import * as fs from "node:fs";

/**
 * Creates a directory and ensures it is actually accessible.
 * On Windows with Azure AD/Entra ID, directories created shortly after
 * wake-from-sleep can end up with broken NTFS ACLs (null DACL) when the
 * cloud SID cannot be resolved without network connectivity. This leaves
 * the directory completely inaccessible to the creating user.
 */
export function ensureAccessibleDir(dirPath: string): void {
  fs.mkdirSync(dirPath, { recursive: true });
  try {
    fs.accessSync(dirPath, fs.constants.R_OK | fs.constants.W_OK);
  } catch {
    try {
      // If we can't access it, try deleting and recreating.
      // This often fixed the "Null DACL" issue on Windows.
      fs.rmSync(dirPath, { recursive: true, force: true });
    } catch {
      // Best effort cleanup.
    }
    fs.mkdirSync(dirPath, { recursive: true });
    fs.accessSync(dirPath, fs.constants.R_OK | fs.constants.W_OK);
  }
}

/**
 * Common retryable model error patterns.
 */
const RETRYABLE_ERROR_PATTERNS = [
  /rate limit/i,
  /overloaded/i,
  /timeout/i,
  /500/i,
  /502/i,
  /503/i,
  /504/i,
  /connection/i,
  /network/i,
];

/**
 * Returns true if the error is likely a transient model/provider failure.
 */
export function isRetryableModelFailure(error: unknown): boolean {
  const message = error instanceof Error ? error.message : String(error);
  return RETRYABLE_ERROR_PATTERNS.some((pattern) => pattern.test(message));
}