/**
 * Error-code registry — PROTOCOL §8.
 *
 * Extensible registry: the closed set of codes that appear in command errors (`response`
 * with `success:false`, §9.3) and async `error` events (§9.4). Codes are string literals so
 * they serialize plainly over the wire — never `Error` objects (§4 design rule #1).
 */
import { Type, type Static } from '@sinclair/typebox';

/**
 * The v0.1 error-code registry. Keys are the stable, wire-facing identifiers; each maps to
 * itself so `ErrorCode` (a `keyof`) and the runtime string agree. Add new codes here only —
 * the type derives automatically.
 */
export const ERROR_CODES = {
  /** Malformed message, bad JSON, failed validation (§8). */
  INVALID_REQUEST: 'INVALID_REQUEST',
  /** Referenced agent_id, request_id, or session entry doesn't exist (§8). */
  NOT_FOUND: 'NOT_FOUND',
  /** Per-agent command sent on a daemon connection without a valid agent_id attachment (§8). */
  NOT_ATTACHED: 'NOT_ATTACHED',
  /** The server refused the operation (rare in v0.1 — the gate runs in-agent) (§8). */
  PERMISSION_DENIED: 'PERMISSION_DENIED',
  /** Version mismatch, message out of sequence (§8). */
  PROTOCOL_ERROR: 'PROTOCOL_ERROR',
  /** An ask hit the headless timeout (ARCHITECTURE §6.2) (§8). */
  TIMEOUT: 'TIMEOUT',
  /** Unexpected server-side failure (§8). */
  INTERNAL_ERROR: 'INTERNAL_ERROR',
  /** Runtime startup failed; the durable agent can be retried (§8). */
  RUNTIME_START_FAILED: 'RUNTIME_START_FAILED',
  /** Existing session state is present but cannot be restored safely. */
  SESSION_CORRUPT: 'SESSION_CORRUPT',
  /** A replay entry exceeds the daemon's safe wire-size cap. */
  REPLAY_ENTRY_TOO_LARGE: 'REPLAY_ENTRY_TOO_LARGE',
  /** The LLM provider call failed (mid-turn) (§8). */
  PROVIDER_ERROR: 'PROVIDER_ERROR',
  /** A tool returned an error (also surfaces as tool_result with is_error) (§8). */
  TOOL_ERROR: 'TOOL_ERROR',
  /** The operation conflicts with current runtime/session state (e.g. compact while a turn is queued/active) (§8). */
  CONFLICT: 'CONFLICT',
} as const;

/** The union of all error-code string literals (single source of truth). */
export type ErrorCode = keyof typeof ERROR_CODES;

/** Runtime-validation schema: the literal union of every registered code. */
export const ErrorCodeSchema = Type.Union(
  (Object.keys(ERROR_CODES) as ErrorCode[]).map((c) => Type.Literal(c)),
);

/** Compile-time check that ErrorCodeSchema's Static matches ErrorCode. */
export type _ErrorCodeStatic = Static<typeof ErrorCodeSchema>;