import java.util.concurrent.Future;

import org.aredis.cache.AsyncRedisClient;
import org.aredis.cache.AsyncRedisConnection;
import org.aredis.cache.AsyncRedisFactory;
import org.aredis.cache.RedisCommand;
import org.aredis.cache.RedisCommandInfo;
import org.aredis.util.pool.AsyncObjectPool;

/*
 * A connection pool is required for commands that use WATCH with MULTI and EXEC.
 *
 * The below program demonstrates the use of WATCH with MULTI and EXEC to add 3 to the number stored
 * in the key hello. This is just for showing the use of WATCH, MULTI, EXEC. You could accomplish
 * the same thing using a single INCRBY command.
 */
public class ConnectionPool {
    public static void main(String args[]) throws Exception {
        String key = "hello";
        AsyncRedisFactory f = new AsyncRedisFactory(null);
        AsyncRedisClient aredis = f.getClient("localhost");
        // Set an initial value for this test
        aredis.submitCommand(RedisCommand.SETEX, key, "300", "5").get();
        int i, maxTries = 10;
        AsyncObjectPool<AsyncRedisConnection> pool = f.getConnectionPool("localhost");
        AsyncRedisConnection con = null;
        i = 0;
        do {
            Future<RedisCommandInfo[]> future = null;
            try {
                con = pool.syncBorrow(0);
                // "WATCH" the key so that the transaction fails if another client writes
                // to the key in between
                con.sendCommand(RedisCommand.WATCH, key);
                // Get the current value as an integer
                int val = con.submitCommand(RedisCommand.GET, key).get().getIntResult(0);
                val += 3;
                // Update the value in a multi-exec transaction
                future = con.submitCommands(new RedisCommandInfo[] {
                   new RedisCommandInfo(RedisCommand.MULTI),
                   new RedisCommandInfo(RedisCommand.SETEX, key, "300", String.valueOf(val)),
                   new RedisCommandInfo(RedisCommand.EXEC)
                });
            }
            finally {
                // Note that the connection is returned to pool as soon as the EXEC command
                // is submitted without waiting for it to finish which is Ok.
                pool.returnToPool(con);
            }
            // On success of EXEC results will contain an Array of CommandInfo objects corresponding to the
            // result of execution of each of the commands between MULTI and exec
            Object results[] = (Object[]) future.get()[2].getResult();
            if(results != null) {
                System.out.println("Result of SETEX command in Transaction: " + ((RedisCommandInfo) results[0]).getResult());
                break;
            }
            // Retries will not be executed in this example because it is a single client
        } while(i < maxTries);
        if(i >= maxTries) {
            System.out.println("Addition to key: " + key + " failed. Is your Redis Server up?");
        }
    }

}