import { Injectable } from '@nestjs/common';
import { createHash } from 'node:crypto';

import { investmentResourceMeta } from '../investment-resource.mapper';
import { PortfolioService } from '../portfolio/portfolio.api';
import { TbankSyncRepository } from '../tbank-sync/tbank-sync.repository';
import { BrokerageAccountDto, BrokerageAccountsResourceDto } from './brokerage-account.dto';

@Injectable()
export class BrokerageAccountsService {
  constructor(
    private readonly portfolio: PortfolioService,
    private readonly sync: TbankSyncRepository,
  ) {}

  async list(userId: string): Promise<BrokerageAccountsResourceDto> {
    const saved = await this.portfolio.saved(userId, 'all');
    const data: BrokerageAccountDto[] | null =
      saved.membership.completeness === 'incomplete'
        ? null
        : saved.accounts.map((account) => ({
            id: account.id,
            name: account.name,
            type: account.type as BrokerageAccountDto['type'],
            openedOn: account.openedOn,
            portfolioSummary: account.snapshot
              ? {
                  totalsByCurrency: account.snapshot.totalsByCurrency,
                  stockPositionCount: account.snapshot.positions.filter(
                    (position) => position.type === 'STOCK',
                  ).length,
                  bondPositionCount: account.snapshot.positions.filter(
                    (position) => position.type === 'BOND',
                  ).length,
                }
              : null,
          }));
    // The read-only result of the last hourly walk; never starts one.
    const hourly = await this.sync.hourly(userId);
    return {
      data,
      meta: investmentResourceMeta({
        resourceKey: 'accounts',
        dataRevision: createHash('sha256')
          .update(
            JSON.stringify([
              saved.membership.dataRevision,
              saved.accounts.map((account) => [
                account.id,
                account.meta.dataRevision,
              ]),
            ]),
          )
          .digest('base64url'),
        availability:
          data === null
            ? 'missing'
            : 'complete',
        fetchedAt: saved.membership.lastSuccessfulAt
          ? new Date(saved.membership.lastSuccessfulAt)
          : null,
        freshForMs: 3_600_000,
        work: null,
        dependencies: saved.accounts.map((account) => account.meta),
      }),
      sync: hourly
        ? {
            state: hourly.state,
            startedAt: hourly.startedAt.toISOString(),
            finishedAt: hourly.finishedAt?.toISOString() ?? null,
            problems: hourly.sections.map((section) => ({
              ...section,
              accountId: section.accountId ?? null,
            })),
          }
        : null,
    };
  }
}