import type { ChatMessage } from "./chat.ts";
import type { Comment } from "./comment.ts";
import type { Dump } from "./dump.ts";
import type { Notification } from "./notification.ts";
import type { Playlist } from "./playlist.ts";
import type { PublicUser } from "./user.ts";

/**
 * The socket protocol. Every message has a `type` discriminant, so each union
 * narrows with a switch. The server sends these as JSON, so the client reads
 * `Wire<ServerToClientMessage>`: its Dates arrive as strings.
 */

// ── Client → Server ──────────────────────────────────────────────────────────

export interface PingMessage {
  type: "ping";
}

export interface PongMessage {
  type: "pong";
}

export interface VoteCastMessage {
  type: "vote_cast";
  dumpId: string;
}

export interface VoteRemoveMessage {
  type: "vote_remove";
  dumpId: string;
}

export interface CommentLikeCastMessage {
  type: "comment_like_cast";
  commentId: string;
}

export interface CommentLikeRemoveMessage {
  type: "comment_like_remove";
  commentId: string;
}

export interface ChatSendMessage {
  type: "chat_send";
  body: string;
  /** Id of the message being replied to, if this is a reply. */
  replyToId?: string;
  /** Client-chosen id echoed on the broadcast (or on the error), so the
   * sender can match the outcome to its pending message. */
  nonce?: string;
}

// Sent while the user is composing (true) and when they stop (false). The
// server rebroadcasts the live set of typers to everyone as ChatTypingUpdate.
export interface ChatTypingMessage {
  type: "chat_typing";
  typing: boolean;
}

// Tells the server whether this client currently has the chatbox open, so that
// mention notifications can be skipped for users who are already reading chat.
export interface ChatFocusMessage {
  type: "chat_focus";
  open: boolean;
}

export interface ChatEditMessage {
  type: "chat_edit";
  id: string;
  body: string;
}

export interface ChatDeleteMessage {
  type: "chat_delete";
  id: string;
}

// The user has seen the chat up to the message created at `at`.
export interface ChatReadMessage {
  type: "chat_read";
  at: string;
}

export type ClientToServerMessage =
  | PingMessage
  | PongMessage
  | VoteCastMessage
  | VoteRemoveMessage
  | CommentLikeCastMessage
  | CommentLikeRemoveMessage
  | ChatSendMessage
  | ChatTypingMessage
  | ChatFocusMessage
  | ChatEditMessage
  | ChatDeleteMessage
  | ChatReadMessage;

// ── Server → Client ──────────────────────────────────────────────────────────

export interface OnlineUser {
  userId: string;
  username: string;
  hasAvatar: boolean;
  avatarVersion?: number;
}

export interface WelcomeMessage {
  type: "welcome";
  users: OnlineUser[];
  myVotes: string[];
  myCommentLikes: string[];
  unreadNotificationCount: number;
  /** The user's chat read marker and the unread count behind it (signed-in
   * users only). */
  chatReadAt?: string;
  unreadChatCount: number;
}

export interface PresenceUpdateMessage {
  type: "presence_update";
  users: OnlineUser[];
}

export interface VotesUpdateMessage {
  type: "votes_update";
  dumpId: string;
  voteCount: number;
  voterId: string;
  action: "cast" | "remove";
}

export interface VoteAckMessage {
  type: "vote_ack";
  dumpId: string;
  action: "cast" | "remove";
  voteCount: number;
}

export interface CommentLikesUpdateMessage {
  type: "comment_likes_update";
  commentId: string;
  likeCount: number;
  likerId: string;
  action: "cast" | "remove";
}

export interface CommentLikeAckMessage {
  type: "comment_like_ack";
  commentId: string;
  action: "cast" | "remove";
  likeCount: number;
}

export interface DumpCreatedMessage {
  type: "dump_created";
  dump: Dump;
}

export interface DumpUpdatedMessage {
  type: "dump_updated";
  dump: Dump;
}

export interface DumpDeletedMessage {
  type: "dump_deleted";
  dumpId: string;
}

export interface PlaylistCreatedMessage {
  type: "playlist_created";
  playlist: Playlist;
}

export interface PlaylistUpdatedMessage {
  type: "playlist_updated";
  playlist: Playlist;
}

export interface PlaylistDeletedMessage {
  type: "playlist_deleted";
  playlistId: string;
  userId: string;
}

export interface PlaylistDumpsUpdatedMessage {
  type: "playlist_dumps_updated";
  playlistId: string;
  /** The members this recipient can see, in order. */
  dumpIds: string[];
  /** Every member, as Playlist.dumpCount counts them. */
  dumpCount: number;
}

export interface UserUpdatedMessage {
  type: "user_updated";
  user: PublicUser;
}

export interface CommentCreatedMessage {
  type: "comment_created";
  comment: Comment;
}

export interface CommentUpdatedMessage {
  type: "comment_updated";
  comment: Comment;
}

export interface CommentDeletedMessage {
  type: "comment_deleted";
  commentId: string;
  dumpId: string;
}

export interface NotificationCreatedMessage {
  type: "notification_created";
  notification: Notification;
}

export interface ErrorMessage {
  type: "error";
  message?: string;
  // Context for optimistic-action failures so the client can revert the exact
  // pending vote/like immediately instead of waiting for its ACK timeout.
  dumpId?: string;
  commentId?: string;
  action?: "cast" | "remove";
  /** Set when a chat action failed, so the client can surface it in the chat. */
  scope?: "chat";
  /** Echo of the failed chat_send's nonce. */
  nonce?: string;
}

export interface ForceLogoutMessage {
  type: "force_logout";
}

export interface ChatMessageMessage {
  type: "chat_message";
  message: ChatMessage;
  /** The sender's nonce, so its pending copy can be retired. */
  nonce?: string;
}

export interface ChatMessageUpdatedMessage {
  type: "chat_message_updated";
  message: ChatMessage;
}

export interface ChatMessageDeletedMessage {
  type: "chat_message_deleted";
  id: string;
}

// The current set of users composing a chat message. Reuses OnlineUser so the
// client can render the same avatars as the presence row.
export interface ChatTypingUpdateMessage {
  type: "chat_typing_update";
  users: OnlineUser[];
}

// The user's read marker moved (from any of their tabs or devices).
export interface ChatReadUpdateMessage {
  type: "chat_read_update";
  readAt: string;
  unread: number;
}

export type ServerToClientMessage =
  | PingMessage
  | PongMessage
  | WelcomeMessage
  | PresenceUpdateMessage
  | VotesUpdateMessage
  | VoteAckMessage
  | CommentLikesUpdateMessage
  | CommentLikeAckMessage
  | DumpCreatedMessage
  | DumpUpdatedMessage
  | DumpDeletedMessage
  | PlaylistCreatedMessage
  | PlaylistUpdatedMessage
  | PlaylistDeletedMessage
  | PlaylistDumpsUpdatedMessage
  | UserUpdatedMessage
  | CommentCreatedMessage
  | CommentUpdatedMessage
  | CommentDeletedMessage
  | NotificationCreatedMessage
  | ErrorMessage
  | ForceLogoutMessage
  | ChatMessageMessage
  | ChatMessageUpdatedMessage
  | ChatMessageDeletedMessage
  | ChatTypingUpdateMessage
  | ChatReadUpdateMessage;