HOST=`hostname -s`
DOMAIN=`hostname -d`
LOG_LEVEL=INFO
DATA_DIR="/var/lib/zookeeper/data"
DATA_LOG_DIR="/var/lib/zookeeper/log"
LOG_DIR="/var/log/zookeeper"
CONF_DIR="/opt/zookeeper/conf"
CLIENT_PORT=2181
SERVER_PORT=2888
ELECTION_PORT=3888
TICK_TIME=2000
INIT_LIMIT=10
SYNC_LIMIT=5
HEAP=2G
MAX_CLIENT_CNXNS=60
SNAP_RETAIN_COUNT=3
PURGE_INTERVAL=0
SERVERS=1

function print_usage() {
echo "\
Usage: start-zookeeper [OPTIONS]
Starts a ZooKeeper server based on the supplied options.
    --servers           The number of servers in the ensemble. The default 
                        value is 1.

    --data_dir          The directory where the ZooKeeper process will store its
                        snapshots. The default is /var/lib/zookeeper/data.

    --data_log_dir      The directory where the ZooKeeper process will store its 
                        write ahead log. The default is 
                        /var/lib/zookeeper/data/log.

    --conf_dir          The directoyr where the ZooKeeper process will store its
                        configuration. The default is /opt/zookeeper/conf.

    --client_port       The port on which the ZooKeeper process will listen for 
                        client requests. The default is 2181.

    --election_port     The port on which the ZooKeeper process will perform 
                        leader election. The default is 3888.

    --server_port       The port on which the ZooKeeper process will listen for 
                        requests from other servers in the ensemble. The 
                        default is 2888. 

    --tick_time         The length of a ZooKeeper tick in ms. The default is 
                        2000.

    --init_limit        The number of Ticks that an ensemble member is allowed 
                        to perform leader election. The default is 10.

    --sync_limit        The maximum session timeout that the ensemble will 
                        allows a client to request. The default is 5.

    --heap              The maximum amount of heap to use. The format is the 
                        same as that used for the Xmx and Xms parameters to the 
                        JVM. e.g. --heap=2G. The default is 2G.

    --max_client_cnxns  The maximum number of client connections that the 
                        ZooKeeper process will accept simultaneously. The 
                        default is 60.

    --snap_retain_count The maximum number of snapshots the ZooKeeper process 
                        will retain if purge_interval is greater than 0. The 
                        default is 3.

    --purge_interval    The number of hours the ZooKeeper process will wait 
                        between purging its old snapshots. If set to 0 old 
                        snapshots will never be purged. The default is 0.

    --max_session_timeout The maximum time in milliseconds for a client session 
                        timeout. The default value is 2 * tick time.

    --min_session_timeout The minimum time in milliseconds for a client session 
                        timeout. The default value is 20 * tick time.

    --log_level         The log level for the zookeeeper server. Either FATAL,
                        ERROR, WARN, INFO, DEBUG. The default is INFO.
      
    --pre_alloc_size    Allocates space in the transaction log file in blocks of preAllocSize kilobytes.
                       The default block size is 64M. 
"
}

function create_data_dirs() {
    if [ ! -d $DATA_DIR  ]; then
        mkdir -p $DATA_DIR
    fi

    if [ ! -d $DATA_LOG_DIR  ]; then
        mkdir -p $DATA_LOG_DIR
    fi

    if [ ! -d $LOG_DIR  ]; then
        mkdir -p $LOG_DIR
    fi
    
    if [ ! -f $ID_FILE ] && [ $SERVERS -gt 1 ]; then
        echo $MY_ID >> $ID_FILE
    fi
}

function print_servers() {
    for (( i=1; i<=$SERVERS; i++ ))
    do
        echo "server.$i=$NAME-$((i-1)).$DOMAIN:$SERVER_PORT:$ELECTION_PORT"
    done
}

function create_config() {
    rm -f $CONFIG_FILE
    echo "#This file was autogenerated DO NOT EDIT" >> $CONFIG_FILE
    echo "clientPort=$CLIENT_PORT" >> $CONFIG_FILE
    echo "dataDir=$DATA_DIR" >> $CONFIG_FILE
    echo "dataLogDir=$DATA_LOG_DIR" >> $CONFIG_FILE
    echo "tickTime=$TICK_TIME" >> $CONFIG_FILE
    echo "initLimit=$INIT_LIMIT" >> $CONFIG_FILE
    echo "syncLimit=$SYNC_LIMIT" >> $CONFIG_FILE
    echo "maxClientCnxns=$MAX_CLIENT_CNXNS" >> $CONFIG_FILE
    echo "minSessionTimeout=$MIN_SESSION_TIMEOUT" >> $CONFIG_FILE
    echo "maxSessionTimeout=$MAX_SESSION_TIMEOUT" >> $CONFIG_FILE
    echo "autopurge.snapRetainCount=$SNAP_RETAIN_COUNT" >> $CONFIG_FILE
    echo "autopurge.purgeInteval=$PURGE_INTERVAL" >> $CONFIG_FILE
    echo "preAllocSize=$PRE_ALLOC_SIZE" >> $CONFIG_FILE
     if [ $SERVERS -gt 1 ]; then
        print_servers >> $CONFIG_FILE
    fi
    cat $CONFIG_FILE >&2
}

function create_jvm_props() {
    rm -f $JAVA_ENV_FILE
    echo "ZOO_LOG_DIR=$LOG_DIR" >> $JAVA_ENV_FILE
    echo "JVMFLAGS=\"-Xmx$HEAP -Xms$HEAP\"" >> $JAVA_ENV_FILE
}

function create_log_props() {
    rm -f $LOGGER_PROPS_FILE
    echo "Creating ZooKeeper log4j configuration"
    echo "zookeeper.root.logger=CONSOLE" >> $LOGGER_PROPS_FILE
    echo "zookeeper.console.threshold="$LOG_LEVEL >> $LOGGER_PROPS_FILE
    echo "log4j.rootLogger=\${zookeeper.root.logger}" >> $LOGGER_PROPS_FILE
    echo "log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender" >> $LOGGER_PROPS_FILE
    echo "log4j.appender.CONSOLE.Threshold=\${zookeeper.console.threshold}" >> $LOGGER_PROPS_FILE
    echo "log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout" >> $LOGGER_PROPS_FILE
    echo "log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} [myid:%X{myid}] - %-5p [%t:%C{1}@%L] - %m%n" >> $LOGGER_PROPS_FILE
}

optspec=":hv-:"
while getopts "$optspec" optchar; do

    case "${optchar}" in
        -)
            case "${OPTARG}" in
                servers=*)
                    SERVERS=${OPTARG##*=}
                    ;;
                data_dir=*)
                    DATA_DIR=${OPTARG##*=}
                    ;;
                data_log_dir=*)
                    DATA_LOG_DIR=${OPTARG##*=}
                    ;;
                log_dir=*)
                    LOG_DIR=${OPTARG##*=}
                    ;;
                conf_dir=*)
                    CONF_DIR=${OPTARG##*=}
                    ;;
                client_port=*)
                    CLIENT_PORT=${OPTARG##*=}
                    ;;
                election_port=*)
                    ELECTION_PORT=${OPTARG##*=}
                    ;;
                server_port=*)
                    SERVER_PORT=${OPTARG##*=}
                    ;;
                tick_time=*)
                    TICK_TIME=${OPTARG##*=}
                    ;;
                init_limit=*)
                    INIT_LIMIT=${OPTARG##*=}
                    ;;
                sync_limit=*)
                    SYNC_LIMIT=${OPTARG##*=}
                    ;;
                heap=*)
                    HEAP=${OPTARG##*=}
                    ;;
                max_client_cnxns=*)
                    MAX_CLIENT_CNXNS=${OPTARG##*=}
                    ;;
                snap_retain_count=*)
                    SNAP_RETAIN_COUNT=${OPTARG##*=}
                    ;;
                purge_interval=*)
                    PURGE_INTERVAL=${OPTARG##*=}
                    ;;
                max_session_timeout=*)
                    MAX_SESSION_TIMEOUT=${OPTARG##*=}
                    ;;
                min_session_timeout=*)
                    MIN_SESSION_TIMEOUT=${OPTARG##*=}
                    ;;
                log_level=*)
                    LOG_LEVEL=${OPTARG##*=}
                    ;;
                pre_alloc_size=*)
                    PRE_ALLOC_SIZE=${OPTARG##*=}
                    ;;
                *)
                    echo "Unknown option --${OPTARG}" >&2
                    exit 1
                    ;;
            esac;;
        h)
            print_usage
            exit
            ;;
        v)
            echo "Parsing option: '-${optchar}'" >&2
            ;;
        *)
            if [ "$OPTERR" != 1 ] || [ "${optspec:0:1}" = ":" ]; then
                echo "Non-option argument: '-${OPTARG}'" >&2
            fi
            ;;
    esac
done

MIN_SESSION_TIMEOUT=${MIN_SESSION_TIMEOUT:- $((TICK_TIME*2))}
MAX_SESSION_TIMEOUT=${MAX_SESSION_TIMEOUT:- $((TICK_TIME*20))}
ID_FILE="$DATA_DIR/myid"
CONFIG_FILE="$CONF_DIR/zoo.cfg"
LOGGER_PROPS_FILE="$CONF_DIR/log4j.properties"
JAVA_ENV_FILE="$CONF_DIR/java.env"
if [[ $HOST =~ (.*)-([0-9]+)$ ]]; then
    NAME=${BASH_REMATCH[1]}
    ORD=${BASH_REMATCH[2]}
else
    echo "Fialed to parse name and ordinal of Pod"
    exit 1
fi

MY_ID=$((ORD+1))

create_config && create_jvm_props && create_log_props && create_data_dirs && exec zkServer.sh start-foreground