// Copyright (c) STACKIT

package sqlserverflexalpha

import (
	"context"
	_ "embed"
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/hashicorp/terraform-plugin-framework/resource/identityschema"

	sqlserverflexalpha2 "tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/services/sqlserverflexalpha/instance/resources_gen"
	sqlserverflexUtils "tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/services/sqlserverflexalpha/utils"

	"github.com/hashicorp/terraform-plugin-framework/path"
	"github.com/hashicorp/terraform-plugin-framework/resource"
	"github.com/hashicorp/terraform-plugin-framework/types"
	"github.com/hashicorp/terraform-plugin-log/tflog"

	"tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/pkg_gen/sqlserverflexalpha"
	"tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/conversion"
	"tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/core"
	"tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/utils"
	wait "tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/wait/sqlserverflexalpha"

	"github.com/stackitcloud/stackit-sdk-go/core/oapierror"
)

// Ensure the implementation satisfies the expected interfaces.
var (
	_ resource.Resource                = &instanceResource{}
	_ resource.ResourceWithConfigure   = &instanceResource{}
	_ resource.ResourceWithImportState = &instanceResource{}
	_ resource.ResourceWithModifyPlan  = &instanceResource{}
	_ resource.ResourceWithIdentity    = &instanceResource{}
)

// NewInstanceResource is a helper function to simplify the provider implementation.
func NewInstanceResource() resource.Resource {
	return &instanceResource{}
}

//nolint:unused // TODO: remove if not needed later
var validNodeTypes []string = []string{
	"Single",
	"Replica",
}

// resourceModel describes the resource data model.
type resourceModel = sqlserverflexalpha2.InstanceModel

type InstanceResourceIdentityModel struct {
	ProjectID  types.String `tfsdk:"project_id"`
	Region     types.String `tfsdk:"region"`
	InstanceID types.String `tfsdk:"instance_id"`
}

// instanceResource is the resource implementation.
type instanceResource struct {
	client       *sqlserverflexalpha.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

	// skip initial empty configuration to avoid follow-up errors
	if req.Config.Raw.IsNull() {
		return
	}
	var configModel sqlserverflexalpha2.InstanceModel
	resp.Diagnostics.Append(req.Config.Get(ctx, &configModel)...)
	if resp.Diagnostics.HasError() {
		return
	}

	if req.Plan.Raw.IsNull() {
		return
	}
	var planModel sqlserverflexalpha2.InstanceModel
	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
	}

	var identityModel InstanceResourceIdentityModel
	identityModel.ProjectID = planModel.ProjectId
	identityModel.Region = planModel.Region
	if !planModel.InstanceId.IsNull() && !planModel.InstanceId.IsUnknown() {
		identityModel.InstanceID = planModel.InstanceId
	}

	resp.Diagnostics.Append(resp.Identity.Set(ctx, identityModel)...)
	if resp.Diagnostics.HasError() {
		return
	}

	resp.Diagnostics.Append(resp.Plan.Set(ctx, planModel)...)
	if resp.Diagnostics.HasError() {
		return
	}
}

//go:embed planModifiers.yaml
var modifiersFileByte []byte

// Schema defines the schema for the resource.
func (r *instanceResource) Schema(ctx context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {

	schema := sqlserverflexalpha2.InstanceResourceSchema(ctx)

	fields, err := utils.ReadModifiersConfig(modifiersFileByte)
	if err != nil {
		resp.Diagnostics.AddError("error during read modifiers config file", err.Error())
		return
	}

	err = utils.AddPlanModifiersToResourceSchema(fields, &schema)
	if err != nil {
		resp.Diagnostics.AddError("error adding plan modifiers", err.Error())
		return
	}
	resp.Schema = schema
}

func (r *instanceResource) IdentitySchema(
	_ context.Context,
	_ resource.IdentitySchemaRequest,
	resp *resource.IdentitySchemaResponse,
) {
	resp.IdentitySchema = identityschema.Schema{
		Attributes: map[string]identityschema.Attribute{
			"project_id": identityschema.StringAttribute{
				RequiredForImport: true, // must be set during import by the practitioner
			},
			"region": identityschema.StringAttribute{
				RequiredForImport: true, // can be defaulted by the provider configuration
			},
			"instance_id": identityschema.StringAttribute{
				RequiredForImport: true, // can be defaulted by the provider configuration
			},
		},
	}
}

// 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
	var model resourceModel
	diags := req.Plan.Get(ctx, &model)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}

	// Read identity data
	var identityData InstanceResourceIdentityModel
	resp.Diagnostics.Append(req.Identity.Get(ctx, &identityData)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectId := identityData.ProjectID.ValueString()
	region := identityData.Region.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectId)
	ctx = tflog.SetField(ctx, "region", region)

	// Generate API request body from model
	payload, err := toCreatePayload(ctx, &model)
	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

	// Set data returned by API in identity
	identity := InstanceResourceIdentityModel{
		ProjectID:  types.StringValue(projectId),
		Region:     types.StringValue(region),
		InstanceID: types.StringValue(instanceId),
	}
	resp.Diagnostics.Append(resp.Identity.Set(ctx, identity)...)
	if resp.Diagnostics.HasError() {
		return
	}

	utils.SetAndLogStateFields(
		ctx, &resp.Diagnostics, &resp.State, map[string]any{
			"id":          utils.BuildInternalTerraformId(projectId, region, instanceId),
			"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,
	).SetTimeout(
		90 * time.Minute,
	).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
	}

	// Map response body to schema
	// err = mapFields(ctx, waitResp, &model, storage, encryption, network, region)
	err = mapFields(ctx, waitResp, &model, resp.Diagnostics)
	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
	}

	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 resourceModel
	diags := req.State.Get(ctx, &model)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}

	// Read identity data
	var identityData InstanceResourceIdentityModel
	resp.Diagnostics.Append(req.Identity.Get(ctx, &identityData)...)
	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)

	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, resp.Diagnostics)
	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
	}

	// Set data returned by API in identity
	identity := InstanceResourceIdentityModel{
		ProjectID:  types.StringValue(projectId),
		Region:     types.StringValue(region),
		InstanceID: types.StringValue(instanceId),
	}
	resp.Diagnostics.Append(resp.Identity.Set(ctx, identity)...)
	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 resourceModel
	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)

	// Generate API request body from model
	payload, err := toUpdatePayload(ctx, &model, resp)
	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.UpdateInstanceRequest(
		ctx,
		projectId,
		region,
		instanceId,
	).UpdateInstanceRequestPayload(*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, resp.Diagnostics)
	// err = mapFields(ctx, waitResp, &model, 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 resourceModel
	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,
) {
	if req.ID != "" {
		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])...)
		return
	}

	// If no ID is provided, attempt to read identity attributes from the import configuration
	var identityData InstanceResourceIdentityModel
	resp.Diagnostics.Append(req.Identity.Get(ctx, &identityData)...)
	if resp.Diagnostics.HasError() {
		return
	}

	projectId := identityData.ProjectID.ValueString()
	region := identityData.Region.ValueString()
	instanceId := identityData.InstanceID.ValueString()

	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("project_id"), projectId)...)
	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("region"), region)...)
	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("instance_id"), instanceId)...)

	tflog.Info(ctx, "SQLServer Flex instance state imported")
}