/**
 * Licensed to JumpMind Inc under one or more contributor
 * license agreements.  See the NOTICE file distributed
 * with this work for additional information regarding
 * copyright ownership.  JumpMind Inc licenses this file
 * to you under the GNU General Public License, version 3.0 (GPLv3)
 * (the "License"); you may not use this file except in compliance
 * with the License.
 *
 * You should have received a copy of the GNU General Public License,
 * version 3.0 (GPLv3) along with this library; if not, see
 * <http://www.gnu.org/licenses/>.
 *
 * 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 org.jumpmind.symmetric.db.db2;

import org.apache.commons.lang.StringUtils;
import org.jumpmind.db.platform.IDatabasePlatform;
import org.jumpmind.db.sql.ISqlTemplate;
import org.jumpmind.db.sql.ISqlTransaction;
import org.jumpmind.symmetric.db.ISymmetricDialect;
import org.jumpmind.symmetric.service.IParameterService;

public class Db2v9SymmetricDialect extends Db2SymmetricDialect implements ISymmetricDialect {

    static final String SYNC_TRIGGERS_DISABLED_USER_VARIABLE = "sync_triggers_disabled";

    static final String SYNC_TRIGGERS_DISABLED_NODE_VARIABLE = "sync_node_disabled";
    
    String syncTriggersDisabledUserVariable;
    
    String syncTriggersDisabledNodeVariable;

    public Db2v9SymmetricDialect(IParameterService parameterService, IDatabasePlatform platform) {
        super(parameterService, platform);
        syncTriggersDisabledUserVariable = this.parameterService.getTablePrefix() + "_" + SYNC_TRIGGERS_DISABLED_USER_VARIABLE;
        syncTriggersDisabledNodeVariable = this.parameterService.getTablePrefix() + "_" + SYNC_TRIGGERS_DISABLED_NODE_VARIABLE;
    }
    
    @Override
    public void createRequiredDatabaseObjects() {
        ISqlTransaction transaction = null;
        try {
            transaction = platform.getSqlTemplate().startSqlTransaction();
            enableSyncTriggers(transaction);
            transaction.commit();
        } catch (Exception e) {
            try {
                log.info("Creating environment variables {} and {}", syncTriggersDisabledUserVariable,
                        syncTriggersDisabledNodeVariable);
                ISqlTemplate template = getPlatform().getSqlTemplate();
                template.update("CREATE VARIABLE "+syncTriggersDisabledNodeVariable+" VARCHAR(50)");
                template.update("GRANT READ on VARIABLE "+syncTriggersDisabledNodeVariable+" TO PUBLIC");
                template.update("GRANT WRITE on VARIABLE "+syncTriggersDisabledNodeVariable+" TO PUBLIC");
                template.update("CREATE VARIABLE "+syncTriggersDisabledUserVariable+" INTEGER");
                template.update("GRANT READ on VARIABLE "+syncTriggersDisabledUserVariable+" TO PUBLIC");
                template.update("GRANT WRITE on VARIABLE "+syncTriggersDisabledUserVariable+" TO PUBLIC");
            } catch (Exception ex) {
                log.error("Error while initializing DB2 dialect", ex);
            }
        } finally {
            close(transaction);
        }

        super.createRequiredDatabaseObjects();
    }
    
    @Override
    public void disableSyncTriggers(ISqlTransaction transaction, String nodeId) {
       transaction.execute("set " + syncTriggersDisabledUserVariable + "=1");
       if (StringUtils.isNotBlank(nodeId)) {
           transaction.execute("set " + syncTriggersDisabledNodeVariable + "='" + nodeId + "'");
       }
    }

    @Override
    public void enableSyncTriggers(ISqlTransaction transaction) {
        transaction.execute("set " + syncTriggersDisabledUserVariable + "=null");
        transaction.execute("set " + syncTriggersDisabledNodeVariable + "=null");
    }

    public String getSyncTriggersExpression() {
        return syncTriggersDisabledUserVariable + " is null";
    }
    
    @Override
    public String getSourceNodeExpression() {
        return syncTriggersDisabledNodeVariable;
    }
    
}