import {
  CanActivate,
  ExecutionContext,
  Injectable,
  UnauthorizedException,
} from "@nestjs/common";
import { JwtService } from "@nestjs/jwt";
import { Request } from "express";
import { RoleEnum } from "src/Types&Enums/role.enum";

@Injectable()
export class GlobalGuard implements CanActivate {
  constructor(private readonly jwtService: JwtService) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const request = context.switchToHttp().getRequest();

    const token = this.extractTokenFromHeader(request);
    if (!token) {
      throw new UnauthorizedException();
    }

    try {
      const payload = await this.jwtService.verifyAsync(token, {
        secret: `${process.env.SECRET}`,
      });

      if (payload.role !== RoleEnum.USER && payload.role !== RoleEnum.FIELD_EXPERT) {
        throw new UnauthorizedException();
      }

      request.user = payload;
      request.identity = request.user;
    } catch {
      throw new UnauthorizedException();
    }
    return true;
  }

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