// The messages between server F's main thread and a thread that holds
// simulation rooms (plan §8.2: rooms in worker_threads, so that a large
// network does not hold up the shared documents). A thread holds several
// rooms, each with a replica of its project's document: the document's
// updates go both ways, a person's messages go in, the room's come out,
// each for one person (a room tells its people apart; the main thread
// numbers them). A room's large binary files (blobs) are F's: the thread
// asks for the ones it has not got, and gives F the ones the simulation
// makes before the document's change that names them.

import type { HostMessage } from '@mdg-filius/protocol';

/** How often, and how long apart, a thread asks again for a blob F has not got (yet). */
export const BLOB_ASKS = 5;
export const BLOB_ASK_AGAIN_MILLISECONDS = 1_000;

export type ToRoomThread =
  /** A room for a project, its document as it is now. */
  | { readonly type: 'open'; readonly room: string; readonly state: Uint8Array }
  | { readonly type: 'doc'; readonly room: string; readonly update: Uint8Array }
  /** A person in the room, by name. */
  | { readonly type: 'connect'; readonly room: string; readonly client: number; readonly name: string }
  | { readonly type: 'client'; readonly room: string; readonly client: number; readonly message: unknown }
  | { readonly type: 'disconnect'; readonly room: string; readonly client: number }
  /** The simulation stopped (what it left written back first); answered by `stopped`. */
  | { readonly type: 'stop'; readonly room: string }
  /** The room ended — stopped first with `writeBack`, else as it is (its project is gone); answered by `closed`. */
  | { readonly type: 'close'; readonly room: string; readonly writeBack: boolean }
  /** The blobs asked for: those F has, and the names of those it has not. */
  | { readonly type: 'blobs'; readonly room: string; readonly blobs: readonly { readonly sha: string; readonly bytes: Uint8Array }[]; readonly missing: readonly string[] };

export type FromRoomThread =
  | { readonly type: 'doc'; readonly room: string; readonly update: Uint8Array }
  | { readonly type: 'host'; readonly room: string; readonly client: number; readonly message: HostMessage }
  | { readonly type: 'stopped'; readonly room: string }
  /** Blobs the document names that the thread has not got. */
  | { readonly type: 'needBlobs'; readonly room: string; readonly shas: readonly string[] }
  /** A blob the simulation made (before the change that names it). */
  | { readonly type: 'blob'; readonly room: string; readonly bytes: Uint8Array }
  | { readonly type: 'closed'; readonly room: string };