#!/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.
#

JAVA_OPTS="-Xmx20m"
FLUME_CLASSPATH=""

if [ -n "${FLUME_CONF_DIR}" -a -f "${FLUME_CONF_DIR}/flume-env.sh" ]; then
    source "$FLUME_CONF_DIR/flume-env.sh"
fi

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

if [ -z "${JAVA_HOME}" ] ; then
    echo "Warning: JAVA_HOME not set!"
    JAVA_DEFAULT=`type -p java`
    [ -n "$JAVA_DEFAULT" ] || error "Unable to find java executable. Is it in your PATH?" 1
    JAVA_BIN=`dirname $JAVA_DEFAULT`
    JAVA_HOME=`dirname $JAVA_BIN`
fi

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 [COMMAND] [OPTION]...

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
  --classpath,-C <cp>   override the classpath completely

node options:
  --conf-file,-f        specify a config file (required)
  --name,-n             the name of this node (required)
  --help,-h             display help text

avro-client options:
  --host,-H <host>      hostname to which events will be sent (required)
  --port,-p <port>      port of the avro source (required)
  --filename,-F <file>  text file to stream to avro source [default: std input]
  --help,-h             display help text

Note that if <conf> directory is specified, then it is always included first
in the classpath.

EOF
}

run_node() {
  local final_cp
  local FLUME_APPLICATION_CLASS

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

  # If the user hasn't overridden the classpath, build it from the lib
  # directory.
  if [ -z "${FLUME_CLASSPATH}" ] ; then
    FLUME_CLASSPATH="${FLUME_HOME}/lib/*"
  else
    warn "FLUME_CLASSPATH set to ${FLUME_CLASSPATH} - Hope you know what you're doing."
  fi

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

  [ -n "$opt_conf" ] || warn "No configuration directory set! Use --conf <dir> to override." 1

  FLUME_APPLICATION_CLASS=$FLUME_NODE_CLASS

  exec $JAVA_HOME/bin/java $JAVA_OPTS -cp "$final_cp" "$FLUME_APPLICATION_CLASS" $*
}

run_avro_client() {
  local final_cp
  local FLUME_APPLICATION_CLASS

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

  # If the user hasn't overridden the classpath, build it from the lib
  # directory.
  if [ -z "${FLUME_CLASSPATH}" ] ; then
    FLUME_CLASSPATH="${FLUME_HOME}/lib/*"
  else
    warn "FLUME_CLASSPATH set to ${FLUME_CLASSPATH} - Hope you know what you're doing."
  fi

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

  [ -n "$opt_conf" ] || warn "No configuration directory set! Use --conf <dir> to override." 1

  FLUME_APPLICATION_CLASS=$FLUME_AVRO_CLIENT_CLASS

  exec $JAVA_HOME/bin/java $JAVA_OPTS -cp "$final_cp" "$FLUME_APPLICATION_CLASS" $*
}

opt_help=""
opt_conf=""

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
    --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=$1
      shift
      ;;
    *)
      args="$args $arg"
      ;;
  esac
done

if [ -z "${FLUME_HOME}" ] ; then
  FLUME_HOME=`dirname $0`
  FLUME_HOME="${FLUME_HOME}/../"
fi

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