/*
 * 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.
 */

package org.apache.jena.sdb.layout2.index;

import org.apache.jena.sdb.layout2.TableDescNodes ;
import org.apache.jena.sdb.sql.SDBConnection ;
import org.apache.jena.sdb.store.TableDesc ;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class TupleLoaderIndexDB2 extends TupleLoaderIndexBase {
	
	private static Logger log = LoggerFactory.getLogger(TupleLoaderIndexDB2.class);
	
	public TupleLoaderIndexDB2(SDBConnection connection, TableDesc tableDesc,
			int chunkSize) {
		super(connection, tableDesc, chunkSize);
	}
	
	@Override
    public String[] getNodeColTypes() {
		return new String[] {"BIGINT", "CLOB", "VARCHAR(10)", "VARCHAR("+TableDescNodes.DatatypeUriLength+")", "INTEGER"};
	}
	
	@Override
    public String getTupleColType() {
		return "BIGINT";
	}
	
	@Override
    public String[] getCreateTempTable() {
		return new String[] { "CREATE TABLE " , " CCSID UNICODE" };
	}
	
	@Override
	public String getClearTempNodes() {
		return "DELETE FROM "+getNodeLoader();
	}
	
	@Override
	public String getClearTempTuples() {
		return "DELETE FROM "+getTupleLoader();
	}
	
	@Override
	public String getLoadTuples() {
		StringBuilder stmt = new StringBuilder();
		
		stmt.append("INSERT INTO ").append(this.getTableName()).append(" \nSELECT DISTINCT ");
		for (int i = 0; i < this.getTableWidth(); i++) {
			if (i != 0) stmt.append(" , ");
			stmt.append("NI").append(i).append(".id");
		}
		stmt.append("\nFROM ").append(getTupleLoader()).append("\n");
		for (int i = 0; i < this.getTableWidth(); i++) {
			stmt.append("JOIN Nodes NI").append(i).append(" ON ("); // No 'AS' in DB2
			stmt.append(getTupleLoader()).append(".t").append(i).append("=NI").append(i).append(".hash)\n");
		}
		stmt.append("LEFT JOIN ").append(getTableName()).append(" ON (");
		for (int i = 0; i < this.getTableWidth(); i++) {
			if (i != 0) stmt.append(" AND ");
			stmt.append("NI").append(i).append(".id");
			stmt.append("=").append(this.getTableName()).append(".").append(this.getTableDesc().getColNames().get(i));
		}
		stmt.append(")\nWHERE\n");
		for (int i = 0; i < this.getTableWidth(); i++) {
			if (i != 0) stmt.append(" OR\n");
			stmt.append(this.getTableName()).append(".").append(this.getTableDesc().getColNames().get(i)).append(" IS NULL");
		}
		
		return stmt.toString();
	}
	
	@Override
	public String getLoadNodes() {
		StringBuilder stmt = new StringBuilder();
                
                stmt.append("LOCK TABLE Nodes IN EXCLUSIVE MODE; ");
		stmt.append("INSERT INTO Nodes \nSELECT (NEXT VALUE FOR nodeid) , "); // Autoindex thingy
		for (int i = 0; i < getNodeColTypes().length; i++) {
			if (i != 0) stmt.append(" , ");
			stmt.append(getNodeLoader()).append(".").append("n").append(i);
		}
		stmt.append("\nFROM ").append(getNodeLoader()).append(" LEFT JOIN Nodes ON (");
		stmt.append(getNodeLoader()).append(".n0=Nodes.hash) \nWHERE Nodes.hash IS NULL"); 
		return stmt.toString();
	}
}