#!/bin/sh -e
#
#    layout: save and restore byobu layouts
#    Copyright (C) 2011-2014 Dustin Kirkland <kirkland@byobu.org>
#
#    Authors: Dustin Kirkland <kirkland@byobu.org>
#
#    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, version 3 of the License.
#
#    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 <http://www.gnu.org/licenses/>.

PKG="byobu"
[ -r "$HOME/.byoburc" ] && . "$HOME/.byoburc"
[ -z "${BYOBU_PREFIX}" ] && export BYOBU_PREFIX="@prefix@" || export BYOBU_PREFIX
. "${BYOBU_PREFIX}/lib/${PKG}/include/common"

# Get the layouts directory
DIR="$BYOBU_CONFIG_DIR/layouts"
mkdir -p "$DIR"
PRESETS="even-horizontal even-vertical main-horizontal main-vertical tiled"
current_panes=$(tmux list-panes | wc -l)

list_layouts() {
	echo
	echo "Byobu Saved Layouts"
	local count=0 i= desc= p=
	for i in $PRESETS "$DIR"/*; do
		desc=${i##*/}
		count=$(expr $count + 1)
		[ -f "$i" ] && p=$(head -n1 "$i")
		[ -n "$p" ] && p=" ($p splits)"
		echo "  $count. $desc$p"
	done
	echo
	_RET="$count"
}

case "$1" in
	"save")
		layout=$(tmux list-windows | grep "(active)$" | sed -e "s/.*\[layout //" -e "s/\] .*(active)$//")
		panes=$(tmux list-panes | wc -l)
		if [ -n "$2" ]; then
			name="$2"
		elif name=$(tmux show-buffer 2>/dev/null) && [ -n "$name" ]; then
			: # name read from tmux paste buffer (set by C-S-F8 keybinding)
		else
			echo
			echo "Restore layout with <shift-F8>, save a layout with <shift-ctrl-F8>"
			while true; do
				list_layouts
				echo -n "Enter a unique name to save this layout: "
				name=$(head -n1)
				valid=1
				for i in $PRESETS "$DIR"/*; do
					i=${i##*/}
					if [ "$i" = "$name" ]; then
						valid=0
					fi
				done
				[ "$valid" = "1" ] && break
			done
		fi
		printf "$panes\n$layout\n" > "$BYOBU_CONFIG_DIR/layouts/$name"
	;;
	"restore")
		if [ -n "$2" ]; then
			# Layout selected on the command line
			name="$2"
		else
			# List the saved layouts, prompt the user to select one
			list_layouts
			count="$_RET"
			while true; do
				echo -n "Select a layout to restore [1-$count]: "
				selected=$(head -n1)
				if [ -n "$selected" ] && [ $selected -le $count ] && [ $selected -ge 1 ]; then
					break
				fi
			done
			count=0
			for i in $PRESETS "$DIR"/*; do
				count=$(expr $count + 1)
				if [ $count -eq $selected ]; then
					name=$(basename "$i")
					break
				fi
			done
		fi
		# Get the details of the selected layout
		panes=
		layout=
		if [ -f "$DIR/$name" ]; then
			panes=$(head -n1 "$DIR/$name")
			layout=$(tail -n1 "$DIR/$name")
		else
			if [ $current_panes -eq 1 ]; then
				panes=4
			else
				panes=0
			fi
			layout="$name"
		fi
		# Create panes if nececessary to restore the layout
		while [ $(tmux list-panes | wc -l) -lt $panes ]; do
			tmux split-window
			tmux select-layout tiled
		done
		# Finally, restore the layout and refresh
		tmux select-layout "$layout"
		tmux source "$BYOBU_PREFIX/share/byobu/profiles/tmuxrc"
	;;
	list)
		list_layouts
		exit 0
	;;
	*)
		echo "ERROR: Invalid argument, try [save|restore|list]" 2>&1
		exit 1
	;;
esac
