/** Wire protocol shared by the EditorRoom Durable Object, the gitfor-fs VS Code extension and agent clients. */

export const EDITOR_WS_PROTOCOL = "gitfor-editor.v1";

/** Binary frames start with a varUint message type, as in y-websocket. */
export const MESSAGE_SYNC = 0;
export const MESSAGE_AWARENESS = 1;

/** Close codes: clients stop on 4401, reconnect read-only on 4403, reconnect normally on 4408. */
export const CLOSE_REVOKED = 4401;
export const CLOSE_DOWNGRADED = 4403;
export const CLOSE_REAUTH = 4408;

/** Y.Map holding per-path metadata; Y.Text contents live under `file:<path>`. */
export const FILES_MAP = "files";
export const TEXT_PREFIX = "file:";

export type FileKind = "text" | "binary" | "lfs" | "too-large" | "symlink" | "gitlink";

/**
 * - `seeded`: loaded from the branch head.
 * - `created`: new in this session.
 * - `deleted`: staged for deletion.
 * - `missing`: requested but absent at head.
 * - `conflict`: changed upstream while edited here.
 */
export type FileState = "seeded" | "created" | "deleted" | "missing" | "conflict";

export type FileMeta = { state: FileState; kind: FileKind; size: number };

export type ChangeStatus = "A" | "M" | "D";

/** JSON text frames from client to room. */
export type ClientControl =
  | { type: "open"; path: string }
  | { type: "create"; path: string }
  | { type: "delete"; path: string }
  | { type: "resolve"; path: string }
  | { type: "ping" };

/** JSON text frames from room to clients. */
export type RoomControl =
  | { type: "welcome"; head: string; branch: string; writable: boolean; user: string; clientLimit: number }
  | { type: "status"; head: string; changes: Array<{ path: string; status: ChangeStatus }>; conflicts: string[] }
  | { type: "committed"; sha: string; branch: string; pullUrl: string | null; by: string }
  | { type: "error"; message: string; path?: string }
  | { type: "pong" };

export function textKey(path: string): string {
  return `${TEXT_PREFIX}${path}`;
}