#!/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

# Find assembly jar
SPARK_ASSEMBLY_JAR=
if [ -f "$SPARK_HOME/RELEASE" ]; then
  ASSEMBLY_DIR="$SPARK_HOME/lib"
else
  ASSEMBLY_DIR="$SPARK_HOME/assembly/target/scala-$SPARK_SCALA_VERSION"
fi

num_jars="$(ls -1 "$ASSEMBLY_DIR" | grep "^spark-assembly.*hadoop.*\.jar$" | wc -l)"
if [ "$num_jars" -eq "0" -a -z "$SPARK_ASSEMBLY_JAR" ]; then
  echo "Failed to find Spark assembly in $ASSEMBLY_DIR." 1>&2
  echo "You need to build Spark before running this program." 1>&2
  exit 1
fi
ASSEMBLY_JARS="$(ls -1 "$ASSEMBLY_DIR" | grep "^spark-assembly.*hadoop.*\.jar$" || true)"
if [ "$num_jars" -gt "1" ]; then
  echo "Found multiple Spark assembly jars in $ASSEMBLY_DIR:" 1>&2
  echo "$ASSEMBLY_JARS" 1>&2
  echo "Please remove all but one jar." 1>&2
  exit 1
fi

SPARK_ASSEMBLY_JAR="${ASSEMBLY_DIR}/${ASSEMBLY_JARS}"

# Verify that versions of java used to build the jars and run Spark are compatible
if [ -n "$JAVA_HOME" ]; then
  JAR_CMD="$JAVA_HOME/bin/jar"
else
  JAR_CMD="jar"
fi

if [ $(command -v "$JAR_CMD") ] ; then
  jar_error_check=$("$JAR_CMD" -tf "$SPARK_ASSEMBLY_JAR" nonexistent/class/path 2>&1)
  if [[ "$jar_error_check" =~ "invalid CEN header" ]]; then
    echo "Loading Spark jar with '$JAR_CMD' failed. " 1>&2
    echo "This is likely because Spark was compiled with Java 7 and run " 1>&2
    echo "with Java 6. (see SPARK-1703). Please use Java 7 to run Spark " 1>&2
    echo "or build Spark with Java 6." 1>&2
    exit 1
  fi
fi

LAUNCH_CLASSPATH="$SPARK_ASSEMBLY_JAR"

# Add the launcher build dir to the classpath if requested.
if [ -n "$SPARK_PREPEND_CLASSES" ]; then
  LAUNCH_CLASSPATH="$SPARK_HOME/launcher/target/scala-$SPARK_SCALA_VERSION/classes:$LAUNCH_CLASSPATH"
fi

export _SPARK_ASSEMBLY="$SPARK_ASSEMBLY_JAR"

# 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 "$LAUNCH_CLASSPATH" org.apache.spark.launcher.Main "$@")

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