feat: Add notifications

toju-app/src/app/domains/notifications/domain/notification.logic.ts

@@ -0,0 +1,158 @@
+import type { Message, Room } from '../../../shared-kernel';
+import type {
+  NotificationDeliveryContext,
+  NotificationDisplayPayload,
+  NotificationsSettings,
+  RoomUnreadCounts
+} from './notification.models';
+
+export const DEFAULT_TEXT_CHANNEL_ID = 'general';
+
+const MESSAGE_PREVIEW_LIMIT = 140;
+
+export function resolveMessageChannelId(message: Pick<Message, 'channelId'>): string {
+  return message.channelId || DEFAULT_TEXT_CHANNEL_ID;
+}
+
+export function getRoomTextChannelIds(room: Room): string[] {
+  const textChannelIds = (room.channels ?? [])
+    .filter((channel) => channel.type === 'text')
+    .map((channel) => channel.id);
+
+  return textChannelIds.length > 0 ? textChannelIds : [DEFAULT_TEXT_CHANNEL_ID];
+}
+
+export function getRoomById(rooms: Room[], roomId: string): Room | null {
+  return rooms.find((room) => room.id === roomId) ?? null;
+}
+
+export function getChannelLabel(room: Room | null, channelId: string): string {
+  const channelName = room?.channels?.find((channel) => channel.id === channelId)?.name;
+
+  return channelName || DEFAULT_TEXT_CHANNEL_ID;
+}
+
+export function getChannelLastReadAt(
+  settings: NotificationsSettings,
+  roomId: string,
+  channelId: string
+): number {
+  return settings.lastReadByChannel[roomId]?.[channelId]
+    ?? settings.roomBaselines[roomId]
+    ?? 0;
+}
+
+export function getRoomTrackingBaseline(settings: NotificationsSettings, room: Room): number {
+  const trackedChannels = getRoomTextChannelIds(room).map((channelId) =>
+    getChannelLastReadAt(settings, room.id, channelId)
+  );
+
+  return Math.min(...trackedChannels, settings.roomBaselines[room.id] ?? Date.now());
+}
+
+export function isRoomMuted(settings: NotificationsSettings, roomId: string): boolean {
+  return settings.mutedRooms[roomId] === true;
+}
+
+export function isChannelMuted(
+  settings: NotificationsSettings,
+  roomId: string,
+  channelId: string
+): boolean {
+  return settings.mutedChannels[roomId]?.[channelId] === true;
+}
+
+export function isMessageVisibleInActiveView(
+  message: Pick<Message, 'channelId' | 'roomId'>,
+  context: NotificationDeliveryContext
+): boolean {
+  return context.currentRoomId === message.roomId
+    && context.activeChannelId === resolveMessageChannelId(message)
+    && context.isWindowFocused
+    && context.isDocumentVisible;
+}
+
+export function shouldDeliverNotification(
+  settings: NotificationsSettings,
+  message: Pick<Message, 'channelId' | 'roomId'>,
+  context: NotificationDeliveryContext
+): boolean {
+  const channelId = resolveMessageChannelId(message);
+
+  if (!settings.enabled) {
+    return false;
+  }
+
+  if (settings.respectBusyStatus && context.currentUser?.status === 'busy') {
+    return false;
+  }
+
+  if (isRoomMuted(settings, message.roomId) || isChannelMuted(settings, message.roomId, channelId)) {
+    return false;
+  }
+
+  return !isMessageVisibleInActiveView(message, context);
+}
+
+export function buildNotificationDisplayPayload(
+  message: Pick<Message, 'channelId' | 'content' | 'senderName'>,
+  room: Room | null,
+  settings: NotificationsSettings,
+  requestAttention: boolean
+): NotificationDisplayPayload {
+  const channelId = resolveMessageChannelId(message);
+  const roomName = room?.name || 'Server';
+  const channelLabel = getChannelLabel(room, channelId);
+
+  return {
+    title: `${roomName} · #${channelLabel}`,
+    body: settings.showPreview
+      ? formatMessagePreview(message.senderName, message.content)
+      : `${message.senderName} sent a new message`,
+    requestAttention
+  };
+}
+
+export function calculateUnreadForRoom(
+  room: Room,
+  messages: Message[],
+  settings: NotificationsSettings,
+  currentUserIds: Set<string>
+): RoomUnreadCounts {
+  const channelCounts = Object.fromEntries(
+    getRoomTextChannelIds(room).map((channelId) => [channelId, 0])
+  ) as Record<string, number>;
+
+  for (const message of messages) {
+    if (message.isDeleted || currentUserIds.has(message.senderId)) {
+      continue;
+    }
+
+    const channelId = resolveMessageChannelId(message);
+
+    if (message.timestamp <= getChannelLastReadAt(settings, room.id, channelId)) {
+      continue;
+    }
+
+    channelCounts[channelId] = (channelCounts[channelId] ?? 0) + 1;
+  }
+
+  return {
+    channelCounts,
+    roomCount: Object.values(channelCounts).reduce((total, count) => total + count, 0)
+  };
+}
+
+function formatMessagePreview(senderName: string, content: string): string {
+  const normalisedContent = content.replace(/\s+/g, ' ').trim();
+
+  if (!normalisedContent) {
+    return `${senderName} sent a new message`;
+  }
+
+  const preview = normalisedContent.length > MESSAGE_PREVIEW_LIMIT
+    ? `${normalisedContent.slice(0, MESSAGE_PREVIEW_LIMIT - 1)}…`
+    : normalisedContent;
+
+  return `${senderName}: ${preview}`;
+}

toju-app/src/app/domains/notifications/domain/notification.models.ts

@@ -0,0 +1,64 @@
+import type {
+  Message,
+  Room,
+  User
+} from '../../../shared-kernel';
+
+export interface NotificationsSettings {
+  enabled: boolean;
+  showPreview: boolean;
+  respectBusyStatus: boolean;
+  mutedRooms: Record<string, boolean>;
+  mutedChannels: Record<string, Record<string, boolean>>;
+  roomBaselines: Record<string, number>;
+  lastReadByChannel: Record<string, Record<string, number>>;
+}
+
+export interface NotificationsUnreadState {
+  roomCounts: Record<string, number>;
+  channelCounts: Record<string, Record<string, number>>;
+}
+
+export interface NotificationDeliveryContext {
+  activeChannelId: string | null;
+  currentRoomId: string | null;
+  currentUser: User | null;
+  isDocumentVisible: boolean;
+  isWindowFocused: boolean;
+  rooms: Room[];
+}
+
+export interface NotificationDisplayPayload {
+  body: string;
+  requestAttention: boolean;
+  title: string;
+}
+
+export interface RoomUnreadCounts {
+  channelCounts: Record<string, number>;
+  roomCount: number;
+}
+
+export function createDefaultNotificationSettings(): NotificationsSettings {
+  return {
+    enabled: true,
+    showPreview: true,
+    respectBusyStatus: true,
+    mutedRooms: {},
+    mutedChannels: {},
+    roomBaselines: {},
+    lastReadByChannel: {}
+  };
+}
+
+export function createEmptyUnreadState(): NotificationsUnreadState {
+  return {
+    roomCounts: {},
+    channelCounts: {}
+  };
+}
+
+export type NotificationMessage = Pick<
+  Message,
+  'channelId' | 'content' | 'id' | 'isDeleted' | 'roomId' | 'senderId' | 'senderName' | 'timestamp'
+>;