package resources

import (
	"context"
	"fmt"

	"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/int64default"
	"github.com/hashicorp/terraform-plugin-framework/types"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"

	"terraform-provider-fission/internal/client"
)

var _ resource.Resource = &EnvironmentResource{}
var _ resource.ResourceWithImportState = &EnvironmentResource{}

// Изменено: 2026-04-14 19:15 UTC.
// Resource для управления Fission Environment через Kubernetes CRD API.
type EnvironmentResource struct {
	client *client.Client
}

type environmentResourceModel struct {
	ID        types.String `tfsdk:"id"`
	Name      types.String `tfsdk:"name"`
	Image     types.String `tfsdk:"image"`
	Version   types.Int64  `tfsdk:"version"`
	PoolSize  types.Int64  `tfsdk:"poolsize"`
	Namespace types.String `tfsdk:"namespace"`
	UID       types.String `tfsdk:"uid"`
}

func NewEnvironmentResource() resource.Resource {
	return &EnvironmentResource{}
}

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

func (r *EnvironmentResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Computed:    true,
				Description: "Идентификатор ресурса (namespace/name).",
			},
			"name": schema.StringAttribute{
				Required:    true,
				Description: "Имя Fission Environment.",
			},
			"image": schema.StringAttribute{
				Required:    true,
				Description: "Runtime image для Environment (например ghcr.io/fission/python-env).",
			},
			"version": schema.Int64Attribute{
				Optional:    true,
				Computed:    true,
				Default:     int64default.StaticInt64(3),
				Description: "Версия спецификации Environment.",
			},
			"poolsize": schema.Int64Attribute{
				Optional:    true,
				Computed:    true,
				Default:     int64default.StaticInt64(3),
				Description: "Размер пула pre-warmed контейнеров.",
			},
			"namespace": schema.StringAttribute{
				Optional:    true,
				Computed:    true,
				Description: "Namespace, где создается Environment. По умолчанию используется provider namespace.",
			},
			"uid": schema.StringAttribute{
				Computed:    true,
				Description: "UID Kubernetes объекта Environment.",
			},
		},
	}
}

// Configure получает клиент из provider.Configure().
func (r *EnvironmentResource) Configure(_ context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
	if req.ProviderData == nil {
		return
	}

	fissionClient, ok := req.ProviderData.(*client.Client)
	if !ok {
		resp.Diagnostics.AddError(
			"Некорректный тип provider data",
			fmt.Sprintf("Ожидался *client.Client, получен: %T", req.ProviderData),
		)
		return
	}

	r.client = fissionClient
}

// Create создает новый Environment CRD объект.
func (r *EnvironmentResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
	var plan environmentResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		return
	}

	namespace := plan.Namespace.ValueString()
	if namespace == "" {
		namespace = r.client.Namespace
	}

	environmentObject := environmentToUnstructured(plan, namespace)
	createdEnvironment, err := r.client.CreateEnvironment(ctx, environmentObject)
	if err != nil {
		resp.Diagnostics.AddError("Ошибка создания Fission Environment", err.Error())
		return
	}

	state := unstructuredToEnvironmentModel(createdEnvironment, plan)
	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
}

// Read синхронизирует Terraform state с текущим состоянием CRD.
func (r *EnvironmentResource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
	var state environmentResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		return
	}

	namespace := state.Namespace.ValueString()
	if namespace == "" {
		namespace = r.client.Namespace
	}

	environmentObject, err := r.client.GetEnvironment(ctx, namespace, state.Name.ValueString())
	if err != nil {
		if client.IsNotFound(err) {
			resp.State.RemoveResource(ctx)
			return
		}

		resp.Diagnostics.AddError("Ошибка чтения Fission Environment", err.Error())
		return
	}

	updatedState := unstructuredToEnvironmentModel(environmentObject, state)
	resp.Diagnostics.Append(resp.State.Set(ctx, &updatedState)...)
}

// Update обновляет существующий Environment CRD объект.
func (r *EnvironmentResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
	var plan environmentResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		return
	}

	namespace := plan.Namespace.ValueString()
	if namespace == "" {
		namespace = r.client.Namespace
	}

	environmentObject := environmentToUnstructured(plan, namespace)
	existingEnvironment, err := r.client.GetEnvironment(ctx, namespace, plan.Name.ValueString())
	if err != nil {
		resp.Diagnostics.AddError("Ошибка получения Environment перед обновлением", err.Error())
		return
	}

	environmentObject.SetResourceVersion(existingEnvironment.GetResourceVersion())
	updatedEnvironment, err := r.client.UpdateEnvironment(ctx, environmentObject)
	if err != nil {
		resp.Diagnostics.AddError("Ошибка обновления Fission Environment", err.Error())
		return
	}

	state := unstructuredToEnvironmentModel(updatedEnvironment, plan)
	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
}

// Delete удаляет Environment CRD объект.
func (r *EnvironmentResource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) {
	var state environmentResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		return
	}

	namespace := state.Namespace.ValueString()
	if namespace == "" {
		namespace = r.client.Namespace
	}

	err := r.client.DeleteEnvironment(ctx, namespace, state.Name.ValueString())
	if err != nil && !client.IsNotFound(err) {
		resp.Diagnostics.AddError("Ошибка удаления Fission Environment", err.Error())
	}
}

// ImportState поддерживает импорт ресурса в формате namespace/name.
func (r *EnvironmentResource) ImportState(ctx context.Context, req resource.ImportStateRequest, resp *resource.ImportStateResponse) {
	namespace, name, err := parseImportID(req.ID)
	if err != nil {
		resp.Diagnostics.AddError("Некорректный формат import ID", err.Error())
		return
	}

	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("id"), req.ID)...)
	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("namespace"), namespace)...)
	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("name"), name)...)
}

// environmentToUnstructured преобразует Terraform model в Kubernetes CRD payload.
func environmentToUnstructured(model environmentResourceModel, namespace string) *unstructured.Unstructured {
	return &unstructured.Unstructured{Object: map[string]interface{}{
		"apiVersion": "fission.io/v1",
		"kind":       "Environment",
		"metadata": map[string]interface{}{
			"name":      model.Name.ValueString(),
			"namespace": namespace,
		},
		"spec": map[string]interface{}{
			"version": model.Version.ValueInt64(),
			"runtime": map[string]interface{}{
				"image": model.Image.ValueString(),
			},
			"poolsize": model.PoolSize.ValueInt64(),
		},
	}}
}

// unstructuredToEnvironmentModel читает нужные поля из CRD объекта обратно в Terraform state.
func unstructuredToEnvironmentModel(environmentObject *unstructured.Unstructured, base environmentResourceModel) environmentResourceModel {
	imageValue, _, _ := unstructured.NestedString(environmentObject.Object, "spec", "runtime", "image")
	versionValue, _, _ := unstructured.NestedInt64(environmentObject.Object, "spec", "version")
	poolsizeValue, _, _ := unstructured.NestedInt64(environmentObject.Object, "spec", "poolsize")

	state := base
	state.Name = types.StringValue(environmentObject.GetName())
	state.Namespace = types.StringValue(environmentObject.GetNamespace())
	state.ID = types.StringValue(fmt.Sprintf("%s/%s", environmentObject.GetNamespace(), environmentObject.GetName()))
	state.UID = types.StringValue(string(environmentObject.GetUID()))

	if imageValue != "" {
		state.Image = types.StringValue(imageValue)
	}
	if versionValue != 0 {
		state.Version = types.Int64Value(versionValue)
	}
	if poolsizeValue != 0 {
		state.PoolSize = types.Int64Value(poolsizeValue)
	}

	return state
}