#!/bin/sh

# Allow bulk operations on a list of selected files.

# Requires: dmenu (or similar), trash (optional), open-file (for open only)

# Usage: sel [-m menu] [command]
# If no command is specified, shows the list of selected files
# Commands:
#	add [files...]: add files to selection
#	addall: add all files in the current folder to selection
#	clear: clear selection
#	cp: copy to current dir, possbily after editing filenames
#	edit: open selection in editor
#	mv: move to current dir, possbily after editing filenames
#	open: open files using open-file
#	rm: remove selected files and clear selection

# TODO: The usage of paste(1) is a bit of a hack, and for example it does
# not work if filenames contain tab characters. Fix this.

# Bug (probably not fixing this, use virename): moving a file to
# itself gives an error and rm is not run.

file="$XDG_DATA_HOME/selectedfiles"
menu="" # default uses dmenu-filepicker default
editor=${EDITOR:-vi}
rm="trash rm"  # replace with rm -r if you don't use trash

usage() {
	echo "Usage: sel [-m MENU] [COMMAND]"
	echo "If no COMMAND is specified, shows the list of selected files"
	echo "Possible commands:"
	echo "	add [files...]: add files to selection"
	echo "	addall: add all files in the current folder to selection"
	echo "	clear: clear selection"
	echo "	cp: copy to current dir, possbily after editing filenames"
	echo "	edit: open selection in editor"
	echo "	mv: move to current dir, possbily after editing filenames"
	echo "	open: open files using open-file"
	echo "	rm: remove selected files and clear selection"
}

while getopts "m:" opt; do
	case "$opt" in
		m)
			menu="$OPTARG"
			;;
		*)
			usage
			exit 1
			;;
	esac
done
shift $((OPTIND - 1))

add() {
	shift 1
	if [ -z "$1" ]; then
		if [ -n "$menu" ]; then
			dmenu-filepicker -m "$menu" >> "$file"
		else
			dmenu-filepicker >> "$file"
		fi
	else
		for i in "$@"; do realpath "$i" >> "$file"; done
	fi
	sort -u -o "$file" "$file"
}

clear() {
	cat /dev/null > "$file"
}

cphere() {
	file2=$(mktemp)
	sed 's/^.*\///' "$file" > "$file2"
	$editor "$file2"
	if [ "$(wc -l "$file"  | awk '{print $1}')" != \
	     "$(wc -l "$file2" | awk '{print $1}')" ]; then
		echo "Error reading new file names"
		return 1
	else
		paste "$file" "$file2" | while read -r f; do
			fold=$(echo "$f" | sed 's/	.*//')
			fnew=$(echo "$f" | sed 's/.*	//')
			cp -R "$fold" ./"$fnew" || return 1
		done
	fi
}

open() {
	while read -r f; do
		open-file "$f"
	done < "$file"
}

remove() {
	while read -r f; do
		$rm "$f"
	done < "$file"
}

if [ -z "$1" ]; then
	cat "$file"
else
case "$1" in
	add)
		add "$@"
		;;
	addall)
		add ./*
		;;
	clear)
		clear
		;;
	cp)
		cphere && clear
		;;
	edit)
		$editor "$file"
		;;
	mv)
		cphere && (remove; clear)
		;;
	open)
		open
		;;
	rm)
		remove && clear
		;;
	*)
		echo "$1: not a valid sel command"
		;;
esac
fi