#!/bin/sh
#
#
# 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.
#

JAVA=`type -p java`
JAVA_OPTS="-Xmx20m"

FLUME_NODE_CLASS="org.apache.flume.node.Application"
FLUME_AVRO_CLIENT_CLASS="org.apache.flume.client.avro.AvroCLIClient"
FLUME_CLASSPATH=""

warn() {
  local msg=$1

  echo "Warning: $msg"
}

error() {
  local msg=$1
  local exit_code=$2

  echo "Error: $msg"

  if [ -n "$exit_code" ] ; then
    exit $exit_code
  fi
}

display_help() {
  cat <<EOF
usage: $0 [help | node] [--no-env]

commands:
  help                display this help text
  node                run a Flume node
  avro-client         run an avro Flume client

global options

  --conf,-c <conf>    use configs in <conf> directory
  --no-env,-E         do not source the flume-env.sh file
  --classpath,-C <cp> override the classpath completely

node options

  --data,-d <dir>     store internal flume data in <dir>

avro-client options

  --host,-H <host>  hostname to which events will be sent
  --port,-p <port>  port of the avro source

Note that the conf directory is always included in the classpath.

EOF

}

run_node() {
  local final_cp

  if [ -n "$opt_conf" ] ; then
    final_cp="$opt_conf:"
  fi

  final_cp="${final_cp}${FLUME_CLASSPATH}"

  [ -n "$JAVA" ] || error "Unable to find java executable. Is it in your PATH?" 1
  [ -n "$FLUME_CLASSPATH" ] || error "Flume classpath is not set! Use flume-env.sh or --classpath <cp>." 1
  [ -n "$opt_conf" ] || warn "No configuration directory set! Use --conf <dir> to override." 1

  FLUME_APPLICATION_CLASS=$FLUME_NODE_CLASS

  $JAVA $JAVA_OPTS -cp $final_cp $FLUME_APPLICATION_CLASS $*
}

run_avro_client() {
  local final_cp

  if [ -n "$opt_conf" ] ; then
    final_cp="$opt_conf:"
  fi

  final_cp="${final_cp}${FLUME_CLASSPATH}"

  [ -n "$JAVA" ] || error "Unable to find java executable. Is it in your PATH?" 1
  [ -n "$FLUME_CLASSPATH" ] || error "Flume classpath is not set! Use flume-env.sh or --classpath <cp>." 1
  [ -n "$opt_conf" ] || warn "No configuration directory set! Use --conf <dir> to override." 1

  FLUME_APPLICATION_CLASS=$FLUME_AVRO_CLIENT_CLASS

  $JAVA $JAVA_OPTS -cp $final_cp $FLUME_APPLICATION_CLASS $*
}

validate_env() {
  [ -z "$CLASSPATH" ] || warn "You have CLASSPATH set to $CLASSPATH - you better know what you're doing!"
}

opt_help=
opt_no_env=
opt_conf=
opt_datadir=

mode=$1
shift

case "$mode" in
  help)
    opt_help=1
    ;;
  node)
    opt_node=1
    ;;
  avro-client)
    opt_avro_client=1
    ;;
  *)
    error "Unknown or unspecified command '$mode'"
    opt_help=1
    ;;
esac

while [ -n "$*" ] ; do
  arg=$1
  shift

  case "$arg" in
    --no-env|-E)
      opt_no_env=1
      ;;
    --conf|-c)
      [ -n "$1" ] || error "Option --conf requires an argument" 1
      opt_conf=$1
      shift
      ;;
    --classpath|-C)
      [ -n "$1" ] || error "Option --classpath requires an argument" 1
      FLUME_CLASSPATH=$1
      shift
      ;;
    --data|-d)
      [ -n "$1" ] || error "Option --data requires an argument" 1
      opt_datadir=$1
      shift
      ;;
    *)
      args="$args $arg"
      ;;
  esac
done

if [ -n "$opt_help" ] ; then
  display_help
elif [ -n "$opt_node" ] ; then
  run_node $args
elif [ -n "$opt_avro_client" ] ; then
  run_avro_client $args
fi