/*
 * InsertOp.java
 */
package org.ngbw.sdk.database;


import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Iterator;
import java.util.List;


/**
 *
 * @author Paul Hoover
 *
 */
class AutoGenKeyInsertOp implements RowOperation {

	// data fields


	private final String m_tableName;
	private final Column<?> m_key;
	private final List<Column<?>> m_columns;


	// constructors


	/**
	 *
	 * @param tableName
	 * @param key
	 * @param columns
	 */
	AutoGenKeyInsertOp(String tableName, Column<?> key, List<Column<?>> columns)
	{
		m_tableName = tableName;
		m_key = key;
		m_columns = columns;
	}


	// public methods


	/**
	 *
	 * @param dbConn
	 * @throws IOException
	 * @throws SQLException
	 */
	@Override
	public void execute(Connection dbConn) throws IOException, SQLException
	{
		StringBuilder stmtBuilder = new StringBuilder();
		Iterator<Column<?>> columns = m_columns.iterator();

		stmtBuilder.append("INSERT INTO ");
		stmtBuilder.append(m_tableName);

		if (columns.hasNext()) {
			stmtBuilder.append(" ( ");
			stmtBuilder.append(columns.next().getName());

			while (columns.hasNext()) {
				stmtBuilder.append(", ");
				stmtBuilder.append(columns.next().getName());
			}

			stmtBuilder.append(" ) VALUES ( ?");

			for (int i = 1 ; i < m_columns.size() ; i += 1)
				stmtBuilder.append(", ?");

			stmtBuilder.append(" )");
		}

		PreparedStatement insertStmt = dbConn.prepareStatement(stmtBuilder.toString(), Statement.RETURN_GENERATED_KEYS);
		ResultSet newKey = null;

		try {
			int index = 1;

			for (columns = m_columns.iterator() ; columns.hasNext() ; index += 1)
				columns.next().setParameter(insertStmt, index);

			insertStmt.executeUpdate();

			newKey = insertStmt.getGeneratedKeys();

			if (newKey.next())
				m_key.assignValue(newKey, 1);
		}
		finally {
			if (newKey != null)
				newKey.close();

			insertStmt.close();

			for (Column<?> col : m_columns)
				col.finishUpdate();
		}
	}
}