chore: expose thoth in lib

Imports a patch previously exclusive to Botstopper.

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/thoth/geoipchecker.go

@@ -0,0 +1,68 @@
+package thoth
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/TecharoHQ/anubis/lib/policy/checker"
+	iptoasnv1 "github.com/TecharoHQ/thoth-proto/gen/techaro/thoth/iptoasn/v1"
+)
+
+func (c *Client) GeoIPCheckerFor(countries []string) checker.Impl {
+	countryMap := map[string]struct{}{}
+	var sb strings.Builder
+	fmt.Fprintln(&sb, "GeoIPChecker")
+	for _, cc := range countries {
+		countryMap[cc] = struct{}{}
+		fmt.Fprintln(&sb, cc)
+	}
+
+	return &GeoIPChecker{
+		IPToASN:   c.IPToASN,
+		Countries: countryMap,
+		hash:      sb.String(),
+	}
+}
+
+type GeoIPChecker struct {
+	IPToASN   iptoasnv1.IpToASNServiceClient
+	Countries map[string]struct{}
+	hash      string
+}
+
+func (gipc *GeoIPChecker) Check(r *http.Request) (bool, error) {
+	ctx, cancel := context.WithTimeout(r.Context(), 500*time.Millisecond)
+	defer cancel()
+
+	ipInfo, err := gipc.IPToASN.Lookup(ctx, &iptoasnv1.LookupRequest{
+		IpAddress: r.Header.Get("X-Real-Ip"),
+	})
+	if err != nil {
+		switch {
+		case errors.Is(err, context.DeadlineExceeded):
+			slog.Debug("error contacting thoth", "err", err, "actionable", false)
+			return false, nil
+		default:
+			slog.Error("error contacting thoth, please contact support", "err", err, "actionable", true)
+			return false, nil
+		}
+	}
+
+	// If IP is not publicly announced, return false
+	if !ipInfo.GetAnnounced() {
+		return false, nil
+	}
+
+	_, ok := gipc.Countries[strings.ToLower(ipInfo.GetCountryCode())]
+
+	return ok, nil
+}
+
+func (gipc *GeoIPChecker) Hash() string {
+	return gipc.hash
+}