/**
 * 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.hcatalog.hbase;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.MiniHBaseCluster;
import org.apache.hadoop.hbase.client.HConnectionManager;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.zookeeper.MiniZooKeeperCluster;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.HiveMetaStoreClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MiniMRCluster;

import java.io.File;
import java.io.IOException;
import java.net.ServerSocket;

/**
 * MiniCluster class composed of a number of Hadoop Minicluster implementations
 * and other necessary daemons needed for testing (HBase, Hive MetaStore, Zookeeper, MiniMRCluster)
 */
public class ManyMiniCluster {

    //MR stuff
    private boolean miniMRClusterEnabled;
    private MiniMRCluster mrCluster;
    private int numTaskTrackers;
    private JobConf jobConf;

    //HBase stuff
    private boolean miniHBaseClusterEnabled;
    private MiniHBaseCluster hbaseCluster;
    private String hbaseRoot;
    private Configuration hbaseConf;
    private String hbaseDir;

    //ZK Stuff
    private boolean miniZookeeperClusterEnabled;
    private MiniZooKeeperCluster zookeeperCluster;
    private int zookeeperPort;
    private String zookeeperDir;

    //DFS Stuff
    private MiniDFSCluster dfsCluster;

    //Hive Stuff
    private boolean miniHiveMetastoreEnabled;
    private HiveConf hiveConf;
    private HiveMetaStoreClient hiveMetaStoreClient;

    private final File workDir;
    private boolean started = false;


    /**
     * create a cluster instance using a builder which will expose configurable options
     * @param workDir working directory ManyMiniCluster will use for all of it's *Minicluster instances
     * @return a Builder instance
     */
    public static Builder create(File workDir) {
        return new Builder(workDir);
    }

    private ManyMiniCluster(Builder b) {
        workDir = b.workDir;
        numTaskTrackers = b.numTaskTrackers;
        hiveConf = b.hiveConf;
        jobConf = b.jobConf;
        hbaseConf = b.hbaseConf;
        miniMRClusterEnabled = b.miniMRClusterEnabled;
        miniHBaseClusterEnabled = b.miniHBaseClusterEnabled;
        miniHiveMetastoreEnabled = b.miniHiveMetastoreEnabled;
        miniZookeeperClusterEnabled = b.miniZookeeperClusterEnabled;
    }

    protected synchronized  void start() {
        try {
            if (!started) {
                FileUtil.fullyDelete(workDir);
                if(miniMRClusterEnabled) {
                    setupMRCluster();
                }
                if(miniZookeeperClusterEnabled || miniHBaseClusterEnabled) {
                    miniZookeeperClusterEnabled = true;
                    setupZookeeper();
                }
                if(miniHBaseClusterEnabled) {
                    setupHBaseCluster();
                }
                if(miniHiveMetastoreEnabled) {
                    setUpMetastore();
                }
            }
        } catch(Exception e) {
            throw new IllegalStateException("Failed to setup cluster",e);
        }
    }

    protected synchronized  void stop() {
        if (hbaseCluster != null) {
            HConnectionManager.deleteAllConnections(true);
            try {
                hbaseCluster.shutdown();
            } catch (Exception e) {
                e.printStackTrace();
            }
            hbaseCluster = null;
        }
        if (zookeeperCluster != null) {
            try {
                zookeeperCluster.shutdown();
            } catch (Exception e) {
                e.printStackTrace();
            }
            zookeeperCluster = null;
        }
        if(mrCluster != null) {
            try {
                mrCluster.shutdown();
            } catch(Exception e) {
                e.printStackTrace();
            }
            mrCluster = null;
        }
        if(dfsCluster != null) {
            try {
                dfsCluster.getFileSystem().close();
                dfsCluster.shutdown();
            } catch(Exception e) {
                e.printStackTrace();
            }
            dfsCluster = null;
        }
        try {
            FileSystem.closeAll();
        } catch (IOException e) {
            e.printStackTrace();
        }
        started = false;
    }

    /**
     * @return Configuration of mini HBase cluster
     */
    public Configuration getHBaseConf() {
        return HBaseConfiguration.create(hbaseConf);
    }

    /**
     * @return Configuration of mini MR cluster
     */
    public Configuration getJobConf() {
        return new Configuration(jobConf);
    }

    /**
     * @return Configuration of Hive Metastore, this is a standalone not a daemon
     */
    public HiveConf getHiveConf() {
        return new HiveConf(hiveConf);
    }

    /**
     * @return Filesystem used by MiniMRCluster and MiniHBaseCluster
     */
    public FileSystem getFileSystem() {
        try {
            return FileSystem.get(jobConf);
        } catch (IOException e) {
            throw new IllegalStateException("Failed to get FileSystem",e);
        }
    }

    /**
     * @return Metastore client instance
     */
    public HiveMetaStoreClient getHiveMetaStoreClient() {
        return hiveMetaStoreClient;
    }

    private void setupMRCluster() {
        try {
            final int jobTrackerPort = findFreePort();
            final int taskTrackerPort = findFreePort();

            if(jobConf == null)
                jobConf = new JobConf();

            jobConf.setInt("mapred.submit.replication", 1);
            //conf.set("hadoop.job.history.location",new File(workDir).getAbsolutePath()+"/history");
            System.setProperty("hadoop.log.dir",new File(workDir,"/logs").getAbsolutePath());

            mrCluster = new MiniMRCluster(jobTrackerPort,
                                          taskTrackerPort,
                                          numTaskTrackers,
                                          getFileSystem().getUri().toString(),
                                          numTaskTrackers,
                                          null,
                                          null,
                                          null,
                                          jobConf);

            jobConf = mrCluster.createJobConf();
        } catch (IOException e) {
            throw new IllegalStateException("Failed to Setup MR Cluster",e);
        }
    }

    private void setupZookeeper() {
        try {
            zookeeperDir = new File(workDir,"zk").getAbsolutePath();
            zookeeperPort = findFreePort();
            zookeeperCluster = new MiniZooKeeperCluster();
            zookeeperCluster.setDefaultClientPort(zookeeperPort);
            zookeeperCluster.startup(new File(zookeeperDir));
        } catch(Exception e) {
            throw new IllegalStateException("Failed to Setup Zookeeper Cluster",e);
        }
    }

    private void setupHBaseCluster() {
        final int numRegionServers = 1;

        try {
            hbaseDir = new File(workDir,"hbase").getAbsolutePath();
            hbaseRoot = "file://" + hbaseDir;

            if(hbaseConf == null)
                hbaseConf = HBaseConfiguration.create();

            hbaseConf.set("hbase.rootdir", hbaseRoot);
            hbaseConf.set("hbase.master", "local");
            hbaseConf.setInt(HConstants.ZOOKEEPER_CLIENT_PORT, zookeeperPort);
            hbaseConf.set(HConstants.ZOOKEEPER_QUORUM, "127.0.0.1");
            hbaseConf.setInt("hbase.master.port", findFreePort());
            hbaseConf.setInt("hbase.master.info.port", -1);
            hbaseConf.setInt("hbase.regionserver.port", findFreePort());
            hbaseConf.setInt("hbase.regionserver.info.port", -1);

            hbaseCluster = new MiniHBaseCluster(hbaseConf, numRegionServers);
            hbaseConf.set("hbase.master", hbaseCluster.getMaster().getServerName().getHostAndPort());
            //opening the META table ensures that cluster is running
            new HTable(hbaseConf, HConstants.META_TABLE_NAME);
        } catch (Exception e) {
            throw new IllegalStateException("Failed to setup HBase Cluster",e);
        }
    }

    private void setUpMetastore() throws Exception {
        if(hiveConf == null)
            hiveConf = new HiveConf(this.getClass());

        //The default org.apache.hadoop.hive.ql.hooks.PreExecutePrinter hook
        //is present only in the ql/test directory
        hiveConf.set(HiveConf.ConfVars.PREEXECHOOKS.varname, "");
        hiveConf.set(HiveConf.ConfVars.POSTEXECHOOKS.varname, "");
        hiveConf.set(HiveConf.ConfVars.HIVE_SUPPORT_CONCURRENCY.varname, "false");
        hiveConf.set(HiveConf.ConfVars.METASTORECONNECTURLKEY.varname,
                     "jdbc:derby:"+new File(workDir+"/metastore_db")+";create=true");
        hiveConf.set(HiveConf.ConfVars.METASTOREWAREHOUSE.toString(),
                     new File(workDir,"warehouse").toString());
        //set where derby logs
        File derbyLogFile = new File(workDir+"/derby.log");
        derbyLogFile.createNewFile();
        System.setProperty("derby.stream.error.file",derbyLogFile.getPath());


//    Driver driver = new Driver(hiveConf);
//    SessionState.start(new CliSessionState(hiveConf));

        hiveMetaStoreClient = new HiveMetaStoreClient(hiveConf);
    }

    private static int findFreePort() throws IOException {
        ServerSocket server = new ServerSocket(0);
        int port = server.getLocalPort();
        server.close();
        return port;
    }

    public static class Builder {
        private File workDir;
        private int numTaskTrackers = 1;
        private JobConf jobConf;
        private Configuration hbaseConf;
        private HiveConf hiveConf;

        private boolean miniMRClusterEnabled = true;
        private boolean miniHBaseClusterEnabled = true;
        private boolean miniHiveMetastoreEnabled = true;
        private boolean miniZookeeperClusterEnabled = true;


        private Builder(File workDir) {
            this.workDir = workDir;
        }

        public Builder numTaskTrackers(int num) {
            numTaskTrackers = num;
            return this;
        }

        public Builder jobConf(JobConf jobConf) {
            this.jobConf = jobConf;
            return this;
        }

        public Builder hbaseConf(Configuration hbaseConf) {
            this.hbaseConf = hbaseConf;
            return this;
        }

        public Builder hiveConf(HiveConf hiveConf) {
            this.hiveConf = hiveConf;
            return this;
        }

        public Builder miniMRClusterEnabled(boolean enabled) {
            this.miniMRClusterEnabled = enabled;
            return this;
        }

        public Builder miniHBaseClusterEnabled(boolean enabled) {
            this.miniHBaseClusterEnabled = enabled;
            return this;
        }

        public Builder miniZookeeperClusterEnabled(boolean enabled) {
            this.miniZookeeperClusterEnabled = enabled;
            return this;
        }

        public Builder miniHiveMetastoreEnabled(boolean enabled) {
            this.miniHiveMetastoreEnabled = enabled;
            return this;
        }


        public ManyMiniCluster build() {
            return new ManyMiniCluster(this);
        }

    }
}