#!/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.
#
set -e

# Figure out where Spark is installed
export SPARK_HOME="$(cd "`dirname "$0"`"/..; pwd)"

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

if [ -z "$1" ]; then
  echo "Usage: spark-class <class> [<args>]" 1>&2
  exit 1
fi

# Find the java binary
if [ -n "${JAVA_HOME}" ]; then
  RUNNER="${JAVA_HOME}/bin/java"
else
  if [ `command -v java` ]; then
    RUNNER="java"
  else
    echo "JAVA_HOME is not set" >&2
    exit 1
  fi
fi

# Look for the launcher. In non-release mode, add the compiled classes directly to the classpath
# instead of looking for a jar file.
SPARK_LAUNCHER_CP=
if [ -f $SPARK_HOME/RELEASE ]; then
  LAUNCHER_DIR="$SPARK_HOME/lib"
  num_jars="$(ls -1 "$LAUNCHER_DIR" | grep "^spark-launcher.*\.jar$" | wc -l)"
  if [ "$num_jars" -eq "0" -a -z "$SPARK_LAUNCHER_CP" ]; then
    echo "Failed to find Spark launcher in $LAUNCHER_DIR." 1>&2
    echo "You need to build Spark before running this program." 1>&2
    exit 1
  fi

  LAUNCHER_JARS="$(ls -1 "$LAUNCHER_DIR" | grep "^spark-launcher.*\.jar$" || true)"
  if [ "$num_jars" -gt "1" ]; then
    echo "Found multiple Spark launcher jars in $LAUNCHER_DIR:" 1>&2
    echo "$LAUNCHER_JARS" 1>&2
    echo "Please remove all but one jar." 1>&2
    exit 1
  fi

  SPARK_LAUNCHER_CP="${LAUNCHER_DIR}/${LAUNCHER_JARS}"
else
  LAUNCHER_DIR="$SPARK_HOME/launcher/target/scala-$SPARK_SCALA_VERSION"
  if [ ! -d "$LAUNCHER_DIR/classes" ]; then
    echo "Failed to find Spark launcher classes in $LAUNCHER_DIR." 1>&2
    echo "You need to build Spark before running this program." 1>&2
    exit 1
  fi
  SPARK_LAUNCHER_CP="$LAUNCHER_DIR/classes"
fi

# The launcher library will print arguments separated by a NULL character, to allow arguments with
# characters that would be otherwise interpreted by the shell. Read that in a while loop, populating
# an array that will be used to exec the final command.
CMD=()
while IFS= read -d '' -r ARG; do
  CMD+=("$ARG")
done < <("$RUNNER" -cp "$SPARK_LAUNCHER_CP" org.apache.spark.launcher.Main "$@")

if [ "${CMD[0]}" = "usage" ]; then
  "${CMD[@]}"
else
  exec "${CMD[@]}"
fi