// Copyright (C) 2010 The Android Open Source Project
//
// 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 com.google.gerrit.server.query.change;

import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gerrit.reviewdb.client.RevId;
import com.google.gerrit.server.index.ChangeField;
import com.google.gerrit.server.index.IndexPredicate;
import com.google.gerrit.server.query.change.ChangeQueryBuilder.Arguments;
import com.google.gwtorm.server.OrmException;
import com.google.gwtorm.server.ResultSet;

import org.eclipse.jgit.lib.AbbreviatedObjectId;
import org.eclipse.jgit.lib.ObjectId;

class CommitPredicate extends IndexPredicate<ChangeData> implements
    ChangeDataSource {
  private final Arguments args;
  private final AbbreviatedObjectId abbrevId;

  CommitPredicate(Arguments args, AbbreviatedObjectId id) {
    super(ChangeField.COMMIT, id.name());
    this.args = args;
    this.abbrevId = id;
  }

  @Override
  public boolean match(final ChangeData object) throws OrmException {
    for (PatchSet p : object.patches()) {
      if (p.getRevision() != null && p.getRevision().get() != null) {
        final ObjectId id = ObjectId.fromString(p.getRevision().get());
        if (abbrevId.prefixCompare(id) == 0) {
          return true;
        }
      }
    }
    return false;
  }

  @Override
  public ResultSet<ChangeData> read() throws OrmException {
    final RevId id = new RevId(abbrevId.name());
    if (id.isComplete()) {
      return ChangeDataResultSet.patchSet(args.changeDataFactory, args.db,
          args.db.get().patchSets().byRevision(id));

    } else {
      return ChangeDataResultSet.patchSet(args.changeDataFactory, args.db,
          args.db.get().patchSets().byRevisionRange(id, id.max()));
    }
  }

  @Override
  public boolean hasChange() {
    return false;
  }

  @Override
  public int getCardinality() {
    return ChangeCosts.CARD_COMMIT;
  }

  @Override
  public int getCost() {
    return ChangeCosts.cost(ChangeCosts.PATCH_SETS_SCAN, getCardinality());
  }
}