import "dart:async";
import "dart:developer" as dev show log;
import "dart:io" show File, Platform;
import "dart:isolate";
import "dart:math" show min;
import "dart:typed_data" show Uint8List, ByteData;

import "package:dart_ui_isolate/dart_ui_isolate.dart";
import "package:flutter/foundation.dart" show debugPrint, kDebugMode;
import "package:logging/logging.dart";
import "package:package_info_plus/package_info_plus.dart";
import "package:photos/core/error-reporting/super_logging.dart";
import "package:photos/core/event_bus.dart";
import "package:photos/db/files_db.dart";
import "package:photos/events/machine_learning_control_event.dart";
import "package:photos/events/people_changed_event.dart";
import "package:photos/extensions/list.dart";
import "package:photos/face/db.dart";
import "package:photos/face/model/box.dart";
import "package:photos/face/model/detection.dart" as face_detection;
import "package:photos/face/model/dimension.dart";
import "package:photos/face/model/face.dart";
import "package:photos/face/model/landmark.dart";
import "package:photos/service_locator.dart";
import 'package:photos/services/machine_learning/face_ml/face_clustering/face_clustering_service.dart';
import "package:photos/services/machine_learning/face_ml/face_clustering/face_db_info_for_clustering.dart";
import 'package:photos/services/machine_learning/face_ml/face_detection/face_detection_service.dart';
import 'package:photos/services/machine_learning/face_ml/face_embedding/face_embedding_service.dart';
import 'package:photos/services/machine_learning/face_ml/face_filtering/face_filtering_constants.dart';
import "package:photos/services/machine_learning/face_ml/face_recognition_service.dart";
import "package:photos/services/machine_learning/face_ml/person/person_service.dart";
import "package:photos/services/machine_learning/file_ml/file_ml.dart";
import "package:photos/services/machine_learning/file_ml/remote_fileml_service.dart";
import 'package:photos/services/machine_learning/ml_exceptions.dart';
import 'package:photos/services/machine_learning/ml_result.dart';
import "package:photos/services/machine_learning/semantic_search/clip/clip_image_encoder.dart";
import "package:photos/services/machine_learning/semantic_search/semantic_search_service.dart";
import "package:photos/utils/image_ml_util.dart";
import "package:photos/utils/local_settings.dart";
import "package:photos/utils/ml_util.dart";
import "package:photos/utils/network_util.dart";
import "package:synchronized/synchronized.dart";

enum FaceMlOperation { analyzeImage, loadModels }

/// This class is responsible for running the full face ml pipeline on images.
///
/// WARNING: For getting the ML results needed for the UI, you should use `FaceSearchService` instead of this class!
///
/// The pipeline consists of face detection, face alignment and face embedding.
class MLService {
  final _logger = Logger("FaceMlService");

  // Flutter isolate things for running the image ml pipeline
  Timer? _inactivityTimer;
  final Duration _inactivityDuration = const Duration(seconds: 120);
  int _activeTasks = 0;
  late DartUiIsolate _isolate;
  late ReceivePort _receivePort = ReceivePort();
  late SendPort _mainSendPort;

  // Singleton pattern
  MLService._privateConstructor();
  static final instance = MLService._privateConstructor();
  factory MLService() => instance;

  final _initModelLock = Lock();
  final _functionLock = Lock();
  final _initIsolateLock = Lock();

  bool _isInitialized = false;
  bool _isModelsInitialized = false;
  bool _isModelsInitUsingEntePlugin = false;
  bool _isIsolateSpawned = false;

  late String client;

  bool get isInitialized => _isInitialized;

  bool get showClusteringIsHappening => _showClusteringIsHappening;

  bool get allModelsLoaded => _isModelsInitialized;

  bool debugIndexingDisabled = false;
  bool _showClusteringIsHappening = false;
  bool _mlControllerStatus = false;
  bool _isIndexingOrClusteringRunning = false;
  bool _shouldPauseIndexingAndClustering = false;

  static const int _fileDownloadLimit = 10;
  static const _kForceClusteringFaceCount = 8000;

  /// Only call this function once at app startup, after that you can directly call [runAllML]
  Future<void> init() async {
    if (LocalSettings.instance.isFaceIndexingEnabled == false ||
        _isInitialized) {
      return;
    }
    _logger.info("init called");

    // Activate FaceRecognitionService
    await FaceRecognitionService.instance.init();

    // Listen on MachineLearningController
    Bus.instance.on<MachineLearningControlEvent>().listen((event) {
      if (LocalSettings.instance.isFaceIndexingEnabled == false) {
        return;
      }
      _mlControllerStatus = event.shouldRun;
      if (_mlControllerStatus) {
        if (_shouldPauseIndexingAndClustering) {
          _shouldPauseIndexingAndClustering = false;
          _logger.info(
            "MLController allowed running ML, faces indexing undoing previous pause",
          );
        } else {
          _logger.info(
            "MLController allowed running ML, faces indexing starting",
          );
        }
        unawaited(runAllML());
      } else {
        _logger.info(
          "MLController stopped running ML, faces indexing will be paused (unless it's fetching embeddings)",
        );
        pauseIndexingAndClustering();
      }
    });

    _isInitialized = true;
    _logger.info('init done');
  }

  Future<void> sync() async {
    await FaceRecognitionService.instance.sync();
  }

  Future<void> runAllML({bool force = false}) async {
    try {
      if (force) {
        _mlControllerStatus = true;
      }
      if (_cannotRunMLFunction() && !force) return;

      await sync();

      final int unclusteredFacesCount =
          await FaceMLDataDB.instance.getUnclusteredFaceCount();
      if (unclusteredFacesCount > _kForceClusteringFaceCount) {
        _logger.info(
          "There are $unclusteredFacesCount unclustered faces, doing clustering first",
        );
        await clusterAllImages();
      }
      await indexAllImages();
      await clusterAllImages();
    } catch (e, s) {
      _logger.severe("runAllML failed", e, s);
      rethrow;
    }
  }

  void pauseIndexingAndClustering() {
    if (_isIndexingOrClusteringRunning) {
      _shouldPauseIndexingAndClustering = true;
    }
  }

  /// Analyzes all the images in the database with the latest ml version and stores the results in the database.
  ///
  /// This function first checks if the image has already been analyzed with the lastest faceMlVersion and stored in the database. If so, it skips the image.
  Future<void> indexAllImages() async {
    if (_cannotRunMLFunction()) return;

    try {
      _isIndexingOrClusteringRunning = true;
      _logger.info('starting image indexing');

      final filesToIndex = await getFilesForMlIndexing();
      final List<List<FileMLInstruction>> chunks =
          filesToIndex.chunks(_fileDownloadLimit);

      int fileAnalyzedCount = 0;
      final Stopwatch stopwatch = Stopwatch()..start();
      outerLoop:
      for (final chunk in chunks) {
        if (!await canUseHighBandwidth()) {
          _logger.info(
            'stopping indexing because user is not connected to wifi',
          );
          break outerLoop;
        }
        final futures = <Future<bool>>[];
        for (final instruction in chunk) {
          if (_shouldPauseIndexingAndClustering) {
            _logger.info("indexAllImages() was paused, stopping");
            break outerLoop;
          }
          await _ensureReadyForInference();
          futures.add(processImage(instruction));
        }
        final awaitedFutures = await Future.wait(futures);
        final sumFutures = awaitedFutures.fold<int>(
          0,
          (previousValue, element) => previousValue + (element ? 1 : 0),
        );
        fileAnalyzedCount += sumFutures;
      }

      _logger.info(
        "`indexAllImages()` finished. Analyzed $fileAnalyzedCount images, in ${stopwatch.elapsed.inSeconds} seconds (avg of ${stopwatch.elapsed.inSeconds / fileAnalyzedCount} seconds per image)",
      );
      _logStatus();
    } catch (e, s) {
      _logger.severe("indexAllImages failed", e, s);
    } finally {
      _isIndexingOrClusteringRunning = false;
      _shouldPauseIndexingAndClustering = false;
    }
  }

  Future<void> clusterAllImages({
    double minFaceScore = kMinimumQualityFaceScore,
    bool clusterInBuckets = true,
  }) async {
    if (_cannotRunMLFunction()) return;

    _logger.info("`clusterAllImages()` called");
    _isIndexingOrClusteringRunning = true;
    final clusterAllImagesTime = DateTime.now();

    _logger.info('Pulling remote feedback before actually clustering');
    await PersonService.instance.fetchRemoteClusterFeedback();

    try {
      _showClusteringIsHappening = true;

      // Get a sense of the total number of faces in the database
      final int totalFaces = await FaceMLDataDB.instance
          .getTotalFaceCount(minFaceScore: minFaceScore);
      final fileIDToCreationTime =
          await FilesDB.instance.getFileIDToCreationTime();
      final startEmbeddingFetch = DateTime.now();
      // read all embeddings
      final result = await FaceMLDataDB.instance.getFaceInfoForClustering(
        minScore: minFaceScore,
        maxFaces: totalFaces,
      );
      final Set<int> missingFileIDs = {};
      final allFaceInfoForClustering = <FaceDbInfoForClustering>[];
      for (final faceInfo in result) {
        if (!fileIDToCreationTime.containsKey(faceInfo.fileID)) {
          missingFileIDs.add(faceInfo.fileID);
        } else {
          allFaceInfoForClustering.add(faceInfo);
        }
      }
      // sort the embeddings based on file creation time, newest first
      allFaceInfoForClustering.sort((b, a) {
        return fileIDToCreationTime[a.fileID]!
            .compareTo(fileIDToCreationTime[b.fileID]!);
      });
      _logger.info(
        'Getting and sorting embeddings took ${DateTime.now().difference(startEmbeddingFetch).inMilliseconds} ms for ${allFaceInfoForClustering.length} embeddings'
        'and ${missingFileIDs.length} missing fileIDs',
      );

      // Get the current cluster statistics
      final Map<int, (Uint8List, int)> oldClusterSummaries =
          await FaceMLDataDB.instance.getAllClusterSummary();

      if (clusterInBuckets) {
        const int bucketSize = 10000;
        const int offsetIncrement = 7500;
        int offset = 0;
        int bucket = 1;

        while (true) {
          if (_shouldPauseIndexingAndClustering) {
            _logger.info(
              "MLController does not allow running ML, stopping before clustering bucket $bucket",
            );
            break;
          }
          if (offset > allFaceInfoForClustering.length - 1) {
            _logger.warning(
              'faceIdToEmbeddingBucket is empty, this should ideally not happen as it should have stopped earlier. offset: $offset, totalFaces: $totalFaces',
            );
            break;
          }
          if (offset > totalFaces) {
            _logger.warning(
              'offset > totalFaces, this should ideally not happen. offset: $offset, totalFaces: $totalFaces',
            );
            break;
          }

          final bucketStartTime = DateTime.now();
          final faceInfoForClustering = allFaceInfoForClustering.sublist(
            offset,
            min(offset + bucketSize, allFaceInfoForClustering.length),
          );

          if (faceInfoForClustering.every((face) => face.clusterId != null)) {
            _logger.info('Everything in bucket $bucket is already clustered');
            if (offset + bucketSize >= totalFaces) {
              _logger.info('All faces clustered');
              break;
            } else {
              _logger.info('Skipping to next bucket');
              offset += offsetIncrement;
              bucket++;
              continue;
            }
          }

          final clusteringResult =
              await FaceClusteringService.instance.predictLinearIsolate(
            faceInfoForClustering.toSet(),
            fileIDToCreationTime: fileIDToCreationTime,
            offset: offset,
            oldClusterSummaries: oldClusterSummaries,
          );
          if (clusteringResult == null) {
            _logger.warning("faceIdToCluster is null");
            return;
          }

          await FaceMLDataDB.instance
              .updateFaceIdToClusterId(clusteringResult.newFaceIdToCluster);
          await FaceMLDataDB.instance
              .clusterSummaryUpdate(clusteringResult.newClusterSummaries);
          Bus.instance.fire(PeopleChangedEvent());
          for (final faceInfo in faceInfoForClustering) {
            faceInfo.clusterId ??=
                clusteringResult.newFaceIdToCluster[faceInfo.faceID];
          }
          for (final clusterUpdate
              in clusteringResult.newClusterSummaries.entries) {
            oldClusterSummaries[clusterUpdate.key] = clusterUpdate.value;
          }
          _logger.info(
            'Done with clustering ${offset + faceInfoForClustering.length} embeddings (${(100 * (offset + faceInfoForClustering.length) / totalFaces).toStringAsFixed(0)}%) in bucket $bucket, offset: $offset, in ${DateTime.now().difference(bucketStartTime).inSeconds} seconds',
          );
          if (offset + bucketSize >= totalFaces) {
            _logger.info('All faces clustered');
            break;
          }
          offset += offsetIncrement;
          bucket++;
        }
      } else {
        final clusterStartTime = DateTime.now();
        // Cluster the embeddings using the linear clustering algorithm, returning a map from faceID to clusterID
        final clusteringResult =
            await FaceClusteringService.instance.predictLinearIsolate(
          allFaceInfoForClustering.toSet(),
          fileIDToCreationTime: fileIDToCreationTime,
          oldClusterSummaries: oldClusterSummaries,
        );
        if (clusteringResult == null) {
          _logger.warning("faceIdToCluster is null");
          return;
        }
        final clusterDoneTime = DateTime.now();
        _logger.info(
          'done with clustering ${allFaceInfoForClustering.length} in ${clusterDoneTime.difference(clusterStartTime).inSeconds} seconds ',
        );

        // Store the updated clusterIDs in the database
        _logger.info(
          'Updating ${clusteringResult.newFaceIdToCluster.length} FaceIDs with clusterIDs in the DB',
        );
        await FaceMLDataDB.instance
            .updateFaceIdToClusterId(clusteringResult.newFaceIdToCluster);
        await FaceMLDataDB.instance
            .clusterSummaryUpdate(clusteringResult.newClusterSummaries);
        Bus.instance.fire(PeopleChangedEvent());
        _logger.info('Done updating FaceIDs with clusterIDs in the DB, in '
            '${DateTime.now().difference(clusterDoneTime).inSeconds} seconds');
      }
      _logger.info('clusterAllImages() finished, in '
          '${DateTime.now().difference(clusterAllImagesTime).inSeconds} seconds');
    } catch (e, s) {
      _logger.severe("`clusterAllImages` failed", e, s);
    } finally {
      _showClusteringIsHappening = false;
      _isIndexingOrClusteringRunning = false;
      _shouldPauseIndexingAndClustering = false;
    }
  }

  Future<bool> processImage(FileMLInstruction instruction) async {
    // TODO: clean this function up
    _logger.info(
      "`processImage` start processing image with uploadedFileID: ${instruction.file.uploadedFileID}",
    );
    bool actuallyRanML = false;

    try {
      final MLResult? result = await _analyzeImageInSingleIsolate(
        instruction,
      );
      if (result == null) {
        if (!_shouldPauseIndexingAndClustering) {
          _logger.severe(
            "Failed to analyze image with uploadedFileID: ${instruction.file.uploadedFileID}",
          );
        }
        return actuallyRanML;
      }
      if (result.facesRan) {
        actuallyRanML = true;
        final List<Face> faces = [];
        if (result.foundNoFaces) {
          debugPrint(
            'No faces detected for file with name:${instruction.file.displayName}',
          );
          faces.add(
            Face.empty(result.fileId, error: result.errorOccured),
          );
        }
        if (result.foundFaces) {
          if (result.decodedImageSize.width == -1 ||
              result.decodedImageSize.height == -1) {
            _logger.severe(
                "decodedImageSize is not stored correctly for image with "
                "ID: ${instruction.file.uploadedFileID}");
            _logger.info(
              "Using aligned image size for image with ID: ${instruction.file.uploadedFileID}. This size is ${result.decodedImageSize.width}x${result.decodedImageSize.height} compared to size of ${instruction.file.width}x${instruction.file.height} in the metadata",
            );
          }
          for (int i = 0; i < result.faces!.length; ++i) {
            final FaceResult faceRes = result.faces![i];
            final detection = face_detection.Detection(
              box: FaceBox(
                x: faceRes.detection.xMinBox,
                y: faceRes.detection.yMinBox,
                width: faceRes.detection.width,
                height: faceRes.detection.height,
              ),
              landmarks: faceRes.detection.allKeypoints
                  .map(
                    (keypoint) => Landmark(
                      x: keypoint[0],
                      y: keypoint[1],
                    ),
                  )
                  .toList(),
            );
            faces.add(
              Face(
                faceRes.faceId,
                result.fileId,
                faceRes.embedding,
                faceRes.detection.score,
                detection,
                faceRes.blurValue,
                fileInfo: FileInfo(
                  imageHeight: result.decodedImageSize.height,
                  imageWidth: result.decodedImageSize.width,
                ),
              ),
            );
          }
        }
        _logger.info("inserting ${faces.length} faces for ${result.fileId}");
        if (!result.errorOccured) {
          await RemoteFileMLService.instance.putFileEmbedding(
            instruction.file,
            instruction.existingRemoteFileML ??
                RemoteFileML.empty(
                  instruction.file.uploadedFileID!,
                ),
            faceEmbedding: result.facesRan
                ? RemoteFaceEmbedding(
                    faces,
                    result.mlVersion,
                    client: client,
                    height: result.decodedImageSize.height,
                    width: result.decodedImageSize.width,
                  )
                : null,
            clipEmbedding: result.clipRan
                ? RemoteClipEmbedding(
                    result.clip!.embedding,
                    version: result.mlVersion,
                    client: client,
                  )
                : null,
          );
        } else {
          _logger.warning(
            'Skipped putting embedding because of error ${result.toJsonString()}',
          );
        }
        await FaceMLDataDB.instance.bulkInsertFaces(faces);
      }

      if (result.clipRan) {
        actuallyRanML = true;
        await SemanticSearchService.storeClipImageResult(
          result.clip!,
          instruction.file,
        );
      }
    } on ThumbnailRetrievalException catch (e, s) {
      _logger.severe(
        'ThumbnailRetrievalException while processing image with ID ${instruction.file.uploadedFileID}, storing empty face so indexing does not get stuck',
        e,
        s,
      );
      await FaceMLDataDB.instance.bulkInsertFaces(
        [Face.empty(instruction.file.uploadedFileID!, error: true)],
      );
      await SemanticSearchService.storeEmptyClipImageResult(
        instruction.file,
      );
      return true;
    } catch (e, s) {
      _logger.severe(
        "Failed to analyze using FaceML for image with ID: ${instruction.file.uploadedFileID}. Not storing any faces, which means it will be automatically retried later.",
        e,
        s,
      );
      return false;
    }
    return actuallyRanML;
  }

  Future<void> _initModelsUsingFfiBasedPlugin() async {
    return _initModelLock.synchronized(() async {
      if (_isModelsInitialized) return;
      _logger.info('initModels called');

      // Get client name
      final packageInfo = await PackageInfo.fromPlatform();
      client = "${packageInfo.packageName}/${packageInfo.version}";
      _logger.info("client: $client");

      // Initialize models
      try {
        await FaceDetectionService.instance.loadModel();
      } catch (e, s) {
        _logger.severe("Could not initialize yolo onnx", e, s);
      }
      try {
        await FaceEmbeddingService.instance.loadModel();
      } catch (e, s) {
        _logger.severe("Could not initialize mobilefacenet", e, s);
      }
      try {
        await ClipImageEncoder.instance.loadModel();
      } catch (e, s) {
        _logger.severe("Could not initialize clip image", e, s);
      }
      _isModelsInitialized = true;
      _logger.info('initModels done');
      _logStatus();
    });
  }

  Future<void> _initModelUsingEntePlugin() async {
    return _initModelLock.synchronized(() async {
      if (_isModelsInitUsingEntePlugin) return;
      _logger.info('initModelUsingEntePlugin called');

      // Get client name
      final packageInfo = await PackageInfo.fromPlatform();
      client = "${packageInfo.packageName}/${packageInfo.version}";
      _logger.info("client: $client");

      // Initialize models
      try {
        await _runInIsolate(
          (FaceMlOperation.loadModels, {}),
        );
        _isModelsInitUsingEntePlugin = true;
      } catch (e, s) {
        _logger.severe("Could not initialize clip image", e, s);
      }
      _logger.info('initModelUsingEntePlugin done');
      _logStatus();
    });
  }

  Future<void> _releaseModels() async {
    return _initModelLock.synchronized(() async {
      _logger.info("dispose called");
      if (!_isModelsInitialized) {
        return;
      }
      try {
        await FaceDetectionService.instance.release();
      } catch (e, s) {
        _logger.severe("Could not dispose yolo onnx", e, s);
      }
      try {
        await FaceEmbeddingService.instance.release();
      } catch (e, s) {
        _logger.severe("Could not dispose mobilefacenet", e, s);
      }
      try {
        await ClipImageEncoder.instance.release();
      } catch (e, s) {
        _logger.severe("Could not dispose clip image", e, s);
      }
      _isModelsInitialized = false;
    });
  }

  Future<void> _initIsolate() async {
    return _initIsolateLock.synchronized(() async {
      if (_isIsolateSpawned) return;
      _logger.info("initIsolate called");

      _receivePort = ReceivePort();

      try {
        _isolate = await DartUiIsolate.spawn(
          _isolateMain,
          _receivePort.sendPort,
        );
        _mainSendPort = await _receivePort.first as SendPort;
        _isIsolateSpawned = true;

        _resetInactivityTimer();
        _logger.info('initIsolate done');
      } catch (e) {
        _logger.severe('Could not spawn isolate', e);
        _isIsolateSpawned = false;
      }
    });
  }

  Future<void> _ensureReadyForInference() async {
    await _initIsolate();
    await _initModelsUsingFfiBasedPlugin();
    if (Platform.isAndroid) {
      await _initModelUsingEntePlugin();
    } else {
      await _initModelsUsingFfiBasedPlugin();
    }
  }

  /// The main execution function of the isolate.
  @pragma('vm:entry-point')
  static void _isolateMain(SendPort mainSendPort) async {
    Logger.root.level = kDebugMode ? Level.ALL : Level.INFO;
    Logger.root.onRecord.listen((LogRecord rec) {
      debugPrint('[MLIsolate] ${rec.toPrettyString()}');
    });
    final receivePort = ReceivePort();
    mainSendPort.send(receivePort.sendPort);
    receivePort.listen((message) async {
      final functionIndex = message[0] as int;
      final function = FaceMlOperation.values[functionIndex];
      final args = message[1] as Map<String, dynamic>;
      final sendPort = message[2] as SendPort;

      try {
        switch (function) {
          case FaceMlOperation.analyzeImage:
            final time = DateTime.now();
            final MLResult result = await MLService._analyzeImageSync(args);
            dev.log(
              "`analyzeImageSync` function executed in ${DateTime.now().difference(time).inMilliseconds} ms",
            );
            sendPort.send(result.toJsonString());
            break;
          case FaceMlOperation.loadModels:
            await FaceDetectionService.instance.loadModel(useEntePlugin: true);
            await FaceEmbeddingService.instance.loadModel(useEntePlugin: true);
            await ClipImageEncoder.instance.loadModel(useEntePlugin: true);
            sendPort.send(true);
            break;
        }
      } catch (e, stackTrace) {
        dev.log(
          "[SEVERE] Error in FaceML isolate: $e",
          error: e,
          stackTrace: stackTrace,
        );
        sendPort
            .send({'error': e.toString(), 'stackTrace': stackTrace.toString()});
      }
    });
  }

  /// The common method to run any operation in the isolate. It sends the [message] to [_isolateMain] and waits for the result.
  Future<dynamic> _runInIsolate(
    (FaceMlOperation, Map<String, dynamic>) message,
  ) async {
    await _initIsolate();
    return _functionLock.synchronized(() async {
      _resetInactivityTimer();

      if (_shouldPauseIndexingAndClustering) {
        return null;
      }

      final completer = Completer<dynamic>();
      final answerPort = ReceivePort();

      _activeTasks++;
      _mainSendPort.send([message.$1.index, message.$2, answerPort.sendPort]);

      answerPort.listen((receivedMessage) {
        if (receivedMessage is Map && receivedMessage.containsKey('error')) {
          // Handle the error
          final errorMessage = receivedMessage['error'];
          final errorStackTrace = receivedMessage['stackTrace'];
          final exception = Exception(errorMessage);
          final stackTrace = StackTrace.fromString(errorStackTrace);
          completer.completeError(exception, stackTrace);
        } else {
          completer.complete(receivedMessage);
        }
      });
      _activeTasks--;

      return completer.future;
    });
  }

  /// Resets a timer that kills the isolate after a certain amount of inactivity.
  ///
  /// Should be called after initialization (e.g. inside `init()`) and after every call to isolate (e.g. inside `_runInIsolate()`)
  void _resetInactivityTimer() {
    _inactivityTimer?.cancel();
    _inactivityTimer = Timer(_inactivityDuration, () {
      if (_activeTasks > 0) {
        _logger.info('Tasks are still running. Delaying isolate disposal.');
        // Optionally, reschedule the timer to check again later.
        _resetInactivityTimer();
      } else {
        _logger.info(
          'Clustering Isolate has been inactive for ${_inactivityDuration.inSeconds} seconds with no tasks running. Killing isolate.',
        );
        _dispose();
      }
    });
  }

  void _dispose() async {
    if (!_isIsolateSpawned) return;
    _logger.info('Disposing isolate and models');
    await _releaseModels();
    _isIsolateSpawned = false;
    _isolate.kill();
    _receivePort.close();
    _inactivityTimer?.cancel();
  }

  /// Analyzes the given image data by running the full pipeline for faces, using [_analyzeImageSync] in the isolate.
  Future<MLResult?> _analyzeImageInSingleIsolate(
    FileMLInstruction instruction,
  ) async {
    final String filePath = await getImagePathForML(instruction.file);

    final Stopwatch stopwatch = Stopwatch()..start();
    late MLResult result;

    try {
      final resultJsonString = await _runInIsolate(
        (
          FaceMlOperation.analyzeImage,
          {
            "enteFileID": instruction.file.uploadedFileID ?? -1,
            "filePath": filePath,
            "runFaces": instruction.shouldRunFaces,
            "runClip": instruction.shouldRunClip,
            "faceDetectionAddress":
                FaceDetectionService.instance.sessionAddress,
            "faceEmbeddingAddress":
                FaceEmbeddingService.instance.sessionAddress,
            "clipImageAddress": ClipImageEncoder.instance.sessionAddress,
          }
        ),
      ) as String?;
      if (resultJsonString == null) {
        if (!_shouldPauseIndexingAndClustering) {
          _logger.severe('Analyzing image in isolate is giving back null');
        }
        return null;
      }
      result = MLResult.fromJsonString(resultJsonString);
    } catch (e, s) {
      _logger.severe(
        "Could not analyze image with ID ${instruction.file.uploadedFileID} \n",
        e,
        s,
      );
      debugPrint(
        "This image with ID ${instruction.file.uploadedFileID} has name ${instruction.file.displayName}.",
      );
      final resultBuilder =
          MLResult.fromEnteFileID(instruction.file.uploadedFileID!)
            ..errorOccurred();
      return resultBuilder;
    }
    stopwatch.stop();
    _logger.info(
      "Finished Analyze image with uploadedFileID ${instruction.file.uploadedFileID}, in "
      "${stopwatch.elapsedMilliseconds} ms (including time waiting for inference engine availability)",
    );

    return result;
  }

  static Future<MLResult> _analyzeImageSync(Map args) async {
    try {
      final int enteFileID = args["enteFileID"] as int;
      final String imagePath = args["filePath"] as String;
      final bool runFaces = args["runFaces"] as bool;
      final bool runClip = args["runClip"] as bool;
      final int faceDetectionAddress = args["faceDetectionAddress"] as int;
      final int faceEmbeddingAddress = args["faceEmbeddingAddress"] as int;
      final int clipImageAddress = args["clipImageAddress"] as int;

      dev.log(
        "Start analyzing image with uploadedFileID: $enteFileID inside the isolate",
      );
      final time = DateTime.now();

      // Decode the image once to use for both face detection and alignment
      final imageData = await File(imagePath).readAsBytes();
      final image = await decodeImageFromData(imageData);
      final ByteData imageByteData = await getByteDataFromImage(image);
      dev.log('Reading and decoding image took '
          '${DateTime.now().difference(time).inMilliseconds} ms');
      final decodedImageSize =
          Dimensions(height: image.height, width: image.width);
      final result = MLResult.fromEnteFileID(enteFileID);
      result.decodedImageSize = decodedImageSize;

      if (runFaces) {
        final resultFaces = await FaceRecognitionService.runFacesPipeline(
          enteFileID,
          image,
          imageByteData,
          faceDetectionAddress,
          faceEmbeddingAddress,
        );
        if (resultFaces.isEmpty) {
          return result..noFaceDetected();
        }
        result.faces = resultFaces;
      }

      if (runClip) {
        final clipResult = await SemanticSearchService.runClipImage(
          enteFileID,
          image,
          imageByteData,
          clipImageAddress,
          useEntePlugin: Platform.isAndroid,
        );
        result.clip = clipResult;
      }

      return result;
    } catch (e, s) {
      dev.log("Could not analyze image: \n e: $e \n s: $s");
      rethrow;
    }
  }

  bool _cannotRunMLFunction({String function = ""}) {
    if (kDebugMode && Platform.isIOS) {
      return false;
    }
    if (_isIndexingOrClusteringRunning) {
      _logger.info(
        "Cannot run $function because indexing or clustering is already running",
      );
      _logStatus();
      return true;
    }
    if (_mlControllerStatus == false) {
      _logger.info(
        "Cannot run $function because MLController does not allow it",
      );
      _logStatus();
      return true;
    }
    if (debugIndexingDisabled) {
      _logger.info(
        "Cannot run $function because debugIndexingDisabled is true",
      );
      _logStatus();
      return true;
    }
    if (_shouldPauseIndexingAndClustering) {
      // This should ideally not be triggered, because one of the above should be triggered instead.
      _logger.warning(
        "Cannot run $function because indexing and clustering is being paused",
      );
      _logStatus();
      return true;
    }
    return false;
  }

  void _logStatus() {
    final String status = '''
    isInternalUser: ${flagService.internalUser}
    isFaceIndexingEnabled: ${LocalSettings.instance.isFaceIndexingEnabled}
    canRunMLController: $_mlControllerStatus
    isIndexingOrClusteringRunning: $_isIndexingOrClusteringRunning
    shouldPauseIndexingAndClustering: $_shouldPauseIndexingAndClustering
    debugIndexingDisabled: $debugIndexingDisabled
    ''';
    _logger.info(status);
  }
}