#!/bin/sh
set -eu

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

help() {
	cat <<-'EOF'

		Options:
		  -g            global file, not specific to a single language
		  -h, --help    show this message

		  FILE          the path for the URL to be constructed


		Build an URL for the given FILE, without the $domain part, adding
		the required $base_url.


		Examples:

		  Get the URL for "about.html", when $base_url is "v2" and $lang is "en":

		    $ url-for 'about.html'
		    /v2/en/about.html


		  Get the URL for "static/favicon.svg", when $base_url is empty:

		    $ url-for -g 'static/favicon.svg'
		    /static/favicon.svg
	EOF
}


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

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

. src/development/lib.sh


FILE="${1:-}"
if [ "$FILE" = '/' ]; then
	FILE=''
fi

. src/lib/base-conf
# shellcheck source=/dev/null
. src/lib/base."${lang:?}".conf

if [ "$GLOBAL" = true ]; then
	L=''
else
	L="${lang:?}/"
fi

printf '%s%s%s' "${base_url:-/}" "$L" "$FILE"