com.nebhale.springone2014.repository.InMemoryGameRepository.java Source code

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Here is the source code for com.nebhale.springone2014.repository.InMemoryGameRepository.java

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/*
 * Copyright 2014 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 com.nebhale.springone2014.repository;

import com.nebhale.springone2014.model.Door;
import com.nebhale.springone2014.model.DoorContent;
import com.nebhale.springone2014.model.Game;
import org.springframework.stereotype.Component;

import java.security.SecureRandom;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicLong;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@Component
final class InMemoryGameRepository implements GameRepository {

    private final Map<Long, Game> games = new HashMap<>();

    private final AtomicLong idGenerator = new AtomicLong();

    private final Object monitor = new Object();

    private final SecureRandom random = new SecureRandom();

    @Override
    public Game create() {
        synchronized (this.monitor) {
            Long id = this.idGenerator.getAndIncrement();
            Game game = new Game(id, createDoors());

            this.games.put(id, game);

            return game;
        }
    }

    @Override
    public Game retrieve(Long id) throws GameDoesNotExistException {
        synchronized (this.monitor) {
            if (!this.games.containsKey(id)) {
                throw new GameDoesNotExistException(id);
            }

            return this.games.get(id);
        }
    }

    @Override
    public void remove(Long id) throws GameDoesNotExistException {
        synchronized (this.monitor) {
            if (!this.games.containsKey(id)) {
                throw new GameDoesNotExistException(id);
            }

            this.games.remove(id);
        }
    }

    private Collection<Door> createDoors() {
        int winner = this.random.nextInt(3);

        return IntStream.range(0, 3).mapToObj(index -> {
            Long id = this.idGenerator.getAndIncrement();
            DoorContent content = (index == winner) ? DoorContent.BICYCLE : DoorContent.SMALL_FURRY_ANIMAL;
            return new Door(id, content);
        }).collect(Collectors.toList());
    }

}