@ita-company/ita-package/src/authentication/authentication-guard.ts

<p align="center"> <a href="http://nestjs.com/" target="blank"><img src="https://nestjs.com/img/logo-small.svg" width="200" alt="Nest Logo" /></a> </p>

import {
  CanActivate,
  ExecutionContext,
  Injectable,
  UnauthorizedException,
} from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { Request } from 'express';
import { SetMetadata } from '@nestjs/common';
import { Reflector } from '@nestjs/core';

export const IS_PUBLIC_KEY = 'isPublic';
export const Public = () => SetMetadata(IS_PUBLIC_KEY, true);

@Injectable()
export class AuthGuard implements CanActivate {
  constructor(private jwtService: JwtService, private reflector: Reflector) { }

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const isPublic = this.reflector.getAllAndOverride<boolean>(IS_PUBLIC_KEY, [
      context.getHandler(),
      context.getClass(),
    ]);
    if (isPublic) {
      // 💡 See this condition
      return true;
    }

    const request = context.switchToHttp().getRequest();
    const token = this.extractTokenFromHeader(request);
    if (!token) {
      throw new UnauthorizedException();
    }
    try {
      const payload = await this.jwtService.verifyAsync(token, {
        secret: 'ita-secret-key',
      });
      // 💡 We're assigning the payload to the request object here
      // so that we can access it in our route handlers
      request['user'] = payload;
    } catch {
      throw new UnauthorizedException();
    }
    return true;
  }

  async signAsync(payload: any): Promise<string> {
    return await this.jwtService.signAsync(payload);
  }

  private extractTokenFromHeader(request: Request): string | undefined {
    const [type, token] = request.headers.authorization?.split(' ') ?? [];
    return type === 'Bearer' ? token : undefined;
  }
}