#!/bin/bash

################################################################################
#
# Small script using `xrandr` and `fzf` to quickly select connected monitors.
#
# TODO:
#       - Add possibility to not only mirror onto all outputs but use the total
#         screen space.
################################################################################

command -v xrandr &>/dev/null || exit 1
command -v fzf &>/dev/null || exit 1

# Grep for all connected outs including their highest resolution,
# throw away additional information and finally merge the out name and
# resolution lines separating them with a tab.
connected_outs="$(
	xrandr -q \
	| grep -A1 ' connected' \
	| sed 's/^[[:space:]]*//' \
	| grep -Eo "^([^ ]* connected|[0-9]+x[0-9]+)" \
	| paste -d " " - - \
	| sed 's/ connected \(.*\)/\t(\1)/'
)"
[[ -n "$connected_outs" ]] || exit 1

# Multi select on connected outs
selected_outs="$(fzf -m --cycle --header "Select outputs" <<<"$connected_outs")"
[[ -n "$selected_outs" ]] || exit 1

# Selection of primary out out of the selected ones if there is more than one.
if [[ $(wc -l <<<"$selected_outs") -gt 1 ]]; then
	primary_out="$(fzf --cycle --header "Select primary" <<<"$selected_outs")"
else
	primary_out="$selected_outs"
fi
# Strip trailing resolution
primary_out="$(cut -d$'\t' -f1 <<<"$primary_out")"
[[ -n "$primary_out" ]] || exit 1

# "Convert" to array and strip trailing resolutions
# Only done here to display the resolutions in the fzf dialogs.
typeset -a selected_outs=($(cut -d$'\t' -f1 <<<"$selected_outs"))
typeset -a connected_outs=($(cut -d$'\t' -f1 <<<"$connected_outs"))

# Build `xrandr` command
typeset -a xrandr_command
xrandr_command+="xrandr"
for out in "${connected_outs[@]}"; do
	xrandr_command+=(--output "$out")

	# TODO: Solution with better performance?
	if printf "%s\n" "${selected_outs[@]}" | grep -qE "^$out$"; then
		# Current out was selected by user
		xrandr_command+=(--auto)
	else
		xrandr_command+=(--off)
	fi

	[[ "$out" != "$primary_out" ]] || xrandr_command+=(--primary)
done

# Print for debugging purposes and finally execute it
printf "%s\n" "${xrandr_command[*]}"
"${xrandr_command[@]}"