import { Injectable, ServiceUnavailableException } from '@nestjs/common';
import { isZero } from '../../../common/decimal';
import {
  TbankAccessService,
  TbankClient,
} from '../../../integrations/tbank/tbank.api';
import { decimal } from '../../../integrations/tbank/decimal';
import { totalsByCurrency } from '../portfolio/portfolio.api';
import { BrokerageAccountDto } from './brokerage-account.dto';

@Injectable()
export class BrokerageAccountsService {
  constructor(
    private readonly access: TbankAccessService,
    private readonly tbank: TbankClient,
  ) {}

  async list(userId: string): Promise<BrokerageAccountDto[]> {
    return this.access.withSupportedAccounts(
      userId,
      async ({ token, accounts }) =>
        Promise.all(
          accounts.map(async (account) => {
            const [portfolioResult, positionsResult] = await Promise.allSettled(
              [
                this.tbank.getPortfolio(token, account.id),
                this.tbank.getPositions(token, account.id),
              ],
            );
            if (
              portfolioResult.status === 'rejected' &&
              !isTbankUnavailable(portfolioResult.reason)
            )
              throw portfolioResult.reason;
            if (
              positionsResult.status === 'rejected' &&
              !isTbankUnavailable(positionsResult.reason)
            )
              throw positionsResult.reason;
            if (
              portfolioResult.status === 'rejected' ||
              positionsResult.status === 'rejected'
            )
              return { ...account, portfolioSummary: null };
            const positions = portfolioResult.value.positions ?? [];
            let stockPositionCount = 0;
            let bondPositionCount = 0;
            for (const position of positions) {
              if (isZero(decimal(position.quantity ?? {}))) continue;
              const type = position.instrumentType?.toLowerCase();
              if (type === 'share') stockPositionCount += 1;
              if (type === 'bond') bondPositionCount += 1;
            }
            return {
              ...account,
              portfolioSummary: {
                totalsByCurrency: totalsByCurrency(
                  positions,
                  positionsResult.value.money ?? [],
                ),
                stockPositionCount,
                bondPositionCount,
              },
            };
          }),
        ),
    );
  }
}

function isTbankUnavailable(error: unknown): boolean {
  if (!(error instanceof ServiceUnavailableException)) return false;
  const response = error.getResponse();
  return (
    typeof response === 'object' &&
    response !== null &&
    'code' in response &&
    response.code === 'TBANK_UNAVAILABLE'
  );
}