refactor: organize backend by business responsibility

src/modules/banking/bank-cards/application/bank-card-input.ts

@@ -0,0 +1,109 @@
+import {
+  BadRequestException,
+  ConflictException,
+  NotFoundException,
+} from '@nestjs/common';
+import { createHash } from 'node:crypto';
+import {
+  bankPaymentSystems,
+  BankPeriodQueryDto,
+  CreateBankCardDto,
+  CreateBankOperationDto,
+} from '../presentation/bank-card.dto';
+import { isCalendarDate, moscowToday } from '../domain/bank-card.calculations';
+import { parseRubMoney } from '../domain/rub-money';
+
+export function fail(code = 'BANK_INVALID_INPUT'): never {
+  throw new BadRequestException({ code });
+}
+export function periodBounds(query: BankPeriodQueryDto) {
+  if (query.month && !query.from && !query.to) {
+    const from = `${query.month}-01`;
+    if (!isCalendarDate(from)) return fail();
+    const end = new Date(`${from}T00:00:00Z`);
+    end.setUTCMonth(end.getUTCMonth() + 1, 0);
+    return { from, to: end.toISOString().slice(0, 10) };
+  }
+  if (
+    query.month ||
+    !query.from ||
+    !query.to ||
+    !isCalendarDate(query.from) ||
+    !isCalendarDate(query.to) ||
+    query.from > query.to
+  )
+    return fail();
+  return { from: query.from, to: query.to };
+}
+export function conflict(code = 'BANK_VERSION_CONFLICT'): never {
+  throw new ConflictException({ code });
+}
+export function missing(): never {
+  throw new NotFoundException({ code: 'BANK_NOT_FOUND' });
+}
+export const fingerprint = (value: unknown) =>
+  createHash('sha256')
+    .update(
+      JSON.stringify(value, (_key, item: unknown) =>
+        typeof item === 'bigint' ? item.toString() : item,
+      ),
+    )
+    .digest('hex');
+export function amount(
+  value: Parameters<typeof parseRubMoney>[0],
+  positive = false,
+) {
+  try {
+    return parseRubMoney(value, positive);
+  } catch {
+    return fail('BANK_INVALID_MONEY');
+  }
+}
+export function calendar(value: string) {
+  if (!isCalendarDate(value)) fail('BANK_INVALID_DATE');
+  return value;
+}
+export function currentDate(value: string) {
+  calendar(value);
+  if (value > moscowToday()) fail('BANK_INVALID_DATE');
+}
+export function name(value: string, max: number) {
+  if (typeof value !== 'string' || !value.trim() || value.trim().length > max)
+    fail();
+  return value.trim();
+}
+export function cardInput(dto: CreateBankCardDto) {
+  const bankName = dto.bankName?.trim() || null;
+  if (bankName && bankName.length > 100) fail();
+  if (dto.lastFour != null && !/^\d{4}$/.test(dto.lastFour)) fail();
+  if (
+    dto.paymentSystem != null &&
+    !bankPaymentSystems.some((system) => system === dto.paymentSystem)
+  )
+    fail();
+  return {
+    ...(dto.paymentSystem == null ? {} : { paymentSystem: dto.paymentSystem }),
+    name: name(dto.name, 100),
+    bankName,
+    lastFour: dto.lastFour || null,
+    openingBalanceKopecks: amount(dto.openingBalance),
+    openingDate: calendar(dto.openingDate),
+  };
+}
+export function operationInput(dto: CreateBankOperationDto) {
+  if (
+    dto.description != null &&
+    (typeof dto.description !== 'string' || dto.description.length > 500)
+  )
+    fail();
+  return {
+    kind: dto.kind,
+    cardId: dto.cardId,
+    targetCardId: dto.targetCardId ?? null,
+    categoryId: dto.categoryId ?? null,
+    originalExpenseId: dto.originalExpenseId ?? null,
+    amountKopecks: amount(dto.amount, true),
+    date: calendar(dto.date),
+    description: dto.description || null,
+  };
+}