#!/bin/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.
#

read -r -d '' USAGE <<END
Usage: run_expansion_services.sh (start|stop) [options]
Options:
  --group_id [unique id for stop services later]
  --java_expansion_service_jar [path to expansion service jar]
  --python_virtualenv_dir [path to virtualenv root dir]
  --python_expansion_service_module [name of expansion service module]
  --java_port [number]
  --python_port [number]
END

while [[ $# -gt 0 ]]; do
  key="$1"
  case $key in
    --group_id)
      GROUP_ID="$2"
      shift
      shift
      ;;
    --java_expansion_service_jar)
      JAVA_EXPANSION_SERVICE_JAR="$2"
      shift
      shift
      ;;
    --python_virtualenv_dir)
      PYTHON_VIRTUALENV_DIR="$2"
      shift
      shift
      ;;
    --python_expansion_service_module)
      PYTHON_EXPANSION_SERVICE_MODULE="$2"
      shift
      shift
      ;;
    --java_port)
      JAVA_PORT="$2"
      shift
      shift
      ;;
    --python_port)
      PYTHON_PORT="$2"
      shift
      shift
      ;;
    start)
      STARTSTOP="$1"
      shift
      ;;
    stop)
      STARTSTOP="$1"
      shift
      ;;
    *)
      echo "Unknown option: $1"
      echo "$USAGE"
      exit 1
      ;;
  esac
done

FILE_BASE="beam-expansion-service"
if [ -n "$GROUP_ID" ]; then
  FILE_BASE="$FILE_BASE-$GROUP_ID"
fi

TEMP_DIR=/tmp
pid=$TEMP_DIR/$FILE_BASE.pid
lock=$TEMP_DIR/$FILE_BASE.lock

# Check whether flock exists since some OS distributions (like MacOS)
# don't have it by default
command -v flock >/dev/null 2>&1
CHECK_FLOCK=$?

if [[ $CHECK_FLOCK -eq 0 ]]; then
  exec 200>$lock
  if ! flock -n 200; then
    echo "script already running."
    exit 0
  fi
fi

case $STARTSTOP in
  start)
    if [ -f "$pid" ]; then
      echo "services already running."
      exit 0
    fi

    echo "Launching Java expansion service @ $JAVA_PORT"
    java -jar $JAVA_EXPANSION_SERVICE_JAR $JAVA_PORT >$TEMP_DIR/$FILE_BASE-java.log 2>&1 </dev/null &
    mypid=$!
    if kill -0 $mypid >/dev/null 2>&1; then
      echo $mypid >> $pid
    else
      echo "Can't start Java expansion service."
    fi

    echo "Launching Python expansion service @ $PYTHON_PORT"
    source $PYTHON_VIRTUALENV_DIR/bin/activate
    python -m $PYTHON_EXPANSION_SERVICE_MODULE -p $PYTHON_PORT >$TEMP_DIR/$FILE_BASE-python.log 2>&1 </dev/null &
    mypid=$!
    if kill -0 $mypid >/dev/null 2>&1; then
      echo $mypid >> $pid
    else
      echo "Can't start Python expansion service."
    fi
    ;;
  stop)
    if [ -f "$pid" ]; then
      while read stop_pid; do
        if kill -0 $stop_pid >/dev/null 2>&1; then
          echo "Stopping expansion service pid: $stop_pid."
          kill $stop_pid
        else
          echo "Skipping invalid pid: $stop_pid."
        fi
      done < $pid
      rm $pid
    fi
    ;;
esac

if [[ $CHECK_FLOCK -eq 0 ]]; then
  flock -u 200
fi