import * as plugins from '../plugins.js';
import { S3Router } from './router.js';
import { MiddlewareStack } from './middleware-stack.js';
import { S3Context } from './context.js';
import { FilesystemStore } from './filesystem-store.js';
import { S3Error } from './s3-error.js';
import { Logger } from './logger.js';
import { MultipartUploadManager } from './multipart-manager.js';
import { ServiceController } from '../controllers/service.controller.js';
import { BucketController } from '../controllers/bucket.controller.js';
import { ObjectController } from '../controllers/object.controller.js';
import type { ISmarts3Config } from '../index.js';

export interface ISmarts3ServerOptions {
  port?: number;
  address?: string;
  directory?: string;
  cleanSlate?: boolean;
  silent?: boolean;
  config?: Required<ISmarts3Config>;
}

/**
 * Custom S3-compatible server implementation
 * Built on native Node.js http module with zero framework dependencies
 */
export class Smarts3Server {
  private httpServer?: plugins.http.Server;
  private router: S3Router;
  private middlewares: MiddlewareStack;
  public store: FilesystemStore; // Made public for direct access from Smarts3 class
  public multipart: MultipartUploadManager; // Made public for controller access
  private options: Required<Omit<ISmarts3ServerOptions, 'config'>>;
  private config: Required<ISmarts3Config>;
  private logger: Logger;

  constructor(options: ISmarts3ServerOptions = {}) {
    this.options = {
      port: options.port ?? 3000,
      address: options.address ?? '0.0.0.0',
      directory: options.directory ?? plugins.path.join(process.cwd(), '.nogit/bucketsDir'),
      cleanSlate: options.cleanSlate ?? false,
      silent: options.silent ?? false,
    };

    // Store config for middleware and feature configuration
    // If no config provided, create minimal default (for backward compatibility)
    this.config = options.config ?? {
      server: {
        port: this.options.port,
        address: this.options.address,
        silent: this.options.silent,
      },
      storage: {
        directory: this.options.directory,
        cleanSlate: this.options.cleanSlate,
      },
      auth: {
        enabled: false,
        credentials: [{ accessKeyId: 'S3RVER', secretAccessKey: 'S3RVER' }],
      },
      cors: {
        enabled: false,
        allowedOrigins: ['*'],
        allowedMethods: ['GET', 'POST', 'PUT', 'DELETE', 'HEAD', 'OPTIONS'],
        allowedHeaders: ['*'],
        exposedHeaders: ['ETag', 'x-amz-request-id', 'x-amz-version-id'],
        maxAge: 86400,
        allowCredentials: false,
      },
      logging: {
        level: 'info',
        format: 'text',
        enabled: true,
      },
      limits: {
        maxObjectSize: 5 * 1024 * 1024 * 1024,
        maxMetadataSize: 2048,
        requestTimeout: 300000,
      },
    };

    this.logger = new Logger(this.config.logging);
    this.store = new FilesystemStore(this.options.directory);
    this.multipart = new MultipartUploadManager(this.options.directory);
    this.router = new S3Router();
    this.middlewares = new MiddlewareStack();

    this.setupMiddlewares();
    this.setupRoutes();
  }

  /**
   * Setup middleware stack
   */
  private setupMiddlewares(): void {
    // CORS middleware (must be first to handle preflight requests)
    if (this.config.cors.enabled) {
      this.middlewares.use(async (req, res, ctx, next) => {
        const origin = req.headers.origin || req.headers.referer;

        // Check if origin is allowed
        const allowedOrigins = this.config.cors.allowedOrigins || ['*'];
        const isOriginAllowed =
          allowedOrigins.includes('*') ||
          (origin && allowedOrigins.includes(origin));

        if (isOriginAllowed) {
          // Set CORS headers
          res.setHeader(
            'Access-Control-Allow-Origin',
            allowedOrigins.includes('*') ? '*' : origin || '*'
          );

          if (this.config.cors.allowCredentials) {
            res.setHeader('Access-Control-Allow-Credentials', 'true');
          }

          // Handle preflight OPTIONS request
          if (req.method === 'OPTIONS') {
            res.setHeader(
              'Access-Control-Allow-Methods',
              (this.config.cors.allowedMethods || []).join(', ')
            );
            res.setHeader(
              'Access-Control-Allow-Headers',
              (this.config.cors.allowedHeaders || []).join(', ')
            );
            if (this.config.cors.maxAge) {
              res.setHeader(
                'Access-Control-Max-Age',
                String(this.config.cors.maxAge)
              );
            }
            res.writeHead(204);
            res.end();
            return; // Don't call next() for OPTIONS
          }

          // Set exposed headers for actual requests
          if (this.config.cors.exposedHeaders && this.config.cors.exposedHeaders.length > 0) {
            res.setHeader(
              'Access-Control-Expose-Headers',
              this.config.cors.exposedHeaders.join(', ')
            );
          }
        }

        await next();
      });
    }

    // Authentication middleware (simple static credentials)
    if (this.config.auth.enabled) {
      this.middlewares.use(async (req, res, ctx, next) => {
        const authHeader = req.headers.authorization;

        // Extract access key from Authorization header
        let accessKeyId: string | undefined;

        if (authHeader) {
          // Support multiple auth formats:
          // 1. AWS accessKeyId:signature
          // 2. AWS4-HMAC-SHA256 Credential=accessKeyId/date/region/service/aws4_request, ...
          if (authHeader.startsWith('AWS ')) {
            accessKeyId = authHeader.substring(4).split(':')[0];
          } else if (authHeader.startsWith('AWS4-HMAC-SHA256')) {
            const credentialMatch = authHeader.match(/Credential=([^/]+)\//);
            accessKeyId = credentialMatch ? credentialMatch[1] : undefined;
          }
        }

        // Check if access key is valid
        const isValid = this.config.auth.credentials.some(
          (cred) => cred.accessKeyId === accessKeyId
        );

        if (!isValid) {
          ctx.throw('AccessDenied', 'Access Denied');
          return;
        }

        await next();
      });
    }

    // Logger middleware
    if (!this.options.silent && this.config.logging.enabled) {
      this.middlewares.use(async (req, res, ctx, next) => {
        const start = Date.now();

        // Log request
        this.logger.request(req.method || 'UNKNOWN', req.url || '/', {
          headers: req.headers,
        });

        await next();

        // Log response
        const duration = Date.now() - start;
        this.logger.response(
          req.method || 'UNKNOWN',
          req.url || '/',
          res.statusCode || 500,
          duration
        );
      });
    }
  }

  /**
   * Setup routes
   */
  private setupRoutes(): void {
    // Service level (/)
    this.router.get('/', ServiceController.listBuckets);

    // Bucket level (/:bucket)
    this.router.put('/:bucket', BucketController.createBucket);
    this.router.delete('/:bucket', BucketController.deleteBucket);
    this.router.get('/:bucket', BucketController.listObjects);
    this.router.head('/:bucket', BucketController.headBucket);

    // Object level (/:bucket/:key*)
    this.router.put('/:bucket/:key*', ObjectController.putObject);
    this.router.post('/:bucket/:key*', ObjectController.postObject); // For multipart operations
    this.router.get('/:bucket/:key*', ObjectController.getObject);
    this.router.head('/:bucket/:key*', ObjectController.headObject);
    this.router.delete('/:bucket/:key*', ObjectController.deleteObject);
  }

  /**
   * Handle incoming HTTP request
   */
  private async handleRequest(
    req: plugins.http.IncomingMessage,
    res: plugins.http.ServerResponse
  ): Promise<void> {
    const context = new S3Context(req, res, this.store, this.multipart);

    try {
      // Execute middleware stack
      await this.middlewares.execute(req, res, context);

      // Route to handler
      const match = this.router.match(context.method, context.url.pathname);

      if (match) {
        context.params = match.params;
        await match.handler(req, res, context, match.params);
      } else {
        context.throw('NoSuchKey', 'The specified resource does not exist');
      }
    } catch (err) {
      await this.handleError(err, context, res);
    }
  }

  /**
   * Handle errors and send S3-compatible error responses
   */
  private async handleError(
    err: any,
    context: S3Context,
    res: plugins.http.ServerResponse
  ): Promise<void> {
    const s3Error = err instanceof S3Error ? err : S3Error.fromError(err);

    // Log the error
    this.logger.s3Error(s3Error.code, s3Error.message, s3Error.status);

    // Log stack trace for server errors
    if (s3Error.status >= 500) {
      this.logger.debug('Error stack trace', {
        stack: err.stack || err.toString(),
      });
    }

    // Send error response
    const errorXml = s3Error.toXML();

    res.writeHead(s3Error.status, {
      'Content-Type': 'application/xml',
      'Content-Length': Buffer.byteLength(errorXml),
    });

    res.end(errorXml);
  }

  /**
   * Start the server
   */
  public async start(): Promise<void> {
    // Initialize store
    await this.store.initialize();

    // Initialize multipart upload manager
    await this.multipart.initialize();

    // Clean slate if requested
    if (this.options.cleanSlate) {
      await this.store.reset();
    }

    // Create HTTP server
    this.httpServer = plugins.http.createServer((req, res) => {
      this.handleRequest(req, res).catch((err) => {
        this.logger.error('Fatal error in request handler', {
          error: err.message,
          stack: err.stack,
        });
        if (!res.headersSent) {
          res.writeHead(500, { 'Content-Type': 'text/plain' });
          res.end('Internal Server Error');
        }
      });
    });

    // Start listening
    await new Promise<void>((resolve, reject) => {
      this.httpServer!.listen(this.options.port, this.options.address, (err?: Error) => {
        if (err) {
          reject(err);
        } else {
          this.logger.info(`S3 server listening on ${this.options.address}:${this.options.port}`);
          resolve();
        }
      });
    });
  }

  /**
   * Stop the server
   */
  public async stop(): Promise<void> {
    if (!this.httpServer) {
      return;
    }

    await new Promise<void>((resolve, reject) => {
      this.httpServer!.close((err?: Error) => {
        if (err) {
          reject(err);
        } else {
          this.logger.info('S3 server stopped');
          resolve();
        }
      });
    });

    this.httpServer = undefined;
  }

  /**
   * Get server port (useful for testing with random ports)
   */
  public getPort(): number {
    if (!this.httpServer) {
      throw new Error('Server not started');
    }

    const address = this.httpServer.address();
    if (typeof address === 'string') {
      throw new Error('Unix socket not supported');
    }

    return address?.port || this.options.port;
  }

  /**
   * Get S3 descriptor for client configuration
   */
  public getS3Descriptor(): {
    accessKey: string;
    accessSecret: string;
    endpoint: string;
    port: number;
    useSsl: boolean;
  } {
    return {
      accessKey: 'S3RVER',
      accessSecret: 'S3RVER',
      endpoint: this.options.address === '0.0.0.0' ? '127.0.0.1' : this.options.address,
      port: this.getPort(),
      useSsl: false,
    };
  }
}