package resources

import (
	"context"
	"fmt"

	"github.com/hashicorp/terraform-plugin-framework/attr"
	"github.com/hashicorp/terraform-plugin-framework/resource"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/booldefault"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/mapdefault"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringdefault"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
	"github.com/hashicorp/terraform-plugin-framework/types"

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

var _ resource.Resource = &IoTDeviceResource{}

// IoTDeviceResource управляет CRD IoTDevice (iot.kube5s.ru/v1alpha1).
type IoTDeviceResource struct {
	client *client.Client
}

type iotDeviceResourceModel struct {
	ID           types.String `tfsdk:"id"`
	Name         types.String `tfsdk:"name"`
	Namespace    types.String `tfsdk:"namespace"`
	DeviceID     types.String `tfsdk:"device_id"`
	Enabled      types.Bool   `tfsdk:"enabled"`
	Metadata     types.Map    `tfsdk:"metadata"`
	Phase        types.String `tfsdk:"phase"`
	MQTTUsername types.String `tfsdk:"mqtt_username"`
	SecretName   types.String `tfsdk:"secret_name"`
	TopicPrefix  types.String `tfsdk:"topic_prefix"`
}

func NewIoTDeviceResource() resource.Resource {
	return &IoTDeviceResource{}
}

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

func (r *IoTDeviceResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		Description: "IoT-устройство, зарегистрированное в платформе sless (CRD iot.kube5s.ru/v1alpha1/IoTDevice).",
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Computed:    true,
				Description: "Идентификатор ресурса (namespace/name).",
			},
			"name": schema.StringAttribute{
				Required:    true,
				Description: "Имя IoTDevice.",
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"namespace": schema.StringAttribute{
				Optional:    true,
				Computed:    true,
				Default:     stringdefault.StaticString("sless"),
				Description: "Namespace IoTDevice. По умолчанию sless.",
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"device_id": schema.StringAttribute{
				Required:    true,
				Description: "Уникальный ID устройства внутри namespace (строчные буквы, цифры, дефис).",
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"enabled": schema.BoolAttribute{
				Optional:    true,
				Computed:    true,
				Default:     booldefault.StaticBool(true),
				Description: "Активно ли устройство.",
			},
			"metadata": schema.MapAttribute{
				Optional:    true,
				Computed:    true,
				ElementType: types.StringType,
				Default:     mapdefault.StaticValue(types.MapValueMust(types.StringType, map[string]attr.Value{})),
				Description: "Произвольные метаданные устройства (модель, локация и т.д.).",
			},
			// Computed (заполняет iot-operator)
			"phase": schema.StringAttribute{
				Computed:    true,
				Description: "Текущая фаза: Active, Disabled, Pending, Error.",
			},
			"mqtt_username": schema.StringAttribute{
				Computed:    true,
				Description: "MQTT username, выданный iot-operator.",
			},
			"secret_name": schema.StringAttribute{
				Computed:    true,
				Description: "Имя K8s Secret с MQTT credentials.",
			},
			"topic_prefix": schema.StringAttribute{
				Computed:    true,
				Description: "MQTT topic prefix для публикации.",
			},
		},
	}
}

func (r *IoTDeviceResource) Configure(_ context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
	if req.ProviderData == nil {
		return
	}
	c, ok := req.ProviderData.(*client.Client)
	if !ok {
		resp.Diagnostics.AddError("Неверный тип провайдера", fmt.Sprintf("ожидался *client.Client, получен %T", req.ProviderData))
		return
	}
	r.client = c
}

func (r *IoTDeviceResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
	var plan iotDeviceResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ns := plan.Namespace.ValueString()
	meta := map[string]string{}
	if !plan.Metadata.IsNull() && !plan.Metadata.IsUnknown() {
		elems := plan.Metadata.Elements()
		for k, v := range elems {
			if sv, ok := v.(types.String); ok {
				meta[k] = sv.ValueString()
			}
		}
	}

	info, err := r.client.CreateIoTDevice(ctx, plan.Name.ValueString(), ns, plan.DeviceID.ValueString(), meta)
	if err != nil {
		resp.Diagnostics.AddError("Ошибка создания IoT device", err.Error())
		return
	}

	plan.ID = types.StringValue(ns + "/" + plan.Name.ValueString())
	plan.Phase = types.StringValue(info.Phase)
	plan.MQTTUsername = types.StringValue(info.MQTTUsername)
	plan.SecretName = types.StringValue(info.SecretName)
	plan.TopicPrefix = types.StringValue(info.TopicPrefix)
	resp.Diagnostics.Append(resp.State.Set(ctx, &plan)...)
}

func (r *IoTDeviceResource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
	var state iotDeviceResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		return
	}

	info, err := r.client.GetIoTDevice(ctx, state.Namespace.ValueString(), state.Name.ValueString())
	if err != nil {
		if client.IsNotFound(err) {
			resp.State.RemoveResource(ctx)
			return
		}
		resp.Diagnostics.AddError("Ошибка чтения IoT device", err.Error())
		return
	}

	state.Phase = types.StringValue(info.Phase)
	state.MQTTUsername = types.StringValue(info.MQTTUsername)
	state.SecretName = types.StringValue(info.SecretName)
	state.TopicPrefix = types.StringValue(info.TopicPrefix)
	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
}

func (r *IoTDeviceResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
	// name/namespace/device_id — RequiresReplace, значит Update только для enabled/metadata.
	// Для простоты: пересоздаём объект.
	var plan iotDeviceResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ns := plan.Namespace.ValueString()
	name := plan.Name.ValueString()

	if err := r.client.DeleteIoTDevice(ctx, ns, name); err != nil && !client.IsNotFound(err) {
		resp.Diagnostics.AddError("Ошибка удаления IoT device при обновлении", err.Error())
		return
	}

	meta := map[string]string{}
	if !plan.Metadata.IsNull() && !plan.Metadata.IsUnknown() {
		elems := plan.Metadata.Elements()
		for k, v := range elems {
			if sv, ok := v.(types.String); ok {
				meta[k] = sv.ValueString()
			}
		}
	}

	info, err := r.client.CreateIoTDevice(ctx, name, ns, plan.DeviceID.ValueString(), meta)
	if err != nil {
		resp.Diagnostics.AddError("Ошибка создания IoT device при обновлении", err.Error())
		return
	}

	plan.Phase = types.StringValue(info.Phase)
	plan.MQTTUsername = types.StringValue(info.MQTTUsername)
	plan.SecretName = types.StringValue(info.SecretName)
	plan.TopicPrefix = types.StringValue(info.TopicPrefix)
	resp.Diagnostics.Append(resp.State.Set(ctx, &plan)...)
}

func (r *IoTDeviceResource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) {
	var state iotDeviceResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		return
	}
	if err := r.client.DeleteIoTDevice(ctx, state.Namespace.ValueString(), state.Name.ValueString()); err != nil {
		resp.Diagnostics.AddError("Ошибка удаления IoT device", err.Error())
	}
}