feat: extend account list portfolio summary (#138)

src/modules/investments/brokerage-accounts/brokerage-accounts.service.ts

@@ -1,10 +1,74 @@
 import { Injectable } from '@nestjs/common';
 import { createHash } from 'node:crypto';
 
+import {
+  decimalFromString,
+  divide,
+  formatDecimal,
+  isZero,
+  multiply,
+} from '../../../common/decimal';
 import { investmentResourceMeta } from '../investment-resource.mapper';
-import { PortfolioService } from '../portfolio/portfolio.api';
+import { sumMoneyByCurrency } from '../portfolio/domain/portfolio-totals';
+import { PortfolioPositionDto, PortfolioService } from '../portfolio/portfolio.api';
 import { hourlyAttempt, TbankSyncRepository } from '../tbank-sync/tbank-sync.repository';
-import { BrokerageAccountDto, BrokerageAccountsResourceDto } from './brokerage-account.dto';
+import {
+  BrokerageAccountDto,
+  BrokerageAccountsResourceDto,
+  UnrealizedReturnDto,
+} from './brokerage-account.dto';
+
+const PERCENT_DECIMAL_PLACES = 2;
+
+function unrealizedReturns(positions: PortfolioPositionDto[]): UnrealizedReturnDto[] {
+  // Cash-like CURRENCY positions must not duplicate the separately returned cash balances.
+  const investments = positions.filter((position) => position.type !== 'CURRENCY');
+  const absolute = sumMoneyByCurrency(
+    investments.flatMap((position) => position.absoluteReturn ? [position.absoluteReturn] : []),
+  );
+  const costs = sumMoneyByCurrency(
+    investments.flatMap((position) =>
+      position.absoluteReturn && position.averagePurchasePrice
+        ? [{
+            currency: position.absoluteReturn.currency,
+            value: formatDecimal(multiply(
+              decimalFromString(position.averagePurchasePrice.value),
+              decimalFromString(position.quantity),
+            )),
+          }]
+        : [],
+    ),
+  );
+  const partial = new Set(
+    investments.flatMap((position) => {
+      const money = position.absoluteReturn
+        ? null
+        : position.averagePurchasePrice ?? position.currentValue;
+      return money ? [money.currency] : [];
+    }),
+  );
+  const currencies = new Set([...absolute, ...costs].map((money) => money.currency));
+  return [...new Set([...currencies, ...partial])]
+    .sort((left, right) => left.localeCompare(right))
+    .map((currency) => {
+      const absoluteReturn = absolute.find((money) => money.currency === currency)?.value ?? '0';
+      const costBasis = costs.find((money) => money.currency === currency)?.value ?? '0';
+      const cost = decimalFromString(costBasis);
+      return {
+        currency,
+        absolute: absoluteReturn,
+        costBasis,
+        percent: isZero(cost)
+          ? null
+          : formatDecimal(divide(
+              multiply(decimalFromString(absoluteReturn), decimalFromString('100')),
+              cost,
+              PERCENT_DECIMAL_PLACES,
+            )),
+        partial: partial.has(currency),
+      };
+    });
+}
 
 @Injectable()
 export class BrokerageAccountsService {
@@ -26,12 +90,20 @@ export class BrokerageAccountsService {
             portfolioSummary: account.snapshot
               ? {
                   totalsByCurrency: account.snapshot.totalsByCurrency,
+                  cashBalances: account.snapshot.cashBalances,
+                  structure: account.snapshot.structure,
+                  unrealizedReturnByCurrency: unrealizedReturns(account.snapshot.positions),
                   stockPositionCount: account.snapshot.positions.filter(
                     (position) => position.type === 'STOCK',
                   ).length,
                   bondPositionCount: account.snapshot.positions.filter(
                     (position) => position.type === 'BOND',
                   ).length,
+                  fundPositionCount: account.snapshot.positions.filter(
+                    (position) => position.type === 'FUND',
+                  ).length,
+                  // The snapshot mapper already drops zero-quantity positions.
+                  totalPositionCount: account.snapshot.positions.length,
                 }
               : null,
           }));