import { randomBytes } from "node:crypto";
import { lstat, rename, unlink } from "node:fs/promises";

export type ProviderRawIdentity = Readonly<{
  reportPath: string;
  reportDev: number;
  reportIno: number;
}>;

export async function cleanupOwnedProviderReport(
  identity: ProviderRawIdentity,
): Promise<boolean> {
  try {
    const metadata = await lstat(identity.reportPath);
    if (!matchesReportIdentity(metadata, identity)) return false;
    const quarantine = `${identity.reportPath}.parent-loss-${process.pid}-${randomBytes(16).toString("hex")}`;
    await rename(identity.reportPath, quarantine);
    const quarantinedMetadata = await lstat(quarantine);
    if (!matchesReportIdentity(quarantinedMetadata, identity)) {
      throw new Error("provider raw output identity changed during parent-loss cleanup");
    }
    await unlink(quarantine);
    return true;
  } catch (error) {
    if (hasErrorCode(error, "ENOENT")) return false;
    throw error;
  }
}

function matchesReportIdentity(
  metadata: Awaited<ReturnType<typeof lstat>>,
  identity: ProviderRawIdentity,
): boolean {
  return metadata.isFile() && !metadata.isSymbolicLink() &&
    metadata.dev === identity.reportDev && metadata.ino === identity.reportIno;
}

function hasErrorCode(error: unknown, code: string): boolean {
  return Boolean(error && typeof error === "object" && "code" in error && error.code === code);
}