#!/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.
################################################################################

# flag indicating if we have already cleared up things after a test
CLEARED=0

JM_WATCHDOG_PID=0
TM_WATCHDOG_PID=0

function stop_watchdogs() {
    if [ ${CLEARED} -eq 0 ]; then

        if ! [ ${JM_WATCHDOG_PID} -eq 0 ]; then
            echo "Killing JM watchdog @ ${JM_WATCHDOG_PID}"
            kill ${JM_WATCHDOG_PID} 2> /dev/null
            wait ${JM_WATCHDOG_PID} 2> /dev/null
        fi

        if ! [ ${TM_WATCHDOG_PID} -eq 0 ]; then
            echo "Killing TM watchdog @ ${TM_WATCHDOG_PID}"
            kill ${TM_WATCHDOG_PID} 2> /dev/null
            wait ${TM_WATCHDOG_PID} 2> /dev/null
        fi

        CLEARED=1
    fi
}

function verify_num_occurences_in_logs() {
    local log_pattern="$1"
    local text="$2"
    local expected_no="$3"

    local actual_no=$(grep -r --include "*${log_pattern}*.log" -e "${text}" "${FLINK_DIR}/log/" | cut -d ":" -f 1 | uniq | wc -l)
    [[ "${expected_no}" -eq "${actual_no}" ]]
}

function verify_logs() {
    local OUTPUT=$FLINK_DIR/log/*.out
    local JM_FAILURES=$1
    local EXIT_CODE=0
    local VERIFY_CHECKPOINTS=$2

    # verify that we have no alerts
    if ! [ `cat ${OUTPUT} | wc -l` -eq 0 ]; then
        echo "FAILURE: Alerts found at the general purpose job."
        EXIT_CODE=1
    fi

    # checks that all apart from the first JM recover the failed jobgraph.
    if ! verify_num_occurences_in_logs 'standalonesession' 'Recovered SubmittedJobGraph' ${JM_FAILURES}; then
        echo "FAILURE: A JM did not take over."
        EXIT_CODE=1
    fi

    if [ "$VERIFY_CHECKPOINTS" = true ]; then
    # search the logs for JMs that log completed checkpoints
        if ! verify_num_occurences_in_logs 'standalonesession' 'Completed checkpoint' $((JM_FAILURES + 1)); then
            echo "FAILURE: A JM did not execute the job."
            EXIT_CODE=1
        fi
    fi

    if [[ $EXIT_CODE != 0 ]]; then
        echo "One or more tests FAILED."
        exit $EXIT_CODE
    fi
}

function jm_watchdog() {
    local EXPECTED_JMS=$1
    local PROCESS_NAME=$2

    while true; do
        local RUNNING_JMS=`jps | grep "${PROCESS_NAME}" | wc -l`;
        local MISSING_JMS=$((EXPECTED_JMS-RUNNING_JMS))
        for (( c=0; c<MISSING_JMS; c++ )); do
            ${@:3}
        done
        sleep 1;
    done
}

function start_jm_cmd {
    local IP_PORT=$1
    "$FLINK_DIR/bin/jobmanager.sh" "start" "localhost" "${IP_PORT}"
}

#######################################
# Start watchdog for JM process

# Arguments:
#   $1: expected number of jms to run
#   $2: process name to monitor
#   $3: command to start new jm
#######################################
function start_ha_jm_watchdog() {
    jm_watchdog $1 $2 ${@:3} &
    JM_WATCHDOG_PID=$!
    echo "Running JM watchdog @ ${JM_WATCHDOG_PID}"
}

function kill_single {
    local JM_PIDS=`jps | grep "$1" | cut -d " " -f 1`
    local JM_PIDS=(${JM_PIDS[@]})
    local PID=${JM_PIDS[0]}
    kill -9 ${PID}

    echo "Killed JM @ ${PID}"
}

# ha prefix to differentiate from the one in common.sh
function ha_tm_watchdog() {
    local JOB_ID=$1
    local EXPECTED_TMS=$2

    # the number of already seen successful checkpoints
    local SUCCESSFUL_CHCKP=0

    while true; do

        # check how many successful checkpoints we have
        # and kill a TM only if the previous one already had some

        local CHECKPOINTS=`curl -s "http://localhost:8081/jobs/${JOB_ID}/checkpoints" | cut -d ":" -f 6 | sed 's/,.*//'`

        if [[ ${CHECKPOINTS} =~ '^[0-9]+$' ]] || [[ ${CHECKPOINTS} == "" ]]; then

            # this may be the case during leader election.
            # in this case we retry later with a smaller interval
            sleep 5; continue

        elif [ "${CHECKPOINTS}" -ne "${SUCCESSFUL_CHCKP}" ]; then

            # we are not only searching for > because when the JM goes down,
            # the job starts with reporting 0 successful checkpoints

            local RUNNING_TMS=`jps | grep 'TaskManager' | wc -l`
            local TM_PIDS=`jps | grep 'TaskManager' | cut -d " " -f 1`

            local MISSING_TMS=$((EXPECTED_TMS-RUNNING_TMS))
            if [ ${MISSING_TMS} -eq 0 ]; then
                # start a new TM only if we have exactly the expected number
                "$FLINK_DIR"/bin/taskmanager.sh start > /dev/null
            fi

            # kill an existing one
            local TM_PIDS=(${TM_PIDS[@]})
            local PID=${TM_PIDS[0]}
            kill -9 ${PID}

            echo "Killed TM @ ${PID}"

            SUCCESSFUL_CHCKP=${CHECKPOINTS}
        fi

        sleep 11;
    done
}

function start_ha_tm_watchdog() {
    ha_tm_watchdog $1 $2 &
    TM_WATCHDOG_PID=$!
    echo "Running TM watchdog @ ${TM_WATCHDOG_PID}"
}