#!/bin/bash

#
#/
#/ Usage:
#/ check-url.sh --proxy=<proxy-url> --warning=<level> --critical=<level> --help <URL>
#/ 
#/ Checks if URL is available
#/ 
#/ Options:
#/  -p, --proxy=<proxy-url>  The proxy server to use
#/  -w, --warning=<sec>      The amount of response time to trigger a warning (in sec)
#/  -c, --critical=<sec>     The amount of response time to trigger a critcal warning (in sec)
#/  -h, --help               Display this help message
#/ 
#/ Exit Codes:
#/  0 Everything OK
#/  1 Warning level exceeded
#/  2 Critical level exceeded
#/  3 Unknown status
#/


Usage() {
    grep '^#/' "${script_dir}/${script_name}" | sed 's/^#\/\w*//'
}

GetOptions() {
    # https://stackoverflow.com/a/29754866
    OPTIONS=p:w:c:h
    LONGOPTS=proxy:,warning:,critical:,help

    # -use ! and PIPESTATUS to get exit code with errexit set
    # -temporarily store output to be able to check for errors
    # -activate quoting/enhanced mode (e.g. by writing out “--options”)
    # -pass arguments only via   -- "$@"   to separate them correctly
    ! PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@")
    if [[ ${PIPESTATUS[0]} -ne 0 ]]; then
        # e.g. return value is 1
        #  then getopt has complained about wrong arguments to stdout
        Usage
        exit 2
    fi

    # read getopt's output this way to handle the quoting right:
    eval set -- "$PARSED"

    # now enjoy the options in order and nicely split until we see --
    while true; do
        case "$1" in
            -p|--proxy)
                proxy="$2"
                shift 2
                ;;
            -w|--warning)
                warn="$2"
                shift 2
                ;;
            -c|--critical)
                crit="$2"
                shift 2
                ;;
            -h|--help)
                Usage
                exit 0
                ;;
            --)
                shift
                break
                ;;
            *)
                echo "URL UNKNOWN - ${1} is not a valid parameter"
                exit 3
                ;;
        esac
    done

    if [ -z ${1+x} ]; then 
        echo "URL UNKNOWN - url not given"
        exit 3
    else 
        url=${1}
    fi
}
LC_NUMERIC="C"
warn=1
crit=2
script_name=$(basename "${0}")
script_dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
url=''
GetOptions "$@"

eval $(curl -L -o /dev/null -s -w 'RESPONSE_CODE=%{response_code}\nRESPONSE_TIME=%{time_total}\nDNS_TIME=%{time_namelookup}\nCONNECT_TIME=%{time_connect}' ${proxy:+"--proxy" "$proxy"} $url)
response_time=$(printf %.3f $(echo ${RESPONSE_TIME}))
dns_time=$(printf %.3f $(echo ${DNS_TIME}))
connect_time=$(printf %.3f $(echo ${CONNECT_TIME}))
rdetail=""
if (( $(echo "$RESPONSE_CODE != 200" | bc -l) )); then
    rval=2
    rmsg="CRITICAL"
    rdetail="$url was not available"
elif (( $(echo "$RESPONSE_TIME < ${warn}" | bc -l) )); then
    rval=0
    rmsg="OK"
elif (( $(echo "$RESPONSE_TIME < ${crit}" | bc -l) )); then
    rval=1
    rmsg="WARNING"
else
    rval=2
    rmsg="CRITICAL"
fi
unit='s'
echo "URL ${rmsg} - ${rdetail:+"$rdetail - "}Response code: ${RESPONSE_CODE} Response Time: ${response_time} DNS Lookup time: ${dns_time} Connect time: ${connect_time}|response=${response_time}${unit} dns-query=${dns_time}${unit} connect=${connect_time}${unit}"
exit $rval