Alpha (#4)

* chore: initial push to be able to work together

* chore: add missing wait folder

* chore: add missing folders

* chore: cleanup alpha branch

* feat: mssql alpha instance (#2)

* fix: remove unused attribute types and functions from backup models

* fix: update API client references to use sqlserverflexalpha package

* fix: update package references to use sqlserverflexalpha and modify user data source model

* fix: add sqlserverflexalpha user data source to provider

* fix: add sqlserverflexalpha user resource and update related functionality

* chore: add stackit_sqlserverflexalpha_user resource and instance_id variable

* fix: refactor sqlserverflexalpha user resource and enhance schema with status and default_database

---------

Co-authored-by: Andre Harms <andre.harms@stackit.cloud>
Co-authored-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>

* feat: add sqlserver instance

* chore: fixing tests

* chore: update docs

---------

Co-authored-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>
Co-authored-by: Andre Harms <andre.harms@stackit.cloud>

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

@@ -0,0 +1,916 @@
+package sqlserverflex
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/hashicorp/terraform-plugin-framework-validators/int64validator"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/boolplanmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/listplanmodifier"
+	sqlserverflexUtils "github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/sqlserverflexalpha/utils"
+
+	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
+	"github.com/hashicorp/terraform-plugin-framework/attr"
+	"github.com/hashicorp/terraform-plugin-framework/path"
+	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
+	"github.com/hashicorp/terraform-plugin-framework/types/basetypes"
+	"github.com/hashicorp/terraform-plugin-log/tflog"
+	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion"
+	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/core"
+	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils"
+	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/validate"
+
+	"github.com/hashicorp/terraform-plugin-framework/resource"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/int64planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/objectplanmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/stackitcloud/stackit-sdk-go/core/oapierror"
+	sqlserverflex "github.com/stackitcloud/terraform-provider-stackit/pkg/sqlserverflexalpha"
+	"github.com/stackitcloud/terraform-provider-stackit/pkg/sqlserverflexalpha/wait"
+)
+
+// Ensure the implementation satisfies the expected interfaces.
+var (
+	_ resource.Resource                = &instanceResource{}
+	_ resource.ResourceWithConfigure   = &instanceResource{}
+	_ resource.ResourceWithImportState = &instanceResource{}
+	_ resource.ResourceWithModifyPlan  = &instanceResource{}
+)
+
+var validNodeTypes []string = []string{
+	"Single",
+	"Replica",
+}
+
+type Model struct {
+	Id             types.String `tfsdk:"id"` // needed by TF
+	InstanceId     types.String `tfsdk:"instance_id"`
+	ProjectId      types.String `tfsdk:"project_id"`
+	Name           types.String `tfsdk:"name"`
+	BackupSchedule types.String `tfsdk:"backup_schedule"`
+	Flavor         types.Object `tfsdk:"flavor"`
+	Encryption     types.Object `tfsdk:"encryption"`
+	IsDeletable    types.Bool   `tfsdk:"is_deletable"`
+	Storage        types.Object `tfsdk:"storage"`
+	Status         types.String `tfsdk:"status"`
+	Version        types.String `tfsdk:"version"`
+	Replicas       types.Int64  `tfsdk:"replicas"`
+	Region         types.String `tfsdk:"region"`
+	Network        types.Object `tfsdk:"network"`
+	Edition        types.String `tfsdk:"edition"`
+	RetentionDays  types.Int64  `tfsdk:"retention_days"`
+}
+
+type encryptionModel struct {
+	KeyRingId      types.String `tfsdk:"keyring_id"`
+	KeyId          types.String `tfsdk:"key_id"`
+	KeyVersion     types.String `tfsdk:"key_version"`
+	ServiceAccount types.String `tfsdk:"service_account"`
+}
+
+var encryptionTypes = map[string]attr.Type{
+	"keyring_id":      basetypes.StringType{},
+	"key_id":          basetypes.StringType{},
+	"key_version":     basetypes.StringType{},
+	"service_account": basetypes.StringType{},
+}
+
+type networkModel struct {
+	ACL             types.List   `tfsdk:"acl"`
+	AccessScope     types.String `tfsdk:"access_scope"`
+	InstanceAddress types.String `tfsdk:"instance_address"`
+	RouterAddress   types.String `tfsdk:"router_address"`
+}
+
+var networkTypes = map[string]attr.Type{
+	"acl":              basetypes.ListType{ElemType: types.StringType},
+	"access_scope":     basetypes.StringType{},
+	"instance_address": basetypes.StringType{},
+	"router_address":   basetypes.StringType{},
+}
+
+// Struct corresponding to Model.FlavorId
+type flavorModel struct {
+	Id          types.String `tfsdk:"id"`
+	Description types.String `tfsdk:"description"`
+	CPU         types.Int64  `tfsdk:"cpu"`
+	RAM         types.Int64  `tfsdk:"ram"`
+	NodeType    types.String `tfsdk:"node_type"`
+}
+
+// Types corresponding to flavorModel
+var flavorTypes = map[string]attr.Type{
+	"id":          basetypes.StringType{},
+	"description": basetypes.StringType{},
+	"cpu":         basetypes.Int64Type{},
+	"ram":         basetypes.Int64Type{},
+	"node_type":   basetypes.StringType{},
+}
+
+// Struct corresponding to Model.Storage
+type storageModel struct {
+	Class types.String `tfsdk:"class"`
+	Size  types.Int64  `tfsdk:"size"`
+}
+
+// Types corresponding to storageModel
+var storageTypes = map[string]attr.Type{
+	"class": basetypes.StringType{},
+	"size":  basetypes.Int64Type{},
+}
+
+// NewInstanceResource is a helper function to simplify the provider implementation.
+func NewInstanceResource() resource.Resource {
+	return &instanceResource{}
+}
+
+// instanceResource is the resource implementation.
+type instanceResource struct {
+	client       *sqlserverflex.APIClient
+	providerData core.ProviderData
+}
+
+// Metadata returns the resource type name.
+func (r *instanceResource) Metadata(_ context.Context, req resource.MetadataRequest, resp *resource.MetadataResponse) {
+	resp.TypeName = req.ProviderTypeName + "_sqlserverflexalpha_instance"
+}
+
+// Configure adds the provider configured client to the resource.
+func (r *instanceResource) Configure(ctx context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
+	var ok bool
+	r.providerData, ok = conversion.ParseProviderData(ctx, req.ProviderData, &resp.Diagnostics)
+	if !ok {
+		return
+	}
+
+	apiClient := sqlserverflexUtils.ConfigureClient(ctx, &r.providerData, &resp.Diagnostics)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	r.client = apiClient
+	tflog.Info(ctx, "SQLServer Flex instance client configured")
+}
+
+// ModifyPlan implements resource.ResourceWithModifyPlan.
+// Use the modifier to set the effective region in the current plan.
+func (r *instanceResource) ModifyPlan(ctx context.Context, req resource.ModifyPlanRequest, resp *resource.ModifyPlanResponse) { // nolint:gocritic // function signature required by Terraform
+	var configModel Model
+	// skip initial empty configuration to avoid follow-up errors
+	if req.Config.Raw.IsNull() {
+		return
+	}
+	resp.Diagnostics.Append(req.Config.Get(ctx, &configModel)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	var planModel Model
+	resp.Diagnostics.Append(req.Plan.Get(ctx, &planModel)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	utils.AdaptRegion(ctx, configModel.Region, &planModel.Region, r.providerData.GetRegion(), resp)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	resp.Diagnostics.Append(resp.Plan.Set(ctx, planModel)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+}
+
+// Schema defines the schema for the resource.
+func (r *instanceResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
+	descriptions := map[string]string{
+		"main":             "SQLServer Flex ALPHA instance resource schema. Must have a `region` specified in the provider configuration.",
+		"id":               "Terraform's internal resource ID. It is structured as \"`project_id`,`region`,`instance_id`\".",
+		"instance_id":      "ID of the SQLServer Flex instance.",
+		"project_id":       "STACKIT project ID to which the instance is associated.",
+		"name":             "Instance name.",
+		"access_scope":     "The access scope of the instance. (e.g. SNA)",
+		"acl":              "The Access Control List (ACL) for the SQLServer Flex instance.",
+		"backup_schedule":  `The backup schedule. Should follow the cron scheduling system format (e.g. "0 0 * * *")`,
+		"region":           "The resource region. If not defined, the provider region is used.",
+		"encryption":       "The encryption block.",
+		"network":          "The network block.",
+		"keyring_id":       "STACKIT KMS - KeyRing ID of the encryption key to use.",
+		"key_id":           "STACKIT KMS - Key ID of the encryption key to use.",
+		"key_version":      "STACKIT KMS - Key version to use in the encryption key.",
+		"service:account":  "STACKIT KMS - service account to use in the encryption key.",
+		"instance_address": "The returned instance IP address of the SQLServer Flex instance.",
+		"router_address":   "The returned router IP address of the SQLServer Flex instance.",
+	}
+
+	resp.Schema = schema.Schema{
+		Description: descriptions["main"],
+		Attributes: map[string]schema.Attribute{
+			"id": schema.StringAttribute{
+				Description: descriptions["id"],
+				Computed:    true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.UseStateForUnknown(),
+				},
+			},
+			"instance_id": schema.StringAttribute{
+				Description: descriptions["instance_id"],
+				Computed:    true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.UseStateForUnknown(),
+				},
+				Validators: []validator.String{
+					validate.UUID(),
+					validate.NoSeparator(),
+				},
+			},
+			"project_id": schema.StringAttribute{
+				Description: descriptions["project_id"],
+				Required:    true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.RequiresReplace(),
+				},
+				Validators: []validator.String{
+					validate.UUID(),
+					validate.NoSeparator(),
+				},
+			},
+			"name": schema.StringAttribute{
+				Description: descriptions["name"],
+				Required:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthAtLeast(1),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile("^[a-z]([-a-z0-9]*[a-z0-9])?$"),
+						"must start with a letter, must have lower case letters, numbers or hyphens, and no hyphen at the end",
+					),
+				},
+			},
+			"backup_schedule": schema.StringAttribute{
+				Description: descriptions["backup_schedule"],
+				Optional:    true,
+				Computed:    true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.UseStateForUnknown(),
+				},
+			},
+			"is_deletable": schema.BoolAttribute{
+				Description: descriptions["is_deletable"],
+				Optional:    true,
+				Computed:    true,
+				PlanModifiers: []planmodifier.Bool{
+					boolplanmodifier.UseStateForUnknown(),
+				},
+			},
+			// TODO - make it either flavor_id or ram, cpu and node_type
+			"flavor": schema.SingleNestedAttribute{
+				PlanModifiers: []planmodifier.Object{
+					objectplanmodifier.RequiresReplace(),
+					objectplanmodifier.UseStateForUnknown(),
+				},
+				Required: true,
+				Attributes: map[string]schema.Attribute{
+					"id": schema.StringAttribute{
+						Optional: true,
+						Computed: true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+							stringplanmodifier.UseStateForUnknown(),
+						},
+					},
+					"description": schema.StringAttribute{
+						Computed: true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.UseStateForUnknown(),
+						},
+					},
+					"node_type": schema.StringAttribute{
+						Required: true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+							stringplanmodifier.UseStateForUnknown(),
+						},
+						Validators: []validator.String{
+							stringvalidator.ConflictsWith([]path.Expression{
+								path.MatchRelative().AtParent().AtName("id"),
+							}...),
+							stringvalidator.OneOfCaseInsensitive(validNodeTypes...),
+							stringvalidator.AlsoRequires([]path.Expression{
+								path.MatchRelative().AtParent().AtName("cpu"),
+								path.MatchRelative().AtParent().AtName("ram"),
+							}...),
+						},
+					},
+					"cpu": schema.Int64Attribute{
+						Required: true,
+						PlanModifiers: []planmodifier.Int64{
+							int64planmodifier.RequiresReplace(),
+							int64planmodifier.UseStateForUnknown(),
+						},
+						Validators: []validator.Int64{
+							int64validator.ConflictsWith([]path.Expression{
+								path.MatchRelative().AtParent().AtName("id"),
+							}...),
+							int64validator.AlsoRequires([]path.Expression{
+								path.MatchRelative().AtParent().AtName("node_type"),
+								path.MatchRelative().AtParent().AtName("ram"),
+							}...),
+						},
+					},
+					"ram": schema.Int64Attribute{
+						Required: true,
+						PlanModifiers: []planmodifier.Int64{
+							int64planmodifier.RequiresReplace(),
+							int64planmodifier.UseStateForUnknown(),
+						},
+						Validators: []validator.Int64{
+							int64validator.ConflictsWith([]path.Expression{
+								path.MatchRelative().AtParent().AtName("id"),
+							}...),
+							int64validator.AlsoRequires([]path.Expression{
+								path.MatchRelative().AtParent().AtName("node_type"),
+								path.MatchRelative().AtParent().AtName("cpu"),
+							}...),
+						},
+					},
+				},
+			},
+			"replicas": schema.Int64Attribute{
+				Computed: true,
+				PlanModifiers: []planmodifier.Int64{
+					int64planmodifier.UseStateForUnknown(),
+				},
+			},
+			"storage": schema.SingleNestedAttribute{
+				Optional: true,
+				Computed: true,
+				PlanModifiers: []planmodifier.Object{
+					objectplanmodifier.UseStateForUnknown(),
+				},
+				Attributes: map[string]schema.Attribute{
+					"class": schema.StringAttribute{
+						Optional: true,
+						Computed: true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+							stringplanmodifier.UseStateForUnknown(),
+						},
+					},
+					"size": schema.Int64Attribute{
+						Optional: true,
+						Computed: true,
+						PlanModifiers: []planmodifier.Int64{
+							int64planmodifier.UseStateForUnknown(),
+						},
+					},
+				},
+			},
+			"version": schema.StringAttribute{
+				Optional: true,
+				Computed: true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.RequiresReplace(),
+					stringplanmodifier.UseStateForUnknown(),
+				},
+			},
+			"edition": schema.StringAttribute{
+				Computed: true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.RequiresReplace(),
+					stringplanmodifier.UseStateForUnknown(),
+				},
+			},
+			"retention_days": schema.Int64Attribute{
+				Optional: true,
+				Computed: true,
+				PlanModifiers: []planmodifier.Int64{
+					int64planmodifier.UseStateForUnknown(),
+				},
+			},
+			"region": schema.StringAttribute{
+				Optional: true,
+				// must be computed to allow for storing the override value from the provider
+				Computed:    true,
+				Description: descriptions["region"],
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.RequiresReplace(),
+				},
+			},
+			"status": schema.StringAttribute{
+				Optional: true,
+				// must be computed to allow for storing the override value from the provider
+				Computed:    true,
+				Description: descriptions["status"],
+			},
+			"encryption": schema.SingleNestedAttribute{
+				Required: true,
+				PlanModifiers: []planmodifier.Object{
+					objectplanmodifier.RequiresReplace(),
+					objectplanmodifier.UseStateForUnknown(),
+				},
+				Attributes: map[string]schema.Attribute{
+					"key_id": schema.StringAttribute{
+						Description: descriptions["key_id"],
+						Required:    true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+						},
+						Validators: []validator.String{
+							validate.NoSeparator(),
+						},
+					},
+					"key_version": schema.StringAttribute{
+						Description: descriptions["key_version"],
+						Required:    true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+						},
+						Validators: []validator.String{
+							validate.NoSeparator(),
+						},
+					},
+					"keyring_id": schema.StringAttribute{
+						Description: descriptions["key_ring_id"],
+						Required:    true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+						},
+						Validators: []validator.String{
+							validate.NoSeparator(),
+						},
+					},
+					"service_account": schema.StringAttribute{
+						Description: descriptions["service_account"],
+						Required:    true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+						},
+						Validators: []validator.String{
+							validate.NoSeparator(),
+						},
+					},
+				},
+				Description: descriptions["encryption"],
+			},
+			"network": schema.SingleNestedAttribute{
+				Required: true,
+				Attributes: map[string]schema.Attribute{
+					"access_scope": schema.StringAttribute{
+						Description: descriptions["access_scope"],
+						Required:    true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.RequiresReplace(),
+							stringplanmodifier.UseStateForUnknown(),
+						},
+						Validators: []validator.String{
+							validate.NoSeparator(),
+						},
+					},
+					"acl": schema.ListAttribute{
+						Description: descriptions["acl"],
+						ElementType: types.StringType,
+						Required:    true,
+						PlanModifiers: []planmodifier.List{
+							listplanmodifier.UseStateForUnknown(),
+						},
+					},
+					"instance_address": schema.StringAttribute{
+						Description: descriptions["instance_address"],
+						Computed:    true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.UseStateForUnknown(),
+						},
+					},
+					"router_address": schema.StringAttribute{
+						Description: descriptions["router_address"],
+						Computed:    true,
+						PlanModifiers: []planmodifier.String{
+							stringplanmodifier.UseStateForUnknown(),
+						},
+					},
+				},
+				Description: descriptions["network"],
+			},
+		},
+	}
+}
+
+// Create creates the resource and sets the initial Terraform state.
+func (r *instanceResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) { // nolint:gocritic // function signature required by Terraform
+	// Retrieve values from plan
+	var model Model
+	diags := req.Plan.Get(ctx, &model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	ctx = core.InitProviderContext(ctx)
+
+	projectId := model.ProjectId.ValueString()
+	region := model.Region.ValueString()
+	ctx = tflog.SetField(ctx, "project_id", projectId)
+	ctx = tflog.SetField(ctx, "region", region)
+
+	var storage = &storageModel{}
+	if !(model.Storage.IsNull() || model.Storage.IsUnknown()) {
+		diags = model.Storage.As(ctx, storage, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	var encryption = &encryptionModel{}
+	if !(model.Encryption.IsNull() || model.Encryption.IsUnknown()) {
+		diags = model.Encryption.As(ctx, encryption, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	var network = &networkModel{}
+	if !(model.Network.IsNull() || model.Network.IsUnknown()) {
+		diags = model.Network.As(ctx, network, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	flavor := &flavorModel{}
+	if !(model.Flavor.IsNull() || model.Flavor.IsUnknown()) {
+		diags = model.Flavor.As(ctx, flavor, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	if flavor.Id.IsNull() || flavor.Id.IsUnknown() {
+		err := loadFlavorId(ctx, r.client, &model, flavor, storage)
+		if err != nil {
+			resp.Diagnostics.AddError(err.Error(), err.Error())
+			return
+		}
+		flavorValues := map[string]attr.Value{
+			"id":          flavor.Id,
+			"description": flavor.Description,
+			"cpu":         flavor.CPU,
+			"ram":         flavor.RAM,
+			"node_type":   flavor.NodeType,
+		}
+		var flavorObject basetypes.ObjectValue
+		flavorObject, diags = types.ObjectValue(flavorTypes, flavorValues)
+		resp.Diagnostics.Append(diags...)
+		if diags.HasError() {
+			return
+		}
+		model.Flavor = flavorObject
+	}
+
+	// Generate API request body from model
+	payload, err := toCreatePayload(&model, storage, encryption, network)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating instance", fmt.Sprintf("Creating API payload: %v", err))
+		return
+	}
+	// Create new instance
+	createResp, err := r.client.CreateInstanceRequest(ctx, projectId, region).CreateInstanceRequestPayload(*payload).Execute()
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating instance", fmt.Sprintf("Calling API: %v", err))
+		return
+	}
+
+	ctx = core.LogResponse(ctx)
+
+	instanceId := *createResp.Id
+	utils.SetAndLogStateFields(ctx, &resp.Diagnostics, &resp.State, map[string]any{
+		"instance_id": instanceId,
+	})
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	// The creation waiter sometimes returns an error from the API: "instance with id xxx has unexpected status Failure"
+	// which can be avoided by sleeping before wait
+	waitResp, err := wait.CreateInstanceWaitHandler(ctx, r.client, projectId, instanceId, region).SetSleepBeforeWait(30 * time.Second).WaitWithContext(ctx)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating instance", fmt.Sprintf("Instance creation waiting: %v", err))
+		return
+	}
+
+	if waitResp.FlavorId == nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating instance", "Instance creation waiting: returned flavor id is nil")
+		return
+	}
+
+	if *waitResp.FlavorId != flavor.Id.ValueString() {
+		core.LogAndAddError(
+			ctx,
+			&resp.Diagnostics,
+			"Error creating instance",
+			fmt.Sprintf("Instance creation waiting: returned flavor id differs (expected: %s, current: %s)", flavor.Id.ValueString(), *waitResp.FlavorId),
+		)
+		return
+	}
+
+	if flavor.CPU.IsNull() || flavor.CPU.IsUnknown() {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating instance", "Instance creation waiting: flavor cpu is null or unknown")
+	}
+	if flavor.RAM.IsNull() || flavor.RAM.IsUnknown() {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating instance", "Instance creation waiting: flavor ram is null or unknown")
+	}
+	// flavorData := getFlavorModelById(ctx, r.client, &model, flavor)
+
+	// Map response body to schema
+	err = mapFields(ctx, waitResp, &model, flavor, storage, encryption, network, region)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating instance", fmt.Sprintf("Processing API payload: %v", err))
+		return
+	}
+	// Set state to fully populated data
+	diags = resp.State.Set(ctx, model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	// After the instance creation, database might not be ready to accept connections immediately.
+	// That is why we add a sleep
+	// TODO - can get removed?
+	time.Sleep(120 * time.Second)
+
+	tflog.Info(ctx, "SQLServer Flex instance created")
+}
+
+// Read refreshes the Terraform state with the latest data.
+func (r *instanceResource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) { // nolint:gocritic // function signature required by Terraform
+	var model Model
+	diags := req.State.Get(ctx, &model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	ctx = core.InitProviderContext(ctx)
+
+	projectId := model.ProjectId.ValueString()
+	instanceId := model.InstanceId.ValueString()
+	region := r.providerData.GetRegionWithOverride(model.Region)
+
+	ctx = tflog.SetField(ctx, "project_id", projectId)
+	ctx = tflog.SetField(ctx, "instance_id", instanceId)
+	ctx = tflog.SetField(ctx, "region", region)
+
+	var flavor = &flavorModel{}
+	if !(model.Flavor.IsNull() || model.Flavor.IsUnknown()) {
+		diags = model.Flavor.As(ctx, flavor, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+
+		err := getFlavorModelById(ctx, r.client, &model, flavor)
+		if err != nil {
+			resp.Diagnostics.AddError(err.Error(), err.Error())
+			return
+		}
+
+		diags = model.Flavor.As(ctx, flavor, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	var storage = &storageModel{}
+	if !(model.Storage.IsNull() || model.Storage.IsUnknown()) {
+		diags = model.Storage.As(ctx, storage, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	var encryption = &encryptionModel{}
+	if !(model.Encryption.IsNull() || model.Encryption.IsUnknown()) {
+		diags = model.Encryption.As(ctx, encryption, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	var network = &networkModel{}
+	if !(model.Network.IsNull() || model.Network.IsUnknown()) {
+		diags = model.Network.As(ctx, network, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	instanceResp, err := r.client.GetInstanceRequest(ctx, projectId, region, instanceId).Execute()
+	if err != nil {
+		oapiErr, ok := err.(*oapierror.GenericOpenAPIError) //nolint:errorlint //complaining that error.As should be used to catch wrapped errors, but this error should not be wrapped
+		if ok && oapiErr.StatusCode == http.StatusNotFound {
+			resp.State.RemoveResource(ctx)
+			return
+		}
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading instance", err.Error())
+		return
+	}
+
+	ctx = core.LogResponse(ctx)
+
+	// Map response body to schema
+	err = mapFields(ctx, instanceResp, &model, flavor, storage, encryption, network, region)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading instance", fmt.Sprintf("Processing API payload: %v", err))
+		return
+	}
+	// Set refreshed state
+	diags = resp.State.Set(ctx, model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	tflog.Info(ctx, "SQLServer Flex instance read")
+}
+
+// Update updates the resource and sets the updated Terraform state on success.
+func (r *instanceResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) { // nolint:gocritic // function signature required by Terraform
+	// Retrieve values from plan
+	var model Model
+	diags := req.Plan.Get(ctx, &model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	ctx = core.InitProviderContext(ctx)
+
+	projectId := model.ProjectId.ValueString()
+	instanceId := model.InstanceId.ValueString()
+	region := model.Region.ValueString()
+
+	ctx = tflog.SetField(ctx, "project_id", projectId)
+	ctx = tflog.SetField(ctx, "instance_id", instanceId)
+	ctx = tflog.SetField(ctx, "region", region)
+
+	var storage = &storageModel{}
+	if !(model.Storage.IsNull() || model.Storage.IsUnknown()) {
+		diags = model.Storage.As(ctx, storage, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	var encryption = &encryptionModel{}
+	if !(model.Encryption.IsNull() || model.Encryption.IsUnknown()) {
+		diags = model.Encryption.As(ctx, encryption, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	var network = &networkModel{}
+	if !(model.Network.IsNull() || model.Network.IsUnknown()) {
+		diags = model.Network.As(ctx, network, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	flavor := &flavorModel{}
+	if !(model.Flavor.IsNull() || model.Flavor.IsUnknown()) {
+		diags = model.Flavor.As(ctx, flavor, basetypes.ObjectAsOptions{})
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	if flavor.Id.IsNull() || flavor.Id.IsUnknown() {
+		err := loadFlavorId(ctx, r.client, &model, flavor, storage)
+		if err != nil {
+			resp.Diagnostics.AddError(err.Error(), err.Error())
+			return
+		}
+		flavorValues := map[string]attr.Value{
+			"id":          flavor.Id,
+			"description": flavor.Description,
+			"cpu":         flavor.CPU,
+			"ram":         flavor.RAM,
+			"node_type":   flavor.NodeType,
+		}
+		var flavorObject basetypes.ObjectValue
+		flavorObject, diags = types.ObjectValue(flavorTypes, flavorValues)
+		resp.Diagnostics.Append(diags...)
+		if diags.HasError() {
+			return
+		}
+		model.Flavor = flavorObject
+	}
+
+	// Generate API request body from model
+	payload, err := toUpdatePayload(&model, storage, network)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error updating instance", fmt.Sprintf("Creating API payload: %v", err))
+		return
+	}
+	// Update existing instance
+	err = r.client.UpdateInstancePartiallyRequest(ctx, projectId, region, instanceId).UpdateInstancePartiallyRequestPayload(*payload).Execute()
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error updating instance", err.Error())
+		return
+	}
+
+	ctx = core.LogResponse(ctx)
+
+	waitResp, err := wait.UpdateInstanceWaitHandler(ctx, r.client, projectId, instanceId, region).WaitWithContext(ctx)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error updating instance", fmt.Sprintf("Instance update waiting: %v", err))
+		return
+	}
+
+	// Map response body to schema
+	err = mapFields(ctx, waitResp, &model, flavor, storage, encryption, network, region)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error updating instance", fmt.Sprintf("Processing API payload: %v", err))
+		return
+	}
+	diags = resp.State.Set(ctx, model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	tflog.Info(ctx, "SQLServer Flex instance updated")
+}
+
+// Delete deletes the resource and removes the Terraform state on success.
+func (r *instanceResource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) { // nolint:gocritic // function signature required by Terraform
+	// Retrieve values from state
+	var model Model
+	diags := req.State.Get(ctx, &model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	ctx = core.InitProviderContext(ctx)
+
+	projectId := model.ProjectId.ValueString()
+	instanceId := model.InstanceId.ValueString()
+	region := model.Region.ValueString()
+	ctx = tflog.SetField(ctx, "project_id", projectId)
+	ctx = tflog.SetField(ctx, "instance_id", instanceId)
+	ctx = tflog.SetField(ctx, "region", region)
+
+	// Delete existing instance
+	err := r.client.DeleteInstanceRequest(ctx, projectId, region, instanceId).Execute()
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error deleting instance", fmt.Sprintf("Calling API: %v", err))
+		return
+	}
+
+	ctx = core.LogResponse(ctx)
+
+	_, err = wait.DeleteInstanceWaitHandler(ctx, r.client, projectId, instanceId, region).WaitWithContext(ctx)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error deleting instance", fmt.Sprintf("Instance deletion waiting: %v", err))
+		return
+	}
+	tflog.Info(ctx, "SQLServer Flex instance deleted")
+}
+
+// ImportState imports a resource into the Terraform state on success.
+// The expected format of the resource import identifier is: project_id,instance_id
+func (r *instanceResource) ImportState(ctx context.Context, req resource.ImportStateRequest, resp *resource.ImportStateResponse) {
+	idParts := strings.Split(req.ID, core.Separator)
+
+	if len(idParts) != 3 || idParts[0] == "" || idParts[1] == "" || idParts[2] == "" {
+		core.LogAndAddError(ctx, &resp.Diagnostics,
+			"Error importing instance",
+			fmt.Sprintf("Expected import identifier with format: [project_id],[region],[instance_id]  Got: %q", req.ID),
+		)
+		return
+	}
+
+	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("project_id"), idParts[0])...)
+	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("region"), idParts[1])...)
+	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("instance_id"), idParts[2])...)
+	tflog.Info(ctx, "SQLServer Flex instance state imported")
+}