#!/usr/bin/env bash

#
# 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.
#

# Runs a Spark command as a daemon.
#
# Environment Variables
#
#   SPARK_CONF_DIR  Alternate conf dir. Default is ${SPARK_PREFIX}/conf.
#   SPARK_LOG_DIR   Where log files are stored.  PWD by default.
#   SPARK_MASTER    host:path where spark code should be rsync'd from
#   SPARK_PID_DIR   The pid files are stored. /tmp by default.
#   SPARK_IDENT_STRING   A string representing this instance of spark. $USER by default
#   SPARK_NICENESS The scheduling priority for daemons. Defaults to 0.
##

usage="Usage: spark-daemon.sh [--config <conf-dir>] (start|stop) <spark-command> <spark-instance-number> <args...>"

# if no args specified, show usage
if [ $# -le 1 ]; then
  echo $usage
  exit 1
fi

sbin=`dirname "$0"`
sbin=`cd "$sbin"; pwd`

. "$sbin/spark-config.sh"

# get arguments

# Check if --config is passed as an argument. It is an optional parameter.
# Exit if the argument is not a directory.

if [ "$1" == "--config" ]
then
  shift
  conf_dir=$1
  if [ ! -d "$conf_dir" ]
  then
    echo "ERROR : $conf_dir is not a directory"
    echo $usage
    exit 1
  else
    export SPARK_CONF_DIR=$conf_dir
  fi
  shift
fi

startStop=$1
shift
command=$1
shift
instance=$1
shift

spark_rotate_log ()
{
    log=$1;
    num=5;
    if [ -n "$2" ]; then
	num=$2
    fi
    if [ -f "$log" ]; then # rotate logs
	while [ $num -gt 1 ]; do
	    prev=`expr $num - 1`
	    [ -f "$log.$prev" ] && mv "$log.$prev" "$log.$num"
	    num=$prev
	done
	mv "$log" "$log.$num";
    fi
}

. "$SPARK_PREFIX/bin/load-spark-env.sh"

if [ "$SPARK_IDENT_STRING" = "" ]; then
  export SPARK_IDENT_STRING="$USER"
fi


export SPARK_PRINT_LAUNCH_COMMAND="1"

# get log directory
if [ "$SPARK_LOG_DIR" = "" ]; then
  export SPARK_LOG_DIR="$SPARK_HOME/logs"
fi
mkdir -p "$SPARK_LOG_DIR"
touch $SPARK_LOG_DIR/.spark_test > /dev/null 2>&1
TEST_LOG_DIR=$?
if [ "${TEST_LOG_DIR}" = "0" ]; then
  rm -f $SPARK_LOG_DIR/.spark_test
else
  chown $SPARK_IDENT_STRING $SPARK_LOG_DIR
fi

if [ "$SPARK_PID_DIR" = "" ]; then
  SPARK_PID_DIR=/tmp
fi

# some variables
export SPARK_LOGFILE=spark-$SPARK_IDENT_STRING-$command-$instance-$HOSTNAME.log
export SPARK_ROOT_LOGGER="INFO,DRFA"
log=$SPARK_LOG_DIR/spark-$SPARK_IDENT_STRING-$command-$instance-$HOSTNAME.out
pid=$SPARK_PID_DIR/spark-$SPARK_IDENT_STRING-$command-$instance.pid

# Set default scheduling priority
if [ "$SPARK_NICENESS" = "" ]; then
    export SPARK_NICENESS=0
fi


case $startStop in

  (start)

    mkdir -p "$SPARK_PID_DIR"

    if [ -f $pid ]; then
      if kill -0 `cat $pid` > /dev/null 2>&1; then
        echo $command running as process `cat $pid`.  Stop it first.
        exit 1
      fi
    fi

    if [ "$SPARK_MASTER" != "" ]; then
      echo rsync from $SPARK_MASTER
      rsync -a -e ssh --delete --exclude=.svn --exclude='logs/*' --exclude='contrib/hod/logs/*' $SPARK_MASTER/ "$SPARK_HOME"
    fi

    spark_rotate_log "$log"
    echo starting $command, logging to $log
    cd "$SPARK_PREFIX"
    nohup nice -n $SPARK_NICENESS "$SPARK_PREFIX"/bin/spark-class $command "$@" >> "$log" 2>&1 < /dev/null &
    newpid=$!
    echo $newpid > $pid
    sleep 2
    # Check if the process has died; in that case we'll tail the log so the user can see
    if ! kill -0 $newpid >/dev/null 2>&1; then
      echo "failed to launch $command:"
      tail -2 "$log" | sed 's/^/  /'
      echo "full log in $log"
    fi
    ;;

  (stop)

    if [ -f $pid ]; then
      if kill -0 `cat $pid` > /dev/null 2>&1; then
        echo stopping $command
        kill `cat $pid`
      else
        echo no $command to stop
      fi
    else
      echo no $command to stop
    fi
    ;;

  (*)
    echo $usage
    exit 1
    ;;

esac