#!/bin/bash
LOG_DIR=/var/log/hive
if [ ! -d $LOG_DIR ]; then
        mkdir -p $LOG_DIR
fi

HOST=$(hostname -I)
START_LOG=$LOG_DIR/hive-start.log
STOP_LOG=$LOG_DIR/hive-stop.log
METASTORE_PORT=9083
HIVESERVER2_PORT=10000
RETRY_TIMES=3

RED='\033[0;31m'
NC='\033[0m'

check_dependencies() {
        if ! nc --version &>/dev/null; then
                echo -e "${RED}Please use apt to install ncat!${NC}"
                return 1
        fi

        if ! pgrep --version &>/dev/null; then
                echo -e "${RED}Please use apt to install procps-ng!${NC}"
                return 1
        fi

        if ! hdfs dfsadmin -report &>/dev/null; then
                echo -e "${RED}Error: HDFS didn't run!${NC}"
                return 1
        fi

        if ! yarn node -list &>/dev/null; then
                echo -e "${RED}Error: YARN didn't run!${NC}"
                return 1
        fi
}

start_metastore() {
        local retry=0

        echo "$(date '+%Y-%m-%d %H:%M:%S') Starting metastore service..." >>$START_LOG
        nohup hive --service metastore -p $METASTORE_PORT >>$START_LOG 2>&1 &
        while [ $retry -lt $RETRY_TIMES ]; do
                sleep 5
                if nc -z $HOST $METASTORE_PORT; then
                        return 0
                fi
                ((retry++))
        done

        if [ $retry -eq $RETRY_TIMES ]; then
                echo -e "${RED}MetaStore failed to start, Check $START_LOG.${NC}"
                return 1
        fi
}

start_hiveserver2() {
        local retry=0

        echo "$(date '+%Y-%m-%d %H:%M:%S') Starting hiveserver2 service...)" >>$START_LOG
        nohup hive --service hiveserver2 >>$START_LOG 2>&1 &
        while [ $retry -le $RETRY_TIMES ]; do
                sleep 5
                if nc -z $HOST $HIVESERVER2_PORT; then
                        return 0
                fi
                ((retry++))
        done

        if [ $retry -eq $RETRY_TIMES ]; then
                echo -e "${RED}HiveServer2 failed to start, Check $START_LOG.${NC}"
                return 1
        fi
}

stop_process() {
        local name=$1
        local pattern=$2
        local pid
        pid=$(pgrep -f "$pattern")

        if [[ -n $pid ]]; then
                echo "Stopping $name..." >>$STOP_LOG
                kill $pid
                sleep 10
                if pgrep -f "$pattern" &>/dev/null; then
                        kill -9 $pid
                fi
        fi
}

case "$1" in
start)
        echo "$(date '+%Y-%m-%d %H:%M:%S') Starting Hive Cluster..." >>$START_LOG
        if ! check_dependencies; then
                exit 1
        fi

        if ! start_metastore; then
                exit 1
        fi

        if ! start_hiveserver2; then
                exit 1
        fi

        echo -e "Hive started successfully."
        ;;
stop)
        echo "$(date '+%Y-%m-%d %H:%M:%S') Stopping Hive Cluster..." >>$STOP_LOG
        stop_process "MetaStore" "metastore"
        stop_process "HiveServer2" "hiveserver2"
        echo "Hive stopped."
        ;;
*)
        echo "Usage: $0 {start|stop}"
        exit 1
        ;;
esac

exit 0

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;

public class App {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        Connection conn = Util.getConnection("org.apache.hive.jdbc.HiveDriver", "jdbc:hive2://172.18.0.2:10000", "root",
                "123456");
        Statement stmt = Util.getStatement(conn);
        stmt.execute("drop table if exists users");
        stmt.execute(
                "create table users (user_id int, fname string, lname string) row format delimited fields terminated by ','");
        stmt.execute("insert into users (user_id, fname, lname) values(222, 'yang', 'yang2')");
        stmt.execute("load data local inpath '/root/CodeProject/hive-advance/data.txt' into table users");

        String sql = "select * from users";
        ResultSet res = stmt.executeQuery(sql);
        ResultSetMetaData meta = res.getMetaData();
        for (int i = 1; i <= meta.getColumnCount(); i++) {
            System.out.print(meta.getColumnName(i) + "\t");
        }
        System.out.println();

        while (res.next()) {
            System.out.print(res.getInt(1) + "\t\t");
            System.out.print(res.getString(2) + "\t\t");
            System.out.print(res.getString(3));
            System.out.println();
        }

        sql = "show tables";
        System.out.println("Running: " + sql);
        res = stmt.executeQuery(sql);
        while (res.next()) {
            System.out.print(res.getString(1));
        }
        System.out.println("");

        sql = "desc users";
        System.out.println("Running: " + sql);
        res = stmt.executeQuery(sql);
        while (res.next()) {
            System.out.println(res.getString(1) + "\t" + res.getString(2));
        }

        Util.closeStatement(stmt);
        Util.closeConnection(conn);
    }
}