#!/bin/sh

# Copyright (C) 2016 Richard Burke, ISC licensed

vc_fatal() {
	echo "$@" >&2
	exit 1
}

vc_usage() {
	vc_fatal "`basename $0` [--selection sel] [--usable|--copy|--paste]"
}

vc_determine_command() {
	if [ -n "$WAYLAND_DISPLAY" ]; then
		for c in wl-copy wl-paste; do
			if type "$c" >/dev/null 2>&1; then
				echo "wlclipboard"
				return 0
			fi
		done
	fi
	
	if [ -n "$DISPLAY" ]; then
		for c in xclip xsel; do
			if type "$c" >/dev/null 2>&1; then
				echo "$c"
				return 0
			fi
		done
	fi

	if [ "$sel" = "primary" ]; then
		vc_fatal "clipboard primary selection is not supported on your platform"
	fi

	if type pbcopy >/dev/null 2>&1; then
		echo 'mac'
		return 0
	fi

	if [ -c /dev/clipboard ]; then
		echo 'cygwin'
		return 0
	fi

	return 1
}

vc_usable() {
	if vc_determine_command >/dev/null 2>&1; then
		exit 0
	fi

	exit 1
}

vc_copy() {
	COPY_CMD="`vc_determine_command 2>/dev/null`"

	if [ $? -ne 0 ] || [ -z "$COPY_CMD" ]; then
		vc_fatal 'System clipboard not supported'
	fi

	vc_${COPY_CMD}_copy

	exit $?
}

vc_paste() {
	PASTE_CMD="`vc_determine_command 2>/dev/null`"

	if [ $? -ne 0 ] || [ -z "$PASTE_CMD" ]; then
		vc_fatal 'System clipboard not supported'
	fi

	vc_${PASTE_CMD}_paste

	exit $?
}

vc_wlclipboard_copy() {
	if [ "$sel" = "primary" ]; then
		wl-copy --primary -t TEXT
	else
		wl-copy -t TEXT
	fi
}

vc_wlclipboard_paste() {
	if [ "$sel" = "primary" ]; then
		wl-paste --primary -t text
	else
		wl-paste -t text
	fi
}

vc_xsel_copy() {
	xsel --"$sel" -bi
}

vc_xsel_paste() {
	xsel --"$sel" -bo
}

vc_xclip_copy() {
	xclip -selection "$sel" -i >/dev/null 2>&1
}

vc_xclip_paste() {
	xclip -selection "$sel" -o
}

vc_mac_copy() {
	pbcopy
}

vc_mac_paste() {
	pbpaste
}

vc_cygwin_copy() {
	cat >/dev/clipboard
}

vc_cygwin_paste() {
	cat /dev/clipboard
}

while [ $# -gt 0 ]; do
	case "$1" in
		--usable) fn=vc_usable;;
		--copy) fn=vc_copy;;
		--paste) fn=vc_paste;;
		--selection) shift; sel="$1";;
		*) ;;
	esac
	shift
done

sel=${sel:-"clipboard"} $fn

vc_usage