backend/src/modules/investments/instruments/application/catalog-discovery.service.ts

import {
  ConflictException,
  Injectable,
  NotFoundException,
} from '@nestjs/common';

import {
  TbankAccessService,
  TbankClient,
  tbankSourceTtlMs,
} from '#src/integrations/tbank/tbank.api';

import { investmentResourceMeta } from '../../investment-resource.mapper';
import { InstrumentErrorCode } from '../domain/instrument-error-code';
import {
  catalogQuery,
  type CatalogQuery,
  catalogScope,
} from '../infrastructure/catalog-discovery.repository';
import {
  catalogSearchLimit,
  selectCatalogInstruments,
} from './catalog-selection';
import { publicInstrument } from './public-instrument';

const UNAMBIGUOUS_MATCH_COUNT = 1;
const FIRST_RESULT_OFFSET = 0;

const tickerAmbiguityLimit = 2;

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

  async search(userId: string, input: CatalogQuery) {
    return this.onlineSearch(userId, catalogQuery(input));
  }

  async detail(
    userId: string,
    instrumentType: 'bond' | 'share',
    uid: string,
  ) {
    const instrument = await this.access.online(userId, ({ token }) =>
      instrumentType === 'share'
        ? this.tbank.getShare(token, uid)
        : this.tbank.getBond(token, uid),
    );
    // RUB-only: a non-RUB instrument line (e.g. USD line of an SPB-traded stock) is not available.
    if (!instrument || instrument.currency?.toUpperCase() !== 'RUB') throw new NotFoundException();
    return {
      data: { ...publicInstrument({ ...instrument, uid }), uid, slug: instrument.ticker?.toUpperCase() ?? uid },
      meta: investmentResourceMeta({
        resourceKey: `${instrumentType}/detail/${uid}`,
        dataRevision: `online:${Date.now()}`,
        availability: 'complete',
        fetchedAt: new Date(),
        freshForMs: tbankSourceTtlMs.portfolio,
        work: null,
      }),
    };
  }

  async byTicker(
    userId: string,
    instrumentType: 'bond' | 'share',
    ticker: string,
  ) {
    const query = ticker.trim().toUpperCase();
    const found = await this.access.online(userId, ({ token }) =>
      instrumentType === 'share'
        ? this.tbank.findShares(token, query)
        : this.tbank.findBonds(token, query),
    );
    const candidates = selectCatalogInstruments(
      found.filter((item) => item.ticker?.trim().toUpperCase() === query),
      query,
      instrumentType,
    );
    const details = await this.access.online(userId, ({ token }) => Promise.all(
      candidates.map((item) => instrumentType === 'share'
        ? this.tbank.getShare(token, item.uid)
        : this.tbank.getBond(token, item.uid)),
    ));
    const matches = candidates.filter((_item, index) =>
      details.at(index)?.currency?.trim().toUpperCase() === 'RUB',
    ).slice(FIRST_RESULT_OFFSET, tickerAmbiguityLimit);
    if (!matches.length) throw new NotFoundException();
    if (matches.length > UNAMBIGUOUS_MATCH_COUNT) {
      throw new ConflictException({
        code:
          instrumentType === 'share'
            ? InstrumentErrorCode.StockTickerAmbiguous
            : InstrumentErrorCode.BondTickerAmbiguous,
      });
    }
    const result = await this.detail(userId, instrumentType, matches[0].uid);
    return { ...result, data: result.data ? { ...result.data, slug: query } : null };
  }

  private async onlineSearch(userId: string, input: CatalogQuery) {
    const { details, instruments, prices } = await this.access.online(userId, async ({ token }) => {
      const found =
        input.instrumentType === 'share'
          ? await this.tbank.findShares(token, input.query)
          : await this.tbank.findBonds(token, input.query);
      const instruments = selectCatalogInstruments(
        input.exactTicker
          ? found.filter((item) => item.ticker?.trim().toUpperCase() === input.query)
          : found,
        input.query,
        input.instrumentType,
      );
      const [details, prices] = await Promise.all([
        Promise.all(
          instruments.map((item) =>
            input.instrumentType === 'share'
              ? this.tbank.getShare(token, item.uid)
              : this.tbank.getBond(token, item.uid),
          ),
        ),
        instruments.length
          ? this.tbank.getLastPrices(token, instruments.map((item) => item.uid))
          : [],
      ]);
      return { details, instruments, prices };
    });
    const fetchedAt = new Date();
    const data = instruments.flatMap((item, index) => {
      const detail = details.at(index);
      if (detail?.currency?.trim().toUpperCase() !== 'RUB') return [];
      return [{
        ...item,
        detail: detail ? publicInstrument({ ...detail, uid: item.uid }) : null,
        price: prices.find((price) => price.instrumentUid === item.uid) ?? null,
      }];
    }).slice(FIRST_RESULT_OFFSET, input.exactTicker ? tickerAmbiguityLimit : catalogSearchLimit);
    return {
      data,
      meta: investmentResourceMeta({
        resourceKey: `search:${catalogScope(input)}`,
        dataRevision: `online:${fetchedAt.toISOString()}`,
        availability: 'complete',
        fetchedAt,
        freshForMs: tbankSourceTtlMs.portfolio,
        work: null,
      }),
    };
  }
}