import {
  Injectable,
  NestMiddleware,
  UnauthorizedException,
} from '@nestjs/common';
import type { Request, Response, NextFunction } from 'express';

export interface AuthenticatedUser {
  id: string;
  role: string;
  permissions: string[];
}

export interface AuthenticatedRequest extends Request {
  user?: AuthenticatedUser;
}

@Injectable()
export class AuthMiddleware implements NestMiddleware {
  use(req: AuthenticatedRequest, _res: Response, next: NextFunction): void {
    const userId = req.headers['x-user-id'] as string | undefined;
    const role = req.headers['x-user-role'] as string | undefined;
    const permissionsHeader = req.headers['x-user-permissions'] as
      | string
      | undefined;

    if (!userId || !role) {
      throw new UnauthorizedException(
        'Missing authentication headers (x-user-id, x-user-role)',
      );
    }

    req.user = {
      id: userId,
      role,
      permissions: permissionsHeader ? permissionsHeader.split(',') : [],
    };
    next();
  }
}