#!/usr/bin/env bash

# Simple CLI to make wallpaper changes with xwallpaper more comfortable

CONF_DIR=${XDG_CONFIG_HOME:-~/.config}/paperchanger
CONF_CURRENT_WP=${CONF_DIR}/current_wallpaper.txt
CONF_PATH=${CONF_DIR}/paperchanger.conf.sh
mkdir -p ${CONF_DIR}

if [[ ! -f ${CONF_DIR} ]]; then
	touch ${CONF_DIR}
fi


if [[ ! -f ${CONF_PATH} ]]; then
	echo '# This is the configuration file used by the paperchanger program

default_directory=' > ${CONF_DIR}/paperchanger.conf.sh
fi

read -r current_file_path < ${CONF_CURRENT_WP}
source ${CONF_PATH}

function _help() {
	echo ""
	echo "A tool to help change the wallpaper in a more comfortable way."
	echo "Uses xwallpaper to load the specified wallpaper."
	echo ""
	echo "Usage: paperchanger [OPTION] [PATH]"
	printf "  %-45s\t%-54s\n" \
		"-h,  --help, help" "Print this help." \
		"-d,  --display, display" "Display the specified wallpaper." \
		"-s,  --set, set" "Set the wallpaper with the path as parameter." \
		"-S,  --Set, Set" "Set the wallpaper with a graphical file chooser." \
		"-ds, --display-and-set, display-and-set" "Set the wallpaper with an path as parameter AND display the specified wallpaper." \
		"-dS, --display-and-Set, display-and-Set" "Set the wallpaper with a graphical file chooser AND display the specified wallpaper." \
        "-p,  --path, path" "Set the path of the default directory as parameter, where the file chooser to select a wallpaper is initially opened." \
        "-P,  --Path, Path" "Set the path of the default directory with a graphical file chooser, where the file chooser to select a file chooser is initially opened." \	
}

function _display() {
	xwallpaper --zoom $current_file_path 
}

function _set() {
	current_file_path="$1"
	echo "$current_file_path" > ${CONF_CURRENT_WP}
}

function _change_config_path() {
	sed -i "s/^default_directory=.*\$/default_directory=${1//\//\\/}/" ${CONF_PATH}
}

case "$#" in
	0)
		_help
		;;
	1)
		case "$1" in
			-h | --help | help)
				_help
				;;
			-d | --display | display)
				if [[ "$current_file_path" == "" ]]; then
					echo "No wallpaper is selected. Please use <paperchanger -s> or <paperchanger -S> first!"
					exit 1
				else
					_display
				fi
				;;
			-S | --Set | Set)
				if [[ "$default_directory" == "" ]]; then
					_set "$(zenity --file-selection)"
				else
					_set "$(zenity --file-selection --filename=$default_directory)"
				fi
				;;
			-dS | --display-and-Set | display-and-Set)
				if [[ "$default_directory" == "" ]]; then
					_set "$(zenity --file-selection)"
				else
					_set "$(zenity --file-selection --filename=$default_directory)"
				fi
				_display
				;;
			-P | --Path | Path)
				_change_config_path "$(zenity --file-selection --directory)/"
				;;
			*)
				echo "Input Error"
				exit 1
				;;
		esac
		;;
	2) 	if [[ "$1" == "-s" || "$1" == "--set" || "$1" == "set" ]]; then
			_set "$2"
		elif [[ "$1" == "-ds" || "$1" == "--display-and-set" || "$1" == "display-and-set" ]]; then
			_set "$2"
			_display
		elif [[ "$1" == "-p" || "$1" == "--path" || "$1" == "path" ]]; then
			_change_config_path "$2"
		else
			echo "Input Error"
			exit 1
		fi
		;;
	*)
		echo "Input error, too many parameters."
		echo "please use paperchanger -h or the man page to get help."
		exit 1
		;;
esac