (in.match(CREATED_NEW_HEAD)) {
                  in.upTo('\n');
              } else if (in.match(CHANGESET)) {
                  createdChangeset = in.textUpTo(BACKS_OUT_CHANGESET);
                  in.upTo('\n');
              } else if (in.match(MERGING_WITH_CHANGESET)) {
                  in.upTo('\n');
              } else {
                  break;
              }
          }
  
          if (createdChangeset == null && merge) {
              if (whenUnknowReturn) {
                  return;
              }
              throw new UnexpectedCommandOutputException(this.getCommand(), null);
          }
  
          super.processStream(in, whenUnknowReturn);
      }
  
  }