# 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.

NODE_DIR="${NODE_DIR}"
PID_DIR="$NODE_DIR/var/run"
LOG_DIR="$NODE_DIR/var/log"

export HADOOP_CONF_DIR="$NODE_DIR/etc/hadoop/conf"
export HADOOP_PID_DIR=$NODE_DIR/var/run

# Mark each process so they can be killed if needed. This is a safety mechanism for
# stopping the processes if the pid file has been removed for whatever reason.
export HADOOP_OPTS+=" -D${KILL_CLUSTER_MARKER}"
export YARN_OPTS+=" -D${KILL_CLUSTER_MARKER}"

# This is for KMS.
export CATALINA_OPTS+=" -D${KILL_CLUSTER_MARKER}"

: ${SERVICE_NAME=$(basename "$0")}
PID_FILE="$PID_DIR/$SERVICE_NAME"

function do_start {
  local CMD="$1"
  shift
  LOG_FILE="$LOG_DIR/$SERVICE_NAME.out"
  "$CMD" "$@" &> "$LOG_FILE" &
  local PID=$!
  echo $PID > "$PID_FILE"
  disown -h $PID
  # Give the process some time to die... if thing go wrong it usually takes at least a
  # few seconds for the process to totallly shutdown
  sleep 5
  if ! pid_exists $PID; then
    echo "Failed to start $SERVICE_NAME. The end of the log ($LOG_FILE) is:"
    tail -20 "$LOG_FILE"
    return 1
  fi
}

function read_pid {
  if [[ -e "$PID_FILE" ]]; then
    cat "$PID_FILE"
  fi
}

function pid_exists {
  if [[ $# -ne 1 ]]; then
    echo pid_exists must be called with a single argument -- the pid to check 1>&2
    exit 1
  fi
  kill -0 $1 &> /dev/null
}

function stop {
  local PID=$(read_pid)
  if [[ -z $PID ]]; then
    echo No PID to stop
    return
  fi
  if pid_exists $PID; then
    kill $PID
  fi

  # Wait up to 120 seconds for the service to stop.
  local TIMEOUT_SECS=120
  local DEADLINE=$(($(date +%s) + $TIMEOUT_SECS))
  while [[ $(date +%s) -lt $DEADLINE ]]; do
    if ! pid_exists $PID; then
      # Remove the pid file so that there is no confusion if the pids wrap
      rm -f $PID_FILE
      return
    fi
    sleep 0.1
  done
  echo "$SERVICE_NAME did not stop after $TIMEOUT_SECS seconds" 1>&2
  return 1
}

function restart {
  if status &>/dev/null; then
    stop
  fi
  start
}

function status {
  local PID=$(read_pid)
  if [[ -z $PID ]]; then
    echo Not started
    return 1
  fi

  if pid_exists $PID; then
    echo Running
  else
    echo Not Running
    return 1
  fi
}