/**
 * The JSON `Envelope` wire protocol shared by every P2P transport.
 *
 * Authoritative state is encoded with the REAL `@colyseus/schema` `Encoder`
 * (see `runtime.ts`) and decoded with the real `Decoder` (`client.ts`). The
 * encoder's `Uint8Array` output rides as a base64 STRING on the envelope
 * (`join-ok.state`, `state-snapshot.state`, `state-patch.patch`), so the whole
 * envelope survives `JSON.stringify` on any transport unchanged. See
 * `wire-bytes.ts`.
 */

export type Envelope =
  | {
      readonly kind: 'join';
      readonly requestId: string;
      readonly room: string;
      readonly options?: unknown;
    }
  | {
      readonly kind: 'join-ok';
      readonly requestId: string;
      readonly sessionId: string;
      /** base64-encoded full-state bytes from `Encoder.encodeAll`/`encodeAllView`. */
      readonly state: string;
      readonly clock: number;
    }
  | { readonly kind: 'join-error'; readonly requestId: string; readonly message: string }
  | { readonly kind: 'message'; readonly type: string; readonly payload?: unknown }
  | {
      readonly kind: 'state-patch';
      /** base64-encoded delta bytes from `Encoder.encode`/`encodeView`. */
      readonly patch: string;
      readonly clock: number;
    }
  | {
      readonly kind: 'state-snapshot';
      /** base64-encoded full-state bytes (resync). */
      readonly state: string;
      readonly clock: number;
    }
  | { readonly kind: 'state-resync'; readonly clock: number }
  | { readonly kind: 'leave'; readonly code?: number; readonly reason?: string }
  | { readonly kind: 'ping'; readonly t: number }
  | { readonly kind: 'pong'; readonly t: number };

export const P2P_CLOSE_CODES = {
  badEnvelope: 4400,
  unauthorized: 4401,
  roomNotFound: 4404,
  joinTimeout: 4408,
  envelopeTooLarge: 4413,
  rateLimited: 4429,
  relayQuotaExceeded: 4430,
  roomFull: 4431,
  hostMissing: 4432,
  relayNotAllowed: 4433,
  internalError: 4500,
} as const;

export type P2PCloseCode = (typeof P2P_CLOSE_CODES)[keyof typeof P2P_CLOSE_CODES];

export function isEnvelope(value: unknown): value is Envelope {
  return typeof value === 'object' && value !== null && 'kind' in value;
}