/**
 * Copyright 1999-2015 dangdang.com.
 * <p>
 * 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.
 * </p>
 */

package test.algorithm;

import java.util.Collection;
import java.util.LinkedHashSet;

import com.dangdang.ddframe.rdb.sharding.api.ShardingValue;
import com.dangdang.ddframe.rdb.sharding.api.strategy.database.SingleKeyDatabaseShardingAlgorithm;
import com.google.common.collect.Range;

public final class ModuloDatabaseShardingAlgorithm implements SingleKeyDatabaseShardingAlgorithm<String>
{

	private static final String DATABASE_PREFIX = "shardingDataSource_";
	
	@Override
	public String doEqualSharding(final Collection<String> dataSourceNames, final ShardingValue<String> shardingValue)
	{
		String result = DATABASE_PREFIX + shardingValue.getValue().substring(0, 4);
		System.out.println("ModuloDatabaseShardingAlgorithm.doEqualSharding(): "+shardingValue + ", " + result);
		return result;
	}

	@Override
	public Collection<String> doInSharding(final Collection<String> dataSourceNames, final ShardingValue<String> shardingValues)
	{
		Collection<String> result = new LinkedHashSet<>(dataSourceNames.size());
		for (String value : shardingValues.getValues())
		{
			result.add(DATABASE_PREFIX + value.substring(0, 4));
		}
		System.out.println("ModuloDatabaseShardingAlgorithm.doInSharding(): "+shardingValues + ", " + result);
		return result;
	}

	@Override
	public Collection<String> doBetweenSharding(final Collection<String> dataSourceNames, final ShardingValue<String> shardingValues)
	{
		Range<String> range = shardingValues.getValueRange();
		int lowerDate = Integer.parseInt(range.lowerEndpoint().substring(0, 4));
		int upperDate = Integer.parseInt(range.upperEndpoint().substring(0, 4));
		
		Collection<String> result = new LinkedHashSet<>();
		result.add(""+lowerDate);
		lowerDate += 1;
		for( ; lowerDate < upperDate; lowerDate++ )
		{
			result.add(""+lowerDate);
		}
		result.add(""+upperDate);

		System.out.println("ModuloDatabaseShardingAlgorithm.doBetweenSharding(): "+shardingValues+", "+result);
		return result;
	}
}