import { ServiceUnavailableException } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { ChannelCredentials, ClientUnaryCall, Metadata, ServiceError, status } from '@grpc/grpc-js';
import { mkdtempSync, writeFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { TBankClientService } from './tbank-client.service';

describe('TBankClientService', () => {
  const unaryCall = {
    cancel: vi.fn(),
    getPeer: vi.fn(),
    getAuthContext: vi.fn(),
  } as unknown as ClientUnaryCall;

  const config = {
    get: vi.fn((key: string, fallback?: unknown) => {
      const values: Record<string, unknown> = {
        'app.tbank.token': 'token-1',
        'app.tbank.appName': 'ksv741.moex-vibe',
        'app.tbank.rateLimitPerSecond': 5,
        'app.tbank.requestTimeoutMs': 10000,
      };

      return values[key] ?? fallback;
    }),
  } as unknown as ConfigService;

  it('builds redacted authorization metadata', () => {
    const service = new TBankClientService(config);
    const metadata = service.createMetadata();

    expect(metadata.get('Authorization')).toEqual(['Bearer token-1']);
    expect(metadata.get('x-app-name')).toEqual(['ksv741.moex-vibe']);
    expect(service.redactMetadata(metadata)).toEqual({
      Authorization: '<redacted>',
      'x-app-name': 'ksv741.moex-vibe',
    });
  });

  it('creates service clients from vendored proto contracts', () => {
    const service = new TBankClientService(config);

    expect(() => service.getServiceClient('UsersService')).not.toThrow();
  });

  it('creates grpc SSL credentials with configured custom CA certificate', () => {
    const caPath = join(mkdtempSync(join(tmpdir(), 'tbank-ca-')), 'root.pem');
    writeFileSync(caPath, '-----BEGIN CERTIFICATE-----\ntest-ca\n-----END CERTIFICATE-----\n');
    const createSslSpy = vi.spyOn(ChannelCredentials, 'createSsl');
    const caConfig = {
      get: vi.fn((key: string, fallback?: unknown) => {
        const values: Record<string, unknown> = {
          'app.tbank.token': 'token-1',
          'app.tbank.caCertPath': caPath,
        };

        return values[key] ?? fallback;
      }),
    } as unknown as ConfigService;
    const service = new TBankClientService(caConfig);

    service.getServiceClient('UsersService');

    const [rootCerts] = createSslSpy.mock.calls.at(-1) ?? [];
    expect(Buffer.isBuffer(rootCerts)).toBe(true);
    expect((rootCerts as Buffer).toString('utf8')).toContain('test-ca');
    createSslSpy.mockRestore();
  });

  it('throws integration unavailable when token is missing', async () => {
    const missingConfig = {
      get: vi.fn((key: string, fallback?: unknown) =>
        key === 'app.tbank.token' ? '' : (fallback as unknown),
      ),
    } as unknown as ConfigService;
    const service = new TBankClientService(missingConfig);

    await expect(
      service.callUnary(
        'UsersService/GetAccounts',
        (_request, _metadata, _options, callback) => {
          callback(null, {});
          return unaryCall;
        },
        {},
      ),
    ).rejects.toThrow(ServiceUnavailableException);
  });

  it('wraps grpc errors with status code and tracking id', async () => {
    const service = new TBankClientService(config);
    const error = Object.assign(new Error('Too many requests'), {
      code: status.RESOURCE_EXHAUSTED,
      details: 'Too many requests',
      metadata: new Metadata(),
    }) as ServiceError;
    error.metadata.set('x-tracking-id', 'tracking-1');

    await expect(
      service.callUnary(
        'OperationsService/GetPortfolio',
        (_request, _metadata, _options, callback) => {
          callback(error, null);
          return unaryCall;
        },
        {},
      ),
    ).rejects.toMatchObject({
      response: expect.objectContaining({
        message: expect.stringContaining('T-Bank upstream error'),
      }),
    });
  });

  it('starts grpc deadline when queued call actually executes', async () => {
    vi.useFakeTimers();
    vi.setSystemTime(new Date('2026-06-17T07:00:00.000Z'));

    try {
      const queuedConfig = {
        get: vi.fn((key: string, fallback?: unknown) => {
          const values: Record<string, unknown> = {
            'app.tbank.token': 'token-1',
            'app.tbank.rateLimitPerSecond': 1,
            'app.tbank.requestTimeoutMs': 1000,
          };

          return values[key] ?? fallback;
        }),
      } as unknown as ConfigService;
      const service = new TBankClientService(queuedConfig);
      const deadlines: number[] = [];
      const startedAt: number[] = [];
      const method = vi.fn((_request, _metadata, options, callback) => {
        deadlines.push((options.deadline as Date).getTime());
        startedAt.push(Date.now());
        callback(null, {});
        return unaryCall;
      });

      const first = service.callUnary('UsersService/GetAccounts', method, {});
      const second = service.callUnary('UsersService/GetAccounts', method, {});

      await first;
      expect(startedAt).toEqual([Date.parse('2026-06-17T07:00:00.000Z')]);

      vi.setSystemTime(new Date('2026-06-17T07:00:01.000Z'));
      await vi.advanceTimersByTimeAsync(1000);
      await second;

      expect(startedAt[1]).toBeGreaterThan(startedAt[0]);
      expect(deadlines).toEqual(startedAt.map((started) => started + 1000));
    } finally {
      vi.useRealTimers();
    }
  });
});