#!/bin/sh
set -eu

usage() {
	cat <<-'EOF'
		Usage:
		  collection-for FILE
		  collection-for -h
	EOF
}

help() {
	cat <<-'EOF'


		Options:
		  -h, --help    show this message

		  FILE          the path of the file to get the collection for


		Say the collection of the given file, using the path of FILE.


		Examples:

		  Get "til" for "src/en/til/some-pt.md":

		    $ collection-for src/en/til/some-pt.md
		    til
	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.sh


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


lang="$(lang-for "$FILE")"
DIR="$(dirname "$FILE")"
PAGE="${FILE%.*}.page"

if [ -e "$PAGE" ]; then
	exit 1
else
	collections | awk -v l="$lang" -v pre="$CONTENT_PREFIX" -v dir="$DIR" '{
		"coll2path " l " " $0 | getline coll_path
		d = pre "/" l "/" coll_path
		sub(/\/$/, "", d)
		if (d == dir) {
			print $0
		}
	}'
fi