#!/bin/sh

# The MIT License (MIT)
#
# Copyright (c) 2026 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.


# center [options...] [width...] [files...]
#
# CENTER-align lines of text, using the (optional) width given and the widest
# line from the input(s). If given a valid number, it's used as the width, or
# the current window width is used by default.
#
# The options are, available both in single and double-dash versions
#
#    -h, -help    show this help message


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

width=80
if echo "$1" | grep -q -E '^[0-9]+$'; then
    width="$1"
    shift
else
    width="$(tput -T xterm cols 2> /dev/null || echo 80)"
fi

[ "$1" = '--' ] && shift

# center-align lines of text, using the current screen width
awk -v width="${width}" '
    {
        gsub(/\r$/, "")
        lines[NR] = $0

        plain = $0
        gsub(/\x1b\[[0-9;]*[A-Za-z]/, "", plain)
        l = length(plain)
        if (maxlen < l) maxlen = l
    }

    END {
        n = (width - maxlen) / 2
        if (n % 1) n = n - (n % 1)
        if (n < 1) n = 80
        fmt = sprintf("%%%ds%%s\n", (n > 0) ? n : 0)
        for (i = 1; i <= NR; i++) printf fmt, "", lines[i]
    }
' "$@"