import {
  App,
  CfnOutput,
  Duration,
  RemovalPolicy,
  Stack,
  StackProps,
} from "aws-cdk-lib";
import {
  MachineImage,
  Instance,
  InstanceClass,
  InstanceSize,
  InstanceType,
  IpAddresses,
  KeyPair,
  Peer,
  Port,
  SecurityGroup,
  SubnetType,
  Vpc,
} from "aws-cdk-lib/aws-ec2";
import {
  Credentials,
  DatabaseInstance,
  DatabaseInstanceEngine,
  PostgresEngineVersion,
} from "aws-cdk-lib/aws-rds";

export class DeployRDSEC2Stack extends Stack {
  constructor(scope: App, id: string, props?: StackProps) {
    super(scope, id, props);

    // create a vpc
    const vpc = new Vpc(this, "main-vpc", {
      ipAddresses: IpAddresses.cidr("10.0.0.0/16"),
      natGateways: 0,
      maxAzs: 2,
      subnetConfiguration: [
        {
          name: "public-subnet-1",
          subnetType: SubnetType.PUBLIC,
          cidrMask: 24,
        },
        {
          name: "isolated-subnet-1",
          subnetType: SubnetType.PRIVATE_ISOLATED,
          cidrMask: 28,
        },
      ],
    });

    // create a security group for the EC2 instance
    const ec2InstanceSG = new SecurityGroup(this, "ec2-instance-sg", {
      vpc,
    });

    ec2InstanceSG.addIngressRule(
      Peer.ipv4(this.node.tryGetContext("sshCidr")),
      Port.tcp(22),
      "allow SSH from the configured client IPv4 CIDR"
    );

    // importing your SSH key
    const keyPair = KeyPair.fromKeyPairName(this, "key-pair", "ec2-demo-key-pair");

    // create the EC2 instance
    const ec2Instance = new Instance(this, "ec2-instance", {
      vpc,
      vpcSubnets: {
        subnetType: SubnetType.PUBLIC,
      },
      securityGroup: ec2InstanceSG,
      instanceType: InstanceType.of(
        InstanceClass.BURSTABLE3,
        InstanceSize.MICRO
      ),
      machineImage: MachineImage.latestAmazonLinux2023(),
      associatePublicIpAddress: true,
      keyPair,
    });

    new CfnOutput(this, "Ec2PublicIp", {
      value: ec2Instance.instancePublicIp,
    });
    // create RDS Instance
    const dbInstance = new DatabaseInstance(this, "db-instance", {
      vpc,
      vpcSubnets: {
        subnetType: SubnetType.PRIVATE_ISOLATED,
      },
      engine: DatabaseInstanceEngine.postgres({
        version: PostgresEngineVersion.VER_16,
      }),
      instanceType: InstanceType.of(
        InstanceClass.BURSTABLE3,
        InstanceSize.MICRO
      ),
      credentials: Credentials.fromGeneratedSecret("postgres"),
      multiAz: false,
      allocatedStorage: 100,
      storageEncrypted: true,
      maxAllocatedStorage: 120,
      allowMajorVersionUpgrade: false,
      autoMinorVersionUpgrade: true,
      backupRetention: Duration.days(0),
      deleteAutomatedBackups: true,
      removalPolicy: RemovalPolicy.DESTROY,
      deletionProtection: false,
      databaseName: "testdb",
      publiclyAccessible: false,
    });

    dbInstance.connections.allowFrom(ec2Instance, Port.tcp(5432));

    new CfnOutput(this, "DbEndpoint", {
      value: dbInstance.instanceEndpoint.hostname,
    });

    new CfnOutput(this, "SecretName", {
      value: dbInstance.secret?.secretName!,
    });
  }
}