#!/bin/sh
set -eu


usage() {
	cat <<-'EOF'
		Usage:
		  absolute [CONTENT...]
		  absolute -h
	EOF
}

help() {
	cat <<-'EOF'

		Options:
		  -h, --help    show this message

		  CONTENT       a literal string to be prefixed


		Add domain prefix to build a full URL.  If CONTENT is not given,
		get data from STDIN.

		Usually used in conjunction with url-for(1).


		Examples:

		  Get the URL for "static/style.css", and make it absolute:

		    $ url-for 'static/style.css' | absolute
		    https://euandre.org/static/style.css


		  Get the absolute variant of a relative URL:

		    $ absolute "$homepage_url"
		    https://euandre.org/pt/
	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))


. src/lib/base.conf


prefix() {
	sed "s|^/\?|https://$domain/|"
}


if [ $# = 0 ]; then
	prefix
else
	for s in "$@"; do
		printf '%s\n' "$s" | prefix
	done
fi