#!/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.


# cio [options...] [filepath...]
#
#
# Clipboard IO automatically figures out whether to copy/paste from/to the
# clipboard, depending on the piping of its standard input/output.
#
# When both its standard input/output are piped, it first updates the text
# clipboard, and then emits its new value to the standard output.
#
# When run unpiped on its own, it just emits the current clipboard value to
# the standard output.
#
# The options are, available both in single and double-dash versions
#
#   -c        clear/empty the clipboard
#   -clear    clear/empty the clipboard
#   -e        clear/empty the clipboard
#   -empty    clear/empty the clipboard
#
#   -h        show this help message
#   -help     show this help message


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

if [ -e /dev/clipboard ]; then
    get_clip='cat /dev/clipboard'
    set_clip='cat > /dev/clipboard'
elif [ -e /usr/bin/wl-paste ]; then
    get_clip='wl-paste --no-newline'
elif [ -e /usr/bin/wclip ]; then
    get_clip='wclip -o'
    set_clip='wclip'
elif [ -e /usr/bin/xclip ]; then
    get_clip='xclip -o'
    set_clip='xclip -sel clip'
elif [ -e /usr/bin/pbpaste ]; then
    get_clip='pbpaste'
fi

if [ -z "${set_clip}" ]; then
    if [ -e /usr/bin/wl-copy ]; then
        set_clip='wl-copy'
    elif [ -e /usr/bin/pbcopy ]; then
        set_clip='pbcopy'
    fi
fi

case "$1" in
    -c|--c|-clear|--clear|-e|--e|-empty|--empty)
        ${set_clip} < /dev/null
        return $?
    ;;
esac

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

emit_clipboard() {
    if [ -z "${get_clip}" ]; then
        printf "can't read the clipboard\n" > /dev/stderr
        exit 1
    fi
    ${get_clip} || exit $?
}

change_clipboard() {
    if [ -z "${set_clip}" ]; then
        printf "can't change the clipboard\n" > /dev/stderr
        exit 1
    fi
    cat "$@" | ${set_clip} || exit $?
}

if [ $# -gt 0 ]; then
    # handle `cio ...` or `cio ... | ...`
    change_clipboard "$@"
    if [ -p /dev/stdout ]; then
        emit_clipboard
    fi
    exit 0
elif [ -p /dev/stdin ]; then
    # handle `... | cio` or `... | cio | ...`
    change_clipboard /dev/stdin
    if [ -p /dev/stdout ]; then
        emit_clipboard
    fi
    exit 0
else
    # handle `cio` or `cio | ...`
    emit_clipboard
    exit 0
fi