/*
 * Copyright by the original author or authors.
 * 
 * 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.bitcoinj.wallet;

import org.bitcoinj.base.Coin;
import org.bitcoinj.core.TransactionOutput;

import java.util.List;

/**
 * A CoinSelector is responsible for picking some outputs to spend, from the list of all possible outputs. It
 * allows you to customize the policies for creation of transactions to suit your needs. The select operation
 * may return a {@link CoinSelection} that has a valueGathered lower than the requested target, if there's not
 * enough money in the wallet.
 */
public interface CoinSelector {
    /**
     * Creates a CoinSelection that tries to meet the target amount of value. The candidates list is given to
     * this call and can be edited freely. See the docs for CoinSelection to learn more, or look a the implementation
     * of {@link DefaultCoinSelector}.
     */
    CoinSelection select(Coin target, List<TransactionOutput> candidates);
}
