backend/src/modules/investments/upcoming-events/upcoming-event.mapper.ts

import type { MoexBondEvent } from '#src/integrations/moex/moex.api';
import type { TbankDividend } from '#src/integrations/tbank/tbank.api';

import {
  decimalFromString,
  formatDecimal,
  multiply,
} from '#src/common/decimal';
import { ISO_DATE_LENGTH, ISO_DATE_START, MILLISECONDS_PER_SECOND } from '#src/common/time';
import { decimal } from '#src/integrations/tbank/decimal';

import { UpcomingEventDto } from './upcoming-events.dto';

export function dividendEvent(
  metadata: Pick<
    UpcomingEventDto,
    'displayName' | 'figi' | 'instrumentUid' | 'isin' | 'logoName' | 'ticker'
  >,
  quantity: ReturnType<typeof decimal>,
  event: TbankDividend,
): UpcomingEventDto {
  return {
    ...metadata,
    type: 'dividend',
    date: new Date(Number(event.recordDate?.seconds) * MILLISECONDS_PER_SECOND)
      .toISOString()
      .slice(ISO_DATE_START, ISO_DATE_LENGTH),
    dateKind: 'registry',
    projectedAmount: event.dividendNet
      ? projectedMoney(
          quantity,
          formatDecimal(decimal(event.dividendNet)),
          event.dividendNet.currency,
        )
      : null,
  };
}

export function bondEvent(
  metadata: Pick<
    UpcomingEventDto,
    'displayName' | 'figi' | 'instrumentUid' | 'isin' | 'logoName' | 'ticker'
  >,
  quantity: ReturnType<typeof decimal>,
  event: MoexBondEvent,
): UpcomingEventDto {
  return {
    ...metadata,
    type: event.type,
    date: event.date,
    dateKind: 'event',
    projectedAmount:
      'value' in event
        ? projectedMoney(quantity, event.value, event.currency)
        : null,
  };
}

function projectedMoney(
  quantity: ReturnType<typeof decimal>,
  value: string,
  currency: string | undefined,
): UpcomingEventDto['projectedAmount'] {
  // RUB-only: projected income in other currencies is filtered out.
  if (currency?.trim().toUpperCase() !== 'RUB') return null;
  return {
    currency: 'RUB',
    value: formatDecimal(multiply(quantity, decimalFromString(value))),
  };
}