feat: route report endpoint

- POST /_seo/api/v1/registry/routes (public, bucket seo-notfound): the
  frontend server reports its static routes with the bearer token
  golem15.seo.route_report_token, else notfound_token (constant-time;
  both empty answer 404); at most 2000 paths
- unknown paths become registry pages (origin reported, kind page, a name
  from the last segment), known ones get reported_at; paths another
  content type owns and invalid ones are skipped; nothing is deleted or
  overwritten, and the report's time marks missing pages

controllers/api/registry.go

@@ -3,16 +3,82 @@ package api
 import (
 	"bytes"
 	"context"
+	"crypto/subtle"
 	"encoding/json"
+	"errors"
 	"net/http"
 	"strconv"
 	"strings"
 
 	"git.golem15.com/golem15/sm-seo-plugin/classes"
 	"git.golem15.com/golem15/sm-seo-plugin/models"
+	"git.golem15.com/golem15/summercms/modules/wire"
 	"gorm.io/gorm"
 )
 
+// maxRouteReportBody caps the route report body: 2000 paths of 2048 bytes
+// with their JSON quoting.
+const maxRouteReportBody = classes.MaxReportedRoutes*(classes.MaxRouteBytes+8) + 1024
+
+// routeReport is the route report body.
+type routeReport struct {
+	Routes []string `json:"routes"`
+}
+
+// RouteReport serves POST /_seo/api/v1/registry/routes (D-33, P33-20): the
+// frontend server reports its static routes with "Authorization: Bearer
+// <token>", golem15.seo.route_report_token (else notfound_token), compared
+// in constant time. Unknown paths become registry pages (origin reported),
+// known ones get reported_at; nothing is deleted or overwritten. It answers
+// 200 with the counts, 401 for a missing or wrong token, 404 when no token
+// is configured (the report is off), and 422 for a malformed body or more
+// than 2000 paths.
+func RouteReport(service func() *classes.Service) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		svc := service()
+		if svc == nil {
+			wire.WriteJSON(w, http.StatusServiceUnavailable, map[string]string{"error": "SEO is not available"})
+			return
+		}
+		want := svc.RouteReportToken()
+		if want == "" {
+			wire.WriteJSON(w, http.StatusNotFound, map[string]string{"error": errNotFound})
+			return
+		}
+		got, ok := strings.CutPrefix(r.Header.Get("Authorization"), "Bearer ")
+		if !ok || subtle.ConstantTimeCompare([]byte(strings.TrimSpace(got)), []byte(want)) != 1 {
+			wire.WriteJSON(w, http.StatusUnauthorized, map[string]string{"error": "Unauthorized"})
+			return
+		}
+		var in routeReport
+		dec := json.NewDecoder(http.MaxBytesReader(w, r.Body, maxRouteReportBody))
+		if err := dec.Decode(&in); err != nil {
+			wire.WriteJSON(w, http.StatusUnprocessableEntity, map[string]string{"error": errInvalidBody})
+			return
+		}
+		if len(in.Routes) > classes.MaxReportedRoutes {
+			wire.WriteJSON(w, http.StatusUnprocessableEntity, map[string]any{"error": "too_many_routes", "max": classes.MaxReportedRoutes})
+			return
+		}
+		var out classes.RouteReport
+		err := write(r.Context(), svc, func(ctx context.Context, tx *gorm.DB) error {
+			var err error
+			out, err = svc.ReportRoutes(ctx, tx, in.Routes)
+			return err
+		})
+		if err != nil {
+			if errors.Is(err, classes.ErrTooManyRoutes) {
+				wire.WriteJSON(w, http.StatusUnprocessableEntity, map[string]any{"error": "too_many_routes", "max": classes.MaxReportedRoutes})
+				return
+			}
+			log.Error("golem15.seo: route report", "error", err)
+			wire.WriteJSON(w, http.StatusInternalServerError, map[string]string{"error": errInternal})
+			return
+		}
+		wire.WriteJSON(w, http.StatusOK, out)
+	}
+}
+
 // ListPagesInput is the query of GET /_seo/api/v1/pages.
 type ListPagesInput struct {
 	Page    int    `json:"page,omitempty" query:"page" jsonschema:"the page number, from 1"`