#!/bin/bash

SYSLOG_IDENTIFIER="cpu_wdt"
CPUWDT_MAIN_TASK_RUNNING_FLAG=true
TIMEOUT=180
KEEPALIVE=60

function log_info()
{
    logger -p info -t ${SYSLOG_IDENTIFIER}  "$@"
}

function usage()
{
    echo "Usage: $0 ACTION [OPTIONS]..."
    echo ""
    echo "Actions:"
    echo "  start    Start CPU WDT"
    echo "  stop     Stop CPU WDT"
    echo ""
    echo "Options:"
    echo "  -h              Show this help"
    echo "  -t <timeout>    WDT timeout period: {30|60|180}, default 180"
    echo "  -k <keepalive>  WDT keep alive period, {1..(timeout-5)}, default 60"
    exit 1
}

function validate_action()
{
    if [[ "${ACTION}" != "start" && "${ACTION}" != "stop" ]]; then
        echo -e "Invalid action: ${ACTION}\n"
        usage
    fi
}

function validate_options()
{
    if [[ ${TIMEOUT} != "30" && ${TIMEOUT} != "60" && ${TIMEOUT} != "180" ]]; then
        echo -e "Invalid timeout value: ${TIMEOUT}\n"
        usage
    fi
    if [[ ${KEEPALIVE} -le 0 || ${KEEPALIVE} -gt $((TIMEOUT - 5)) ]]; then
        echo "Invalid keepalive value: ${KEEPALIVE}"
        echo ""
        usage
    fi
}

trap 'log_info "Caught SIGHUP - ignoring..."' SIGHUP
trap 'log_info "Caught SIGINT - exiting..."; CPUWDT_MAIN_TASK_RUNNING_FLAG=false' SIGINT
trap 'log_info "Caught SIGTERM - exiting..."; CPUWDT_MAIN_TASK_RUNNING_FLAG=false' SIGTERM

ACTION=$1
shift
validate_action

while getopts "t:k:" OPTION; do
    case $OPTION in
    t)
        TIMEOUT=${OPTARG}
        ;;
    k)
        KEEPALIVE=${OPTARG}
        ;;
    *)
        usage
    esac
done

validate_options

if [[ "${ACTION}" == "start" ]]; then
    # enable
    log_info "Enable CPU WDT.."
    watchdogutil arm -s "${TIMEOUT}" > /dev/null
    log_info "CPU WDT has been enabled with $TIMEOUT seconds timeout"

    # keep alive
    log_info "Enable keep alive messaging every $KEEPALIVE seconds"
    while [[ ${CPUWDT_MAIN_TASK_RUNNING_FLAG} == "true" ]]; do
        watchdogutil arm -s "${TIMEOUT}" > /dev/null
        log_info "Keep alive message sent [RC=$?]. Will sleep ${KEEPALIVE} seconds."
        sleep "${KEEPALIVE}"
    done
    log_info "Keep alive messaging has been disabled"
fi

log_info "Disable CPU WDT.."
watchdogutil disarm
log_info "CPU WDT has been disabled!"