refactor: organize backend by business responsibility

src/modules/banking/bank-cards/application/get-bank-summary.use-case.ts

@@ -0,0 +1,40 @@
+import { Injectable } from '@nestjs/common';
+import { BankSummaryQueryDto } from '../presentation/bank-card.dto';
+import { bankSummary } from '../domain/bank-card.calculations';
+import { rubMoney } from '../domain/rub-money';
+
+import { periodBounds } from './bank-card-input';
+import { BankCardsRepository } from '../infrastructure/bank-cards.repository';
+@Injectable()
+export class GetBankSummaryUseCase {
+  constructor(private readonly repository: BankCardsRepository) {}
+
+  async execute(userId: string, query: BankSummaryQueryDto) {
+    const period = periodBounds(query);
+    const { operations, categories } = await this.repository.summaryData(
+      userId,
+      period,
+      query.cardId,
+    );
+    const totals = bankSummary(period, operations);
+    return {
+      month: query.month,
+      ...period,
+      cardId: query.cardId ?? null,
+      expenses: rubMoney(totals.expenses),
+      refunds: rubMoney(totals.refunds),
+      net: rubMoney(totals.net),
+      categories: totals.categories.map((row) => {
+        const category = categories.find((c) => c.id === row.categoryId);
+        if (!category) throw new Error('Bank operation category is missing');
+        return {
+          categoryId: row.categoryId,
+          categoryName: category.name,
+          expenses: rubMoney(row.expenses),
+          refunds: rubMoney(row.refunds),
+          net: rubMoney(row.net),
+        };
+      }),
+    };
+  }
+}