bring in khatru and eventstore.

khatru/deleting.go

@@ -0,0 +1,85 @@
+package khatru
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func (rl *Relay) handleDeleteRequest(ctx context.Context, evt *nostr.Event) error {
+	// event deletion -- nip09
+	for _, tag := range evt.Tags {
+		if len(tag) >= 2 {
+			var f nostr.Filter
+
+			switch tag[0] {
+			case "e":
+				f = nostr.Filter{IDs: []string{tag[1]}}
+			case "a":
+				spl := strings.Split(tag[1], ":")
+				if len(spl) != 3 {
+					continue
+				}
+				kind, err := strconv.Atoi(spl[0])
+				if err != nil {
+					continue
+				}
+				author := spl[1]
+				identifier := spl[2]
+				f = nostr.Filter{
+					Kinds:   []int{kind},
+					Authors: []string{author},
+					Tags:    nostr.TagMap{"d": []string{identifier}},
+					Until:   &evt.CreatedAt,
+				}
+			default:
+				continue
+			}
+
+			ctx := context.WithValue(ctx, internalCallKey, struct{}{})
+			for _, query := range rl.QueryEvents {
+				ch, err := query(ctx, f)
+				if err != nil {
+					continue
+				}
+				target := <-ch
+				if target == nil {
+					continue
+				}
+				// got the event, now check if the user can delete it
+				acceptDeletion := target.PubKey == evt.PubKey
+				var msg string
+				if !acceptDeletion {
+					msg = "you are not the author of this event"
+				}
+				// but if we have a function to overwrite this outcome, use that instead
+				for _, odo := range rl.OverwriteDeletionOutcome {
+					acceptDeletion, msg = odo(ctx, target, evt)
+				}
+
+				if acceptDeletion {
+					// delete it
+					for _, del := range rl.DeleteEvent {
+						if err := del(ctx, target); err != nil {
+							return err
+						}
+					}
+
+					// if it was tracked to be expired that is not needed anymore
+					rl.expirationManager.removeEvent(target.ID)
+				} else {
+					// fail and stop here
+					return fmt.Errorf("blocked: %s", msg)
+				}
+
+				// don't try to query this same event again
+				break
+			}
+		}
+	}
+
+	return nil
+}