feat: managing returns

lib/ui/bal_page/view_model/bal_view_model.dart

@@ -1,19 +1,37 @@
 import 'package:flutter/widgets.dart';
 import 'package:seshat/data/repositories/bal_repository.dart';
+import 'package:seshat/data/repositories/owner_repository.dart';
 import 'package:seshat/domain/models/bal.dart';
+import 'package:seshat/domain/models/bal_stats.dart';
+import 'package:seshat/domain/models/book.dart';
+import 'package:seshat/domain/models/book_instance.dart';
+import 'package:seshat/domain/models/enums.dart';
+import 'package:seshat/domain/models/return_owner.dart';
+import 'package:seshat/domain/models/search_result.dart';
 import 'package:seshat/utils/command.dart';
 import 'package:seshat/utils/result.dart';
 
 class BalViewModel extends ChangeNotifier {
-  BalViewModel({required BalRepository balRepository, required this.id})
-    : _balRepository = balRepository {
+  BalViewModel({
+    required BalRepository balRepository,
+    required this.id,
+    required OwnerRepository ownerRepository,
+  }) : _balRepository = balRepository,
+       _ownerRepository = ownerRepository {
     load = Command0(_load)..execute();
   }
 
   final BalRepository _balRepository;
+  final OwnerRepository _ownerRepository;
+
+  /*
+ * =====================
+ * =====< General >=====
+ * =====================
+*/
 
   Bal? _bal;
-  int? id;
+  int id;
   Bal? get bal => _bal;
   bool isABalOngoing = false;
 
@@ -64,9 +82,55 @@ class BalViewModel extends ChangeNotifier {
     return result;
   }
 
+  /*
+ * ============================
+ * =====< State Specific >=====
+ * ============================
+*/
+
+  // Specific to ended state
+  List<ReturnOwner>? owedToOwners;
+  double? totalOwed;
+  BalStats? stats;
+
+  Future<void> applyAccountingOwners(
+    List<ReturnOwner> owners,
+    Map<String, Book> books,
+  ) async {
+    owedToOwners = owners;
+    for (ReturnOwner owedToOwner in owedToOwners!) {
+      var res = await _ownerRepository.getOwnerById(owedToOwner.ownerId);
+      switch (res) {
+        case Ok():
+          owedToOwner.owner = res.value;
+          break;
+        default:
+      }
+      owedToOwner.owed = [];
+      for (BookInstance instance in owedToOwner.owedInstances) {
+        final bookId = instance.bookId;
+        owedToOwner.owed.add(SearchResult(instance, books[bookId.toString()]!));
+      }
+    }
+  }
+
+  Future<Result<void>> returnById(ReturnType type, int ownerId) async {
+    final result = await _balRepository.returnToId(id, ownerId, type);
+    final result2 = await _balRepository.getAccounting(id);
+    switch (result2) {
+      case Ok():
+        applyAccountingOwners(result2.value.owners, result2.value.books);
+        break;
+      case Error():
+        debugPrint(result2.error.toString());
+    }
+    notifyListeners();
+    return result;
+  }
+
   /*
  * =================================
- * =====[ COMMAND AND LOADING ]=====
+ * =====< COMMAND AND LOADING >=====
  * =================================
 */
 
@@ -78,20 +142,32 @@ class BalViewModel extends ChangeNotifier {
     final result1 = await _loadBal();
     switch (result1) {
       case Ok():
-        isLoaded = true;
+        isLoaded = (_bal == null || _bal?.state != BalState.ended)
+            ? true
+            : false;
         break;
       default:
         break;
     }
+    debugPrint("$isLoaded");
+    if (_bal?.state == BalState.ended) {
+      final result2 = await _loadEnded();
+      debugPrint("Hello");
+      switch (result2) {
+        case Ok():
+          isLoaded = true;
+          break;
+        case Error():
+          debugPrint("No ${result2.error}");
+          break;
+      }
+    }
     notifyListeners();
     return result1;
   }
 
   Future<Result<void>> _loadBal() async {
-    if (id == null) {
-      return Result.error(Exception("No id given"));
-    }
-    final result = await _balRepository.balById(id!);
+    final result = await _balRepository.balById(id);
     switch (result) {
       case Ok():
         _bal = result.value;
@@ -102,4 +178,22 @@ class BalViewModel extends ChangeNotifier {
 
     return result;
   }
+
+  Future<Result<void>> _loadEnded() async {
+    final result = await _balRepository.getAccountingNoCache(id);
+    switch (result) {
+      case Ok():
+        applyAccountingOwners(result.value.owners, result.value.books);
+        break;
+      default:
+    }
+    final result2 = await _balRepository.getBalStats(id);
+    switch (result2) {
+      case Ok():
+        stats = result2.value;
+        break;
+      default:
+    }
+    return result;
+  }
 }