#!/bin/bash

#Command transformation script

# Hadoop's hadoop jar command invokes RunJar which copies all the class files into a  temp dir.
# This leads to increase in the startup time. Hence,  the command  is invoked manually in the form of
# $HADOOP_HOME/bin/hadoop <splunk_main_class>. The splunk jar is exported into HADOOP_CLASSPATH
# If the sudobash is not the typical hadoop command , the command formed  will be : /bin/bash <rest of the args>
# The scipts also  takes care of executing under MAPREDUCE_USER  when it is present in the env


OLD_SPLUNK_JAR1_NAME=SplunkMR-s6.0-h1.0.jar
OLD_SPLUNK_JAR2_NAME=SplunkMR-s6.0-h2.0.jar
OLD_SPLUNK_JAR3_NAME=SplunkMR-s6.0-hy2.0.jar

# ERP-695 delete old SplunkMR jars at the first time of upgrading Hunk
function deleteOldSplunkMRJars() {
	SPLUNKMR_OLD_JAR1="$SPLUNK_HOME/bin/jars/$OLD_SPLUNK_JAR1_NAME"
	SPLUNKMR_OLD_JAR2="$SPLUNK_HOME/bin/jars/$OLD_SPLUNK_JAR2_NAME"
	SPLUNKMR_OLD_JAR3="$SPLUNK_HOME/bin/jars/$OLD_SPLUNK_JAR3_NAME"

	if [ -f $SPLUNKMR_OLD_JAR1 ]; then
		log "Deleting an old version of SplunkMR jar: $SPLUNKMR_OLD_JAR1"
		rm -f $SPLUNKMR_OLD_JAR1
	fi

	if [ -f $SPLUNKMR_OLD_JAR2 ]; then
		log "Deleting an old version of SplunkMR jar: $SPLUNKMR_OLD_JAR2"
		rm -f $SPLUNKMR_OLD_JAR2
	fi

	if [ -f $SPLUNKMR_OLD_JAR3 ]; then
		log "Deleting an old version of SplunkMR jar: $SPLUNKMR_OLD_JAR3"
		rm -f $SPLUNKMR_OLD_JAR3
	fi
}

deleteOldSplunkMRJars

# ERP-695 replace old SplunkMR jar name to the new one
function replaceOldSplunkMRJar() {
	s=$1
	s=${s//$OLD_SPLUNK_JAR1_NAME/SplunkMR-h1\.jar}
	s=${s//$OLD_SPLUNK_JAR2_NAME/SplunkMR-h2\.jar}
	s=${s//$OLD_SPLUNK_JAR3_NAME/SplunkMR-hy2\.jar}
	echo $s
}

ARGS="$@"
ARGS="$(replaceOldSplunkMRJar "$ARGS")"

#DEFAULT COMMAND
COMMAND="/bin/bash $ARGS"

#Hadoop Command
HADOOP_COMMAND=$1

#Splunk Jar Name
SPLUNK_JAR="$(replaceOldSplunkMRJar $3)"

function log() {
    timestamp=""
    if [ "$SPLUNK_LOG_INCLUDE_TIMESTAMP" != "" ]; then
        timestamp=`date "+%Y-%m-%d %H:%M:%S.%3N %z "`
    fi
    # leaving no space between the possible timestamp and log level.
    # Hunk will treat lines that doesn't start with a log level as an error.
    log_level="DEBUG"
    if [ "$2" != "" ]; then
        log_level="$2"
    fi
    echo "$timestamp""$log_level " $1 >&2
}

function log_error() {
    log "$1" "ERROR"
}

log "MAPREDUCE_USER=$MAPREDUCE_USER, SPLUNK_HOME=$SPLUNK_HOME, HADOOP_CLASSPATH=$HADOOP_CLASSPATH"

#####
# Check if this is the usual command, else do not construct command
function checkSplunkMR() {
        if [[ $HADOOP_COMMAND =~ .*hadoop$ ]]; then
                if [[ "$2" == "jar" ]]; then
                        if [[ "$3" =~ SplunkMR.*jar$ ]]; then
                                if [[ "$4" == "com.splunk.mr.SplunkMR" ]]; then
                                        echo "true"
                                fi
                        fi

                fi
        fi
}

# Decrypt AWS access and secret keys.
function decrypt_aws_creds {
    S3_CREDS_FILE="$1"
    SPLUNK_SECRET_FILE="$2"
    GPG_BIN=${GPG_BIN:-/usr/bin/gpg}
    CREDS=$(mktemp)
    $GPG_BIN --no-use-agent --yes --batch --decrypt --passphrase-file "$SPLUNK_SECRET_FILE" --output ${CREDS} "$S3_CREDS_FILE" > /dev/null 2>&1
    source ${CREDS}
    rm -f ${CREDS}
}

# Mask AWS keys
function mask_aws_keys {
    local SECRET_MASK="s/fs\.s3a\.secret\.key=[^ ]*/fs\.s3a\.secret\.key=\*\*\*\*/g"
    MASKED_COMMAND=$(echo "$1" | sed -e "$SECRET_MASK")
}

# Get AWS credentials
function get_aws_creds {
    PARAMS=()
    for ARG in "$@"; do
        if [[ -n $(echo "$ARG" | grep "\-Dfs\.s3a\.access\.key\=") ]]; then
            ACCESS_KEY=$(echo "$ARG" | cut -d= -f2)
        elif [[ -n $(echo "$ARG" | grep "\-Dfs\.s3a\.secret\.key\=") ]]; then
            SECRET_KEY=$(echo "$ARG" | cut -d= -f2)
        elif [[ -n $(echo "$ARG" | grep "encrypted_aws_creds") ]]; then
            ENCRYPTED_AWS_CREDS=$(echo "$ARG" | cut -d= -f2)
        elif [[ -n $(echo "$ARG" | grep "splunk_secret") ]]; then
            SPLUNK_SECRET=$(echo "$ARG" | cut -d= -f2)
        else
            PARAMS+=("$ARG")
        fi
    done
    if [[ -n "$ACCESS_KEY" && -n "$SECRET_KEY" ]]; then
        PARAMS+=("-Dfs.s3a.access.key=$ACCESS_KEY" "-Dfs.s3a.secret.key=$SECRET_KEY")
    elif [[ -n "$ENCRYPTED_AWS_CREDS" && -n "$SPLUNK_SECRET" ]]; then
        decrypt_aws_creds "$ENCRYPTED_AWS_CREDS" "$SPLUNK_SECRET"
        PARAMS+=("-Dfs.s3a.access.key=$AWS_ACCESS_KEY_ID" "-Dfs.s3a.secret.key=$AWS_SECRET_ACCESS_KEY")
    fi
}

######
#Check if the hadoop RunJar is intended purpose, else exit 1
function checkIfHadoopRunJar(){
    if [[ $(checkSplunkMR $ARGS) != "true" ]]; then
        echo "false"
    else
        #Construct the command, $4 is the main class we need to call and args following $4 are args to the main class.
        get_aws_creds "${@:4}"
        echo "$HADOOP_COMMAND ${PARAMS[@]}"
    fi
}
#####

# add third party jars to classpath
if [[ "$HUNK_THIRDPARTY_JARS" != "" ]]; then
     ADD_TO_CLASSPATH=`eval echo ${HUNK_THIRDPARTY_JARS//,/:}`
#else
#     TP_COM_DIR_PREFIX="$SPLUNK_HOME/bin/jars/thirdparty/common"
#     TP_HIV_DIR_PREFIX="$SPLUNK_HOME/bin/jars/thirdparty/hive"
#     ADD_TO_CLASSPATH="$TP_COM_DIR_PREFIX/avro-1.7.4.jar:$TP_COM_DIR_PREFIX/avro-mapred-1.7.4.jar:$TP_COM_DIR_PREFIX/commons-compress-1.5.jar:$TP_COM_DIR_PREFIX/commons-io-2.1.jar:" \
#                      "$TP_COM_DIR_PREFIX/libfb303-0.9.0.jar:$TP_COM_DIR_PREFIX/parquet-hive-bundle-1.5.0.jar$TP_COM_DIR_PREFIX/snappy-java-1.0.5.jar:" \
#                      "$TP_HIV_DIR_PREFIX/hive-exec-0.12.0.jar:$TP_HIV_DIR_PREFIX/hive-metastore-0.12.0.jar:$TP_HIV_DIR_PREFIX/hive-serde-0.12.0.jar"
fi

# add aws related jars to the classpath if the hunk oem app is installed
# this app should only be installed on the AMI
if [ -d "$SPLUNK_HOME/etc/apps/splunk_emr/" ] ; then
   ADD_TO_CLASSPATH="$ADD_TO_CLASSPATH:$SPLUNK_HOME"'/bin/jars/thirdparty/aws/*'
fi

RUNJAR_CMD=$(checkIfHadoopRunJar $ARGS)
if [[ "$RUNJAR_CMD"   != "false" ]]; then
        ADD_TO_CLASSPATH=$ADD_TO_CLASSPATH:$SPLUNK_JAR
	log "Adding SplunkMR jar to classpath ..."

	COMMAND=$RUNJAR_CMD
else
    log "Providers other than SplunkMR not supported."
    exit 1
fi

mask_aws_keys "$COMMAND"

export HADOOP_CLASSPATH=$HADOOP_CLASSPATH:$ADD_TO_CLASSPATH
if [[ "$HADOOP_USER_CLASSPATH_FIRST" != "" ]]; then
    export HADOOP_USER_CLASSPATH_FIRST="$HADOOP_USER_CLASSPATH_FIRST"
fi
log "HADOOP_USER_CLASSPATH_FIRST=$HADOOP_USER_CLASSPATH_FIRST"

log "HADOOP_CLASSPATH=$HADOOP_CLASSPATH"

log "Invoking command: $MASKED_COMMAND"

#Start process as MAPREDUCE_USER
if [[ $MAPREDUCE_USER != "" ]]; then
       	log "sudo -E -u $MAPREDUCE_USER  $MASKED_COMMAND "
       	sudo -E -u $MAPREDUCE_USER  $COMMAND
else
        $COMMAND
fi

rc=$?

if [ $rc != 0 ]; then
	log_error "Error while invoking command: $MASKED_COMMAND - Return code: $rc"
	exit $rc
fi