Add support for custom user labels (thunder-app#1434)

* Add support for user labels

* Reformat auto-gen db file

* Fix tests

* Move dialog tertiary action to left

* Add comments to UserLabel model parameters

* Add comment to UserLabel class

* Add downgrade strategy

lib/account/models/user_label.dart

@@ -0,0 +1,94 @@
+import 'package:drift/drift.dart';
+import 'package:flutter/foundation.dart';
+
+import 'package:thunder/core/database/database.dart';
+import 'package:thunder/main.dart';
+import 'package:thunder/utils/instance.dart';
+
+/// Represents a UserLabel, which is used to associate a textual description along with a Lemmy user.
+/// Contains helper methods to load/save corresponding objects in the database.
+class UserLabel {
+  /// The ID of the object in the database (should never need to be set explicitly).
+  final String id;
+
+  /// The username of the user being labeled (in the form [email protected]).
+  /// Use [usernameFromParts] to consistently generate this.
+  final String username;
+
+  /// The label which is being applied to the user.
+  final String label;
+
+  const UserLabel({
+    required this.id,
+    required this.username,
+    required this.label,
+  });
+
+  UserLabel copyWith({String? id}) => UserLabel(
+        id: id ?? this.id,
+        username: username,
+        label: label,
+      );
+
+  static Future<UserLabel?> upsertUserLabel(UserLabel userLabel) async {
+    try {
+      // Check if the userLabel with the given username already exists
+      final existingUserLabel = await (database.select(database.userLabels)..where((t) => t.username.equals(userLabel.username))).getSingleOrNull();
+
+      if (existingUserLabel == null) {
+        // Insert new userLabel if it doesn't exist
+        int id = await database.into(database.userLabels).insert(
+              UserLabelsCompanion.insert(
+                username: userLabel.username,
+                label: userLabel.label,
+              ),
+            );
+        return userLabel.copyWith(id: id.toString());
+      } else {
+        // Update existing userLabel if it exists
+        await database.update(database.userLabels).replace(
+              UserLabelsCompanion(
+                id: Value(existingUserLabel.id),
+                username: Value(userLabel.username),
+                label: Value(userLabel.label),
+              ),
+            );
+        return userLabel.copyWith(id: existingUserLabel.id.toString());
+      }
+    } catch (e) {
+      debugPrint(e.toString());
+      return null;
+    }
+  }
+
+  static Future<UserLabel?> fetchUserLabel(String username) async {
+    if (username.isEmpty) return null;
+
+    try {
+      return await (database.select(database.userLabels)..where((t) => t.username.equals(username))).getSingleOrNull().then((userLabel) {
+        if (userLabel == null) return null;
+        return UserLabel(
+          id: userLabel.id.toString(),
+          username: userLabel.username,
+          label: userLabel.label,
+        );
+      });
+    } catch (e) {
+      debugPrint(e.toString());
+      return null;
+    }
+  }
+
+  static Future<void> deleteUserLabel(String username) async {
+    try {
+      await (database.delete(database.userLabels)..where((t) => t.username.equals(username))).go();
+    } catch (e) {
+      debugPrint(e.toString());
+    }
+  }
+
+  /// Generates a username string that can be used to uniquely identify entries in the UserLabels table
+  static String usernameFromParts(String username, String actorId) {
+    return '$username@${fetchInstanceNameFromUrl(actorId)}';
+  }
+}

lib/core/database/database.dart

@@ -13,12 +13,29 @@ import 'package:thunder/core/database/tables.dart';
 
 part 'database.g.dart';
 
-@DriftDatabase(tables: [Accounts, Favorites, LocalSubscriptions])
+@DriftDatabase(tables: [Accounts, Favorites, LocalSubscriptions, UserLabels])
 class AppDatabase extends _$AppDatabase {
   AppDatabase() : super(_openConnection());
 
   @override
-  int get schemaVersion => 1;
+  int get schemaVersion => 2;
+
+  @override
+  MigrationStrategy get migration => MigrationStrategy(
+        onUpgrade: (migrator, from, to) async {
+          // If we are migrating from 1 to anything higher
+          if (from == 1 && to > 1) {
+            // Create the UserLabels table
+            await migrator.createTable(userLabels);
+          }
+
+          // If we are downgrading from 2 or higher to 1
+          if (from >= 2 && to == 1) {
+            // Delete the UserBales table
+            await migrator.deleteTable('user_labels');
+          }
+        },
+      );
 }
 
 /// Opens a connection to the database.

lib/core/database/tables.dart

@@ -22,3 +22,9 @@ class LocalSubscriptions extends Table {
   TextColumn get actorId => text()();
   TextColumn get icon => text().nullable()();
 }
+
+class UserLabels extends Table {
+  IntColumn get id => integer().autoIncrement()();
+  TextColumn get username => text()();
+  TextColumn get label => text()();
+}

lib/l10n/app_en.arb

@@ -57,6 +57,10 @@
   "@addToFavorites": {
     "description": "Action to add a community in drawer to favorites"
   },
+  "addUserLabel": "Add User Label",
+  "@addUserLabel": {
+    "description": "Action for adding a user label"
+  },
   "addedCommunityToSubscriptions": "Subscribed to community",
   "@addedCommunityToSubscriptions": {},
   "addedInstanceMod": "Added Instance Mod",
@@ -979,6 +983,10 @@
   "@keywordFilters": {
     "description": "Subcategory in Settings -> Filters"
   },
+  "label": "Label",
+  "@label": {
+    "description": "Text field label for a user label"
+  },
   "language": "Language",
   "@language": {
     "description": "Label when creating or editing a post."
@@ -2365,6 +2373,10 @@
   "@userFormat": {
     "description": "Setting for user full name format"
   },
+  "userLabelHint": "This is my favorite user",
+  "@userLabelHint": {
+    "description": "Hint text for adding a new user label"
+  },
   "userNameColor": "User Name Color",
   "@userNameColor": {
     "description": "Setting for username color"