import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { BadRequestException, ValidationError, ValidationPipe } from '@nestjs/common';
import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
import { SwaggerDocumentOptions } from '@nestjs/swagger';

async function bootstrap() {
  const app = await NestFactory.create(AppModule, {
    cors: {
      "origin": "*",
      "methods": "GET,HEAD,PUT,PATCH,POST,DELETE",
      "preflightContinue": false,
      "optionsSuccessStatus": 204
    }
  });

  function extractConstraints(validationErrors: ValidationError[]) {
    const constraints: { [key: string]: string }[] = [];

    function traverse(errors: ValidationError[]) {
      // console.log(errors);
      // console.log("--------------");
      for (const error of errors) {
        // If the error has constraints, add them to the list

        // console.log(error);
        // console.log("--------------");

        if (error.constraints) {
          constraints.push(error.constraints);
        }
        // // If there are children, recursively traverse them
        if (error.children && error.children.length > 0) {
          traverse(error.children);
        }
      }
    }

    traverse(validationErrors);
    return constraints;
  }

  const customExceptionFactory = (validationErrors: ValidationError[]) => {

    let res = extractConstraints(validationErrors);

    let newResult = res.map(x => {
      const errorMessage = x[Object.keys(x)[0]];

      return { message: errorMessage };
    }).filter(Boolean);

    return new BadRequestException({ message: 'Validation failed', errors: newResult });
  };

  app.useGlobalPipes(new ValidationPipe({
    transform: true,
    exceptionFactory: customExceptionFactory,
    whitelist: true,
    stopAtFirstError: true,
    forbidNonWhitelisted: true,
  }));

  // app.useGlobalPipes(new ValidationPipe({ exceptionFactory:customExceptionFactory, whitelist: true, forbidNonWhitelisted: true, transform: true }));
  const config = new DocumentBuilder()
    .setTitle('API')
    .setDescription('API description')
    .setVersion('1.0')
    .addServer("http://localhost:3000", "Development Server 1")
    .addServer("https://dev.alphaomegainfosys.com/test-api", "Development Server 2")
    .build();

  const options: SwaggerDocumentOptions = {
    autoTagControllers: false,
  };
  const documentFactory = () => SwaggerModule.createDocument(app, config, options);
  SwaggerModule.setup('api', app, documentFactory);

  await app.listen(process.env.PORT ?? 3000);
}
bootstrap();