import {
  Injectable,
  CanActivate,
  ExecutionContext,
  HttpException,
} from '@nestjs/common';
import { Request } from 'express';
import { AuditAction } from 'src/modules/objects/audit/audit.enum';
import { AuditService } from 'src/modules/objects/audit/audit.service';
import { IPLimitService } from 'src/modules/utility/services/iplimit.service';

@Injectable()
export class LoginAntispamGuard implements CanActivate {
  constructor(private iplimit: IPLimitService, private audit: AuditService) {}

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

    if (['GET', 'OPTIONS'].includes(request.method)) return true;

    const known = this.iplimit.getAddressLimit(request.ip);
    if (known && known.attempts >= 3) {
      if (known.attempts >= 5) {
        let reported = false;
        if (!known.reported) {
          reported = true;
          await this.audit.insertAudit(
            AuditAction.THROTTLE,
            `antispam-guard ${known.attempts} attempts`,
            undefined,
            request.ip,
            request.header('user-agent'),
          );
        }

        const limitMinutes = known.attempts > 10 ? 30 : 10; // Half-Hour
        this.iplimit.limitUntil(request.ip, limitMinutes * 60 * 1000, reported);

        await new Promise((resolve) =>
          setTimeout(resolve, known.attempts * 1000),
        );

        throw new HttpException(
          `Too Many Requests. Try again in ${limitMinutes} minutes.`,
          429,
        );
      }

      await new Promise((resolve) => setTimeout(resolve, 1000));
    }

    this.iplimit.limitUntil(request.ip, 30 * 1000); // 30 seconds

    return true;
  }
}