/*
 * Copyright 2012-2015 org.opencloudb.
 *  
 * 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 org.opencloudb.server.handler;

import org.opencloudb.parser.util.ParseUtil;
import org.opencloudb.server.ServerConnection;
import org.opencloudb.server.parser.ServerParse;
import org.opencloudb.server.parser.ServerParseSelect;
import org.opencloudb.server.response.SelectDatabase;
import org.opencloudb.server.response.SelectIdentity;
import org.opencloudb.server.response.SelectLastInsertId;
import org.opencloudb.server.response.SelectUser;
import org.opencloudb.server.response.SelectVersion;
import org.opencloudb.server.response.SelectVersionComment;
import org.opencloudb.server.response.SessionIncrement;
import org.opencloudb.server.response.SessionIsolation;

/**
 * @author mycat
 */
public final class SelectHandler {

	public static void handle(String stmt, ServerConnection c, int offs) {
		int offset = offs;
		switch (ServerParseSelect.parse(stmt, offs)) {
		case ServerParseSelect.VERSION_COMMENT:
			SelectVersionComment.response(c);
			break;
		case ServerParseSelect.DATABASE:
			SelectDatabase.response(c);
			break;
		case ServerParseSelect.USER:
			SelectUser.response(c);
			break;
		case ServerParseSelect.VERSION:
			SelectVersion.response(c);
			break;
		case ServerParseSelect.SESSION_INCREMENT:
			SessionIncrement.response(c);
			break;
		case ServerParseSelect.SESSION_ISOLATION:
			SessionIsolation.response(c);
			break;
		case ServerParseSelect.LAST_INSERT_ID:
			// offset = ParseUtil.move(stmt, 0, "select".length());
			loop: for (; offset < stmt.length(); ++offset) {
				switch (stmt.charAt(offset)) {
				case ' ':
					continue;
				case '/':
				case '#':
					offset = ParseUtil.comment(stmt, offset);
					continue;
				case 'L':
				case 'l':
					break loop;
				}
			}
			offset = ServerParseSelect.indexAfterLastInsertIdFunc(stmt, offset);
			offset = ServerParseSelect.skipAs(stmt, offset);
			SelectLastInsertId.response(c, stmt, offset);
			break;
		case ServerParseSelect.IDENTITY:
			// offset = ParseUtil.move(stmt, 0, "select".length());
			loop: for (; offset < stmt.length(); ++offset) {
				switch (stmt.charAt(offset)) {
				case ' ':
					continue;
				case '/':
				case '#':
					offset = ParseUtil.comment(stmt, offset);
					continue;
				case '@':
					break loop;
				}
			}
			int indexOfAtAt = offset;
			offset += 2;
			offset = ServerParseSelect.indexAfterIdentity(stmt, offset);
			String orgName = stmt.substring(indexOfAtAt, offset);
			offset = ServerParseSelect.skipAs(stmt, offset);
			SelectIdentity.response(c, stmt, offset, orgName);
			break;
		default:
			c.execute(stmt, ServerParse.SELECT);
		}
	}

}