import { INestApplication } from '@nestjs/common';
import { Test } from '@nestjs/testing';
import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
import { readFile } from 'node:fs/promises';
import { resolve } from 'node:path';
import { AppModule } from './../src/app.module';
import { configureApp } from './../src/main';

function canonicalize(value: unknown): unknown {
  if (Array.isArray(value)) return value.map(canonicalize);
  if (value && typeof value === 'object') {
    return Object.fromEntries(
      Object.entries(value)
        .sort(([left], [right]) => left.localeCompare(right))
        .map(([key, nestedValue]) => [key, canonicalize(nestedValue)]),
    );
  }
  return value;
}

describe('OpenAPI contract (integration)', () => {
  let app: INestApplication;

  beforeAll(async () => {
    const module = await Test.createTestingModule({
      imports: [AppModule],
    }).compile();
    app = module.createNestApplication();
    configureApp(app);
    await app.init();
  });

  afterAll(() => app.close());

  it('matches the committed frontend OpenAPI snapshot', async () => {
    const runtimeDocument = SwaggerModule.createDocument(
      app,
      new DocumentBuilder()
        .setTitle('WealthLedger API')
        .setVersion('v1')
        .build(),
    );
    const snapshot = JSON.parse(
      await readFile(
        resolve(__dirname, '../../frontend/src/shared/api/spec/openapi.json'),
        'utf8',
      ),
    ) as unknown;

    expect(canonicalize(runtimeDocument)).toEqual(canonicalize(snapshot));
  });
});