/*
 * Copyright (C) 2022 Yubico.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import 'dart:math';

import 'package:flutter_gen/gen_l10n/app_localizations.dart';

import '../../app/message.dart';
import '../../app/models.dart';
import '../../widgets/utf8_utils.dart';
import '../keys.dart';
import '../models.dart';
import 'add_account_page.dart';
import 'add_multi_account_page.dart';

/// Calculates the available space for issuer and account name.
///
/// Returns a record of the space available for the issuer and account name,
/// respectively, based on the current state of the credential.
(int, int) getRemainingKeySpace(
    {required OathType oathType,
    required int period,
    required String issuer,
    required String name}) {
  int remaining = 64; // The field is 64 bytes in total.

  if (oathType == OathType.totp && period != defaultPeriod) {
    // Non-standard TOTP periods are stored as part of this data, as a "D/"- prefix.
    remaining -= '$period/'.length;
  }
  int issuerSpace = byteLength(issuer);
  if (issuer.isNotEmpty) {
    // Issuer is separated from name with a ":", if present.
    issuerSpace += 1;
  }

  return (
    // Always reserve at least one character for name
    remaining - 1 - max(byteLength(name), 1),
    remaining - issuerSpace,
  );
}

/// Gets a textual name for the account, based on the issuer and name.
String getTextName(OathCredential credential) {
  return credential.issuer != null
      ? '${credential.issuer} (${credential.name})'
      : credential.name;
}

void handleUri(
  final withContext,
  final credentials,
  String? uri,
  DevicePath? devicePath,
  OathState? state,
  AppLocalizations l10n,
) async {
  List<CredentialData> creds =
      uri != null ? CredentialData.fromUri(Uri.parse(uri)) : [];
  await withContext((context) async {
    if (creds.isEmpty) {
      showMessage(context, l10n.l_qr_not_found);
    } else if (creds.length == 1) {
      await showBlurDialog(
        context: context,
        builder: (context) => OathAddAccountPage(
          devicePath,
          state,
          credentials: credentials,
          credentialData: creds[0],
        ),
      );
    } else {
      await showBlurDialog(
        context: context,
        builder: (context) => OathAddMultiAccountPage(devicePath, state, creds,
            key: migrateAccountAction),
      );
    }
  });
}