feat: add an owner + sell screen

lib/data/repositories/book_instance_repository.dart

@@ -0,0 +1 @@
+class BookInstanceRepository {}

lib/data/repositories/book_repository.dart

@@ -0,0 +1 @@
+class BookRepository {}

lib/data/repositories/owner_repository.dart

@@ -1,8 +1,5 @@
 import 'dart:async';
-import 'dart:convert';
 
-import 'package:flutter/foundation.dart';
-import 'package:rxdart/rxdart.dart';
 import 'package:seshat/data/services/api_client.dart';
 import 'package:seshat/data/services/websocket_client.dart';
 import 'package:seshat/domain/models/owner.dart';
@@ -17,22 +14,25 @@ class OwnerRepository {
 
   final ApiClient _apiClient;
   final WebsocketClient _wsClient;
-  final BehaviorSubject<Owner> _ownersController = BehaviorSubject<Owner>(
-    sync: true,
-  );
   late final StreamSubscription sub;
   List<Owner>? _cachedOwners;
 
-  Future<Result<Owner>> postOwner(
+  /// Adds an [Owner] to the database, and gets the resulting [Owner].
+  Future<Result<Owner>> addOwner(
     String firstName,
     String lastName,
     String contact,
   ) async {
-    return Result.ok(
-      Owner(firstName: firstName, lastName: lastName, contact: contact, id: 50),
-    );
+    var response = await _apiClient.addOwner(firstName, lastName, contact);
+    switch (response) {
+      case Ok():
+        return Result.ok(response.value);
+      case Error():
+        return Result.error(response.error);
+    }
   }
 
+  /// Fetches all the [Owner]s from the database, and subscribes to updates
   Future<Result<List<Owner>>> getOwners() async {
     if (_cachedOwners == null) {
       final result = await _apiClient.getOwners();
@@ -43,9 +43,7 @@ class OwnerRepository {
       }
 
       sub = _wsClient.owners.listen((owner) {
-        debugPrint("\n\n\n\n[3] Added : $owner\n\n\n\n");
         _cachedOwners!.add(owner);
-        _ownersController.add(owner);
       });
 
       return result;
@@ -54,8 +52,6 @@ class OwnerRepository {
     }
   }
 
-  Stream<Owner> get liveOwners => _ownersController.stream;
-
   dispose() {
     sub.cancel();
   }