#!/usr/bin/env bash

set -e

edit_dir_base="$XDG_RUNTIME_DIR/edit"

_pre_checks() {
	if [ -z "$EDITOR" ]; then
		echo "EDITOR is not set"
		exit 1
	fi
}

_pre_checks_file() {
	if [ -z "$1" ]; then
		echo "No file specified"
		exit 1
	fi
	if sudo test -d "$1"; then
		echo "Cannot edit directory"
		exit 1
	fi
}

_readlink() {
	sudo readlink -fn "$1"
}

_get_edit_directory() {
	target_dir=$(dirname "$1")
	edit_dir_sub=$(_readlink "$target_dir" | md5sum | awk '{ print $1 }')

	edit_directory="$edit_dir_base/$edit_dir_sub"
	echo "$edit_directory"
}

_get_edit_file() {
	target=$(_readlink "$1")
	target_name=$(basename "$target")
	edit_directory=$(_get_edit_directory "$target")

	edit_file="$edit_directory/$target_name"
	echo "$edit_file"
}

_prepare_for_edit() {
	target=$(_readlink "$1")

	_pre_checks_file "$target"

	edit_directory=$(_get_edit_directory "$target")
	edit_file=$(_get_edit_file "$target")

	mkdir -p "$edit_directory"

	user=$(id -un)
	group=$(id -gn)

	if sudo test -e "$target"; then
		sudo cp -i "$target" "$edit_file"
		sudo chown "$user":"$group" "$edit_file"
	else
		touch "$edit_file"
	fi

	echo "$edit_file"
}

_pre_checks

# Prepare all files for editing and collect the names of the edit files
all_edit_files=()
for arg in "$@"; do
	edit_file=$(_prepare_for_edit "$arg")
	all_edit_files+=("$edit_file")
done

$EDITOR "${all_edit_files[@]}"

# Copy all edit files back
for arg in "$@"; do
	edit_file=$(_get_edit_file "$arg")
	sudo cp "$edit_file" "$arg" && rm "$edit_file"

	edit_directory=$(_get_edit_directory "$target")
	# Try to remove the directory, but don't fail if it's not empty
	rm -d "$edit_directory" 2>/dev/null || true
done