Tidy up polling now that datastore bug is fixed

A server side datastore bug [1] has been fixed. This allows us to
refactor polling the relevant async operation in a way that
is less specific to the resource type.

[1] FF-28659

internal/async/async.go

@@ -0,0 +1,166 @@
+package async
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"github.com/HewlettPackard/hpegl-pcbe-terraform-resources/internal/client"
+	"github.com/HewlettPackard/hpegl-pcbe-terraform-resources/internal/sdk/async/dataservices"
+)
+
+type Operation struct {
+	ctx                    context.Context
+	client                 client.PCBeClient
+	operationID            string
+	associatedResourceType string
+	opResp                 dataservices.V1beta1AsyncOperationsItemAsyncOperationsGetResponseable
+}
+
+// New returns a new Operation struct that can be used to poll
+// pre-existing asynchronous operations for any resource type.
+func New(
+	ctx context.Context,
+	client client.PCBeClient,
+	OperationID string,
+	associatedResourceType string,
+) Operation {
+	a := Operation{}
+	a.ctx = ctx
+	a.client = client
+	a.operationID = OperationID
+	a.associatedResourceType = associatedResourceType
+
+	return a
+}
+
+func (a Operation) GetSourceResourceURI() (string, error) {
+	if a.opResp == nil {
+		msg := "GetSourceResourceURI requies a non-nil opResp"
+
+		return "", errors.New(msg)
+	}
+
+	if a.opResp.GetSourceResourceUri() == nil {
+		msg := "GetSourceResourceURI requies a non-nil GetSourceResourceUri"
+
+		return "", errors.New(msg)
+	}
+
+	return *a.opResp.GetSourceResourceUri(), nil
+}
+
+func (a Operation) GetAssociatedResourceURI() (string, error) {
+	if a.opResp == nil {
+		msg := "GetAssociatedResourceURI requies a non-nil opResp"
+
+		return "", errors.New(msg)
+	}
+
+	if len(a.opResp.GetAssociatedResources()) != 1 {
+		msg := "GetAssociatedResourceURI requires exactly one associatedResource"
+
+		return "", errors.New(msg)
+
+	}
+
+	if a.opResp.GetAssociatedResources()[0].GetTypeEscaped() == nil {
+		msg := "GetAssociatedResourceURI requires a non-nil associatedResource type"
+
+		return "", errors.New(msg)
+	}
+
+	typeEscaped := *(a.opResp.GetAssociatedResources()[0].GetTypeEscaped())
+	if typeEscaped != a.associatedResourceType {
+		msg := "GetAssociatedResourceURI type mismatch (" + typeEscaped +
+			" != " + a.associatedResourceType + ")"
+
+		return "", errors.New(msg)
+	}
+
+	if a.opResp.GetAssociatedResources()[0].GetResourceUri() == nil {
+		msg := "GetAssociatedResourceURI requires a non-nil associatedResource uri"
+
+		return "", errors.New(msg)
+	}
+
+	return *(a.opResp.GetAssociatedResources()[0].GetResourceUri()), nil
+}
+
+// Poll waits for an asynchronous operation to complete
+// It is not thread safe (but does not currently need to be)
+// Typically the operation flow will be:
+//
+//	a := New(...)
+//	a.Poll()
+//	uri ... = a.GetAssociatedResourceURI()
+func (a *Operation) Poll() error {
+	maxPolls := int(a.client.Config.MaxPolls)
+	pollWaitTime := time.Duration(a.client.Config.PollInterval) * time.Second
+
+	asyncClient, err := a.client.NewAsyncClient(a.ctx)
+	if err != nil {
+		msg := "error polling async operation " + a.operationID + ": " +
+			err.Error()
+
+		return errors.New(msg)
+	}
+
+	var opResp dataservices.V1beta1AsyncOperationsItemAsyncOperationsGetResponseable
+	arc := dataservices.
+		V1beta1AsyncOperationsAsyncOperationsItemRequestBuilderGetRequestConfiguration{}
+
+	for count := 1; ; count++ {
+		opResp, err = asyncClient.DataServices().
+			V1beta1().
+			AsyncOperations().
+			ById(a.operationID).
+			Get(a.ctx, &arc)
+
+		if err != nil {
+			msg := "error polling async operation " + a.operationID + ": " + err.Error()
+
+			return errors.New(msg)
+		}
+
+		if opResp == nil {
+			msg := "error polling async operation " + a.operationID + ": " +
+				"nil op response"
+
+			return errors.New(msg)
+		}
+
+		opRespState := opResp.GetState()
+		if opRespState == nil {
+			msg := "error polling async operation " + a.operationID + ": " +
+				"operation has nil state"
+
+			return errors.New(msg)
+		}
+
+		// TODO: (API) Use enum not string for state when FF-28181 is fixed
+		if *opRespState == "FAILED" {
+			msg := "error polling async operation " + a.operationID + "operation state FAILED"
+
+			return errors.New(msg)
+		}
+
+		// TODO: (API) Use enum not string for state when FF-28181 is fixed
+		if *opRespState == "SUCCEEDED" {
+			a.opResp = opResp
+
+			break
+		}
+
+		if count == maxPolls {
+			msg := "error polling async operation " + a.operationID + ": " +
+				"max polls exceeded"
+
+			return errors.New(msg)
+		}
+
+		time.Sleep(pollWaitTime)
+	}
+
+	return nil
+}

internal/constants/constants.go

@@ -3,10 +3,12 @@
 package constants
 
 const (
-	ProviderType          = "hpegl"
-	ProviderBlock         = "pc"
-	NameFilter            = "name eq "
-	HciClusterUUIDFilter  = "hciClusterUuid eq "
-	AndFilter             = " and "
+	ProviderType         = "hpegl"
+	ProviderBlock        = "pc"
+	NameFilter           = "name eq "
+	HciClusterUUIDFilter = "hciClusterUuid eq "
+	AndFilter            = " and "
+
 	TaskHypervisorCluster = "hypervisor-cluster" // task's "associatedResources" string
+	TaskDatastore         = "datastore"          // task's "associatedResources" string
 )