chore: changed and refactored providers (#36)

## Description

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At least please give us some description what you are trying to achieve and why your change is needed. -->

relates to #1234

## Checklist

- [ ] Issue was linked above
- [ ] Code format was applied: `make fmt`
- [ ] Examples were added / adjusted (see `examples/` directory)
- [x] Docs are up-to-date: `make generate-docs` (will be checked by CI)
- [ ] Unit tests got implemented or updated
- [ ] Acceptance tests got implemented or updated (see e.g. [here](f5f99d1709/stackit/internal/services/dns/dns_acc_test.go))
- [x] Unit tests are passing: `make test` (will be checked by CI)
- [x] No linter issues: `make lint` (will be checked by CI)

Co-authored-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>
Reviewed-on: #36
Reviewed-by: Marcel_Henselin <marcel.henselin@stackit.cloud>
Co-authored-by: Andre Harms <andre.harms@stackit.cloud>
Co-committed-by: Andre Harms <andre.harms@stackit.cloud>

stackit/internal/services/sqlserverflexalpha/instance/functions.go

@@ -14,26 +14,21 @@ import (
 	sqlserverflexResGen "tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/services/sqlserverflexalpha/instance/resources_gen"
 )
 
-func mapResponseToModel(
+// instanceModel is a type constraint for models that can be mapped from a GetInstanceResponse.
+type instanceModel interface {
+	*dataSourceModel | *resourceModel
+}
+
+func mapFields[T instanceModel](
 	ctx context.Context,
 	resp *sqlserverflex.GetInstanceResponse,
-	m *sqlserverflexResGen.InstanceModel,
+	m T,
 	tfDiags diag.Diagnostics,
 ) error {
-	m.BackupSchedule = types.StringValue(resp.GetBackupSchedule())
-	m.Edition = types.StringValue(string(resp.GetEdition()))
-	m.Encryption = handleEncryption(m, resp)
-	m.FlavorId = types.StringValue(resp.GetFlavorId())
-	m.Id = types.StringValue(resp.GetId())
-	m.InstanceId = types.StringValue(resp.GetId())
-	m.IsDeletable = types.BoolValue(resp.GetIsDeletable())
-	m.Name = types.StringValue(resp.GetName())
 	netAcl, diags := types.ListValueFrom(ctx, types.StringType, resp.Network.GetAcl())
 	tfDiags.Append(diags...)
 	if diags.HasError() {
-		return fmt.Errorf(
-			"error converting network acl response value",
-		)
+		return fmt.Errorf("error converting network acl response value")
 	}
 	net, diags := sqlserverflexResGen.NewNetworkValue(
 		sqlserverflexResGen.NetworkValue{}.AttributeTypes(ctx),
@@ -46,22 +41,8 @@ func mapResponseToModel(
 	)
 	tfDiags.Append(diags...)
 	if diags.HasError() {
-		return fmt.Errorf(
-			"error converting network response value",
-			"access_scope",
-			types.StringValue(string(resp.Network.GetAccessScope())),
-			"acl",
-			netAcl,
-			"instance_address",
-			types.StringValue(resp.Network.GetInstanceAddress()),
-			"router_address",
-			types.StringValue(resp.Network.GetRouterAddress()),
-		)
+		return fmt.Errorf("error converting network response value")
 	}
-	m.Network = net
-	m.Replicas = types.Int64Value(int64(resp.GetReplicas()))
-	m.RetentionDays = types.Int64Value(resp.GetRetentionDays())
-	m.Status = types.StringValue(string(resp.GetStatus()))
 
 	stor, diags := sqlserverflexResGen.NewStorageValue(
 		sqlserverflexResGen.StorageValue{}.AttributeTypes(ctx),
@@ -74,14 +55,47 @@ func mapResponseToModel(
 	if diags.HasError() {
 		return fmt.Errorf("error converting storage response value")
 	}
-	m.Storage = stor
 
-	m.Version = types.StringValue(string(resp.GetVersion()))
+	// The interface conversion is safe due to the type constraint.
+	model := any(m)
+
+	if rm, ok := model.(*resourceModel); ok {
+		rm.BackupSchedule = types.StringValue(resp.GetBackupSchedule())
+		rm.Edition = types.StringValue(string(resp.GetEdition()))
+		rm.Encryption = handleEncryption(rm.Encryption, resp)
+		rm.FlavorId = types.StringValue(resp.GetFlavorId())
+		rm.Id = types.StringValue(resp.GetId())
+		rm.InstanceId = types.StringValue(resp.GetId())
+		rm.IsDeletable = types.BoolValue(resp.GetIsDeletable())
+		rm.Name = types.StringValue(resp.GetName())
+		rm.Network = net
+		rm.Replicas = types.Int64Value(int64(resp.GetReplicas()))
+		rm.RetentionDays = types.Int64Value(resp.GetRetentionDays())
+		rm.Status = types.StringValue(string(resp.GetStatus()))
+		rm.Storage = stor
+		rm.Version = types.StringValue(string(resp.GetVersion()))
+	} else if dm, ok := model.(*dataSourceModel); ok {
+		dm.BackupSchedule = types.StringValue(resp.GetBackupSchedule())
+		dm.Edition = types.StringValue(string(resp.GetEdition()))
+		dm.Encryption = handleEncryption(dm.Encryption, resp)
+		dm.FlavorId = types.StringValue(resp.GetFlavorId())
+		dm.Id = types.StringValue(resp.GetId())
+		dm.InstanceId = types.StringValue(resp.GetId())
+		dm.IsDeletable = types.BoolValue(resp.GetIsDeletable())
+		dm.Name = types.StringValue(resp.GetName())
+		dm.Network = net
+		dm.Replicas = types.Int64Value(int64(resp.GetReplicas()))
+		dm.RetentionDays = types.Int64Value(resp.GetRetentionDays())
+		dm.Status = types.StringValue(string(resp.GetStatus()))
+		dm.Storage = stor
+		dm.Version = types.StringValue(string(resp.GetVersion()))
+	}
+
 	return nil
 }
 
 func handleEncryption(
-	m *sqlserverflexResGen.InstanceModel,
+	encryptionValue sqlserverflexResGen.EncryptionValue,
 	resp *sqlserverflex.GetInstanceResponse,
 ) sqlserverflexResGen.EncryptionValue {
 	if !resp.HasEncryption() ||
@@ -91,10 +105,10 @@ func handleEncryption(
 		resp.Encryption.KekKeyVersion == nil ||
 		resp.Encryption.ServiceAccount == nil {
 
-		if m.Encryption.IsNull() || m.Encryption.IsUnknown() {
+		if encryptionValue.IsNull() || encryptionValue.IsUnknown() {
 			return sqlserverflexResGen.NewEncryptionValueNull()
 		}
-		return m.Encryption
+		return encryptionValue
 	}
 
 	enc := sqlserverflexResGen.NewEncryptionValueNull()