/**
 * The permanent step of account deletion (2026-09-30). One tick finds pending
 * requests whose 7 days are over and calls `purge_deleted_account` for each.
 * The database function is all-or-nothing, so a failed purge leaves the
 * account exactly as it was; the attempt is counted and the next tick retries
 * until MAX_ATTEMPTS. Logs carry counts and codes only, never ids or emails.
 */

export const ACCOUNT_DELETION_MAX_ATTEMPTS = 5;
export const ACCOUNT_DELETION_BATCH = 20;
export const ACCOUNT_DELETION_TICK_MS = 30 * 60 * 1000;
export const ACCOUNT_DELETION_FIRST_TICK_MS = 60 * 1000;

export type AccountDeletionWorkerDeps = Readonly<{
  now: () => Date;
  listDue: (nowIso: string, limit: number, maxAttempts: number) => Promise<readonly string[]>;
  purge: (requestId: string) => Promise<{ ok: true; status: string } | { ok: false; code: string }>;
  markFailed: (requestId: string, code: string) => Promise<void>;
  log: (line: string) => void;
}>;

export type AccountDeletionTickResult = Readonly<{ due: number; completed: number; skipped: number; failed: number }>;

export function purgeErrorCode(message: string | undefined): string {
  if (message?.includes("account_deletion_purge_incomplete")) return "purge_incomplete";
  if (message?.includes("account_deletion_request_not_found")) return "request_not_found";
  return "purge_failed";
}

export async function runAccountDeletionTick(deps: AccountDeletionWorkerDeps): Promise<AccountDeletionTickResult> {
  const due = await deps.listDue(deps.now().toISOString(), ACCOUNT_DELETION_BATCH, ACCOUNT_DELETION_MAX_ATTEMPTS);
  let completed = 0;
  let skipped = 0;
  let failed = 0;
  for (const requestId of due) {
    const result = await deps.purge(requestId);
    if (result.ok) {
      if (result.status === "completed") completed += 1; else skipped += 1;
      continue;
    }
    failed += 1;
    await deps.markFailed(requestId, result.code);
  }
  if (due.length > 0) {
    deps.log(`[account-deletion-worker] due=${due.length} completed=${completed} skipped=${skipped} failed=${failed}`);
  }
  return { due: due.length, completed, skipped, failed };
}