const ASCII_EQUIVALENTS: Record<string, string> = {
  "—": "-",
  "–": "-",
  "‘": "'",
  "“": '"',
  "”": '"',
  "…": "...",
};

/**
 * Error messages thrown from server actions are forwarded to the client via
 * the `X-Error` response header, which only accepts Latin-1 (ByteString)
 * values — undici throws a TypeError on anything above U+00FF and the request
 * dies with a 500 before the client can display the message. Map common
 * typographic characters to ASCII and drop anything else outside Latin-1.
 */
export function clientSafeMessage(message: string): string {
  const mapped = message.replace(/[—–‘“”…]/g, (char) => ASCII_EQUIVALENTS[char] ?? char);
  return mapped.replace(/[^\t\n\r\x20-\x7E\u00A0-\u00FF]/g, "");
}

export class RouteError extends Error {
  constructor(
    message: string,
    public statusCode: number = 500,
    public title: string = "Error",
    public code: string = "internal_error",
  ) {
    super(message);
    this.name = "RouteError";
  }
}

export class NotFoundError extends RouteError {
  constructor(message: string = "Page not found") {
    super(message, 404, "Not Found", "not_found");
  }
}

export class ForbiddenError extends RouteError {
  constructor(message: string = "Access denied", code: string = "forbidden") {
    super(message, 403, "Forbidden", code);
  }
}

export class UnauthorizedError extends RouteError {
  constructor(message: string = "Please sign in to continue") {
    super(message, 401, "Unauthorized", "unauthorized");
  }
}

export function isRouteError(error: unknown): error is RouteError {
  return (
    error instanceof RouteError ||
    (error instanceof Error && error.name === "RouteError") ||
    (typeof error === "object" &&
      error !== null &&
      "name" in error &&
      (error as { name: unknown }).name === "RouteError")
  );
}