#!/bin/sh

# Copyright (c) 2024 frosty <passedgoandgot200@gmail.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

set -eu

VERSION="1.0.0"

# shellcheck disable=SC1091
[ -f "${XDG_CONFIG_HOME:-$HOME/.config}/user-dirs.dirs" ] && . "${XDG_CONFIG_HOME:-$HOME/.config}/user-dirs.dirs"
OUTPUT_DIRECTORY=${XDG_SCREENSHOTS_DIR:-${XDG_PICTURES_DIR:-$HOME}}
FILENAME_BASE="screenshot"
FILENAME_DATE_FORMAT="%Y-%m-%d_%H-%M-%S"

QUIET=
COPY=
OVERLAY=
SAVE=

err() {
	echo "$@" >&2
}

die() {
	err "${0##*/}: $1"
	exit 1
}

notify() {
	notify-send "${0##*/}" "$@"
}

screenshot_select() {
	maim -qsu "$@"
}

screenshot_full() {
	maim -qu "$@"
}

usage() {
	err "usage: ${0##*/} [-hVqcos] [TYPE] [FILE]"
	err
	err " -h	show this message and exit"
	err " -V	show version information and exit"
	err " -q	suppress program output"
	err " -c	copy image to clipboard"
	err " -o	overlay image on screen"
	err " -s	save image to disk"
}

version() {
	err "${0##*/} v$VERSION"
	err
	err "Copyright (c) 2024 frosty <passedgoandgot200@gmail.com>"
	err
	err "This program is free software: you can redistribute it and/or modify"
	err "it under the terms of the GNU General Public License as published by"
	err "the Free Software Foundation, either version 3 of the License, or"
	err "(at your option) any later version."
}

while getopts :hVqcos opt; do
	case "$opt" in
		h) usage; exit 0 ;;
		V) version; exit 0 ;;
		q) QUIET=1 ;;
		c) COPY=1 ;;
		o) OVERLAY=1 ;;
		s) SAVE=1 ;;
		*) die "invalid option: -$OPTARG" ;;
	esac
done

shift $((OPTIND - 1))

SCREENSHOT_TYPE=${1:-select}
FILE_PATH=${2:-}

case "$SCREENSHOT_TYPE" in
	select|full) ;;
	*) usage; exit 1 ;;
esac

if [ -n "$SAVE" ]; then
	FILE_PATH=${FILE_PATH:-$OUTPUT_DIRECTORY/$FILENAME_BASE-$(date "+$FILENAME_DATE_FORMAT").png}
else
	FILE_PATH="/tmp/${0##*/}-$(date '+%s').png"
fi

screenshot_"$SCREENSHOT_TYPE" "$FILE_PATH" || exit 0

[ -z "$QUIET" ] && notify "Screenshot taken"

[ -n "$COPY" ] && xclip -sel clip -t image/png "$FILE_PATH"
[ -n "$OVERLAY" ] && feh --class no-decor -x "$FILE_PATH"

[ -z "$SAVE" ] && rm "$FILE_PATH"