i3-settree: Add first implementation of an i3 tree restorer

i3-settree

@@ -0,0 +1,105 @@
+#! /usr/bin/env bash
+#
+# i3-settree
+# Restore an i3 layout using a list of saved trees
+# Copyright (C) 2018 salt <salt@lap-th-e560-0>
+#
+# Distributed under terms of the MIT license.
+#
+
+# Pedantry
+# shellcheck disable=1117
+
+# Globals
+name="$(basename -- "$0")"
+treespath="${XDG_CONFIG_DIR:-$HOME/.config}/i3/trees"
+
+# Helpers
+log() {
+	[ -z "$1" ] && return 1
+	printf "%s: %s\n" \
+		"$name" \
+		"$1"
+	return 0
+}
+prepare_input() {
+	options=""
+	for file in "$treespath"/*; do
+		if ! [ -r "$file" ]; then
+			# Cannot read the file; skip it
+			continue
+		fi
+		if ! [ -f "$file" ]; then
+			# Glob failed and no files exist; error
+			return 1
+		fi
+		if [ -z "$options" ]; then
+			options="$file"
+		else
+			options="$options
+$file"
+		fi
+	done
+	printf "%s" \
+		"$options"
+	return 0
+}
+
+# Steps
+step_validate_deps() {
+	# Ensure we have all the programs we need to do this
+	for dep in rofi i3-msg; do
+		if ! command -v "$dep" > /dev/null 2>&1; then
+			log "Could not validate dependency \"$dep\""
+			return 1
+		fi
+	done
+	return 0
+}
+step_validate_files() {
+	# Ensure we actually have tree files to set
+	if ! [ -d "$treespath" ]; then
+		mkdir -p "$treespath" > /dev/null 2>&1
+		if [ -d "$treespath" ]; then
+			log "Trees path was created: $treespath"
+			log "Put your modified i3-save-tree trees there"
+			return 1
+		else
+			log "Failed to create trees path: $treespath"
+			log "Are permissions set correctly? Is the filesystem mounted read-write?"
+			return 1
+		fi
+	fi
+	return 0
+}
+step_get_input() {
+	# Get the user input, store it in $choice
+	choice="$(rofi -dmenu -p "append tree" <<< "$(prepare_input)")"
+	if [ -z "$choice" ]; then
+		log "User cancelled the operation"
+		return 1
+	fi
+}
+step_act() {
+	# Do the do
+	# Using a case statement here in case I want to implement saving
+	# functionality later
+	case "$choice" in
+		*)
+			i3-msg "append_layout $choice" > /dev/null 2>&1
+			return $!
+			;;
+	esac
+}
+
+# Main
+main() {
+	step_validate_deps || return 50
+	step_validate_files || return 51
+	step_get_input || return 52
+	step_act
+	return $!
+}
+
+main "$@"
+