#!/bin/sh
set -eu

usage() {
	cat <<-'EOF'
		Usage:
		  with-email [-s SUBJECT] COMMAND...
		  with-email -h
	EOF
}

help() {
	cat <<-'EOF'

		Options:
		  -s SUBJECT    set the subject of the email
		  -h, --help    show this message

		  COMMAND       the command to be wrapped


		Executes COMMAND and send all of its output via email
		to eu@euandre.org.


		Examples:

		  Run a script and use the default subject:

		    $ with-email -- ./script

		  Run a command and use a custom subject:

		    $ with-email -s 'CRONJOB' echo 123
	EOF
}

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

SUBJECT='NO SUBJECT'
while getopts 's:h' flag; do
	case "$flag" in
		s)
			SUBJECT="$OPTARG"
			;;
		h)
			usage
			help
			exit
			;;
		*)
			usage >&2
			exit 2
			;;
	esac
done
shift $((OPTIND - 1))

eval "$(assert-arg -- "${1:-}" 'COMMAND...')"

now() {
	date '+%Y-%m-%dT%H:%M:%S%Z'
}

OUT="$(mkstemp)"
trap 'rm -f "$OUT"' EXIT
{
	printf 'Running command: %s\n' "$*"
	printf 'Starting at: %s\n' "$(now)"
	printf '\n'

	STATUS=0
	"$@" || STATUS=$?

	printf '\n'
	printf '\nFinished at: %s\n' "$(now)"
} 1>"$OUT" 2>&1

email -s "(exit status: $STATUS) - $SUBJECT" eu@euandre.org < "$OUT"