import 'reflect-metadata';
import { randomUUID } from 'node:crypto';
import { resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import { NestFactory } from '@nestjs/core';
import { NestExpressApplication } from '@nestjs/platform-express';
import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
import type { NextFunction, Request, Response } from 'express';
import helmet from 'helmet';

import { AppModule } from './app.module.js';
import { ApiErrorFilter } from './common/api-error.filter.js';
import { APP_CONFIG, type AppConfig } from './config/app-config.module.js';
import { AppLogger } from './logging/app-logger.js';

type RequestWithId = Request & {
    requestId?: string;
};

export async function createApplication() {
    const app = await NestFactory.create<NestExpressApplication>(AppModule, {
        bodyParser: false,
        // 自定义日志器安装前保留 Nest 启动日志，避免配置错误没有可见诊断。
        logger: ['error', 'warn', 'log'],
    });
    const config = app.get<AppConfig>(APP_CONFIG);
    const logger = new AppLogger(config.LOG_LEVEL);
    app.useLogger(logger);

    if (config.trustedProxyCidrs.length > 0) {
        // 仅在部署明确声明代理网段时信任转发头，避免伪造客户端 IP。
        app.getHttpAdapter()
            .getInstance()
            .set('trust proxy', config.trustedProxyCidrs);
    }

    app.enableCors({
        origin: (origin, callback) => {
            // Extension API calls are bearer-token authenticated. Allow only Chrome
            // extension origins in addition to the configured Web application.
            if (!origin || origin === config.WEB_ORIGIN || /^chrome-extension:\/\/[a-p]{32}$/.test(origin)) {
                callback(null, true);
                return;
            }
            callback(null, false);
        },
        credentials: true,
        methods: ['GET', 'POST', 'PUT', 'PATCH', 'DELETE', 'OPTIONS'],
        allowedHeaders: [
            'Authorization',
            'Content-Type',
            'Idempotency-Key',
            'If-Match',
            'X-Atlas-Platform-Id',
            'X-Request-Id',
        ],
        exposedHeaders: ['X-Request-Id'],
    });
    // Helmet、body 限制、请求 ID 与全局错误过滤器必须在业务路由前注册。
    app.use(helmet({ contentSecurityPolicy: false }));
    // 批量佣金文件可达 2 MiB，专用入口预留元数据空间，其他 API 保留原限制。
    app.useBodyParser('json', {
        limit: 3 * 1024 * 1024,
        type: (req) => (req as Request).path.startsWith('/api/system/pricing/commissions') && Boolean((req as Request).is('application/json')),
    });
    app.useBodyParser('json', { limit: config.API_BODY_LIMIT_BYTES });
    app.useBodyParser('urlencoded', {
        limit: config.API_BODY_LIMIT_BYTES,
        extended: true,
    });
    app.use(
        (request: RequestWithId, response: Response, next: NextFunction) => {
            const typedRequest = request;
            const typedResponse = response;
            const suppliedId = typedRequest.headers['x-request-id'];
            // 合法调用方提供的 request ID 可贯穿上游链路；其他情况由服务端生成。
            const requestId =
                typeof suppliedId === 'string' &&
                /^[A-Za-z0-9_-]{8,128}$/.test(suppliedId)
                    ? suppliedId
                    : `req_${randomUUID()}`;
            const startedAt = performance.now();
            typedRequest.requestId = requestId;
            typedResponse.setHeader('X-Request-Id', requestId);
            typedResponse.on('finish', () => {
                logger.log('http_request_completed', {
                    request_id: requestId,
                    method: typedRequest.method,
                    path: typedRequest.originalUrl,
                    status_code: typedResponse.statusCode,
                    duration_ms: Math.round(performance.now() - startedAt),
                });
            });
            next();
        },
    );
    app.useGlobalFilters(new ApiErrorFilter(logger));
    app.setGlobalPrefix('api', { exclude: ['health', 'ready'] });
    app.enableShutdownHooks();

    if (config.swaggerEnabled) {
        // Swagger 仅描述运行时已注册路由；冻结接口契约仍以 docs/api 为准。
        const swaggerConfig = new DocumentBuilder()
            .setTitle('Atlas Seller Kit API')
            .setDescription('Atlas 卖家工作台 HTTP API 文档')
            .setVersion('0.1.0')
            .addBearerAuth(
                { type: 'http', scheme: 'bearer', bearerFormat: 'JWT' },
                'access-token',
            )
            .build();
        const swaggerDocument = SwaggerModule.createDocument(
            app,
            swaggerConfig,
        );
        SwaggerModule.setup('api-docs', app, swaggerDocument, {
            swaggerOptions: { persistAuthorization: true },
        });
    }

    return { app, config, logger };
}

export async function bootstrap() {
    const { app, config, logger } = await createApplication();
    await app.listen(config.API_PORT);
    logger.log('api_started', {
        port: config.API_PORT,
        swagger_enabled: config.swaggerEnabled,
    });
}

// 测试复用应用工厂时不自动监听固定端口，只有直接运行入口才启动服务。
if (
    process.argv[1] &&
    resolve(process.argv[1]) === fileURLToPath(import.meta.url)
) {
    void bootstrap().catch((error: unknown) => {
        const details =
            error instanceof Error
                ? {
                      name: error.name,
                      message: error.message,
                      stack: error.stack,
                  }
                : error;
        console.error(
            JSON.stringify({
                timestamp: new Date().toISOString(),
                level: 'error',
                message: 'api_startup_failed',
                error: details,
            }),
        );
        process.exitCode = 1;
    });
}