malice

import type { MessageKind, RoomSummary, TimelineItem } from './types';

const RECENT_MS = 5 * 60 * 1000;

export interface NotificationSource {

  senderId: string | null;

  senderName: string | null;

  senderAvatar: string | null;

  kind: MessageKind | null;

  body: string | null;

  undecryptable: boolean;

  highlight: boolean;

}

export interface NotificationPlan {

  title: string;

  body: string;

  tag: string;

  renotify: boolean;

  roomId: string;

  iconMxc: string | null;

}

export function notifyingCount(room: RoomSummary): number {

  if (room.space || room.membership !== 'Joined' || room.notification_mode === 'Mute') return 0;

  if (room.notification_mode === 'MentionsAndKeywordsOnly') return room.unread_mentions;

  return room.unread_messages + room.unread_mentions;

}

export function badgeTotal(rooms: RoomSummary[]): number {

  return rooms.reduce((sum, room) => sum + notifyingCount(room), 0);

}

export function roomTag(roomId: string): string {

  return `room:${roomId}`;

}

export interface Arrival {

  mention: boolean;

}

export function arrivalIn(previous: RoomSummary | undefined, next: RoomSummary, now: number): Arrival | null {

  if (!previous || notifyingCount(next) <= notifyingCount(previous)) return null;

  const at = next.latest_event_timestamp_ms;

  if (at !== null && now - at > RECENT_MS) return null;

  return { mention: next.unread_mentions > previous.unread_mentions };

}

export function isRoomWatched(roomId: string, openRoomId: string | null, visible: boolean, focused: boolean): boolean {

  return visible && focused && roomId === openRoomId;

}

export function sourceFromTimeline(items: TimelineItem[] | undefined): NotificationSource | null {

  if (!items) return null;

  for (let i = items.length - 1; i >= 0; i--) {

    const item = items[i];

    if (item.kind !== 'event') continue;

    const { event } = item;

    if (event.own) return null;

    const content = event.content;

    const common = {

      senderId: event.sender.user_id,

      senderName: event.sender.display_name,

      senderAvatar: event.sender.avatar

    };

    if (content.kind === 'Message') {

      return { ...common, kind: content.message.kind, body: content.message.body, undecryptable: false, highlight: event.highlight === true };

    }

    if (content.kind === 'Sticker') return { ...common, kind: null, body: content.body, undecryptable: false, highlight: event.highlight === true };

    if (content.kind === 'UnableToDecrypt') return { ...common, kind: null, body: null, undecryptable: true, highlight: false };

  }

  return null;

}

export function sourceFromSummary(room: RoomSummary): NotificationSource | null {

  const latest = room.latest_event;

  if (!latest || latest.send_state.kind !== 'Sent') return null;

  const hero = room.heroes.find((h) => h.user_id === latest.sender);

  return {

    senderId: latest.sender,

    senderName: hero?.display_name ?? null,

    senderAvatar: hero?.avatar ?? null,

    kind: latest.kind,

    body: latest.body,

    undecryptable: false,

    highlight: false

  };

}

const MEDIA_LABEL: Partial<Record<string, string>> = {

  Image: 'Sent an image',

  Video: 'Sent a video',

  Audio: 'Sent an audio message',

  File: 'Sent a file',

  Location: 'Shared a location'

};

function previewText(source: NotificationSource, sender: string): string | null {

  if (source.undecryptable) return null;

  const kind = typeof source.kind === 'string' ? source.kind : null;

  const label = kind ? MEDIA_LABEL[kind] : undefined;

  const text = source.body?.trim();

  if (label) return label;

  if (!text) return null;

  return kind === 'Emote' ? `${sender} ${text}` : text;

}

function localPart(userId: string): string {

  const name = userId.startsWith('@') ? userId.slice(1) : userId;

  const colon = name.indexOf(':');

  return colon > 0 ? name.slice(0, colon) : name;

}

export function planNotification(

  room: RoomSummary,

  source: NotificationSource | null,

  arrival: Arrival

): NotificationPlan {

  const sender = source?.senderName ?? (source?.senderId ? localPart(source.senderId) : null);

  const text = source && sender ? previewText(source, sender) : null;

  const generic = room.direct ? 'New message' : 'New messages';

  let body: string;

  if (!text) body = sender && !room.direct ? `${sender}: ${generic}` : generic;

  else body = room.direct || !sender || source?.kind === 'Emote' ? text : `${sender}: ${text}`;

  return {

    title: room.direct && sender ? sender : room.name,

    body,

    tag: roomTag(room.room_id),

    renotify: arrival.mention || source?.highlight === true,

    roomId: room.room_id,

    iconMxc: (room.direct ? source?.senderAvatar : null) ?? room.avatar

  };

}