/*
 * 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:async';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:logging/logging.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:window_manager/window_manager.dart';
import 'package:yubico_authenticator/app/logging.dart';

import '../app/models.dart';
import '../app/state.dart';
import '../core/state.dart';
import 'models.dart';
import 'rpc.dart';

final _log = Logger('state');

// This must be initialized before use in initialize.dart.
final rpcProvider = Provider<RpcSession>((ref) {
  throw UnimplementedError();
});

final rpcStateProvider = StateNotifierProvider<_RpcStateNotifier, RpcState>(
  (ref) => _RpcStateNotifier(ref.watch(rpcProvider)),
);

class _RpcStateNotifier extends StateNotifier<RpcState> {
  final RpcSession rpc;

  _RpcStateNotifier(this.rpc) : super(const RpcState('unknown', false)) {
    _init();
  }

  _init() async {
    final response = await rpc.command('get', []);
    if (mounted) {
      state = RpcState.fromJson(response['data']);
    }
  }
}

final _windowStateProvider =
    StateNotifierProvider<_WindowStateNotifier, WindowState>(
        (ref) => _WindowStateNotifier());

final desktopWindowStateProvider = Provider<WindowState>(
  (ref) => ref.watch(_windowStateProvider),
);

class _WindowStateNotifier extends StateNotifier<WindowState>
    with WindowListener {
  Timer? _idleTimer;

  _WindowStateNotifier()
      : super(WindowState(focused: true, visible: true, active: true)) {
    _init();
  }

  void _init() async {
    windowManager.addListener(this);
    // isFocused is not supported on Linux, assume focused
    if (!Platform.isLinux) {
      _idleTimer = Timer(const Duration(seconds: 5), () async {
        final focused = await windowManager.isFocused();
        if (mounted && !focused) {
          state = state.copyWith(active: false);
        }
      });
    }
  }

  @override
  void dispose() {
    windowManager.removeListener(this);
    super.dispose();
  }

  @override
  set state(WindowState value) {
    _log.debug('Window state changed: $value');
    super.state = value;
  }

  @override
  void onWindowEvent(String eventName) {
    if (mounted) {
      switch (eventName) {
        case 'blur':
          state = state.copyWith(focused: false);
          _idleTimer?.cancel();
          _idleTimer = Timer(const Duration(seconds: 5), () async {
            if (mounted) {
              state = state.copyWith(active: false);
            }
          });
          break;
        case 'focus':
          state = state.copyWith(focused: true, active: true);
          _idleTimer?.cancel();
          break;
        case 'minimize':
          state = state.copyWith(visible: false, active: false);
          _idleTimer?.cancel();
          break;
        case 'restore':
          state = state.copyWith(visible: true, active: true);
          _idleTimer?.cancel();
          break;
        default:
          _log.traffic('Window event ignored: $eventName');
      }
    }
  }
}

final desktopClipboardProvider = Provider<AppClipboard>(
  (ref) => _DesktopClipboard(),
);

class _DesktopClipboard extends AppClipboard {
  @override
  bool platformGivesFeedback() {
    return false;
  }

  @override
  Future<void> setText(String toClipboard, {bool isSensitive = false}) async {
    await Clipboard.setData(ClipboardData(text: toClipboard));
  }
}

final desktopSupportedThemesProvider = StateProvider<List<ThemeMode>>(
  (ref) => ThemeMode.values,
);

class DesktopCurrentDeviceNotifier extends CurrentDeviceNotifier {
  static const String _lastDevice = 'APP_STATE_LAST_DEVICE';
  DeviceNode? _deviceNode;

  @override
  DeviceNode? build() {
    SharedPreferences prefs = ref.watch(prefProvider);
    var devices = ref.watch(attachedDevicesProvider);

    if (!devices.contains(_deviceNode)) {
      final lastDevice = prefs.getString(_lastDevice) ?? '';
      try {
        _deviceNode = devices.firstWhere((dev) => dev.path.key == lastDevice,
            orElse: () => devices.whereType<UsbYubiKeyNode>().first);
      } on StateError {
        _deviceNode = null;
      }
    }
    return _deviceNode;
  }

  @override
  setCurrentDevice(DeviceNode? device) {
    state = device;
    ref.read(prefProvider).setString(_lastDevice, device?.path.key ?? '');
  }
}