#!/bin/bash
# 'getCurrentStat to sort' simultaneously on many target using bash V5+.
# Sample of distributing complex bash commands through many hosts, using ssh
# then datas are get/retrieved then formated remotelly, finally all outputs,
# are simply sorted to be printed out.
# Note: As all output are sent on only one line, race condition mixing
# output of different target on same line seem unlikely possible,
# for more robust solution see the 'getCurrentStat bash for sh' alternative.
# (C) 2023-2024 Felix Hauri - felix@f-hauri.ch
# Licensed under terms of GPL v3. www.gnu.org

## Note: Host list is ignored if arguments (list of user@hosts) are submited!!
## To use an external file replace the following by: exec {hostList}</path/file
exec {hostList}<<EOHostList
#   Target: user@host-or-ip	Text full description

    pi@192.168.1.7		Private NAS
    user@somewhere.not		My web server
    root@10.1.33.4		Private backup through vpn
EOHostList

percent() { # usage: percent <value> <ref val> [varname]
    local p=000$(( ${1}00000/$2 ));
    # shellcheck disable=SC2059 disable=SC2086
    printf ${3+-v} $3 %.2f ${p::-3}.${p: -3}
}
textSize(){ # usage: textSize <value> [varname]
    local i=$(( $1 >= 1<<50 ? 5 : $1 >= 1<<40 ? 4 : $1 >= 1<<30 ? 3 :
		$1 >= 1<<20 ? 2 : $1 > 1023 ? 1 : 0 )) a=(K M G T P)
    # shellcheck disable=SC1105 disable=SC2210 disable=SC2035
    (( i > 4 ? i+=-2 : 0 )) && a=( "${a[@]:2}" ) && set -- $(( $1>>20 )) "$2"
    local r=00$(( 1000 * $1 / ( 1024**i ) ))
    # shellcheck disable=SC2059 disable=SC2086
    printf -v $2 %.2f%s ${r::-3}.${r: -3} ${a[i]}
}
collectCpuMemDiskStat() { # Collect infos, format and print them.
    local order=$1
    shopt -s extglob
    read -r upt idl </proc/uptime
    { read -r _;read -ra mem;read -ra swap ;}< <(LC_ALL=C free)
    declare -i otot=0 ouse=0
    while read -r _ typ tot use _ ; do
	case $typ in
	    ext*|xfs*|reiser*|ntfs*|btrfs|fat*)
		otot+=$tot ouse+=$use
		;;
	esac
    done < <(LANG=C df -PlkT)
    if [[ -d /sys/firmware/devicetree/base ]]; then
       mapfile -d '' -t model < /sys/firmware/devicetree/base/model
    else
	while read -r line; do
	    case $line in
		model\ name* )
		    line=${line#*: }
		    model[0]=${line//(*([! ]))}
		    break
		    ;;
	    esac
	done </proc/cpuinfo
    fi
    ncpu=$(grep -c processor /proc/cpuinfo )
    percent $(( ${upt/.} * ncpu - ${idl/.} )) $(( ${upt/.} * ncpu )) pcpu
    percent "${mem[2]}" "${mem[1]}" pmem
    percent "${swap[2]}" "${swap[1]}" pswap
    percent "$ouse" "$otot" pdsk
    textSize "${mem[1]}" hmem
    textSize "$otot" hdsk 
    # shellcheck disable=SC2154
    printf '%d %-13s %-35s %7s %7s %6.2f%% %6.2f%% %6.2f%% %6.2f%% %s\n' \
	   "${order}" "$HOSTNAME" "${model::35}" "$hmem" "$hdsk" "$pcpu" \
	   "$pmem" "$pswap" "$pdsk" "$3"
}
run1ssh() {
    order+=1
    ssh "$1" bash  < <(
	declare -f collectCpuMemDiskStat percent textSize
	printf 'collectCpuMemDiskStat %q %q %q\n' \
	       "$order" "$1" "$2"
    )
}
declare -i order

printf '%-13s %-35s %7s %7s %7s %7s %7s %7s %s\n' \
       Host Model Mem Disk CPU Mem Swap Disk Description
if (($#)); then
    for host; do
	run1ssh "$host"{,} &
    done
else
    while read -ru $hostList host desc; do
	case $host in
	    \#*|'' ) ;;
	    * ) run1ssh "$host" "$desc" &
	    ;;
	esac
    done
fi |
    sort -n |
    sed 's/^[[:digit:]]* //'