import software.amazon.awssdk.services.iot.IotClient;
import software.amazon.awssdk.services.iot.model.*;
import software.amazon.awssdk.services.iotdataplane.IotDataPlaneClient;
import software.amazon.awssdk.services.iotdataplane.model.DeleteThingShadowRequest;
import software.amazon.awssdk.services.iotdataplane.model.GetThingShadowRequest;
import software.amazon.awssdk.services.iotdataplane.model.IotDataPlaneException;
import software.amazon.awssdk.services.kinesisvideo.KinesisVideoClient;
import software.amazon.awssdk.services.kinesisvideo.model.DeleteSignalingChannelRequest;
import software.amazon.awssdk.services.kinesisvideo.model.DescribeSignalingChannelRequest;
import software.amazon.awssdk.services.kinesisvideo.model.DescribeSignalingChannelResponse;
import software.amazon.awssdk.services.kinesisvideo.model.DeleteStreamRequest;
import software.amazon.awssdk.services.kinesisvideo.model.DescribeStreamRequest;
import software.amazon.awssdk.services.kinesisvideo.model.DescribeStreamResponse;
import software.amazon.awssdk.services.kinesisvideo.model.KinesisVideoException;
import software.amazon.awssdk.arns.Arn;

import java.util.Arrays;
import java.util.List;

public void deleteDevice(
    final String thingName,
    final IotClient iotClient,
    final IotDataPlaneClient iotDataPlaneClient,
    final KinesisVideoClient kvsClient
) {
    // Validate if device exists
    System.out.println("Checking if device exist.");
    try {
        iotClient.describeThing(DescribeThingRequest.builder().thingName(deviceId).build());
    } catch (ResourceNotFoundException e){
        System.out.printf("Thing %s doesn't exist.%n", deviceId);
        return;
    }

    System.out.println("Deleting thing shadows");

    // null represents classic shadow which does not have a name
    // If more shadows are created for additional features, add them here
    List<String> shadowNames = Arrays.asList(null, "provision", "snapshot", "videoEncoder");

    for (String shadowName: shadowNames) {
        try {
            GetThingShadowRequest getThingShadowRequest = GetThingShadowRequest.builder()
                .thingName(deviceId)
                .shadowName(shadowName)
                .build();
            iotDataPlaneClient.getThingShadow(getThingShadowRequest);
            // if ResourceNotFoundException is not thrown, shadow exists
            try {
                DeleteThingShadowRequest deleteThingShadowRequest = DeleteThingShadowRequest.builder()
                    .thingName(deviceId)
                    .shadowName(shadowName)
                    .build();
                iotDataPlaneClient.deleteThingShadow(deleteThingShadowRequest);
            } catch (IotDataPlaneException e) {
                System.out.println(e);
            }
        } catch (software.amazon.awssdk.services.iotdataplane.model.ResourceNotFoundException e) {
            // shadow does not exist, no-op
        }
    }

    ListThingPrincipalsRequest listThingPrincipalsRequest = ListThingPrincipalsRequest.builder()
        .thingName(deviceId)
        .build();
    try {
        List<String> principals = iotClient.listThingPrincipals(listThingPrincipalsRequest).principals();

        System.out.println("Detaching cert from device");

        for (String principal: principals) {
            DetachThingPrincipalRequest detachThingPrincipalRequest = DetachThingPrincipalRequest.builder()
                .principal(principal)
                .thingName(deviceId)
                .build();
            iotClient.detachThingPrincipal(detachThingPrincipalRequest);

            Arn arn = Arn.fromString(principal);
            ArnResource arnResource = arn.resource();
            if (arnResource.resourceType().orElse("").equals("cert")) {
                ListAttachedPoliciesRequest listAttachedPoliciesRequest = ListAttachedPoliciesRequest.builder()
                    .target(principal)
                    .build();
                List<Policy> policies = iotClient.listAttachedPolicies(listAttachedPoliciesRequest).policies();

                System.out.println("Detaching policies from cert");

                for (Policy policy: policies) {
                    DetachPolicyRequest detachPolicyRequest = DetachPolicyRequest.builder()
                        .policyName(policy.policyName())
                        .target(principal)
                        .build();
                    iotClient.detachPolicy(detachPolicyRequest);
                }

                // Certificate must be deactivated before being deleted
                System.out.println("Deactivating cert");

                String certificateId = arnResource.resource();
                UpdateCertificateRequest updateCertificateRequest = UpdateCertificateRequest.builder()
                    .certificateId(certificateId)
                    .newStatus(CertificateStatus.INACTIVE)
                    .build();
                iotClient.updateCertificate(updateCertificateRequest);

                System.out.println("Deleting cert");

                DeleteCertificateRequest deleteCertificateRequest = DeleteCertificateRequest.builder()
                    .certificateId(certificateId)
                    .build();
                iotClient.deleteCertificate(deleteCertificateRequest);
            }
        }
    } catch (IotException e) {
        System.out.println(e);
    }

    System.out.println("Deleting KVS stream");

    // By default, only 1 KVS stream (name=deviceId) is created.
    // If more are created, add them here
    try {
        DescribeStreamRequest describeStreamRequest = DescribeStreamRequest.builder()
                .streamName(deviceId)
                .build();
        DescribeStreamResponse describeStreamResponse = kvsClient.describeStream(describeStreamRequest);
        DeleteStreamRequest deleteStreamRequest = DeleteStreamRequest.builder()
            .streamARN(describeStreamResponse.streamInfo().streamARN())
            .build();
        kvsClient.deleteStream(deleteStreamRequest);
    } catch (KinesisVideoException e) {
        System.out.println(e);
    }

    System.out.println("Deleting KVS signaling channels");

    // By default, only 2 KVS signaling channels are created with deviceId and the following suffixes.
    // If more are created, add them here
    List<String> channelSuffixes = List.of("%s-LiveStreamSignalingChannel", "%s-PlaybackSignalingChannel");

    for (String suffix: channelSuffixes) {  
        String signalingChannelName = String.format(suffix, deviceId);  
        try {
            DescribeSignalingChannelRequest describeSignalingChannelRequest = DescribeSignalingChannelRequest.builder()
                .channelName(signalingChannelName)
                .build();
            DescribeSignalingChannelResponse describeSignalingChannelResponse = kvsClient.describeSignalingChannel(describeSignalingChannelRequest);
            DeleteSignalingChannelRequest deleteSignalingChannelRequest = DeleteSignalingChannelRequest.builder()
                .channelARN(describeSignalingChannelResponse.channelInfo().channelARN())
                .build();
            kvsClient.deleteSignalingChannel(deleteSignalingChannelRequest);
        } catch (KinesisVideoException e) {
            System.out.println(e);
        }
    }

    System.out.println("Deleting thing");
    DeleteThingRequest deleteThingRequest = DeleteThingRequest.builder()
        .thingName(deviceId)
        .build();
    try {
        iotClient.deleteThing(deleteThingRequest);
    } catch (IotException e) {
        System.out.println(e);
    }
}