/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.zookeeper.test;

import static org.junit.jupiter.api.Assertions.fail;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import org.apache.zookeeper.PortAssignment;
import org.apache.zookeeper.ZKTestCase;
import org.apache.zookeeper.server.quorum.QuorumPeer;
import org.apache.zookeeper.server.quorum.QuorumPeer.QuorumServer;
import org.apache.zookeeper.server.quorum.QuorumPeer.ServerState;
import org.apache.zookeeper.server.quorum.Vote;
import org.apache.zookeeper.server.quorum.flexible.QuorumHierarchical;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class FLEZeroWeightTest extends ZKTestCase {

    private static final Logger LOG = LoggerFactory.getLogger(HierarchicalQuorumTest.class);

    Properties qp;

    int count;
    Map<Long, QuorumServer> peers;
    ArrayList<LEThread> threads;
    File[] tmpdir;
    int[] port;

    volatile Vote[] votes;

    @BeforeEach
    public void setUp() throws Exception {
        count = 9;

        peers = new HashMap<>(count);
        threads = new ArrayList<>(count);
        votes = new Vote[count];
        tmpdir = new File[count];
        port = new int[count];

        String config = "group.1=0:1:2\n"
                                + "group.2=3:4:5\n"
                                + "group.3=6:7:8\n"
                                + "weight.0=1\n"
                                + "weight.1=1\n"
                                + "weight.2=1\n"
                                + "weight.3=0\n"
                                + "weight.4=0\n"
                                + "weight.5=0\n"
                                + "weight.6=0\n"
                                + "weight.7=0\n"
                                + "weight.8=0";

        ByteArrayInputStream is = new ByteArrayInputStream(config.getBytes());
        this.qp = new Properties();
        qp.load(is);
    }

    @AfterEach
    public void tearDown() throws Exception {
        for (int i = 0; i < threads.size(); i++) {
            LEThread leThread = threads.get(i);
            // shutdown() has to be explicitly called for every thread to
            // make sure that resources are freed properly and all fixed network ports
            // are available for other test cases
            QuorumBase.shutdown(leThread.peer);
        }
    }

    class LEThread extends Thread {

        int i;
        QuorumPeer peer;
        boolean fail;

        LEThread(QuorumPeer peer, int i) {
            this.i = i;
            this.peer = peer;
            LOG.info("Constructor: {}", getName());
        }

        public void run() {
            try {
                Vote v = null;
                fail = false;
                while (true) {

                    //while(true) {
                    peer.setPeerState(ServerState.LOOKING);
                    LOG.info("Going to call leader election.");
                    v = peer.getElectionAlg().lookForLeader();
                    if (v == null) {
                        LOG.info("Thread {} got a null vote", i);
                        return;
                    }

                    /*
                     * A real zookeeper would take care of setting the current vote. Here
                     * we do it manually.
                     */
                    peer.setCurrentVote(v);

                    LOG.info("Finished election: {}, {}", i, v.getId());
                    votes[i] = v;

                    if ((peer.getPeerState() == ServerState.LEADING) && (peer.getMyId() > 2)) {
                        fail = true;
                    }

                    if ((peer.getPeerState() == ServerState.FOLLOWING) || (peer.getPeerState()
                                                                                   == ServerState.LEADING)) {
                        break;
                    }
                }
                LOG.debug("Thread {} votes {}", i, v);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }

    @Test
    public void testZeroWeightQuorum() throws Exception {
        LOG.info("TestZeroWeightQuorum: {}, {}", getTestName(), count);
        for (int i = 0; i < count; i++) {
            InetSocketAddress addr1 = new InetSocketAddress("127.0.0.1", PortAssignment.unique());
            InetSocketAddress addr2 = new InetSocketAddress("127.0.0.1", PortAssignment.unique());
            InetSocketAddress addr3 = new InetSocketAddress("127.0.0.1", PortAssignment.unique());
            port[i] = addr3.getPort();
            qp.setProperty("server." + i, "127.0.0.1:" + addr1.getPort() + ":" + addr2.getPort() + ";" + port[i]);
            peers.put(Long.valueOf(i), new QuorumServer(i, addr1, addr2, addr3));
            tmpdir[i] = ClientBase.createTmpDir();
        }

        for (int i = 0; i < count; i++) {
            QuorumHierarchical hq = new QuorumHierarchical(qp);
            QuorumPeer peer = new QuorumPeer(peers, tmpdir[i], tmpdir[i], port[i], 3, i, 1000, 2, 2, 2, hq);
            peer.startLeaderElection();
            LEThread thread = new LEThread(peer, i);
            thread.start();
            threads.add(thread);
        }
        LOG.info("Started threads {}", getTestName());

        for (int i = 0; i < threads.size(); i++) {
            threads.get(i).join(15000);
            if (threads.get(i).isAlive()) {
                fail("Threads didn't join");
            } else {
                if (threads.get(i).fail) {
                    fail("Elected zero-weight server");
                }
            }
        }
    }

}
