feat: Update how messages load and sync, allow plugins to import messages

toju-app/src/app/domains/chat/domain/rules/message-sync.rules.ts

@@ -1,5 +1,11 @@
-/** Maximum number of recent messages to include in sync inventories. */
-export const INVENTORY_LIMIT = 1000;
+/** Maximum number of messages to include in sync inventories.
+ *
+ * The inventory protocol now ships every message in the room (id, ts, rc, ac)
+ * chunked at `CHUNK_SIZE`, so peers converge on the full history regardless
+ * of how lopsided their message counts are. The constant remains as a safety
+ * ceiling for pathological rooms.
+ */
+export const INVENTORY_LIMIT = 1_000_000;
 
 /** Number of messages per chunk for inventory / batch transfers. */
 export const CHUNK_SIZE = 200;
@@ -14,7 +20,7 @@ export const SYNC_POLL_SLOW_MS = 900_000;
 export const SYNC_TIMEOUT_MS = 5_000;
 
 /** Large limit used for legacy full-sync operations. */
-export const FULL_SYNC_LIMIT = 10_000;
+export const FULL_SYNC_LIMIT = 1_000_000;
 
 /** Inventory item representing a message's sync state. */
 export interface InventoryItem {

toju-app/src/app/domains/chat/feature/chat-messages/chat-messages.component.html

@@ -11,6 +11,8 @@
     [isAdmin]="isAdmin()"
     [bottomPadding]="composerBottomPadding()"
     [conversationKey]="conversationKey()"
+    [loadingOlder]="loadingOlder()"
+    [conversationExhausted]="conversationExhausted()"
     (replyRequested)="setReplyTo($event)"
     (deleteRequested)="handleDeleteRequested($event)"
     (editSaved)="handleEditSaved($event)"
@@ -20,6 +22,7 @@
     (imageOpened)="openLightbox($event)"
     (imageContextMenuRequested)="openImageContextMenu($event)"
     (embedRemoved)="handleEmbedRemoved($event)"
+    (loadOlderRequested)="handleLoadOlderRequested($event)"
   />
 
   <div

toju-app/src/app/domains/chat/feature/chat-messages/chat-messages.component.ts

@@ -8,6 +8,8 @@ import {
   inject,
   signal
 } from '@angular/core';
+import { toObservable, toSignal } from '@angular/core/rxjs-interop';
+import { switchMap } from 'rxjs/operators';
 import { Store } from '@ngrx/store';
 import { ElectronBridgeService } from '../../../../core/platform/electron/electron-bridge.service';
 import { ViewportService } from '../../../../core/platform';
@@ -18,7 +20,9 @@ import { KlipyGif, KlipyService } from '../../application/services/klipy.service
 import { MessagesActions } from '../../../../store/messages/messages.actions';
 import {
   selectAllMessages,
+  selectConversationExhausted,
   selectMessagesLoading,
+  selectMessagesLoadingOlder,
   selectMessagesSyncing
 } from '../../../../store/messages/messages.selectors';
 import { selectCurrentUser, selectIsCurrentUserAdmin } from '../../../../store/users/users.selectors';
@@ -72,6 +76,7 @@ export class ChatMessagesComponent {
 
   readonly loading = this.store.selectSignal(selectMessagesLoading);
   readonly syncing = this.store.selectSignal(selectMessagesSyncing);
+  readonly loadingOlder = this.store.selectSignal(selectMessagesLoadingOlder);
   readonly currentUser = this.store.selectSignal(selectCurrentUser);
   readonly isAdmin = this.store.selectSignal(selectIsCurrentUserAdmin);
 
@@ -83,6 +88,12 @@ export class ChatMessagesComponent {
   });
 
   readonly conversationKey = computed(() => `${this.currentRoom()?.id ?? 'no-room'}:${this.activeChannelId() ?? 'general'}`);
+  readonly conversationExhausted = toSignal(
+    toObservable(this.conversationKey).pipe(
+      switchMap((key) => this.store.select(selectConversationExhausted(key)))
+    ),
+    { initialValue: false }
+  );
   readonly klipyEnabled = computed(() => this.klipy.isEnabled(this.currentRoom()));
   readonly composerBottomPadding = signal(140);
   readonly klipyGifPickerAnchorRight = signal(16);
@@ -213,6 +224,22 @@ export class ChatMessagesComponent {
     );
   }
 
+  handleLoadOlderRequested(event: { beforeTimestamp: number; limit: number }): void {
+    const roomId = this.currentRoom()?.id;
+
+    if (!roomId)
+      return;
+
+    this.store.dispatch(
+      MessagesActions.loadOlderMessages({
+        roomId,
+        channelId: this.activeChannelId() ?? 'general',
+        beforeTimestamp: event.beforeTimestamp,
+        limit: event.limit
+      })
+    );
+  }
+
   toggleKlipyGifPicker(): void {
     const nextState = !this.showKlipyGifPicker();
 

toju-app/src/app/domains/chat/feature/chat-messages/components/message-item/chat-message-item.component.ts

@@ -2,6 +2,7 @@
 import { CommonModule } from '@angular/common';
 import { FormsModule } from '@angular/forms';
 import {
+  ChangeDetectionStrategy,
   Component,
   computed,
   ElementRef,
@@ -153,6 +154,7 @@ interface MissingPluginEmbedFallback {
   ],
   templateUrl: './chat-message-item.component.html',
   styleUrl: './chat-message-item.component.scss',
+  changeDetection: ChangeDetectionStrategy.OnPush,
   host: {
     style: 'display: contents;'
   }

toju-app/src/app/domains/chat/feature/chat-messages/components/message-list/chat-message-list.component.ts

@@ -2,6 +2,7 @@
 import { CommonModule } from '@angular/common';
 import {
   AfterViewChecked,
+  ChangeDetectionStrategy,
   Component,
   ElementRef,
   OnDestroy,
@@ -48,6 +49,7 @@ declare global {
     ThemeNodeDirective
   ],
   templateUrl: './chat-message-list.component.html',
+  changeDetection: ChangeDetectionStrategy.OnPush,
   host: {
     style: 'display: contents;'
   }
@@ -82,6 +84,16 @@ export class ChatMessageListComponent implements AfterViewChecked, OnDestroy {
   readonly imageOpened = output<Attachment>();
   readonly imageContextMenuRequested = output<ChatMessageImageContextMenuEvent>();
   readonly embedRemoved = output<ChatMessageEmbedRemoveEvent>();
+  /**
+   * Emitted when the user scrolls up past the in-store window and the
+   * component needs the parent to fetch an older page from the DB.
+   */
+  readonly loadOlderRequested = output<{ beforeTimestamp: number; limit: number }>();
+
+  /** True while a DB-backed older-page fetch dispatched by the parent is in flight. */
+  readonly loadingOlder = input(false);
+  /** True once the parent has paginated all the way back to the start of DB history. */
+  readonly conversationExhausted = input(false);
 
   private readonly PAGE_SIZE = 50;
 
@@ -141,6 +153,21 @@ export class ChatMessageListComponent implements AfterViewChecked, OnDestroy {
     return lookup;
   });
 
+  /**
+   * O(1) index of messages by id, built once per `allMessages()` change.
+   * Used by `findRepliedMessage` so each rendered row doing a reply lookup
+   * costs a Map.get instead of an Array.find over the full message list.
+   */
+  private readonly messagesById = computed<ReadonlyMap<string, Message>>(() => {
+    const index = new Map<string, Message>();
+
+    for (const message of this.allMessages()) {
+      index.set(message.id, message);
+    }
+
+    return index;
+  });
+
   private bottomScrollObserver: MutationObserver | null = null;
   private bottomScrollTimer: ReturnType<typeof setTimeout> | null = null;
   private boundOnImageLoad: (() => void) | null = null;
@@ -150,12 +177,41 @@ export class ChatMessageListComponent implements AfterViewChecked, OnDestroy {
   private lastMessageCount = 0;
   private initialScrollPending = true;
   private prismHighlightScheduled = false;
+  /**
+   * Set when an older-page DB fetch is in flight. While true, the
+   * `onMessagesChanged` effect treats incoming message-count growth as a
+   * prepend (older history arriving) and preserves the user's scroll
+   * position instead of running sticky-bottom / new-messages-indicator
+   * logic.
+   */
+  private pendingOlderFetchScrollHeight: number | null = null;
 
   private readonly onConversationChanged = effect(() => {
     void this.conversationKey();
     this.resetScrollingState();
   });
 
+  /**
+   * Clears the in-flight older-fetch flag when the parent reports the
+   * load has finished (regardless of how many rows were returned, even
+   * zero). Without this, `loadingMore` would stick on if the DB had no
+   * rows older than the cursor.
+   */
+  private readonly onLoadingOlderChanged = effect(() => {
+    const inFlight = this.loadingOlder();
+
+    if (!inFlight && this.pendingOlderFetchScrollHeight !== null) {
+      // If onMessagesChanged already consumed the pending state because
+      // rows arrived, this is a no-op; otherwise we clear it now.
+      queueMicrotask(() => {
+        if (this.pendingOlderFetchScrollHeight !== null) {
+          this.pendingOlderFetchScrollHeight = null;
+          this.loadingMore.set(false);
+        }
+      });
+    }
+  });
+
   private readonly onMessagesChanged = effect(() => {
     const currentCount = this.channelMessages().length;
     const element = this.messagesContainer?.nativeElement;
@@ -170,6 +226,36 @@ export class ChatMessageListComponent implements AfterViewChecked, OnDestroy {
       return;
     }
 
+    // Handle older-history backfill: messages were prepended, not appended.
+    // Reveal the new rows by widening the display window, and preserve the
+    // user's visual scroll position across the height change. We skip the
+    // sticky-bottom / new-messages-indicator logic entirely for this path.
+    if (this.pendingOlderFetchScrollHeight !== null && currentCount > this.lastMessageCount) {
+      const previousScrollHeight = this.pendingOlderFetchScrollHeight;
+      const previousScrollTop = element.scrollTop;
+      const newlyLoaded = currentCount - this.lastMessageCount;
+
+      this.pendingOlderFetchScrollHeight = null;
+      this.displayLimit.update((limit) => limit + newlyLoaded);
+
+      requestAnimationFrame(() => {
+        requestAnimationFrame(() => {
+          const container = this.messagesContainer?.nativeElement;
+
+          if (container) {
+            const newScrollHeight = container.scrollHeight;
+
+            container.scrollTop = previousScrollTop + (newScrollHeight - previousScrollHeight);
+          }
+
+          this.loadingMore.set(false);
+        });
+      });
+
+      this.lastMessageCount = currentCount;
+      return;
+    }
+
     const distanceFromBottom = element.scrollHeight - element.scrollTop - element.clientHeight;
     const newMessages = currentCount > this.lastMessageCount;
     const forceLocalSendScroll = this.shouldForceLocalSendScroll();
@@ -232,7 +318,7 @@ export class ChatMessageListComponent implements AfterViewChecked, OnDestroy {
     if (!messageId)
       return undefined;
 
-    return this.allMessages().find((message) => message.id === messageId);
+    return this.messagesById().get(messageId);
   }
 
   onScroll(): void {
@@ -252,32 +338,68 @@ export class ChatMessageListComponent implements AfterViewChecked, OnDestroy {
       this.stopBottomScrollWatch();
     }
 
-    if (element.scrollTop < 150 && this.hasMoreMessages() && !this.loadingMore()) {
-      this.loadMore();
+    if (element.scrollTop < 150 && !this.loadingMore()) {
+      const canFetchOlderFromDb =
+        !this.hasMoreMessages()
+        && !this.conversationExhausted()
+        && !this.loadingOlder()
+        && this.channelMessages().length > 0;
+
+      if (this.hasMoreMessages() || canFetchOlderFromDb) {
+        this.loadMore();
+      }
     }
   }
 
   loadMore(): void {
-    if (this.loadingMore() || !this.hasMoreMessages())
+    if (this.loadingMore())
       return;
 
-    this.loadingMore.set(true);
+    // Case 1: there are still in-store messages above the rendered window.
+    // Just widen the display window and preserve scroll position.
+    if (this.hasMoreMessages()) {
+      this.loadingMore.set(true);
 
-    const element = this.messagesContainer?.nativeElement;
-    const previousScrollHeight = element?.scrollHeight ?? 0;
+      const element = this.messagesContainer?.nativeElement;
+      const previousScrollHeight = element?.scrollHeight ?? 0;
 
-    this.displayLimit.update((limit) => limit + this.PAGE_SIZE);
+      this.displayLimit.update((limit) => limit + this.PAGE_SIZE);
 
-    requestAnimationFrame(() => {
       requestAnimationFrame(() => {
-        if (element) {
-          const newScrollHeight = element.scrollHeight;
+        requestAnimationFrame(() => {
+          if (element) {
+            const newScrollHeight = element.scrollHeight;
 
-          element.scrollTop += newScrollHeight - previousScrollHeight;
-        }
+            element.scrollTop += newScrollHeight - previousScrollHeight;
+          }
 
-        this.loadingMore.set(false);
+          this.loadingMore.set(false);
+        });
       });
+
+      return;
+    }
+
+    // Case 2: in-store window is exhausted. Ask the parent to fetch the
+    // next older page from the DB. The parent dispatches loadOlderMessages
+    // and the resulting store update is handled by onMessagesChanged via
+    // pendingOlderFetchScrollHeight (prepend-aware scroll preservation).
+    if (this.loadingOlder() || this.conversationExhausted())
+      return;
+
+    const all = this.channelMessages();
+
+    if (all.length === 0)
+      return;
+
+    const oldest = all[0];
+    const element = this.messagesContainer?.nativeElement;
+
+    this.loadingMore.set(true);
+    this.pendingOlderFetchScrollHeight = element?.scrollHeight ?? 0;
+    this.loadOlderRequested.emit({
+      beforeTimestamp: oldest.timestamp,
+      limit: this.PAGE_SIZE
     });
   }
 
@@ -359,6 +481,8 @@ export class ChatMessageListComponent implements AfterViewChecked, OnDestroy {
     this.showNewMessagesBar.set(false);
     this.lastMessageCount = 0;
     this.displayLimit.set(this.PAGE_SIZE);
+    this.pendingOlderFetchScrollHeight = null;
+    this.loadingMore.set(false);
   }
 
   private startBottomScrollWatch(): void {