#!/bin/sh

# The MIT License (MIT)
#
# Copyright © 2025 pacman64
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the “Software”), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# ctop [seconds...] [options...]
#
#
# Clean TOP runs `top` using better default settings, and offers easier-to-use
# command-line options. Updates happen every 2 seconds by default, unless you
# change it by giving an argument which looks like a number, with or without
# decimals.
#
# The name comes from the fact that regular `top` shows some output when quit,
# while this wrapper tool doesn't.
#
# As when running `top` directly, pressing `q` quits, while pressing `h` shows
# the help screen, which you also quit by pressing `q` while in it. You can
# also force-quit this tool by pressing Ctrl+C.
#
# The options are, available both in single and double-dash versions
#
#   -cpu    reverse-sort entries by latest sampled CPU use
#
#   -h      show this help message
#   -help   show this help message
#
#   -id     sort entries by PID
#   -pid    sort entries by PID
#
#   -m      reverse-sort entries by latest sampled RSS/RES (memory) use
#   -mem    reverse-sort entries by latest sampled RSS/RES (memory) use
#   -res    reverse-sort entries by latest sampled RSS/RES (memory) use
#   -rss    reverse-sort entries by latest sampled RSS/RES (memory) use
#
#   -sh     reverse-sort entries by latest sampled shared memory use
#   -shr    reverse-sort entries by latest sampled shared memory use
#
#   -time   reverse-sort entries by running time
#
#   -usr    sort entries by user
#   -user   sort entries by user
#
#   -vir    reverse-sort entries by latest sampled VIRTual memory use
#   -virt   reverse-sort entries by latest sampled VIRTual memory use


case "$1" in
    -h|--h|-help|--help)
        awk '/^# +ctop /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
        exit 0
    ;;
esac

cmd='top'
sort=''
seconds=2
number_regex='^(\.[0-9]+|[1-9]+(\.[0-9]+)?)$'

for arg in "$@"; do
    if [ "${arg}" = '--' ]; then
        break
    fi

    case "${arg}" in
        -cpu|--cpu) sort="-o %CPU";;
        -id|--id|-pid|--pid) sort="-o PID";;
        -m|--m|-mem|--mem|-res|--res|-rss|--rss) sort="-o RES";;
        -sh|--sh|-shr|--shr) sort="-o SHR";;
        -t|--t|-time|--time|-time+|--time+) sort="-o TIME+";;
        -usr|--usr|-user|--user) sort="-o USER";;
        -vir|--vir|-virt|--virt) sort="-o VIRT";;
        *)
            if echo "${arg}" | grep -E -q "${number_regex}"; then
                seconds="${arg}"
            else
                cmd="${cmd} ${arg}"
            fi
        ;;
    esac
done

# restore previous screen contents when sent an INT signal, which usually
# happens by pressing Ctrl+C
trap 'tput rmcup; exit 130' INT

tput smcup
${cmd} -d "${seconds}" ${sort}
code=$?
tput rmcup
exit "${code}"