#!/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.


# hima [options...] [regexes...]
#
#
# HIlight MAtches ANSI-styles matching regular expressions along lines read
# from the standard input. The regular-expression mode used is a superset of
# the commonly-used "extended-mode".
#
# All ANSI-style sequences from stdin are removed, to avoid messing those up:
# the only ANSI styles left in the output will be from the matches, if any.
#
# Also, multiple matches in a line never overlap: at each step along a line,
# the earliest-starting match among the regexes always wins, as the order
# regexes are given among the arguments never matters.
#
# The options are, available both in single and double-dash versions
#
#     -h, -help      show this help message
#     -f, -filter    filter out (ignore) lines with no matches
#     -i, -ins       match regexes case-insensitively


filter=0
case_insensitive=0

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

    case "$1" in
        -f|--f|-filter|--filter)
            filter=1
            shift
            continue
        ;;

        -h|--h|-help|--help)
            awk '/^# +hima /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
            exit 0
        ;;

        -i|--i|-ins|--ins)
            case_insensitive=1
            shift
            continue
        ;;
    esac

    break
done

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

command='awk'
if { [ -p /dev/stdout ] || [ -t 1 ]; } && [ -e /usr/bin/stdbuf ]; then
    command='stdbuf -oL awk'
fi

ci='
    BEGIN {
        if (IGNORECASE == "") {
            m = "your `awk` command lacks case-insensitive regex-matching"
            print(m) > "/dev/stderr"
            exit 125
        }
        IGNORECASE = 1
    }
'
if [ "${case_insensitive}" -eq 0 ]; then
    ci=''
fi

expr="$(awk '
    BEGIN {
        for (i = 1; i < ARGC; i++) {
            if (i > 1) printf "|"
            printf "(%s)", ARGV[i]
        }
        exit
    }
' "$@")"

${command} -v expr="${expr}" -v filter="${filter}" "${ci}"'
    {
        # ignore cursor-movers and style-changers
        gsub(/\x1b\[[0-9;]*[A-Za-z]/, "")

        # ignore OSC sequences
        gsub(/\x1b\][^\x1b]+\x1b\\/, "")

        if (filter && $0 !~ expr) next

        gsub(expr, "\x1b[7m&\x1b[0m")
        print
    }
'