package sqlserverflexbeta

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

	"github.com/hashicorp/terraform-plugin-framework/path"
	"github.com/hashicorp/terraform-plugin-framework/resource"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
	"github.com/hashicorp/terraform-plugin-framework/types"
	"github.com/hashicorp/terraform-plugin-framework/types/basetypes"
	"github.com/hashicorp/terraform-plugin-log/tflog"
	"github.com/stackitcloud/stackit-sdk-go/core/config"
	"github.com/stackitcloud/stackit-sdk-go/core/oapierror"

	"tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/conversion"
	wait "tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/wait/sqlserverflexbeta"

	"github.com/stackitcloud/stackit-sdk-go/services/sqlserverflex/v3beta1api"

	"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"

	sqlserverflexbetaResGen "tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit/internal/services/sqlserverflexbeta/instance/resources_gen"
)

var (
	_ resource.Resource                = &instanceResource{}
	_ resource.ResourceWithConfigure   = &instanceResource{}
	_ resource.ResourceWithImportState = &instanceResource{}
	_ resource.ResourceWithModifyPlan  = &instanceResource{}
)

func NewInstanceResource() resource.Resource {
	return &instanceResource{}
}

type instanceResource struct {
	client       *v3beta1api.APIClient
	providerData core.ProviderData
}

// LocalInstanceModel describes the resource data model.
type LocalInstanceModel struct {
	sqlserverflexbetaResGen.InstanceModel
	Flavor types.Object `tfsdk:"flavor"`
}

// LocalFlavorModel Struct corresponding to Model.Flavor
type LocalFlavorModel struct {
	Id          types.String `tfsdk:"id"`
	Description types.String `tfsdk:"description"`
	CPU         types.Int64  `tfsdk:"cpu"`
	RAM         types.Int64  `tfsdk:"ram"`
}

func (r *instanceResource) Metadata(
	_ context.Context,
	req resource.MetadataRequest,
	resp *resource.MetadataResponse,
) {
	resp.TypeName = req.ProviderTypeName + "_sqlserverflexbeta_instance"
}

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

func (r *instanceResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) {
	s := sqlserverflexbetaResGen.InstanceResourceSchema(ctx)
	s.Attributes["flavor"] = schema.SingleNestedAttribute{
		Optional:           true,
		DeprecationMessage: "Please use flavor_id instead.",
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Computed: true,
				PlanModifiers: []planmodifier.String{
					UseStateForUnknownIfFlavorUnchanged(req),
				},
			},
			"description": schema.StringAttribute{
				Computed: true,
				PlanModifiers: []planmodifier.String{
					UseStateForUnknownIfFlavorUnchanged(req),
				},
			},
			"cpu": schema.Int64Attribute{
				DeprecationMessage: "Please use flavor_id instead.",
				Optional:           true,
			},
			"ram": schema.Int64Attribute{
				DeprecationMessage: "Please use flavor_id instead.",
				Optional:           true,
			},
		},
	}

	s.Attributes["flavor_id"] = schema.StringAttribute{
		Optional:            true,
		Description:         "The id of the instance flavor.",
		MarkdownDescription: "The id of the instance flavor.",
	}

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

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

// 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
	}

	apiClientConfigOptions := []config.ConfigurationOption{
		config.WithCustomAuth(r.providerData.RoundTripper),
		utils.UserAgentConfigOption(r.providerData.Version),
	}
	if r.providerData.SQLServerFlexCustomEndpoint != "" {
		apiClientConfigOptions = append(
			apiClientConfigOptions,
			config.WithEndpoint(r.providerData.SQLServerFlexCustomEndpoint),
		)
	} else {
		apiClientConfigOptions = append(apiClientConfigOptions, config.WithRegion(r.providerData.GetRegion()))
	}
	apiClient, err := v3beta1api.NewAPIClient(apiClientConfigOptions...)
	if err != nil {
		resp.Diagnostics.AddError(
			"Error configuring API client",
			fmt.Sprintf(
				"Configuring client: %v. This is an error related to the provider configuration, not to the resource configuration",
				err,
			),
		)
		return
	}
	r.client = apiClient
	tflog.Info(ctx, "sqlserverflexbeta.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 LocalInstanceModel
	resp.Diagnostics.Append(req.Config.Get(ctx, &configModel)...)
	if resp.Diagnostics.HasError() {
		return
	}

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

func (r *instanceResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
	var data LocalInstanceModel
	crateErr := "[SQL Server Flex BETA - Create] error"

	// Read Terraform plan data into the model
	resp.Diagnostics.Append(req.Plan.Get(ctx, &data)...)

	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectID := data.ProjectId.ValueString()
	region := data.Region.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectID)
	ctx = tflog.SetField(ctx, "region", region)

	// determine flavor ID
	var flModel = &LocalFlavorModel{}
	if !(data.Flavor.IsNull() || data.Flavor.IsUnknown()) {
		diags := data.Flavor.As(ctx, flModel, basetypes.ObjectAsOptions{})
		resp.Diagnostics.Append(diags...)
		if resp.Diagnostics.HasError() {
			return
		}

		flavors, err := getAllFlavors(ctx, r.client.DefaultAPI, projectID, region)
		if err != nil {
			core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading flavors", fmt.Sprintf("getAllFlavors: %v", err))
			return
		}
		tflog.Debug(ctx, fmt.Sprintf("loaded flavors: %d", len(flavors)))

		var foundFlavors []v3beta1api.ListFlavors
		for _, flavor := range flavors {
			if flModel.CPU.ValueInt64() != int64(flavor.Cpu) {
				// tflog.Debug(ctx, fmt.Sprintf("flavor - cpu did not match (%d - %d)", flModel.CPU.ValueInt64(), flavor.Cpu))
				continue
			}
			if flModel.RAM.ValueInt64() != int64(flavor.Memory) {
				// tflog.Debug(ctx, fmt.Sprintf("flavor - ram did not match (%d - %d)", flModel.RAM.ValueInt64(), flavor.Memory))
				continue
			}
			tmpNodeType := "Single"
			if data.Replicas.ValueInt64() > 1 {
				tmpNodeType = "Replica"
			}
			if strings.ToLower(tmpNodeType) != strings.ToLower(flavor.NodeType) {
				//tflog.Debug(
				//	ctx,
				//	fmt.Sprintf(
				//		"flavor - nodeType did not match ('%s' - '%s')",
				//		strings.ToLower(tmpNodeType),
				//		strings.ToLower(flavor.NodeType),
				//	),
				//)
				continue
			}
			tflog.Debug(ctx, fmt.Sprintf("found flavor %s, checking storage classes", flavor.Id))
			for _, sc := range flavor.StorageClasses {
				if data.Storage.Class.ValueString() != sc.Class {
					continue
				}
				tflog.Debug(ctx, fmt.Sprintf("found storage class '%s' for flavor '%s', checking storage classes", sc.Class, flavor.Id))
				foundFlavors = append(foundFlavors, flavor)
			}
		}
		if len(foundFlavors) == 0 {
			resp.Diagnostics.AddError("get flavor", "could not find requested flavor")
			return
		}
		if len(foundFlavors) > 1 {
			resp.Diagnostics.AddError("get flavor", "found too many matching flavors")
			return
		}

		f := foundFlavors[0]
		flModel.Description = types.StringValue(f.Description)
		flModel.Id = utils.BuildInternalTerraformId(data.ProjectId.ValueString(), region, f.Id)
		data.FlavorId = types.StringValue(f.Id)
		//flModel. .MaxGb = types.Int32Value(f.MaxGB)
		//flModel.MinGb = types.Int32Value(f.MinGB)
	}

	// Generate API request body from model
	payload, err := toCreatePayload(ctx, &data)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			crateErr,
			fmt.Sprintf("Creating API payload: %v", err),
		)
		return
	}

	// Create new Instance
	createResp, err := r.client.DefaultAPI.CreateInstanceRequest(
		ctx,
		projectID,
		region,
	).CreateInstanceRequestPayload(*payload).Execute()
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, crateErr, fmt.Sprintf("Calling API: %v", err))
		return
	}

	ctx = core.LogResponse(ctx)

	instanceID := createResp.Id
	data.InstanceId = types.StringValue(instanceID)
	data.Id = utils.BuildInternalTerraformId(projectID, region, instanceID)

	// Set data returned by API in id
	resp.Diagnostics.Append(
		resp.State.SetAttribute(
			ctx,
			path.Root("id"),
			utils.BuildInternalTerraformId(projectID, region, instanceID),
		)...,
	)
	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("instance_id"), instanceID)...)

	waitResp, err := wait.CreateInstanceWaitHandler(
		ctx,
		r.client.DefaultAPI,
		projectID,
		instanceID,
		region,
	).SetSleepBeforeWait(
		10 * time.Second,
	).SetTimeout(
		90 * time.Minute,
	).WaitWithContext(ctx)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			crateErr,
			fmt.Sprintf("Instance creation waiting: %v", err),
		)
		return
	}

	if waitResp.Id == "" {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			crateErr,
			"Instance creation waiting: returned id is nil",
		)
		return
	}

	// Map response body to schema
	err = mapResponseToModel(ctx, waitResp, &data, resp.Diagnostics)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			crateErr,
			fmt.Sprintf("processing API payload: %v", err),
		)
		return
	}

	// Save data into Terraform state
	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)

	tflog.Info(ctx, "sqlserverflexbeta.Instance created")
}

func (r *instanceResource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
	var data LocalInstanceModel

	// Read Terraform prior state data into the model
	resp.Diagnostics.Append(req.State.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectID := data.ProjectId.ValueString()
	region := data.Region.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectID)
	ctx = tflog.SetField(ctx, "region", region)

	instanceID := data.InstanceId.ValueString()
	ctx = tflog.SetField(ctx, "instance_id", instanceID)

	instanceResp, err := r.client.DefaultAPI.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 = mapResponseToModel(ctx, instanceResp, &data, resp.Diagnostics)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			"Error reading instance",
			fmt.Sprintf("Processing API payload: %v", err),
		)
		return
	}

	// Save updated data into Terraform state
	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	tflog.Info(ctx, "sqlserverflexbeta.Instance read")
}

func (r *instanceResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
	var data LocalInstanceModel
	updateInstanceError := "Error updating instance"

	resp.Diagnostics.Append(req.Plan.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectID := data.ProjectId.ValueString()
	region := data.Region.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectID)
	ctx = tflog.SetField(ctx, "region", region)

	instanceID := data.InstanceId.ValueString()
	ctx = tflog.SetField(ctx, "instance_id", instanceID)

	// Generate API request body from model
	payload, err := toUpdatePayload(ctx, &data, resp)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			updateInstanceError,
			fmt.Sprintf("Creating API payload: %v", err),
		)
		return
	}
	// Update existing instance
	err = r.client.DefaultAPI.UpdateInstanceRequest(
		ctx,
		projectID,
		region,
		instanceID,
	).UpdateInstanceRequestPayload(*payload).Execute()
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, updateInstanceError, err.Error())
		return
	}

	ctx = core.LogResponse(ctx)

	waitResp, err := wait.
		UpdateInstanceWaitHandler(ctx, r.client.DefaultAPI, projectID, instanceID, region).
		SetSleepBeforeWait(10 * time.Second).
		SetTimeout(90 * time.Minute).
		WaitWithContext(ctx)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			updateInstanceError,
			fmt.Sprintf("Instance update waiting: %v", err),
		)
		return
	}

	// Map response body to schema
	err = mapResponseToModel(ctx, waitResp, &data, resp.Diagnostics)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			updateInstanceError,
			fmt.Sprintf("Processing API payload: %v", err),
		)
		return
	}

	// Save updated data into Terraform state
	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	tflog.Info(ctx, "sqlserverflexbeta.Instance updated")
}

func (r *instanceResource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) {
	var data LocalInstanceModel

	// Read Terraform prior state data into the model
	resp.Diagnostics.Append(req.State.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectID := data.ProjectId.ValueString()
	region := data.Region.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectID)
	ctx = tflog.SetField(ctx, "region", region)

	instanceID := data.InstanceId.ValueString()
	ctx = tflog.SetField(ctx, "instance_id", instanceID)

	// Delete existing instance
	err := r.client.DefaultAPI.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)

	delResp, err := wait.DeleteInstanceWaitHandler(ctx, r.client.DefaultAPI, projectID, instanceID, region).
		SetSleepBeforeWait(10 * time.Second).
		SetTimeout(90 * time.Minute).
		WaitWithContext(ctx)
	if err != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			"Error deleting instance",
			fmt.Sprintf("Instance deletion waiting: %v", err),
		)
		return
	}

	if delResp != nil {
		core.LogAndAddError(
			ctx,
			&resp.Diagnostics,
			"Error deleting instance",
			"wait handler returned non nil result",
		)
		return
	}

	resp.State.RemoveResource(ctx)

	tflog.Info(ctx, "sqlserverflexbeta.Instance deleted")
}

// ImportState imports a resource into the Terraform state on success.
// The expected format of the resource import identifier is: project_id,zone_id,record_set_id
func (r *instanceResource) ImportState(
	ctx context.Context,
	req resource.ImportStateRequest,
	resp *resource.ImportStateResponse,
) {
	ctx = core.InitProviderContext(ctx)

	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("id"), utils.BuildInternalTerraformId(idParts...).ValueString())...)
	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, "Sqlserverflexbeta instance state imported")
}