import type {
  AgentAvailability,
  Bootstrap,
  Channel,
  InboxItem,
  InboxState,
  Message,
  Notification,
  SearchResult,
  Ticket,
  TicketState,
  User,
} from "@lynkd/messaging-inbox-sdk";

/**
 * The contract every BFF handler talks to. This is the ONE seam between the UI
 * and a real backend. Two implementations:
 *   - MockBackend  (default) — the in-memory store
 *   - IiosBackend  — proxies the real IIOS service
 * Selected by BFF_BACKEND ("mock" | "iios"). All methods are async so a network
 * backend drops in without changing the routes.
 */
export interface Backend {
  bootstrap(): Promise<Bootstrap>;
  listChannels(): Promise<Channel[]>;
  createChannel(input: { name: string; kind?: string; topic?: string; memberIds?: string[] }): Promise<Channel>;
  addMember(channelId: string, userId: string): Promise<Channel | null>;
  removeMember(channelId: string, userId: string): Promise<Channel | null>;
  markRead(channelId: string): Promise<Channel | null>;
  setStatus(text: string | undefined, emoji: string | undefined, clearAt?: number): Promise<User>;
  updateMe(patch: { name?: string; title?: string; avatarColor?: string; avatarUrl?: string | null; presence?: string }): Promise<User>;
  channelMessages(channelId: string): Promise<Message[]>;
  thread(channelId: string, parentId: string): Promise<{ parent: Message | null; replies: Message[] }>;
  send(channelId: string, body: string, opts?: { parentId?: string; scheduledFor?: number; attachments?: import("@lynkd/messaging-inbox-sdk").Attachment[]; threadRootId?: string | null }): Promise<Message>;
  editMessage(channelId: string, messageId: string, body: string): Promise<Message | null>;
  deleteMessage(channelId: string, messageId: string): Promise<{ ok: boolean }>;
  react(channelId: string, messageId: string, emoji: string): Promise<Message | null>;
  pin(channelId: string, messageId: string): Promise<Message | null>;
  save(channelId: string, messageId: string): Promise<Message | null>;
  savedMessages(): Promise<Message[]>;
  threadParents(): Promise<Message[]>;
  listInbox(state?: InboxState): Promise<InboxItem[]>;
  patchInbox(id: string, state: InboxState): Promise<InboxItem | null>;
  listTickets(scope?: string): Promise<Ticket[]>;
  getTicket(id: string): Promise<Ticket | null>;
  patchTicket(id: string, state: TicketState): Promise<Ticket | null>;
  replyTicket(id: string, body: string): Promise<Ticket | null>;
  availability(): Promise<AgentAvailability[]>;
  search(q: string): Promise<SearchResult[]>;
  notifications(): Promise<Notification[]>;
}