Allow users to delete their messages

No more than 30 minutes old

src/lib/components/ChatSidebar.svelte

@@ -9,7 +9,10 @@
   } from "$lib/chat.svelte";
   import { auth, openLogin } from "$lib/auth.svelte";
   import { isGroupAdmin } from "$lib/admins.svelte";
-  import { requestDelete } from "$lib/moderation.svelte";
+  import {
+    requestDelete,
+    withinSelfDeleteWindow,
+  } from "$lib/moderation.svelte";
   import {
     withJoin,
     membershipOf,
@@ -51,6 +54,13 @@
     !!auth.user && isGroupAdmin(auth.user.pubkey, activeGroup.id),
   );
 
+  const isOwnMessage = (msg: ChatMessageData) =>
+    auth.user?.pubkey === msg.pubkey;
+
+  // Admins moderate anything; authors self-delete their own.
+  const canDeleteMessage = (msg: ChatMessageData) =>
+    canModerate || isOwnMessage(msg);
+
   // Sending needs membership regardless of flags. Only gate a confirmed guest;
   // while membership resolves the input stays (withJoin nets a stray send), so a
   // member never flashes "Join to chat".
@@ -72,7 +82,13 @@
   function requestDeleteMessage(msg: ChatMessageData) {
     openMenuId = null;
     requestDelete(
-      { eventId: msg.id, groupId: activeGroup.id, label: "message" },
+      {
+        eventId: msg.id,
+        groupId: activeGroup.id,
+        label: "message",
+        self: !canModerate,
+        eventKind: 9,
+      },
       () => removeChatMessage(msg.id),
     );
   }
@@ -383,15 +399,19 @@
                         class="w-full px-3 py-1.5 text-left hover:bg-neutral-50 dark:text-neutral-100 dark:hover:bg-neutral-800"
                         >Reply</button
                       >
-                      {#if canModerate}
+                      {#if canDeleteMessage(msg)}
+                        {@const tooOld =
+                          !canModerate &&
+                          !withinSelfDeleteWindow(msg.createdAt)}
                         <button
                           role="menuitem"
+                          disabled={tooOld}
                           onclick={(e) => {
                             e.stopPropagation();
                             requestDeleteMessage(msg);
                           }}
-                          class="w-full px-3 py-1.5 text-left text-red-600 hover:bg-red-50 dark:hover:bg-neutral-800"
+                          class="w-full px-3 py-1.5 text-left text-red-600 hover:bg-red-50 disabled:cursor-not-allowed disabled:text-neutral-400 disabled:hover:bg-transparent dark:hover:bg-neutral-800 dark:disabled:text-neutral-600"
-                          >Delete</button
+                          >Delete{tooOld ? " (too old)" : ""}</button
                         >
                       {/if}
                     </div>

src/lib/moderation.svelte.ts

@@ -1,12 +1,24 @@
 import { auth } from "$lib/auth.svelte";
 import { publishForum } from "$lib/relay";
 
+// Users may delete their own posts only within this window; afterwards the relay
+// also refuses (pyramid caps group self-deletes at 2h, we're stricter on top).
+export const SELF_DELETE_WINDOW = 30 * 60; // seconds
+
+export function withinSelfDeleteWindow(createdAt: number): boolean {
+  return Math.floor(Date.now() / 1000) - createdAt <= SELF_DELETE_WINDOW;
+}
+
 // What's pending deletion, surfaced to the confirmation modal. `label` is the
-// noun shown in the dialog copy ("discussion", "reply", "message").
+// noun shown in the dialog copy ("discussion", "reply", "message"). `self` picks
+// the mechanism: authors delete via NIP-09 (kind 5), admins moderate via
+// NIP-29 (kind 9005). `eventKind` feeds the NIP-09 `k` tag.
 type DeleteTarget = {
   eventId: string;
   groupId: string;
   label: string;
+  self?: boolean;
+  eventKind?: number;
 };
 
 let target = $state<DeleteTarget | null>(null);
@@ -45,8 +57,9 @@ export function cancelDelete() {
   error = null;
 }
 
-// NIP-29 kind:9005 delete-event. The relay enforces the role check and only
+// Authors self-delete with NIP-09 (kind 5); admins moderate with NIP-29
-// resolves the publish (OK: true) once it has processed the deletion.
+// (kind 9005). The relay enforces the matching rule (author match / role) and
+// only resolves the publish (OK: true) once it has processed the deletion.
 export async function confirmDelete(reason?: string) {
   if (!target) return;
   if (!auth.signer) {
@@ -56,21 +69,28 @@ export async function confirmDelete(reason?: string) {
   busy = true;
   error = null;
 
+  const kind = target.self ? 5 : 9005;
   const tags: string[][] = [
     ["h", target.groupId],
     ["e", target.eventId],
   ];
+  if (target.self && target.eventKind !== undefined) {
+    tags.push(["k", String(target.eventKind)]);
+  }
 
   try {
     const signed = await auth.signer.signEvent({
-      kind: 9005,
+      kind,
       created_at: Math.floor(Date.now() / 1000),
       tags,
       content: reason?.trim() ?? "",
     });
 
     const timeout = new Promise<never>((_, reject) =>
-      setTimeout(() => reject(new Error("Relay did not respond in time")), 8000),
+      setTimeout(
+        () => reject(new Error("Relay did not respond in time")),
+        8000,
+      ),
     );
     await Promise.race([Promise.all(publishForum(signed)), timeout]);
 

src/routes/thread/[id]/+page.svelte

@@ -12,7 +12,10 @@
   } from "$lib/thread.svelte";
   import { auth, openLogin } from "$lib/auth.svelte";
   import { isGroupAdmin } from "$lib/admins.svelte";
-  import { requestDelete } from "$lib/moderation.svelte";
+  import {
+    requestDelete,
+    withinSelfDeleteWindow,
+  } from "$lib/moderation.svelte";
   import { showToast } from "$lib/toast.svelte";
   import {
     withJoin,
@@ -142,6 +145,12 @@
     !!auth.user && !!detail && isGroupAdmin(auth.user.pubkey, detail.groupId),
   );
 
+  const isOwnPost = (p: PostData) => auth.user?.pubkey === p.pubkey;
+
+  // Whose delete a post can offer: admins moderate anything; authors self-delete
+  // their own (the button still shows when too old, just disabled).
+  const canDeletePost = (p: PostData) => canModerate || isOwnPost(p);
+
   let openMenuId = $state<string | null>(null);
 
   function toggleMenu(id: string, e: MouseEvent) {
@@ -150,13 +159,21 @@
   }
 
   // Deleting the OP removes the whole thread, so leave the page; a reply just
-  // disappears in place.
+  // disappears in place. Admins moderate (kind 9005); authors self-delete
+  // (kind 5) only inside the time window.
   function requestDeletePost(p: PostData, isOp: boolean) {
     if (!detail) return;
     const groupId = detail.groupId;
+    const self = !canModerate;
     openMenuId = null;
     requestDelete(
-      { eventId: p.id, groupId, label: isOp ? "discussion" : "reply" },
+      {
+        eventId: p.id,
+        groupId,
+        label: isOp ? "discussion" : "reply",
+        self,
+        eventKind: isOp ? 11 : 1111,
+      },
       () => {
         if (isOp) {
           showToast("Discussion deleted");
@@ -326,7 +343,9 @@
           >
         </div>
         <div class="ml-4 flex flex-shrink-0 items-center gap-1">
-          {#if canModerate}
+          {#if canDeletePost(p)}
+            {@const tooOld =
+              !canModerate && !withinSelfDeleteWindow(p.createdAt)}
             <div class="relative">
               <button
                 onclick={(e) => toggleMenu(p.id, e)}
@@ -353,12 +372,13 @@
                 >
                   <button
                     role="menuitem"
+                    disabled={tooOld}
                     onclick={(e) => {
                       e.stopPropagation();
                       requestDeletePost(p, index === 0);
                     }}
-                    class="w-full px-3 py-1.5 text-left text-red-600 hover:bg-red-50"
+                    class="w-full px-3 py-1.5 text-left text-red-600 hover:bg-red-50 disabled:cursor-not-allowed disabled:text-neutral-400 disabled:hover:bg-transparent dark:disabled:text-neutral-600"
-                    >Delete</button
+                    >Delete{tooOld ? " (too old)" : ""}</button
                   >
                 </div>
               {/if}