package arm

import (
	"context"
	"errors"
	"fmt"
	"net/url"
	"strings"
	"sync"
	"time"

	"github.com/hashicorp/packer-plugin-sdk/multistep"
	packersdk "github.com/hashicorp/packer-plugin-sdk/packer"
	"github.com/hashicorp/packer-plugin-sdk/retry"
	"github.com/hashicorp/packer/builder/azure/common/constants"
)

type StepDeployTemplate struct {
	client           *AzureClient
	deploy           func(ctx context.Context, resourceGroupName string, deploymentName string) error
	delete           func(ctx context.Context, deploymentName, resourceGroupName string) error
	disk             func(ctx context.Context, resourceGroupName string, computeName string) (string, string, error)
	deleteDisk       func(ctx context.Context, imageType string, imageName string, resourceGroupName string) error
	deleteDeployment func(ctx context.Context, state multistep.StateBag) error
	say              func(message string)
	error            func(e error)
	config           *Config
	factory          templateFactoryFunc
	name             string
}

func NewStepDeployTemplate(client *AzureClient, ui packersdk.Ui, config *Config, deploymentName string, factory templateFactoryFunc) *StepDeployTemplate {
	var step = &StepDeployTemplate{
		client:  client,
		say:     func(message string) { ui.Say(message) },
		error:   func(e error) { ui.Error(e.Error()) },
		config:  config,
		factory: factory,
		name:    deploymentName,
	}

	step.deploy = step.deployTemplate
	step.delete = step.deleteDeploymentResources
	step.disk = step.getImageDetails
	step.deleteDisk = step.deleteImage
	step.deleteDeployment = step.deleteDeploymentObject
	return step
}

func (s *StepDeployTemplate) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
	s.say("Deploying deployment template ...")

	var resourceGroupName = state.Get(constants.ArmResourceGroupName).(string)
	s.say(fmt.Sprintf(" -> ResourceGroupName : '%s'", resourceGroupName))
	s.say(fmt.Sprintf(" -> DeploymentName    : '%s'", s.name))

	return processStepResult(
		s.deploy(ctx, resourceGroupName, s.name),
		s.error, state)
}

func (s *StepDeployTemplate) Cleanup(state multistep.StateBag) {
	defer func() {
		err := s.deleteDeployment(context.Background(), state)
		if err != nil {
			s.say(err.Error())
		}
	}()

	ui := state.Get("ui").(packersdk.Ui)
	ui.Say("\nDeleting individual resources ...")

	deploymentName := s.name
	resourceGroupName := state.Get(constants.ArmResourceGroupName).(string)
	// Get image disk details before deleting the image; otherwise we won't be able to
	// delete the disk as the image request will return a 404
	computeName := state.Get(constants.ArmComputeName).(string)
	imageType, imageName, err := s.disk(context.TODO(), resourceGroupName, computeName)

	if err != nil && !strings.Contains(err.Error(), "ResourceNotFound") {
		ui.Error(fmt.Sprintf("Could not retrieve OS Image details: %s", err))
	}
	err = s.delete(context.TODO(), deploymentName, resourceGroupName)
	if err != nil {
		s.reportIfError(err, resourceGroupName)
	}

	// The disk was not found on the VM, this is an error.
	if imageType == "" && imageName == "" {
		ui.Error(fmt.Sprintf("Failed to find temporary OS disk on VM.  Please delete manually.\n\n"+
			"VM Name: %s\n"+
			"Error: %s", computeName, err))
		return
	}

	ui.Say(fmt.Sprintf(" Deleting -> %s : '%s'", imageType, imageName))
	err = s.deleteDisk(context.TODO(), imageType, imageName, resourceGroupName)
	if err != nil {
		ui.Error(fmt.Sprintf("Error deleting resource.  Please delete manually.\n\n"+
			"Name: %s\n"+
			"Error: %s", imageName, err))
	}
}

func (s *StepDeployTemplate) deployTemplate(ctx context.Context, resourceGroupName string, deploymentName string) error {
	deployment, err := s.factory(s.config)
	if err != nil {
		return err
	}

	f, err := s.client.DeploymentsClient.CreateOrUpdate(ctx, resourceGroupName, deploymentName, *deployment)
	if err != nil {
		s.say(s.client.LastError.Error())
		return err
	}

	err = f.WaitForCompletionRef(ctx, s.client.DeploymentsClient.Client)
	if err == nil {
		s.say(s.client.LastError.Error())
	}

	return err
}

func (s *StepDeployTemplate) deleteDeploymentObject(ctx context.Context, state multistep.StateBag) error {
	deploymentName := s.name
	resourceGroupName := state.Get(constants.ArmResourceGroupName).(string)
	ui := state.Get("ui").(packersdk.Ui)

	ui.Say(fmt.Sprintf("Removing the created Deployment object: '%s'", deploymentName))
	f, err := s.client.DeploymentsClient.Delete(ctx, resourceGroupName, deploymentName)
	if err != nil {
		return err
	}

	return f.WaitForCompletionRef(ctx, s.client.DeploymentsClient.Client)
}

func (s *StepDeployTemplate) getImageDetails(ctx context.Context, resourceGroupName string, computeName string) (string, string, error) {
	//We can't depend on constants.ArmOSDiskVhd being set
	var imageName, imageType string
	vm, err := s.client.VirtualMachinesClient.Get(ctx, resourceGroupName, computeName, "")
	if err != nil {
		return imageName, imageType, err
	}

	if vm.StorageProfile.OsDisk.Vhd != nil {
		imageType = "image"
		imageName = *vm.StorageProfile.OsDisk.Vhd.URI
		return imageType, imageName, nil
	}

	imageType = "Microsoft.Compute/disks"
	imageName = *vm.StorageProfile.OsDisk.ManagedDisk.ID

	return imageType, imageName, nil
}

//TODO(paulmey): move to helpers file
func deleteResource(ctx context.Context, client *AzureClient, resourceType string, resourceName string, resourceGroupName string) error {
	switch resourceType {
	case "Microsoft.Compute/virtualMachines":
		f, err := client.VirtualMachinesClient.Delete(ctx, resourceGroupName, resourceName)
		if err == nil {
			err = f.WaitForCompletionRef(ctx, client.VirtualMachinesClient.Client)
		}
		return err
	case "Microsoft.KeyVault/vaults":
		_, err := client.VaultClientDelete.Delete(ctx, resourceGroupName, resourceName)
		return err
	case "Microsoft.Network/networkInterfaces":
		f, err := client.InterfacesClient.Delete(ctx, resourceGroupName, resourceName)
		if err == nil {
			err = f.WaitForCompletionRef(ctx, client.InterfacesClient.Client)
		}
		return err
	case "Microsoft.Network/virtualNetworks":
		f, err := client.VirtualNetworksClient.Delete(ctx, resourceGroupName, resourceName)
		if err == nil {
			err = f.WaitForCompletionRef(ctx, client.VirtualNetworksClient.Client)
		}
		return err
	case "Microsoft.Network/networkSecurityGroups":
		f, err := client.SecurityGroupsClient.Delete(ctx, resourceGroupName, resourceName)
		if err == nil {
			err = f.WaitForCompletionRef(ctx, client.SecurityGroupsClient.Client)
		}
		return err
	case "Microsoft.Network/publicIPAddresses":
		f, err := client.PublicIPAddressesClient.Delete(ctx, resourceGroupName, resourceName)
		if err == nil {
			err = f.WaitForCompletionRef(ctx, client.PublicIPAddressesClient.Client)
		}
		return err
	}
	return nil
}

func (s *StepDeployTemplate) deleteImage(ctx context.Context, imageType string, imageName string, resourceGroupName string) error {
	// Managed disk
	if imageType == "Microsoft.Compute/disks" {
		xs := strings.Split(imageName, "/")
		diskName := xs[len(xs)-1]
		f, err := s.client.DisksClient.Delete(ctx, resourceGroupName, diskName)
		if err == nil {
			err = f.WaitForCompletionRef(ctx, s.client.DisksClient.Client)
		}
		return err
	}

	// VHD image
	u, err := url.Parse(imageName)
	if err != nil {
		return err
	}
	xs := strings.Split(u.Path, "/")
	if len(xs) < 3 {
		return errors.New("Unable to parse path of image " + imageName)
	}
	var storageAccountName = xs[1]
	var blobName = strings.Join(xs[2:], "/")

	blob := s.client.BlobStorageClient.GetContainerReference(storageAccountName).GetBlobReference(blobName)
	_, err = blob.BreakLease(nil)
	if err != nil && !strings.Contains(err.Error(), "LeaseNotPresentWithLeaseOperation") {
		s.say(s.client.LastError.Error())
		return err
	}

	return blob.Delete(nil)
}

func (s *StepDeployTemplate) deleteDeploymentResources(ctx context.Context, deploymentName, resourceGroupName string) error {
	var maxResources int32 = 50
	deploymentOperations, err := s.client.DeploymentOperationsClient.ListComplete(ctx, resourceGroupName, deploymentName, &maxResources)
	if err != nil {
		s.reportIfError(err, resourceGroupName)
		return err
	}

	resources := map[string]string{}

	for deploymentOperations.NotDone() {
		deploymentOperation := deploymentOperations.Value()
		// Sometimes an empty operation is added to the list by Azure
		if deploymentOperation.Properties.TargetResource == nil {
			_ = deploymentOperations.Next()
			continue
		}

		resourceName := *deploymentOperation.Properties.TargetResource.ResourceName
		resourceType := *deploymentOperation.Properties.TargetResource.ResourceType

		s.say(fmt.Sprintf("Adding to deletion queue -> %s : '%s'", resourceType, resourceName))
		resources[resourceType] = resourceName

		if err = deploymentOperations.Next(); err != nil {
			return err
		}
	}

	var wg sync.WaitGroup
	wg.Add(len(resources))

	for resourceType, resourceName := range resources {
		go func(resourceType, resourceName string) {
			defer wg.Done()
			retryConfig := retry.Config{
				Tries:      10,
				RetryDelay: (&retry.Backoff{InitialBackoff: 10 * time.Second, MaxBackoff: 600 * time.Second, Multiplier: 2}).Linear,
			}

			err = retryConfig.Run(ctx, func(ctx context.Context) error {
				s.say(fmt.Sprintf("Attempting deletion -> %s : '%s'", resourceType, resourceName))
				err := deleteResource(ctx, s.client,
					resourceType,
					resourceName,
					resourceGroupName)
				if err != nil {
					s.say(fmt.Sprintf("Error deleting resource. Will retry.\n"+
						"Name: %s\n"+
						"Error: %s\n", resourceName, err.Error()))
				}
				return err
			})
			if err != nil {
				s.reportIfError(err, resourceName)
			}
		}(resourceType, resourceName)
	}

	s.say("Waiting for deletion of all resources...")
	wg.Wait()

	return nil
}

func (s *StepDeployTemplate) reportIfError(err error, resourceName string) {
	if err != nil {
		s.say(fmt.Sprintf("Error deleting resource. Please delete manually.\n\n"+
			"Name: %s\n"+
			"Error: %s", resourceName, err.Error()))
		s.error(err)
	}
}