refactor!: support RUB only (WealthLedger/main#55) (#204)

BREAKING CHANGE: per-currency API fields replaced with single RUB Money.

src/modules/investments/portfolio/infrastructure/tbank-portfolio.mapper.ts

@@ -8,13 +8,12 @@ import {
   multiply,
   subtract,
 } from '#src/common/decimal';
-import { decimal } from '#src/integrations/tbank/decimal';
+import { decimal, rubMoney } from '#src/integrations/tbank/decimal';
 import {
   metadataKey,
   type TbankInstrument,
   type TbankMoney,
   TbankPortfolio,
-  TbankPositions,
 } from '#src/integrations/tbank/tbank.api';
 
 import type { Classification } from '../application/position-classification.service';
@@ -22,6 +21,8 @@ import type { PortfolioDto, PortfolioPositionDto } from '../presentation/portfol
 
 import { portfolioStructure } from '../domain/portfolio-structure';
 
+const RUB = 'RUB';
+
 const types: Record<string, string> = {
   share: 'STOCK',
   bond: 'BOND',
@@ -35,32 +36,36 @@ const types: Record<string, string> = {
 
 function mapPortfolio(
   upstream: NonNullable<TbankPortfolio['positions']>,
-  cash: TbankMoney[],
+  cashBalances: TbankMoney[],
   metadata: ReadonlyMap<string, { data?: null | TbankInstrument }>,
   lastSuccessfulAt: string,
   classification: ReadonlyMap<string, Classification> = new Map(),
 ): PortfolioDto {
   const positions = upstream
+    // Currency positions mirror cash balances and are non-RUB holdings by definition.
+    .filter((position) => types[position.instrumentType?.toLowerCase() ?? ''] !== 'CURRENCY' &&
+      (!position.currentPrice?.currency?.trim() || position.currentPrice.currency.trim().toUpperCase() === RUB))
     .map((position) => mapPosition(position, metadata.get(metadataKey(position))?.data ?? null, classification.get(metadataKey(position))))
     .filter((position): position is PortfolioPositionDto => position !== null);
-  const balances = new Map<string, ReturnType<typeof decimal>>();
-  for (const value of cash) {
-    const currency = value.currency?.trim().toUpperCase();
-    const amount = decimal(value);
-    if (!currency || isZero(amount)) continue;
-    balances.set(currency, add(balances.get(currency) ?? decimal({}), amount));
+  let cashTotal = decimal({});
+  for (const value of cashBalances) {
+    if (value.currency?.trim().toUpperCase() !== RUB) continue;
+    cashTotal = add(cashTotal, decimal(value));
   }
-  const cashBalances = [...balances].map(([currency, value]) => ({
-    currency,
-    value: formatDecimal(value),
-  }));
+  const cash: Money = { currency: RUB, value: formatDecimal(cashTotal) };
+  let total = cashTotal;
+  for (const position of positions) {
+    if (!position.currentValue) continue;
+    total = add(total, decimalFromString(position.currentValue.value));
+  }
+  const totals: Money = { currency: RUB, value: formatDecimal(total) };
   return {
     lastSuccessfulAt,
     isStale: false,
-    totalsByCurrency: totalsByCurrency(upstream, cash),
+    totals,
     positions,
-    cashBalances,
-    structure: portfolioStructure(positions, cashBalances),
+    cash,
+    structure: portfolioStructure(positions, [cash]),
   };
 }
 
@@ -73,16 +78,16 @@ function mapPosition(
   if (isZero(quantity)) return null;
   const figi = position.figi?.trim() || null;
   const instrumentUid = position.instrumentUid?.trim() || null;
-  const currentPrice = money(position.currentPrice);
-  const averagePurchasePrice = money(position.averagePositionPrice);
+  const currentPrice = rubMoney(position.currentPrice);
+  const averagePurchasePrice = rubMoney(position.averagePositionPrice);
   const currentValue = currentPrice && {
-    currency: currentPrice.currency,
+    currency: RUB,
     value: formatDecimal(multiply(quantity, decimalFromString(currentPrice.value))),
   };
   const absoluteReturn =
-    currentPrice && averagePurchasePrice && currentPrice.currency === averagePurchasePrice.currency
+    currentPrice && averagePurchasePrice
       ? {
-          currency: currentPrice.currency,
+          currency: RUB,
           value: formatDecimal(multiply(
             subtract(decimalFromString(currentPrice.value), decimalFromString(averagePurchasePrice.value)),
             quantity,
@@ -106,44 +111,4 @@ function mapPosition(
   };
 }
 
-function money(value: TbankMoney | undefined): Money | null {
-  const currency = value?.currency?.trim().toUpperCase();
-  return currency && value
-    ? { currency, value: formatDecimal(decimal(value)) }
-    : null;
-}
-
-function totalsByCurrency(
-  positions: NonNullable<TbankPortfolio['positions']>,
-  money: NonNullable<TbankPositions['money']>,
-): Money[] {
-  const totals = new Map<string, ReturnType<typeof decimal>>();
-  const addTotal = (
-    currency: string | undefined,
-    amount: ReturnType<typeof decimal>,
-  ) => {
-    const normalizedCurrency = currency?.trim().toUpperCase();
-    if (!normalizedCurrency || isZero(amount)) return;
-    totals.set(
-      normalizedCurrency,
-      add(totals.get(normalizedCurrency) ?? decimal({}), amount),
-    );
-  };
-
-  for (const value of money) addTotal(value.currency, decimal(value));
-  for (const position of positions) {
-    const price = position.currentPrice;
-    // CURRENCY positions mirror the cash balances already added above.
-    if (!price || types[position.instrumentType?.toLowerCase() ?? ''] === 'CURRENCY') continue;
-    addTotal(
-      price.currency,
-      multiply(decimal(position.quantity ?? {}), decimal(price)),
-    );
-  }
-
-  return [...totals]
-    .filter(([, value]) => !isZero(value))
-    .map(([currency, value]) => ({ currency, value: formatDecimal(value) }));
-}
-
-export { mapPortfolio, totalsByCurrency };
+export { mapPortfolio };