import 'reflect-metadata';
import './config/load-env';
import type { CorsOptions } from '@nestjs/common/interfaces/external/cors-options.interface';
import type { INestApplication } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { json, urlencoded } from 'express';
import { AppModule } from './app.module';

type ExpressLikeApp = {
  set?: (key: string, value: boolean | number | string) => void;
};

function isProduction() {
  return process.env.NODE_ENV === 'production';
}

function parseBoolean(value: string | undefined, fallback: boolean) {
  if (value === undefined) return fallback;

  const normalized = value.trim().toLowerCase();
  if (['1', 'true', 'yes', 'on'].includes(normalized)) return true;
  if (['0', 'false', 'no', 'off'].includes(normalized)) return false;

  return fallback;
}

function parseCommaList(value: string | undefined) {
  return (value ?? '')
    .split(',')
    .map((item) => item.trim())
    .filter(Boolean);
}

function createCorsOptions(): CorsOptions {
  const allowedOrigins = parseCommaList(process.env.CORS_ORIGINS);

  return {
    origin:
      allowedOrigins.length > 0
        ? (origin, callback) => {
            if (!origin || allowedOrigins.includes(origin)) {
              callback(null, true);
              return;
            }

            callback(new Error('Origin is not allowed by CORS'), false);
          }
        : !isProduction(),
    methods: ['GET', 'POST', 'PATCH', 'PUT', 'DELETE', 'OPTIONS'],
    allowedHeaders: [
      'authorization',
      'content-type',
      'x-request-id',
      'x-api-encrypted',
      'x-api-session-id',
      'x-api-client-public-key'
    ],
    exposedHeaders: ['content-disposition', 'x-request-id', 'x-api-encrypted'],
    maxAge: 86400
  };
}

function configureTrustProxy(app: INestApplication) {
  const express = app.getHttpAdapter().getInstance() as ExpressLikeApp;
  const shouldTrustProxy = parseBoolean(process.env.TRUST_PROXY, isProduction());

  express.set?.('trust proxy', shouldTrustProxy);
}

function requestBodyLimit() {
  return process.env.REQUEST_BODY_LIMIT || process.env.MAX_REQUEST_BODY_SIZE || '160mb';
}

async function bootstrap() {
  const app = await NestFactory.create(AppModule, { bodyParser: false });
  const bodyLimit = requestBodyLimit();

  app.use(json({ limit: bodyLimit }));
  app.use(urlencoded({ limit: bodyLimit, extended: true }));
  configureTrustProxy(app);
  app.enableCors(createCorsOptions());
  app.setGlobalPrefix('api');

  const port = Number(process.env.PORT ?? 3000);
  await app.listen(port, '0.0.0.0');

  // eslint-disable-next-line no-console
  console.log(`Backend API listening on http://127.0.0.1:${port}/api`);
}

void bootstrap();