import { Construct } from 'constructs'
import { App, Stack, StackProps } from 'aws-cdk-lib'
import * as cdk from 'aws-cdk-lib'
import * as ec2 from 'aws-cdk-lib/aws-ec2'
import * as elbv2 from 'aws-cdk-lib/aws-elasticloadbalancingv2'
import * as elbv2Targtes from 'aws-cdk-lib/aws-elasticloadbalancingv2-targets'

export class NlbStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);

    const vpc = new ec2.Vpc(this, 'VPC', {
      maxAzs: 2,
      natGateways: 0,
      subnetConfiguration: [{
        name: 'PublicSubnet',
        subnetType: ec2.SubnetType.PUBLIC,
      }],
    })

    const securityGroup = new ec2.SecurityGroup(this, 'SecurityGroup', {
      vpc,
      allowAllOutbound: true,
    })
    securityGroup.addIngressRule(
        ec2.Peer.anyIpv4(),
        ec2.Port.tcp(80),
    )
    const bastion = new ec2.BastionHostLinux(this, 'EC2', {
      vpc,
      securityGroup,
      instanceType: ec2.InstanceType.of(
          ec2.InstanceClass.BURSTABLE4_GRAVITON,
          ec2.InstanceSize.MICRO,
      ),
    })

    const nlb = new elbv2.NetworkLoadBalancer(this, 'NLB', {
      vpc,
      internetFacing: true,
      vpcSubnets: {
        subnetType: ec2.SubnetType.PUBLIC,
      },
    })
    const nlbListener = nlb.addListener(
        'NLBListener',
        {
          port: 80
        },
    )
    nlbListener.addTargets('NLBTargets', {
      protocol: elbv2.Protocol.TCP,
      port: 80,
      targets: [
          new elbv2Targtes.InstanceTarget(
              bastion.instance,
              80
          )
      ],
      healthCheck: {
        protocol: elbv2.Protocol.TCP,
        port: '80',
        interval: cdk.Duration.seconds(6),
        timeout: cdk.Duration.seconds(2),   //  Custom health check timeouts should be supported.
        healthyThresholdCount: 2,
        unhealthyThresholdCount: 2,
      },
    })
  }
}

const app = new App();
new NlbStack(app, 'my-test-stack', {
    env: { account: '', region: '' },
});