import 'dart:convert';

import 'package:collection/collection.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:immich_mobile/providers/authentication.provider.dart';
import 'package:immich_mobile/entities/asset.entity.dart';
import 'package:immich_mobile/models/server_info/server_version.model.dart';
import 'package:immich_mobile/entities/store.entity.dart';
import 'package:immich_mobile/providers/asset.provider.dart';
import 'package:immich_mobile/providers/db.provider.dart';
import 'package:immich_mobile/providers/server_info.provider.dart';
import 'package:immich_mobile/services/sync.service.dart';
import 'package:immich_mobile/utils/debounce.dart';
import 'package:logging/logging.dart';
import 'package:openapi/api.dart';
import 'package:socket_io_client/socket_io_client.dart';

enum PendingAction {
  assetDelete,
  assetUploaded,
  assetHidden,
}

class PendingChange {
  final String id;
  final PendingAction action;
  final dynamic value;

  const PendingChange(
    this.id,
    this.action,
    this.value,
  );

  @override
  String toString() => 'PendingChange(id: $id, action: $action, value: $value)';

  @override
  bool operator ==(Object other) {
    if (identical(this, other)) return true;

    return other is PendingChange && other.id == id && other.action == action;
  }

  @override
  int get hashCode => id.hashCode ^ action.hashCode;
}

class WebsocketState {
  final Socket? socket;
  final bool isConnected;
  final List<PendingChange> pendingChanges;

  WebsocketState({
    this.socket,
    required this.isConnected,
    required this.pendingChanges,
  });

  WebsocketState copyWith({
    Socket? socket,
    bool? isConnected,
    List<PendingChange>? pendingChanges,
  }) {
    return WebsocketState(
      socket: socket ?? this.socket,
      isConnected: isConnected ?? this.isConnected,
      pendingChanges: pendingChanges ?? this.pendingChanges,
    );
  }

  @override
  String toString() =>
      'WebsocketState(socket: $socket, isConnected: $isConnected)';

  @override
  bool operator ==(Object other) {
    if (identical(this, other)) return true;

    return other is WebsocketState &&
        other.socket == socket &&
        other.isConnected == isConnected;
  }

  @override
  int get hashCode => socket.hashCode ^ isConnected.hashCode;
}

class WebsocketNotifier extends StateNotifier<WebsocketState> {
  WebsocketNotifier(this._ref)
      : super(
          WebsocketState(socket: null, isConnected: false, pendingChanges: []),
        );

  final _log = Logger('WebsocketNotifier');
  final Ref _ref;
  final Debouncer _debounce =
      Debouncer(interval: const Duration(milliseconds: 500));

  /// Connects websocket to server unless already connected
  void connect() {
    if (state.isConnected) return;
    final authenticationState = _ref.read(authenticationProvider);

    if (authenticationState.isAuthenticated) {
      final accessToken = Store.get(StoreKey.accessToken);
      try {
        final endpoint = Uri.parse(Store.get(StoreKey.serverEndpoint));
        final headers = {"x-immich-user-token": accessToken};
        if (endpoint.userInfo.isNotEmpty) {
          headers["Authorization"] =
              "Basic ${base64.encode(utf8.encode(endpoint.userInfo))}";
        }

        debugPrint("Attempting to connect to websocket");
        // Configure socket transports must be specified
        Socket socket = io(
          endpoint.origin,
          OptionBuilder()
              .setPath("${endpoint.path}/socket.io")
              .setTransports(['websocket'])
              .enableReconnection()
              .enableForceNew()
              .enableForceNewConnection()
              .enableAutoConnect()
              .setExtraHeaders(headers)
              .build(),
        );

        socket.onConnect((_) {
          debugPrint("Established Websocket Connection");
          state = WebsocketState(
            isConnected: true,
            socket: socket,
            pendingChanges: state.pendingChanges,
          );
        });

        socket.onDisconnect((_) {
          debugPrint("Disconnect to Websocket Connection");
          state = WebsocketState(
            isConnected: false,
            socket: null,
            pendingChanges: state.pendingChanges,
          );
        });

        socket.on('error', (errorMessage) {
          _log.severe("Websocket Error - $errorMessage");
          state = WebsocketState(
            isConnected: false,
            socket: null,
            pendingChanges: state.pendingChanges,
          );
        });

        socket.on('on_upload_success', _handleOnUploadSuccess);
        socket.on('on_config_update', _handleOnConfigUpdate);
        socket.on('on_asset_delete', _handleOnAssetDelete);
        socket.on('on_asset_trash', _handleServerUpdates);
        socket.on('on_asset_restore', _handleServerUpdates);
        socket.on('on_asset_update', _handleServerUpdates);
        socket.on('on_asset_stack_update', _handleServerUpdates);
        socket.on('on_asset_hidden', _handleOnAssetHidden);
        socket.on('on_new_release', _handleReleaseUpdates);
      } catch (e) {
        debugPrint("[WEBSOCKET] Catch Websocket Error - ${e.toString()}");
      }
    }
  }

  void disconnect() {
    debugPrint("Attempting to disconnect from websocket");

    var socket = state.socket?.disconnect();

    if (socket?.disconnected == true) {
      state = WebsocketState(
        isConnected: false,
        socket: null,
        pendingChanges: state.pendingChanges,
      );
    }
  }

  void stopListenToEvent(String eventName) {
    debugPrint("Stop listening to event $eventName");
    state.socket?.off(eventName);
  }

  void listenUploadEvent() {
    debugPrint("Start listening to event on_upload_success");
    state.socket?.on('on_upload_success', _handleOnUploadSuccess);
  }

  void addPendingChange(PendingAction action, dynamic value) {
    final now = DateTime.now();
    state = state.copyWith(
      pendingChanges: [
        ...state.pendingChanges,
        PendingChange(now.millisecondsSinceEpoch.toString(), action, value),
      ],
    );
    _debounce.run(handlePendingChanges);
  }

  Future<void> _handlePendingDeletes() async {
    final deleteChanges = state.pendingChanges
        .where((c) => c.action == PendingAction.assetDelete)
        .toList();
    if (deleteChanges.isNotEmpty) {
      List<String> remoteIds =
          deleteChanges.map((a) => a.value.toString()).toList();
      await _ref.read(syncServiceProvider).handleRemoteAssetRemoval(remoteIds);
      state = state.copyWith(
        pendingChanges: state.pendingChanges
            .whereNot((c) => deleteChanges.contains(c))
            .toList(),
      );
    }
  }

  Future<void> _handlePendingUploaded() async {
    final uploadedChanges = state.pendingChanges
        .where((c) => c.action == PendingAction.assetUploaded)
        .toList();
    if (uploadedChanges.isNotEmpty) {
      List<AssetResponseDto?> remoteAssets = uploadedChanges
          .map((a) => AssetResponseDto.fromJson(a.value))
          .toList();
      for (final dto in remoteAssets) {
        if (dto != null) {
          final newAsset = Asset.remote(dto);
          await _ref.watch(assetProvider.notifier).onNewAssetUploaded(newAsset);
        }
      }
      state = state.copyWith(
        pendingChanges: state.pendingChanges
            .whereNot((c) => uploadedChanges.contains(c))
            .toList(),
      );
    }
  }

  Future<void> _handlingPendingHidden() async {
    final hiddenChanges = state.pendingChanges
        .where((c) => c.action == PendingAction.assetHidden)
        .toList();
    if (hiddenChanges.isNotEmpty) {
      List<String> remoteIds =
          hiddenChanges.map((a) => a.value.toString()).toList();
      final db = _ref.watch(dbProvider);
      await db.writeTxn(() => db.assets.deleteAllByRemoteId(remoteIds));

      state = state.copyWith(
        pendingChanges: state.pendingChanges
            .whereNot((c) => hiddenChanges.contains(c))
            .toList(),
      );
    }
  }

  void handlePendingChanges() async {
    await _handlePendingUploaded();
    await _handlePendingDeletes();
    await _handlingPendingHidden();
  }

  void _handleOnConfigUpdate(dynamic _) {
    _ref.read(serverInfoProvider.notifier).getServerFeatures();
    _ref.read(serverInfoProvider.notifier).getServerConfig();
  }

  // Refresh updated assets
  void _handleServerUpdates(dynamic _) {
    _ref.read(assetProvider.notifier).getAllAsset();
  }

  void _handleOnUploadSuccess(dynamic data) =>
      addPendingChange(PendingAction.assetUploaded, data);

  void _handleOnAssetDelete(dynamic data) =>
      addPendingChange(PendingAction.assetDelete, data);

  void _handleOnAssetHidden(dynamic data) =>
      addPendingChange(PendingAction.assetHidden, data);

  _handleReleaseUpdates(dynamic data) {
    // Json guard
    if (data is! Map) {
      return;
    }

    final json = data.cast<String, dynamic>();
    final serverVersionJson =
        json.containsKey('serverVersion') ? json['serverVersion'] : null;
    final releaseVersionJson =
        json.containsKey('releaseVersion') ? json['releaseVersion'] : null;
    if (serverVersionJson == null || releaseVersionJson == null) {
      return;
    }

    final serverVersionDto =
        ServerVersionResponseDto.fromJson(serverVersionJson);
    final releaseVersionDto =
        ServerVersionResponseDto.fromJson(releaseVersionJson);
    if (serverVersionDto == null || releaseVersionDto == null) {
      return;
    }

    final serverVersion = ServerVersion.fromDto(serverVersionDto);
    final releaseVersion = ServerVersion.fromDto(releaseVersionDto);
    _ref
        .read(serverInfoProvider.notifier)
        .handleNewRelease(serverVersion, releaseVersion);
  }
}

final websocketProvider =
    StateNotifierProvider<WebsocketNotifier, WebsocketState>((ref) {
  return WebsocketNotifier(ref);
});