refactor(mobile): services and providers (#9232)

* refactor(mobile): services and provider

* providers

mobile/lib/services/hash.service.dart

@@ -0,0 +1,156 @@
+import 'dart:io';
+
+import 'package:flutter/foundation.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:immich_mobile/services/background.service.dart';
+import 'package:immich_mobile/entities/android_device_asset.entity.dart';
+import 'package:immich_mobile/entities/asset.entity.dart';
+import 'package:immich_mobile/entities/device_asset.entity.dart';
+import 'package:immich_mobile/entities/ios_device_asset.entity.dart';
+import 'package:immich_mobile/providers/db.provider.dart';
+import 'package:immich_mobile/extensions/string_extensions.dart';
+import 'package:isar/isar.dart';
+import 'package:logging/logging.dart';
+import 'package:photo_manager/photo_manager.dart';
+
+class HashService {
+  HashService(this._db, this._backgroundService);
+  final Isar _db;
+  final BackgroundService _backgroundService;
+  final _log = Logger('HashService');
+
+  /// Returns all assets that were successfully hashed
+  Future<List<Asset>> getHashedAssets(
+    AssetPathEntity album, {
+    int start = 0,
+    int end = 0x7fffffffffffffff,
+    Set<String>? excludedAssets,
+  }) async {
+    final entities = await album.getAssetListRange(start: start, end: end);
+    final filtered = excludedAssets == null
+        ? entities
+        : entities.where((e) => !excludedAssets.contains(e.id)).toList();
+    return _hashAssets(filtered);
+  }
+
+  /// Converts a list of [AssetEntity]s to [Asset]s including only those
+  /// that were successfully hashed. Hashes are looked up in a DB table
+  /// [AndroidDeviceAsset] / [IOSDeviceAsset] by local id. Only missing
+  /// entries are newly hashed and added to the DB table.
+  Future<List<Asset>> _hashAssets(List<AssetEntity> assetEntities) async {
+    const int batchFileCount = 128;
+    const int batchDataSize = 1024 * 1024 * 1024; // 1GB
+
+    final ids = assetEntities
+        .map(Platform.isAndroid ? (a) => a.id.toInt() : (a) => a.id)
+        .toList();
+    final List<DeviceAsset?> hashes = await _lookupHashes(ids);
+    final List<DeviceAsset> toAdd = [];
+    final List<String> toHash = [];
+
+    int bytes = 0;
+
+    for (int i = 0; i < assetEntities.length; i++) {
+      if (hashes[i] != null) {
+        continue;
+      }
+      final file = await assetEntities[i].originFile;
+      if (file == null) {
+        final fileName = await assetEntities[i].titleAsync.catchError((error) {
+          _log.warning(
+            "Failed to get title for asset ${assetEntities[i].id}",
+          );
+
+          return "";
+        });
+
+        _log.warning(
+          "Failed to get file for asset ${assetEntities[i].id}, name: $fileName, created on: ${assetEntities[i].createDateTime}, skipping",
+        );
+        continue;
+      }
+      bytes += await file.length();
+      toHash.add(file.path);
+      final deviceAsset = Platform.isAndroid
+          ? AndroidDeviceAsset(id: ids[i] as int, hash: const [])
+          : IOSDeviceAsset(id: ids[i] as String, hash: const []);
+      toAdd.add(deviceAsset);
+      hashes[i] = deviceAsset;
+      if (toHash.length == batchFileCount || bytes >= batchDataSize) {
+        await _processBatch(toHash, toAdd);
+        toAdd.clear();
+        toHash.clear();
+        bytes = 0;
+      }
+    }
+    if (toHash.isNotEmpty) {
+      await _processBatch(toHash, toAdd);
+    }
+    return _mapAllHashedAssets(assetEntities, hashes);
+  }
+
+  /// Lookup hashes of assets by their local ID
+  Future<List<DeviceAsset?>> _lookupHashes(List<Object> ids) =>
+      Platform.isAndroid
+          ? _db.androidDeviceAssets.getAll(ids.cast())
+          : _db.iOSDeviceAssets.getAllById(ids.cast());
+
+  /// Processes a batch of files and saves any successfully hashed
+  /// values to the DB table.
+  Future<void> _processBatch(
+    final List<String> toHash,
+    final List<DeviceAsset> toAdd,
+  ) async {
+    final hashes = await _hashFiles(toHash);
+    bool anyNull = false;
+    for (int j = 0; j < hashes.length; j++) {
+      if (hashes[j]?.length == 20) {
+        toAdd[j].hash = hashes[j]!;
+      } else {
+        _log.warning("Failed to hash file ${toHash[j]}, skipping");
+        anyNull = true;
+      }
+    }
+    final validHashes = anyNull
+        ? toAdd.where((e) => e.hash.length == 20).toList(growable: false)
+        : toAdd;
+    await _db.writeTxn(
+      () => Platform.isAndroid
+          ? _db.androidDeviceAssets.putAll(validHashes.cast())
+          : _db.iOSDeviceAssets.putAll(validHashes.cast()),
+    );
+    _log.fine("Hashed ${validHashes.length}/${toHash.length} assets");
+  }
+
+  /// Hashes the given files and returns a list of the same length
+  /// files that could not be hashed have a `null` value
+  Future<List<Uint8List?>> _hashFiles(List<String> paths) async {
+    final List<Uint8List?>? hashes =
+        await _backgroundService.digestFiles(paths);
+    if (hashes == null) {
+      throw Exception("Hashing ${paths.length} files failed");
+    }
+    return hashes;
+  }
+
+  /// Converts [AssetEntity]s that were successfully hashed to [Asset]s
+  List<Asset> _mapAllHashedAssets(
+    List<AssetEntity> assets,
+    List<DeviceAsset?> hashes,
+  ) {
+    final List<Asset> result = [];
+    for (int i = 0; i < assets.length; i++) {
+      if (hashes[i] != null && hashes[i]!.hash.isNotEmpty) {
+        result.add(Asset.local(assets[i], hashes[i]!.hash));
+      }
+    }
+    return result;
+  }
+}
+
+final hashServiceProvider = Provider(
+  (ref) => HashService(
+    ref.watch(dbProvider),
+    ref.watch(backgroundServiceProvider),
+  ),
+);