/*
 * Copyright DataStax, Inc.
 *
 * 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.datastax.driver.core;

import com.datastax.driver.core.utils.CassandraVersion;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import java.util.concurrent.TimeUnit;

import static com.datastax.driver.core.Assertions.assertThat;
import static com.datastax.driver.core.Assertions.fail;
import static com.datastax.driver.core.Host.State.DOWN;
import static com.datastax.driver.core.Host.State.UP;
import static com.datastax.driver.core.TestUtils.nonDebouncingQueryOptions;

/**
 * Due to C* gossip bugs, system.peers may report nodes that are gone from the cluster.
 * <p/>
 * This class tests scenarios where these nodes have been recommissioned to another cluster and
 * come back up. The driver must detect that they are not part of the cluster anymore, and ignore them.
 */
public class RecommissionedNodeTest {
    private static final Logger logger = LoggerFactory.getLogger(RecommissionedNodeTest.class);

    CCMBridge.Builder mainCcmBuilder, otherCcmBuilder;
    CCMAccess mainCcm, otherCcm;
    Cluster mainCluster;

    @Test(groups = "long")
    public void should_ignore_recommissioned_node_on_reconnection_attempt() throws Exception {
        mainCcmBuilder = CCMBridge.builder().withNodes(3);
        mainCcm = CCMCache.get(mainCcmBuilder);

        // node1 will be our "recommissioned" node, for now we just stop it so that it stays in the peers table.
        mainCcm.stop(1);
        mainCcm.waitForDown(1);

        // Now start the driver that will connect to node2 and node3, and consider node1 down
        mainCluster = Cluster.builder()
                .addContactPoints(mainCcm.addressOfNode(2).getAddress())
                .withPort(mainCcm.getBinaryPort())
                .withQueryOptions(nonDebouncingQueryOptions()).build();
        mainCluster.connect();
        waitForCountUpHosts(mainCluster, 2);
        // From that point, reconnections to node1 have been scheduled.

        // Start another ccm that will reuse node1's address
        otherCcmBuilder = CCMBridge.builder()
                .withStoragePort(mainCcm.getStoragePort())
                .withThriftPort(mainCcm.getThriftPort())
                .withBinaryPort(mainCcm.getBinaryPort())
                .withNodes(1);
        otherCcm = CCMCache.get(otherCcmBuilder);
        otherCcm.waitForUp(1);

        // Give the driver the time to notice the node is back up and try to connect to it.
        TimeUnit.SECONDS.sleep(32);

        assertThat(countUpHosts(mainCluster)).isEqualTo(2);
    }

    @Test(groups = "long")
    public void should_ignore_recommissioned_node_on_control_connection_reconnect() throws Exception {
        mainCcmBuilder = CCMBridge.builder().withNodes(2);
        mainCcm = CCMCache.get(mainCcmBuilder);
        mainCcm.stop(1);
        mainCcm.waitForDown(1);

        // Start the driver, the control connection will be on node2
        mainCluster = Cluster.builder()
                .addContactPoints(mainCcm.addressOfNode(2).getAddress())
                .withPort(mainCcm.getBinaryPort())
                .withQueryOptions(nonDebouncingQueryOptions()).build();
        mainCluster.connect();
        waitForCountUpHosts(mainCluster, 1);

        // Start another ccm that will reuse node1's address
        otherCcmBuilder = CCMBridge.builder()
                .withStoragePort(mainCcm.getStoragePort())
                .withThriftPort(mainCcm.getThriftPort())
                .withBinaryPort(mainCcm.getBinaryPort())
                .withNodes(1);
        otherCcm = CCMCache.get(otherCcmBuilder);
        otherCcm.waitForUp(1);

        // Stop node2, the control connection gets defunct
        mainCcm.stop(2);
        TimeUnit.SECONDS.sleep(32);

        // The driver should not try to reconnect the control connection to node1
        assertThat(mainCluster).hasClosedControlConnection();
    }

    @Test(groups = "long")
    public void should_ignore_recommissioned_node_on_session_init() throws Exception {
        // Simulate the bug before starting the cluster
        mainCcmBuilder = CCMBridge.builder().withNodes(2);
        mainCcm = CCMCache.get(mainCcmBuilder);
        mainCcm.stop(1);
        mainCcm.waitForDown(1);

        otherCcmBuilder = CCMBridge.builder()
                .withStoragePort(mainCcm.getStoragePort())
                .withThriftPort(mainCcm.getThriftPort())
                .withBinaryPort(mainCcm.getBinaryPort())
                .withNodes(1);
        otherCcm = CCMCache.get(otherCcmBuilder);
        otherCcm.waitForUp(1);

        // Start the driver, it should only connect to node 2
        mainCluster = Cluster.builder()
                .addContactPoints(mainCcm.addressOfNode(2).getAddress())
                .withPort(mainCcm.getBinaryPort())
                .withQueryOptions(nonDebouncingQueryOptions()).build();

        // When we first initialize the Cluster, all hosts are marked UP
        assertThat(mainCluster).host(2).hasState(UP);
        assertThat(mainCluster).host(1).hasState(UP);

        // Create a session. This will try to open a pool to node 1 and find out that the cluster name doesn't match.
        mainCluster.connect();

        // Node 1 should now be DOWN with no reconnection attempt
        assertThat(mainCluster).host(1)
                .goesDownWithin(10, TimeUnit.SECONDS)
                .hasState(DOWN)
                .isNotReconnectingFromDown();
    }

    @Test(groups = "long", enabled=false, description="Disabled because requires specific C* version, not essential")
    @CassandraVersion("3.0.0")
    public void should_ignore_node_that_does_not_support_protocol_version_on_session_init() throws Exception {
        // Simulate the bug before starting the cluster
        mainCcmBuilder = CCMBridge.builder().withNodes(2);
        mainCcm = CCMCache.get(mainCcmBuilder);
        mainCcm.stop(1);
        mainCcm.waitForDown(1);

        otherCcmBuilder = CCMBridge.builder().withNodes(1)
                .withStoragePort(mainCcm.getStoragePort())
                .withThriftPort(mainCcm.getThriftPort())
                .withBinaryPort(mainCcm.getBinaryPort())
                .withVersion(VersionNumber.parse("2.1.20"));
        otherCcm = CCMCache.get(otherCcmBuilder);
        otherCcm.waitForUp(1);

        // Start the driver, it should only connect to node 2
        mainCluster = Cluster.builder()
                .addContactPoints(mainCcm.addressOfNode(2).getAddress())
                .withPort(mainCcm.getBinaryPort())
                .withQueryOptions(nonDebouncingQueryOptions()).build();

        // Create a session. This will try to open a pool to node 1 and find that it doesn't support protocol version.
        mainCluster.connect();

        // Node 1 should now be DOWN with no reconnection attempt
        assertThat(mainCluster).host(1)
                .goesDownWithin(10, TimeUnit.SECONDS)
                .hasState(DOWN)
                .isNotReconnectingFromDown();
    }

    @BeforeMethod(groups = "long")
    public void clearFields() {
        // Clear cluster and ccm instances between tests.
        mainCluster = null;
        mainCcmBuilder = null;
        otherCcmBuilder = null;
        mainCcm = null;
        otherCcm = null;
    }

    @AfterMethod(groups = "long", alwaysRun = true)
    public void teardown() {
        if (mainCluster != null)
            mainCluster.close();
        if (mainCcmBuilder != null)
            CCMCache.remove(mainCcmBuilder);
        if (otherCcmBuilder != null)
            CCMCache.remove(otherCcmBuilder);
        if (mainCcm != null)
            mainCcm.close();
        if (otherCcm != null)
            otherCcm.close();
    }

    private static int countUpHosts(Cluster cluster) {
        int ups = 0;
        for (Host host : cluster.getMetadata().getAllHosts()) {
            if (host.isUp())
                ups += 1;
        }
        return ups;
    }

    private static void waitForCountUpHosts(Cluster cluster, int expectedCount) throws InterruptedException {
        int maxRetries = 10;
        int interval = 6;

        for (int i = 0; i <= maxRetries; i++) {
            int actualCount = countUpHosts(cluster);
            if (actualCount == expectedCount)
                return;

            if (i == maxRetries)
                fail(String.format("Up host count didn't reach %d after %d seconds",
                        expectedCount, i * interval));
            else
                logger.debug("Counted {} up hosts after {} seconds", actualCount, i * interval);

            TimeUnit.SECONDS.sleep(interval);
        }
    }
}
