import * as express from 'express';
import * as path from 'path';
import * as fs from 'fs';
import * as morgan from 'morgan';
import { v4 as uuid } from 'uuid';
import signaling from './signaling';
import { log, LogLevel } from './log';
import Options from './class/options';
import { reset as resetHandler } from './class/httphandler';
import { initSwagger } from './swagger';

const cors = require('cors');
const multer = require('multer');

const AVATAR_UPLOAD_LIMIT_BYTES = 2 * 1024 * 1024;
const ALLOWED_AVATAR_MIME_TYPES = new Set(['image/jpeg', 'image/png', 'image/webp', 'image/gif']);
const ALLOWED_AVATAR_EXTENSIONS = new Set(['.jpg', '.jpeg', '.png', '.webp', '.gif']);

function safeAvatarExtension(file: any): string {
  const originalExt = path.extname(file.originalname || '').toLowerCase();
  if (ALLOWED_AVATAR_EXTENSIONS.has(originalExt)) {
    return originalExt;
  }

  switch (file.mimetype) {
    case 'image/jpeg':
      return '.jpg';
    case 'image/png':
      return '.png';
    case 'image/webp':
      return '.webp';
    case 'image/gif':
      return '.gif';
    default:
      return '';
  }
}

function isAllowedAvatar(file: any): boolean {
  return ALLOWED_AVATAR_MIME_TYPES.has(file.mimetype) && safeAvatarExtension(file).length > 0;
}

export const createServer = (config: Options): express.Express => {
  const app: express.Express = express();
  resetHandler(config.mode);

  if (config.logging !== 'none') {
    app.use(morgan(config.logging));
  }

  app.use(cors({ origin: '*' }));
  app.use(express.urlencoded({ extended: true }));
  app.use(express.json());

  app.get('/config', (_req, res) => res.json({
    useWebSocket: config.type === 'websocket',
    startupMode: config.mode,
    logging: config.logging,
    protocol: config.secure ? 'https' : 'http',
    port: config.port
  }));

  app.use('/signaling', signaling);
  app.use(express.static(path.join(__dirname, '../client/public')));
  app.use('/module', express.static(path.join(__dirname, '../client/src')));

  app.get('/', (_req, res) => {
    const indexPagePath = path.join(__dirname, '../client/public/index.html');
    fs.access(indexPagePath, (err) => {
      if (err) {
        log(LogLevel.warn, `Can't find file '${indexPagePath}'`);
        res.status(404).send(`Can't find file ${indexPagePath}`);
        return;
      }

      res.sendFile(indexPagePath);
    });
  });

  initSwagger(app, config);

  const storage = multer.diskStorage({
    destination: (_req: any, _file: any, cb: (error: Error | null, destination: string) => void) => {
      const uploadDir = path.join(__dirname, '../client/public/uploads/avatars');
      if (!fs.existsSync(uploadDir)) {
        fs.mkdirSync(uploadDir, { recursive: true });
      }
      cb(null, uploadDir);
    },
    filename: (_req: any, file: any, cb: (error: Error | null, filename: string) => void) => {
      cb(null, file.originalname);
    }
  });

  const upload = multer({
    storage,
    limits: {
      fileSize: AVATAR_UPLOAD_LIMIT_BYTES
    },
    fileFilter: (_req: express.Request, file: any, cb: (error: Error | null, acceptFile?: boolean) => void) => {
      if (!isAllowedAvatar(file)) {
        cb(new Error('Only jpg, png, webp, or gif avatars are allowed'));
        return;
      }

      cb(null, true);
    }
  });

  app.post('/api/upload/avatar', (req: express.Request, res: express.Response) => {
    upload.single('avatar')(req, res, (error: Error) => {
      if (error) {
        log(LogLevel.warn, 'Avatar upload rejected:', error.message);
        const isSizeLimit = error.name === 'MulterError' && (error as any).code === 'LIMIT_FILE_SIZE';
        res.status(400).json({
          success: false,
          message: isSizeLimit ? 'Avatar file is too large' : error.message
        });
        return;
      }

      const request = req as any;
      if (!request.file) {
        res.status(400).json({ success: false, message: 'No file uploaded' });
        return;
      }

      const ext = safeAvatarExtension(request.file);
      if (!ext) {
        fs.unlink(request.file.path, () => undefined);
        res.status(400).json({ success: false, message: 'Unsupported avatar file type' });
        return;
      }

      const oldPath = request.file.path;
      const newFilename = `avatar_${uuid()}${ext}`;
      const newPath = path.join(path.dirname(oldPath), newFilename);

      fs.rename(oldPath, newPath, (err) => {
        if (err) {
          log(LogLevel.error, 'Error renaming file:', err);
          res.status(500).json({ success: false, message: 'Avatar rename failed' });
          return;
        }

        res.json({ success: true, avatarUrl: `/uploads/avatars/${newFilename}` });
      });
    });
  });

  app.use('/uploads', express.static(path.join(__dirname, '../client/public/uploads')));

  return app;
};