#!/bin/bash

INDIR="$HOME/wp/curr"
OUTDIR="$HOME/wp/curr"

mkdir -p "$OUTDIR"

sedstr="\([0-9][0-9]*\)x\([0-9][0-9]*\)+\([0-9][0-9]*\)+\([0-9][0-9]*\)"
monitors="$(xrandr -q | grep '[0-9]*x[0-9]*+[0-9]*+[0-9]*' | cut -f1 -d' ' | tr '\n' '~')"

function getinfo() {
	xrandr -q | grep "^$1" | grep -o "[0-9][0-9]*x[0-9][0-9]*+[0-9][0-9]*+[0-9][0-9]*"
}

function getres() {
	getinfo "$1" | sed "s:$sedstr:\1x\2:"
}

function getoff() {
	getinfo "$1" | sed "s:$sedstr:+\3+\4:"
}

function getwidth() {
	getinfo "$1" | sed "s:$sedstr:\1:"
}

function getheight() {
	getinfo "$1" | sed "s:$sedstr:\2:"
}

function getleft() {
	getinfo "$1" | sed "s:$sedstr:\3:"
}

function gettop() {
	getinfo "$1" | sed "s:$sedstr:\4:"
}

function screenres() {
	xrandr -q | grep "^Screen 0" | sed 's:^.*current \([0-9][0-9]*\) x \([0-9][0-9]*\).*$:\1x\2:'
}

function run() {
	echo "$@"
	"$@" || exit 1
}

function main() {
	all="$OUTDIR/all-$monitors.png"
	all_blur="$OUTDIR/all-${monitors}_blur.png"
	if [ ! -e "$all" ] || [ ! -e "$all_blur" ] \
			|| [ "$INDIR/motif.png" -nt "$all" ] \
			|| [ "$INDIR/panorama.png" -nt "$all" ] \
			|| [ "$(realpath "$INDIR/motif.png")" -nt "$all" ] \
			|| [ "$(realpath "$INDIR/panorama.png")" -nt "$all" ]; then

		local joinargs=()

		while [ -n "$1" ] && [ "$1" != "--" ]; do
			if xrandr --listmonitors | grep -q "$1"; then
				local res="$(getres "$1")"
				run convert "$INDIR/motif.png" -resize "$res^" -gravity center -extent "$res" "$OUTDIR/$1.png"
				joinargs+=("$OUTDIR/$1.png" -geometry "$(getoff "$1")" -composite)
			fi
			shift
		done

		shift

		if [ -n "$1" ]; then
			local splitargs=()
			local off=0
			local maxh=0
			while [ -n "$1" ]; do
				if xrandr --listmonitors | grep -q "$1"; then
					splitargs+=(\( -clone 0 -gravity West -extent "$(getres "$1")+$off+0" -write "$OUTDIR/$1.png" +delete \))
					joinargs+=("$OUTDIR/$1.png" -geometry "$(getoff "$1")" -composite)
					off=$((off + $(getwidth "$1")))
					if [ "$maxh" -lt "$(getheight "$1")" ]; then
						maxh="$(getheight "$1")"
					fi
				fi
				shift
			done

			run convert -respect-parenthesis "$INDIR/panorama.png" -gravity Center -resize "${off}x${maxh}^" -crop "${off}x${maxh}+0+0^" "${splitargs[@]}" "jpg:/dev/null"
		fi

		run convert -respect-parenthesis -size "$(screenres)" 'xc:#000000' "${joinargs[@]}" "$all"
		run convert "$all" -blur 0x20 "$all_blur"
	fi

	test -e "$OUTDIR/all.png" && rm "$OUTDIR/all.png"
	ln -sf "$all" "$OUTDIR/all.png"
	test -e "$OUTDIR/all_blur.png" && rm "$OUTDIR/all_blur.png"
	ln -sf "$all_blur" "$OUTDIR/all_blur.png"
}

main "$@"