#!/bin/sh

# The MIT License (MIT)
#
# Copyright © 2020-2025 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.


# pot [options...]
#
# A task watcher (similar to `top`) which shows all current processes using
# colors, so things are easier to scan/read. All data come from periodically
# running the `ps` command: when not given any `ps`-specific options, the
# default is to run `ps aux --sort=pid`.
#
# The options are, available in single and double-dashed versions
#
#   -c      reverse-sort entries by latest sampled CPU use
#   -cpu    reverse-sort entries by latest sampled CPU use
#
#   -h      show this help message
#   -help   show this help message
#
#   -m      reverse-sort entries by latest sampled RSS (memory) use
#   -mem    reverse-sort entries by latest sampled RSS (memory) use
#   -rss    reverse-sort entries by latest sampled RSS (memory) use
#
#   -u      sort/group entries by user
#   -user   sort/group entries by user


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

for arg in "$@"; do
    case "${arg}" in
        --) break;;
        a|u|x|au|ax|ua|ux|xa|xu) select="${select}${arg}";;
        aux|axu|uax|uxa|xau|xua) select="${select}${arg}";;
        -c|--c|-cpu|--cpu) sort="--sort=-%cpu,-rss";;
        -i|--i|-id|--id|-pid|--pid) sort="--sort=pid";;
        -m|--m|-mem|--mem|-rss|--rss) sort="--sort=-rss,-%cpu";;
        -u|--u|-user|--user) sort="--sort=user,-%cpu,-rss";;
        # -u|--u|-user|--user) sort="--sort=user,-rss,-%cpu";;
        --sort=*) sort="${arg}";;
        -compact|--compact|-tight|--tight) compact=1;;
        *)
            if echo "${arg}" | grep -q '^[1-9][0-9]*$' > /dev/null; then
                seconds="${arg}"
            fi
        ;;
    esac
done

options="${select:-aux} ${sort:---sort=pid}"

gather='res="$(ps '"${options}"')"; echo "${res}"'

# sed to color-code values and make them more readable
big="s-([0-9]{1,3})([0-9]{6}|[0-9]{3})( |$)-\x1b[36m\1\x1b[0m\2\3-g"
zeros="s- (0\.0|0:00) - \x1b[34m\1\x1b[0m -g"
root="/^root/s-\x1b\[0m-\x1b[0m\x1b[33m-g; /^root/s-^-\x1b[33m-"
colors="${big}; ${root}; ${zeros}; s-\\\$-\x1b[0m-"

if [ "${compact}" = 1 ]; then
    exec watch -n "${seconds:-2}" -c "${gather}"' | sed -E "'"${colors}"'"'
else
    # awk code to insert empty lines, and more easily follow lines horizontally
    lines="(NR - 1) % 5 == 1 { print empty } 1"
    exec watch -n "${seconds:-2}" -c \
        "${gather}"' | sed -E "'"${colors}"'" | awk "'"${lines}"'"'
fi