import { Injectable } from '@nestjs/common';
import { randomUUID } from 'node:crypto';
import { StructuredLogger } from '../../common/logging/structured-logger.service';
import {
  TbankAccessService,
  type TbankSyncAttempt,
} from './tbank-access.service';
import { TbankClient } from './tbank.client';

@Injectable()
export class TbankMembershipService {
  private readonly processRunId = randomUUID();
  private readonly active = new Map<string, Promise<void>>();
  private reservations: Promise<unknown> = Promise.resolve();

  constructor(
    private readonly access: TbankAccessService,
    private readonly tbank: TbankClient,
    private readonly logger: StructuredLogger,
  ) {}

  request(userId: string, revision: string, force = false) {
    const reservation = this.reservations.then(async () => {
      const requested = await this.access.reserveMembership(
        userId,
        revision,
        this.processRunId,
        new Set(this.active.keys()),
        force,
      );
      if (!requested) return null;
      const { id, attemptId } = requested.work;
      if (requested.launch) {
        const done = new Promise<void>((resolve) => setImmediate(resolve))
          .then(() => this.execute({ userId, revision, id, attemptId }))
          .catch(() =>
            this.logger.event('error', 'tbank.membership.persistence_failed', {
              userId,
              code: 'TBANK_UNAVAILABLE',
            }),
          )
          .finally(() => this.active.delete(attemptId));
        this.active.set(attemptId, done);
      }
      return { id, done: this.active.get(attemptId) ?? Promise.resolve() };
    });
    this.reservations = reservation.catch(() => undefined);
    return reservation;
  }

  private async execute(attempt: TbankSyncAttempt) {
    try {
      const token = await this.access.tokenForAttempt(attempt);
      if (!token) return;
      await this.access.publishMembership(
        attempt,
        await this.tbank.getOpenAccounts(token),
        new Date(),
        true,
      );
    } catch (error) {
      await this.access.failMembership(
        attempt,
        error instanceof Error && error.message === 'INVALID_TBANK_TOKEN',
      );
    }
  }
}