#!/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.
#

if [ -z "${SPARK_HOME}" ]; then
  export SPARK_HOME="$(cd "`dirname "$0"`"/..; pwd)"
fi

source "${SPARK_HOME}"/bin/load-spark-env.sh
export _SPARK_CMD_USAGE="Usage: ./bin/pyspark [options]"

# In Spark 2.0, IPYTHON and IPYTHON_OPTS are removed and pyspark fails to launch if either option
# is set in the user's environment. Instead, users should set PYSPARK_DRIVER_PYTHON=ipython 
# to use IPython and set PYSPARK_DRIVER_PYTHON_OPTS to pass options when starting the Python driver
# (e.g. PYSPARK_DRIVER_PYTHON_OPTS='notebook').  This supports full customization of the IPython
# and executor Python executables.

# Fail noisily if removed options are set
if [[ -n "$IPYTHON" || -n "$IPYTHON_OPTS" ]]; then
  echo "Error in pyspark startup:" 
  echo "IPYTHON and IPYTHON_OPTS are removed in Spark 2.0+. Remove these from the environment and set PYSPARK_DRIVER_PYTHON and PYSPARK_DRIVER_PYTHON_OPTS instead."
  exit 1
fi

# Default to standard python interpreter unless told otherwise
if [[ -z "$PYSPARK_DRIVER_PYTHON" ]]; then
  PYSPARK_DRIVER_PYTHON="${PYSPARK_PYTHON:-"python"}"
fi

WORKS_WITH_IPYTHON=$(python -c 'import sys; print(sys.version_info >= (2, 7, 0))')

# Determine the Python executable to use for the executors:
if [[ -z "$PYSPARK_PYTHON" ]]; then
  if [[ $PYSPARK_DRIVER_PYTHON == *ipython* && ! WORKS_WITH_IPYTHON ]]; then
    echo "IPython requires Python 2.7+; please install python2.7 or set PYSPARK_PYTHON" 1>&2
    exit 1
  else
    PYSPARK_PYTHON=python
  fi
fi
export PYSPARK_PYTHON

# Add the PySpark classes to the Python path:
export PYTHONPATH="${SPARK_HOME}/python/:$PYTHONPATH"
export PYTHONPATH="${SPARK_HOME}/python/lib/py4j-0.10.3-src.zip:$PYTHONPATH"

# Load the PySpark shell.py script when ./pyspark is used interactively:
export OLD_PYTHONSTARTUP="$PYTHONSTARTUP"
export PYTHONSTARTUP="${SPARK_HOME}/python/pyspark/shell.py"

# For pyspark tests
if [[ -n "$SPARK_TESTING" ]]; then
  unset YARN_CONF_DIR
  unset HADOOP_CONF_DIR
  export PYTHONHASHSEED=0
  exec "$PYSPARK_DRIVER_PYTHON" -m $1
  exit
fi

export PYSPARK_DRIVER_PYTHON
export PYSPARK_DRIVER_PYTHON_OPTS
exec "${SPARK_HOME}"/bin/spark-submit pyspark-shell-main --name "PySparkShell" "$@"