/*
 * 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.
 */
/**
 * (created at 2011-11-21)
 */
package org.opencloudb.route.function;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;

import org.opencloudb.config.model.rule.RuleAlgorithm;

/**
 * @author mycat
 */
public class PartitionByFileMap implements RuleAlgorithm {

	private String mapFile;
	private Map<Integer, Integer> app2Partition;

	@Override
	public void init() {

		initialize();
	}

	public void setMapFile(String mapFile) {
		this.mapFile = mapFile;
	}

	@Override
	public Integer calculate(String columnValue) {
		Integer value = Integer.valueOf(columnValue);
		Integer rst = null;
		Integer pid = app2Partition.get(value);
		if (pid != null) {
			rst = pid;
		}
		return rst;
	}

	private void initialize() {
		BufferedReader in = null;
		try {
			// FileInputStream fin = new FileInputStream(new File(fileMapPath));
			InputStream fin = this.getClass().getClassLoader()
					.getResourceAsStream(mapFile);
			if (fin == null) {
				throw new RuntimeException("can't find class resource file "
						+ mapFile);
			}
			in = new BufferedReader(new InputStreamReader(fin));
			app2Partition = new HashMap<Integer, Integer>();
			for (String line = null; (line = in.readLine()) != null;) {
				line = line.trim();
				if (line.startsWith("#") || line.startsWith("//"))
					continue;
				int ind = line.indexOf('=');
				if (ind < 0)
					continue;
				try {
					String key = line.substring(0, ind).trim();
					int pid = Integer.parseInt(line.substring(ind + 1).trim());
					app2Partition.put(Integer.parseInt(key), pid);
				} catch (Exception e) {
				}
			}
		} catch (Exception e) {
			if (e instanceof RuntimeException) {
				throw (RuntimeException) e;
			} else {
				throw new RuntimeException(e);
			}

		} finally {
			try {
				in.close();
			} catch (Exception e2) {
			}
		}
	}
}