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 *   Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.
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package org.apache.cayenne.merge;

import java.util.List;

import org.apache.cayenne.dba.DbAdapter;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.map.DbEntity;

/**
 * Common abstract superclass for all {@link MergerToken}s going from the model to the
 * database.
 * 
 */
public abstract class AbstractToDbToken implements MergerToken, Comparable<MergerToken> {
    
    public final MergeDirection getDirection() {
        return MergeDirection.TO_DB;
    }

    public void execute(MergerContext mergerContext) {
        for (String sql : createSql(mergerContext.getAdapter())) {
            mergerContext.executeSql(sql);
        }
    }

    @Override
    public String toString() {
        StringBuilder ts = new StringBuilder();
        ts.append(getTokenName());
        ts.append(' ');
        ts.append(getTokenValue());
        ts.append(' ');
        ts.append(getDirection());
        return ts.toString();
    }

    public abstract List<String> createSql(DbAdapter adapter);
    
    abstract static class Entity extends AbstractToDbToken {
        
        private DbEntity entity;

        public Entity(DbEntity entity) {
            this.entity = entity;
        }

        public DbEntity getEntity() {
            return entity;
        }

        public String getTokenValue() {
            return getEntity().getName();
        }
        
        public int compareTo(MergerToken o) {
            // default order as tokens are created
            return 0;
        }

    }

    abstract static class EntityAndColumn extends Entity {
        
        private DbAttribute column;
        
        public EntityAndColumn(DbEntity entity, DbAttribute column) {
            super(entity);
            this.column = column;
        }

        public DbAttribute getColumn() {
            return column;
        }
        
        @Override
        public String getTokenValue() {
            return getEntity().getName() + "." + getColumn().getName();
        }
        
    }
}
