#!/usr/bin/env bash
# Fetches the month's DB-IP Lite city and ASN databases (CC BY 4.0, https://db-ip.com) into the directory PrivaPub reads
# them from (Statistics:GeoDirectory). The app swaps to new files on its own; a failed download leaves the old ones.
set -euo pipefail
dir="${GEO_DIR:-/var/lib/privapub/geo}"
tmp=$(mktemp -d); trap 'rm -rf "$tmp"' EXIT
this=$(date -u +%Y-%m)
last=$(date -u -d "$(date -u +%Y-%m-15) -1 month" +%Y-%m)
for kind in city asn; do
	got=""
	for month in "$this" "$last"; do
		if curl -fsS --max-time 900 -o "$tmp/$kind.gz" "https://download.db-ip.com/free/dbip-$kind-lite-$month.mmdb.gz"; then
			got=$month; break
		fi
	done
	[ -n "$got" ] || { echo "no $kind database for $this or $last" >&2; exit 1; }
	gunzip -t "$tmp/$kind.gz"
	gunzip -c "$tmp/$kind.gz" > "$tmp/dbip-$kind-lite.mmdb"
	[ "$(stat -c %s "$tmp/dbip-$kind-lite.mmdb")" -gt 1000000 ] || { echo "the $kind database is too small" >&2; exit 1; }
	install -m 640 "$tmp/dbip-$kind-lite.mmdb" "$dir/.dbip-$kind-lite.mmdb.new"
	mv -f "$dir/.dbip-$kind-lite.mmdb.new" "$dir/dbip-$kind-lite.mmdb"
	echo "$kind: DB-IP Lite $got"
done