#!/bin/sh
set -eu

usage() {
	cat <<-'EOF'
		Usage:
		  category FILENAME
		  html -h
	EOF
}

help() {
	cat <<-'EOF'


		Options:
		  -h, --help    show this message

		  FILENAME      the name of the input file .md file


		Process the FILENAME, and generate a the derived category files.


		Examples:

		  Generate the categories for a pastebin:

		    $ categories src/a-paste.md > src/a-paste.categoryentry
	EOF
}


for f in "$@"; do
	case "$f" 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.sh

FILENAME="${1:-}"
eval "$(assert_arg "$FILENAME" 'FILENAME')"


# shellcheck source=/dev/null
. "${FILENAME%.md}.conf"
DIR="$(dirname "$FILENAME")"



echo "${categories:-}" | tr ' ' '\n' | grep . | while read -r category; do
	echo "$FILENAME" > "$DIR/${date_iso:?}.$category.categorysort"
done

envsubst < src/lib/category.html