refactor: organize backend by business responsibility

src/integrations/tbank/tbank-account.policy.ts

@@ -0,0 +1,57 @@
+import { TbankAccount } from './tbank.client';
+
+const accountTypes = {
+  ACCOUNT_TYPE_TINKOFF: { type: 'BROKERAGE', name: 'Брокерский счет' },
+  ACCOUNT_TYPE_TINKOFF_IIS: {
+    type: 'INDIVIDUAL_INVESTMENT',
+    name: 'ИИС',
+  },
+  ACCOUNT_TYPE_INVEST_BOX: { type: 'INVEST_BOX', name: 'Инвесткопилка' },
+  ACCOUNT_TYPE_INVEST_FUND: {
+    type: 'MONEY_MARKET_FUND',
+    name: 'Фонд денежного рынка',
+  },
+} as const;
+
+type AccountType = keyof typeof accountTypes;
+export type SupportedTbankAccount = {
+  id: string;
+  name: string;
+  type: (typeof accountTypes)[AccountType]['type'];
+  openedOn: string | null;
+};
+
+export function supportedTbankAccounts(
+  accounts: TbankAccount[],
+): SupportedTbankAccount[] {
+  return accounts.flatMap((account) => {
+    const details = accountTypes[account.type as AccountType];
+    if (!details) return [];
+    return [
+      {
+        id: account.id,
+        name: account.name.trim() || details.name,
+        type: details.type,
+        openedOn: openedOn(account.openedDate?.seconds),
+      },
+    ];
+  });
+}
+
+export function accessibleTbankAccount(
+  accounts: TbankAccount[],
+  accountId: string,
+): TbankAccount | null {
+  return (
+    accounts.find(
+      (account) => account.id === accountId && account.type in accountTypes,
+    ) ?? null
+  );
+}
+
+function openedOn(seconds: string | number | undefined): string | null {
+  if (seconds === undefined) return null;
+  const date = new Date(Number(seconds) * 1000);
+  if (Number.isNaN(date.valueOf())) return null;
+  return date.toISOString().slice(0, 10);
+}