#!/bin/sh
set -eu

usage() {
	cat <<-'EOF'
		Usage:
		  e [FILE]
		  e -h
	EOF
}

help() {
	cat <<-'EOF'


		Options:
		  -h, --help    show this message

		  FILE          path to the file


		Flexibly run a text editor, either directly or in a pipe.

		The editor used is either $VISUAL or $EDITOR, with a fallback to
		vi in case any of those variables aren't defined.


		Examples:

		  Edit "file.txt":

		    $ e file.txt


		  Manipulate the content of a pipe midway:

		    $ seq 10 | e | grep 5
	EOF
}

for flag in "$@"; do
	case "$flag" in
		(--)
			break
			;;
		(--help)
			usage
			help
			exit
			;;
		(*)
			;;
	esac
done

while getopts 'h' flag; do
	case "$flag" in
		(h)
			usage
			help
			exit
			;;
		(*)
			usage >&2
			exit 2
			;;
	esac
done
shift $((OPTIND - 1))


CMD="${VISUAL:-${EDITOR:-vi}}"
if [ "$CMD" = 'e' ]; then
	CMD='vi'
fi

if [ ! -t 0 ]; then
	F="$(mkstemp)"
	trap 'rm -f "$F"' EXIT
	cat > "$F"
	exec 0</dev/tty
	exec 3>&1
	exec 1>/dev/tty
	$CMD "$F"
	cat "$F" >&3
else
	if [ $# -eq 0 ]; then
		f="$(fzf --select-1 --exit-0 < "$XDG_DATA_HOME"/euandreh/e.list.txt)"
		if [ -n "$f" ]; then
			history -s e "$f"
			sh -c "$CMD $f"
		fi
	else
		$CMD "$@"
	fi
fi