feat: add "Convert to Thread" action on room messages (#370)

Co-authored-by: Aditya Chaudhary <30+useradityaa@noreply.coracle.social>

src/app/components/RoomItemMenu.svelte

@@ -6,6 +6,7 @@
   import TrashBin2 from "@assets/icons/trash-bin-2.svg?dataurl"
   import Danger from "@assets/icons/danger.svg?dataurl"
   import Pin from "@assets/icons/pin.svg?dataurl"
+  import NotesMinimalistic from "@assets/icons/notes-minimalistic.svg?dataurl"
   import Button from "@lib/components/Button.svelte"
   import Icon from "@lib/components/Icon.svelte"
   import Confirm from "@lib/components/Confirm.svelte"
@@ -13,6 +14,7 @@
   import Report from "@app/components/Report.svelte"
   import PinboardSelect from "@app/components/PinboardSelect.svelte"
   import EventDeleteConfirm from "@app/components/EventDeleteConfirm.svelte"
+  import ThreadCreate from "@app/components/ThreadCreate.svelte"
   import {app, relayManagement, roomPinLists, user} from "@app/core"
   import {deriveUserIsSpaceAdmin} from "@app/management"
   import {ROOM, deriveUserIsRoomAdmin} from "@app/rooms"
@@ -38,6 +40,11 @@
     pushModal(PinboardSelect, {url, event})
   }
 
+  const createThread = () => {
+    onClick()
+    pushModal(ThreadCreate, {url, h, parent: event})
+  }
+
   const report = () => {
     onClick()
     pushModal(Report, {url, event})
@@ -100,6 +107,14 @@
       Add to Library
     </Button>
   </li>
+  {#if h}
+    <li>
+      <Button onclick={createThread}>
+        <Icon size={4} icon={NotesMinimalistic} />
+        Create a Thread
+      </Button>
+    </li>
+  {/if}
   {#if h && $userIsRoomAdmin}
     <li>
       <Button onclick={togglePin}>

src/app/components/RoomItemMenuMobile.svelte

@@ -9,6 +9,7 @@
   import SmileCircle from "@assets/icons/smile-circle.svg?dataurl"
   import MenuDots from "@assets/icons/menu-dots.svg?dataurl"
   import Pin from "@assets/icons/pin.svg?dataurl"
+  import NotesMinimalistic from "@assets/icons/notes-minimalistic.svg?dataurl"
   import Button from "@lib/components/Button.svelte"
   import Link from "@lib/components/Link.svelte"
   import Icon from "@lib/components/Icon.svelte"
@@ -18,6 +19,7 @@
   import ZapButton from "@app/components/ZapButton.svelte"
   import EventInfo from "@app/components/EventInfo.svelte"
   import EventDeleteConfirm from "@app/components/EventDeleteConfirm.svelte"
+  import ThreadCreate from "@app/components/ThreadCreate.svelte"
   import {reactions, relays, roomPinLists, user} from "@app/core"
   import {ROOM, deriveUserIsRoomAdmin} from "@app/rooms"
   import {ENABLE_ZAPS} from "@app/env"
@@ -50,6 +52,8 @@
 
   const showEmojiPicker = () => pushModal(EmojiPicker, {onClick: onEmoji}, {replaceState: true})
 
+  const createThread = () => pushModal(ThreadCreate, {url, h, parent: event}, {replaceState: true})
+
   const sendReply = () => {
     history.back()
     reply()
@@ -101,6 +105,12 @@
           {isPinned ? "Unpin Message" : "Pin Message"}
         </Button>
       {/if}
+      {#if h}
+        <Button class="button button-neutral w-full" onclick={createThread}>
+          <Icon size={4} icon={NotesMinimalistic} />
+          Create a Thread
+        </Button>
+      {/if}
       {#if ENABLE_ZAPS}
         <ZapButton replaceState {url} {event} class="button button-neutral w-full">
           <Icon size={4} icon={Bolt} />

src/app/components/ThreadCreate.svelte

@@ -1,7 +1,10 @@
 <script lang="ts">
   import {writable} from "svelte/store"
+  import * as nip19 from "nostr-tools/nip19"
   import {Thread} from "@welshman/domain"
   import {publish} from "@welshman/app"
+  import {toNostrURI} from "@welshman/util"
+  import type {TrustedEvent} from "@welshman/util"
   import {isMobile, preventDefault} from "@lib/html"
   import Paperclip from "@assets/icons/paperclip-2.svg?dataurl"
   import AltArrowLeft from "@assets/icons/alt-arrow-left.svg?dataurl"
@@ -31,9 +34,16 @@
     url: string
     h?: string
     shareToChat?: boolean
+    // pre-fills the thread body with an embedded quote of this event (see
+    // "Create a Thread" in RoomItemMenu/RoomItemMenuMobile) — an unrelated
+    // in-progress draft still wins, same as opening this modal any other way.
+    parent?: TrustedEvent
   }
 
-  const {url, h, shareToChat = false}: Props = $props()
+  const {url, h, shareToChat = false, parent}: Props = $props()
+  const pointerContent = parent
+    ? toNostrURI(nip19.neventEncode({...parent, relays: [url]}))
+    : undefined
   const draftKey = new DraftKey<Values>(`thread:${url}:${h ?? ""}`)
   const initialValues = draftKey.get()
   const shouldProtect = $relays.hasNip(url, 70)
@@ -100,7 +110,7 @@
   let loading = $state(false)
 
   let title = $state(initialValues?.title ?? "")
-  let content = $state(initialValues?.content ?? "")
+  let content = $state(initialValues?.content ?? pointerContent ?? "")
 
   const onChange = (json: object) => {
     content = json