#!/usr/bin/env bash
#
# check status of a list of systemd service units
# + accept service name with or without extension (.service)
# + default to system wide services but accept --user services with the :uid
# + alarm by bullet coloration and blinking
#
# requirements: systemd

# GENERAL ###########################################################

# locale env
unset LC_ALL
export LC_MESSAGES=C

# check if module was disabled
module_disable=${module_services_disable:=0}
if (($module_disable == 1)); then
    exit 1
fi

# colors
c_txt=${c_txt:="39"}
c_txt_emphase=${c_txt_emphase:="35"}
c_txt_deco=${c_txt_deco:="97"}
c_txt_invert=${c_txt_invert:="30"}
c_bg=${c_bg_sec:="47"}
c_danger=${c_danger:="31"}
c_warning=${c_warning:="33"}
c_success=${c_success:="32"}
c_title=${c_title:="${c_bg};1;${c_txt_invert}m"}

# OPTIONS ###########################################################

# array of services
if [[ $module_services ]]; then
    services=(${module_services[@]})
else
    services=("cron.service" "dbus.service:1000" "user2service:1002")
fi
IFS=$'\n' services=($(sort <<<"${services[*]}"))
unset IFS

# column max-width
width=${module_services_width:="80"}

# PREPARATIONS ######################################################

# get status
# + dim status if the service does not exist or if the user is not root and the service has another uid
serviceStatus=()
for service in "${services[@]}"; do
    uid=${service/*:/}
    # script executed as root and the service to check is from a user
    if [[ $service = *:* ]] && [[ "$(id -u)" == "0" ]]; then
        service=${service/.service/}
        service=${service/:[0-9]*/}
        serviceexist=$(machinectl -q shell --uid="$uid" .host /usr/bin/systemctl list-units --user -q --plain --no-pager --full --all -t service 2>/dev/null \
            | awk '$1 ~ /\.service$/ { sub("\\.service$", "", $1); print $1 }' \
            | /usr/bin/grep "$service")
        if [[ "$serviceexist" ]] ;then
            status=$(machinectl -q shell --uid="$uid" .host /usr/bin/systemctl is-active --user "$service")
            if [[ $status = inactive* ]]; then
                serviceStatus+=("inactive")
            elif [[ $status = active* ]]; then
                serviceStatus+=("active")
            else
                serviceStatus+=("hidden")
            fi
        else
            serviceStatus+=("hidden")
        fi
    # script executed by the same user as the service user
    elif [[ $service = *:* ]] && [[ "$(id -u)" == "$uid" ]]; then
        service=${service/.service/}
        service=${service/:[0-9]*/}
        serviceexist=$(/usr/bin/systemctl list-units --user -q --plain --no-pager --full --all -t service 2>/dev/null \
            | awk '$1 ~ /\.service$/ { sub("\\.service$", "", $1); print $1 }' \
            | /usr/bin/grep "$service")
        if [[ "$serviceexist" ]] ;then
            serviceStatus+=($(/usr/bin/systemctl --user is-active "$service"))
        else
            serviceStatus+=("hidden")
        fi
    # script executed by another user than root and than the service user
    elif [[ $service = *:* ]]; then
        serviceStatus+=("hidden")
    # system service
    else
        service=${service/.service/}
        service=${service/:[0-9]*/}
        serviceexist=$(/usr/bin/systemctl list-units -q --plain --no-pager --full --all -t service 2>/dev/null \
            | awk '$1 ~ /\.service$/ { sub("\\.service$", "", $1); print $1 }' \
            | /usr/bin/grep "$service")
        if [[ "$serviceexist" ]] ;then
            serviceStatus+=($(/usr/bin/systemctl is-active "$service"))
        else
            serviceStatus+=("hidden")
        fi
    fi
done

# OUTPUT ############################################################

# output header
echo -e "\n\e[${c_title} Services checks  \e[0m\n"

# output checklist
line=" "
lineLen=1
for i in "${!serviceStatus[@]}"
do
    service=${services[$i]/.service/}
    service=${service^}

    # Next line and next line length
    next="   $service "
    nextLen=$((1+${#next}))

    # If the current line will exceed the max column with then echo and start a new line
    if [[ $((lineLen+nextLen)) -gt $width ]]; then
        echo -e "$line"
        lineLen=1
        line=" "
    fi

    lineLen=$((lineLen+nextLen))

    # Color the next line green if it's active, red if inactive, else orange
    if [[ "${serviceStatus[$i]}" == "active" ]]
    then
        line+=" \e[${c_success}m●\e[0m \e[${c_txt}m$service\e[0m "
    elif [[ "${serviceStatus[$i]}" == "inactive" ]]
    then
        line+=" \e[1;5;${c_danger}m▲\e[0m \e[1;${c_txt}m$service\e[0m "
    else
        line+=" \e[1;2;${c_warning}m▲\e[0m \e[1;2;${c_txt}m$service\e[0m "
    fi
done

# echo what is left
echo -e "$line"