import { getDb } from './db';

/** Ein gespeicherter Passkey (WebAuthn-Credential) für den Single-User. */
export interface PasskeyRecord {
  credentialId: string; // base64url
  publicKey: Uint8Array<ArrayBuffer>;
  counter: number;
  transports: string[];
  label: string;
  createdAt: string;
  lastUsedAt: string | null;
}

interface PasskeyRow {
  credential_id: string;
  public_key: Buffer;
  counter: number;
  transports: string;
  label: string;
  created_at: string;
  last_used_at: string | null;
}

function fromRow(row: PasskeyRow): PasskeyRecord {
  let transports: string[] = [];
  try {
    const parsed = JSON.parse(row.transports);
    if (Array.isArray(parsed)) transports = parsed;
  } catch {
    /* ignore malformed transports */
  }
  return {
    credentialId: row.credential_id,
    // Uint8Array.from kopiert in einen frischen ArrayBuffer (passt zum von
    // @simplewebauthn erwarteten Uint8Array<ArrayBuffer>).
    publicKey: Uint8Array.from(row.public_key),
    counter: row.counter,
    transports,
    label: row.label,
    createdAt: row.created_at,
    lastUsedAt: row.last_used_at,
  };
}

/** Alle Passkeys, neueste zuerst. */
export function listPasskeys(): PasskeyRecord[] {
  return (
    getDb().prepare('SELECT * FROM passkeys ORDER BY created_at DESC').all() as PasskeyRow[]
  ).map(fromRow);
}

export function getPasskey(credentialId: string): PasskeyRecord | undefined {
  const row = getDb()
    .prepare('SELECT * FROM passkeys WHERE credential_id = ?')
    .get(credentialId) as PasskeyRow | undefined;
  return row ? fromRow(row) : undefined;
}

export function insertPasskey(record: {
  credentialId: string;
  publicKey: Uint8Array;
  counter: number;
  transports: string[];
  label: string;
}): void {
  getDb()
    .prepare(
      `INSERT INTO passkeys (credential_id, public_key, counter, transports, label)
       VALUES (@credentialId, @publicKey, @counter, @transports, @label)`
    )
    .run({
      credentialId: record.credentialId,
      publicKey: Buffer.from(record.publicKey),
      counter: record.counter,
      transports: JSON.stringify(record.transports ?? []),
      label: record.label,
    });
}

/** Aktualisiert Counter und last_used_at nach erfolgreicher Anmeldung (Replay-Schutz). */
export function updatePasskeyUsage(credentialId: string, counter: number): void {
  getDb()
    .prepare(
      `UPDATE passkeys SET counter = @counter, last_used_at = datetime('now')
       WHERE credential_id = @credentialId`
    )
    .run({ credentialId, counter });
}

export function deletePasskey(credentialId: string): boolean {
  return (
    getDb().prepare('DELETE FROM passkeys WHERE credential_id = ?').run(credentialId).changes > 0
  );
}