package disks

import (
	"context"
	"reflect"
	"strconv"
	"time"

	"github.com/hashicorp/terraform-plugin-framework-timeouts/resource/timeouts"
	"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/types"
	"github.com/hashicorp/terraform-plugin-log/tflog"
	"repository.basistech.ru/BASIS/decort-golang-sdk/pkg/cloudapi/disks"
	"repository.basistech.ru/BASIS/terraform-provider-dynamix/internal/client"
	"repository.basistech.ru/BASIS/terraform-provider-dynamix/internal/constants"
	"repository.basistech.ru/BASIS/terraform-provider-dynamix/internal/service/cloudapi/disks/flattens"
	"repository.basistech.ru/BASIS/terraform-provider-dynamix/internal/service/cloudapi/disks/models"
	"repository.basistech.ru/BASIS/terraform-provider-dynamix/internal/service/cloudapi/disks/schemas"
	"repository.basistech.ru/BASIS/terraform-provider-dynamix/internal/service/cloudapi/disks/utilities"
)

// Ensure the implementation satisfies the expected interfaces.
var (
	_ resource.Resource                = &resourceDisk{}
	_ resource.ResourceWithImportState = &resourceDisk{}
)

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

// resourceDisk is the resource implementation.
type resourceDisk struct {
	client *client.Client
}

// Create creates the resource and sets the initial Terraform state.
func (r *resourceDisk) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
	// Get plan to create resource group
	var plan models.ResourceDiskModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Create resourceDisk: Error receiving the plan")
		return
	}

	contextCreateMap := map[string]any{
		"account_id": plan.AccountID.ValueInt64(),
		"disk_name":  plan.DiskName.ValueString(),
		"size_max":   plan.SizeMax.ValueInt64(),
		"gid":        plan.GID.ValueInt64(),
	}
	tflog.Info(ctx, "Create resourceDisk: got plan successfully", contextCreateMap)
	tflog.Info(ctx, "Create resourceDisk: start creating", contextCreateMap)

	// Set timeouts
	createTimeout, diags := plan.Timeouts.Create(ctx, constants.Timeout600s)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Create resourceDisk: Error set timeout")
		return
	}
	tflog.Info(ctx, "Create resourceDisk: set timeouts successfully", map[string]any{
		"account_id":    plan.AccountID.ValueInt64(),
		"disk_name":     plan.DiskName.ValueString(),
		"size_max":      plan.SizeMax.ValueInt64(),
		"gid":           plan.GID.ValueInt64(),
		"createTimeout": createTimeout})

	ctx, cancel := context.WithTimeout(ctx, createTimeout)
	defer cancel()

	// Check if input values are valid in the platform
	tflog.Info(ctx, "Create resourceDisk: starting input checks", contextCreateMap)
	resp.Diagnostics.Append(resourceDiskCreateInputChecks(ctx, &plan, r.client)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Create resourceDisk: Error input checks")
		return
	}
	tflog.Info(ctx, "Create resourceDisk: input checks successful", contextCreateMap)

	// Make create request and get response
	createReq := utilities.CreateRequestResourceDisk(ctx, &plan)
	tflog.Info(ctx, "Create resourceDisk: before call CloudAPI().Disks().Create", map[string]any{"req": createReq})
	diskId, err := r.client.CloudAPI().Disks().Create(ctx, createReq)
	if err != nil {
		resp.Diagnostics.AddError(
			"Create resourceDisk: unable to Create Disk",
			err.Error(),
		)
		return
	}
	plan.Id = types.StringValue(strconv.Itoa(int(diskId)))
	tflog.Info(ctx, "Create resourceDisk: disk created", map[string]any{"diskId": diskId, "disk_name": plan.DiskName.ValueString()})

	// additional settings after disk creation: in case of failures, warnings are added to resp.Diagnostics,
	// because additional settings failure is not critical. If errors were added instead of warnings, terraform
	// framework would mark resource as tainted and delete it, which would be unwanted behaviour.

	// sets io limits to disk if needed, warnings added to resp.Diagnostics in case of failure.
	if !plan.IOTune.IsUnknown() {
		resp.Diagnostics.Append(utilities.LimitIOCreateDisk(ctx, diskId, &plan, r.client)...)
	}

	// share disk if needed, warnings added to resp.Diagnostics in case of failure.
	if !plan.Shareable.IsUnknown() && plan.Shareable.ValueBool() { // if shareable = true
		resp.Diagnostics.Append(utilities.ShareableCreateDisk(ctx, diskId, r.client)...)
	}

	tflog.Info(ctx, "Create resourceDisk: resource creation is completed", map[string]any{"disk_id": diskId})

	// Map response body to schema and populate Computed attribute values
	resp.Diagnostics.Append(flattens.DiskResource(ctx, &plan, r.client)...)
	if resp.Diagnostics.HasError() {
		return
	}

	// Set data last update
	plan.LastUpdated = types.StringValue(time.Now().Format(time.RFC850))

	// Set state to fully populated data
	resp.Diagnostics.Append(resp.State.Set(ctx, plan)...)
	if resp.Diagnostics.HasError() {
		return
	}
}

// Read refreshes the Terraform state with the latest data.
func (r *resourceDisk) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
	// Get current state
	var state models.ResourceDiskModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Read resourceDisk: Error get state")
		return
	}
	tflog.Info(ctx, "Read resourceDisk: got state successfully", map[string]any{"disk_id": state.Id.ValueString()})

	// Set timeouts
	readTimeout, diags := state.Timeouts.Read(ctx, constants.Timeout300s)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Read resourceDisk: Error set timeout")
		return
	}
	tflog.Info(ctx, "Read resourceDisk: set timeouts successfully", map[string]any{
		"disk_id":     state.Id.ValueString(),
		"readTimeout": readTimeout})

	ctx, cancel := context.WithTimeout(ctx, readTimeout)
	defer cancel()

	// read status
	resp.Diagnostics.Append(utilities.DiskReadStatus(ctx, &state, r.client)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Read resourceDisk: Error reading disk status")
		return
	}

	// Overwrite items with refreshed state
	resp.Diagnostics.Append(flattens.DiskResource(ctx, &state, r.client)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Read resourceDisk: Error flatten disk")
		return
	}

	// Set refreshed state
	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Read resourceDisk: Error set state")
		return
	}
	tflog.Info(ctx, "End read resourceDisk")
}

// Update updates the resource and sets the updated Terraform state on success.
func (r *resourceDisk) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
	// Retrieve values from plan
	var plan models.ResourceDiskModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Update resourceDisk: Error receiving the plan")
		return
	}
	tflog.Info(ctx, "Update resourceDisk: got plan successfully", map[string]any{"disk_id": plan.Id.ValueString()})

	// Retrieve values from state
	var state models.ResourceDiskModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Update resourceDisk: Error receiving the state")
		return
	}
	tflog.Info(ctx, "Update resourceDisk: got state successfully", map[string]any{"disk_id": state.Id.ValueString()})

	// Set timeouts
	updateTimeout, diags := plan.Timeouts.Update(ctx, constants.Timeout300s)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Update resourceDisk: Error set timeout")
		return
	}
	tflog.Info(ctx, "Update resourceDisk: set timeouts successfully", map[string]any{
		"disk_id":       state.Id.ValueString(),
		"updateTimeout": updateTimeout})

	ctx, cancel := context.WithTimeout(ctx, updateTimeout)
	defer cancel()

	// Checking if inputs are valid
	tflog.Info(ctx, "Update resourceDisk: starting input checks", map[string]any{"disk_id": plan.Id.ValueString()})
	resp.Diagnostics.Append(resourceDiskUpdateInputChecks(ctx, &plan, &state, r.client)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Update resourceDisk: Error input checks")
		return
	}
	tflog.Info(ctx, "Update resourceDisk: input checks successful", map[string]any{"disk_id": state.Id.ValueString()})

	diskId, err := strconv.Atoi(state.Id.ValueString())
	if err != nil {
		resp.Diagnostics.AddError("Update resourceDisk: Cannot parse disk ID from state", err.Error())
		return
	}

	// resize disk
	if !plan.SizeMax.Equal(state.SizeMax) {
		resp.Diagnostics.Append(utilities.SizeMaxUpdateDisk(ctx, uint64(diskId), &plan, &state, r.client)...)
		if resp.Diagnostics.HasError() {
			tflog.Error(ctx, "Update resourceDisk: Error resizing disk")
			return
		}
	}

	// rename disk
	if !plan.DiskName.Equal(state.DiskName) {
		resp.Diagnostics.Append(utilities.NameUpdateDisk(ctx, uint64(diskId), &plan, r.client)...)
		if resp.Diagnostics.HasError() {
			tflog.Error(ctx, "Update resourceDisk: Error renaming disk")
			return
		}
	}

	// change io limits
	if !reflect.DeepEqual(plan.IOTune, state.IOTune) && !plan.IOTune.IsUnknown() {
		resp.Diagnostics.Append(utilities.LimitIOUpdateDisk(ctx, uint64(diskId), &plan, r.client)...)
		if resp.Diagnostics.HasError() {
			tflog.Error(ctx, "Update resourceDisk: Error setting new io limits to disk")
			return
		}
	}

	// share/unshare disk
	if !plan.Shareable.Equal(state.Shareable) && !plan.Shareable.IsUnknown() {
		resp.Diagnostics.Append(utilities.ShareableUpdateDisk(ctx, uint64(diskId), plan.Shareable.ValueBool(), r.client)...)
		if resp.Diagnostics.HasError() {
			tflog.Error(ctx, "Update resourceDisk: Error with disk share/unshare")
			return
		}
	}

	tflog.Info(ctx, "Update resourceDisk: disk update is completed", map[string]any{"disk_id": plan.Id.ValueString()})

	// Map response body to schema and populate Computed attribute values
	resp.Diagnostics.Append(flattens.DiskResource(ctx, &plan, r.client)...)
	if resp.Diagnostics.HasError() {
		return
	}

	// Set data last update
	plan.LastUpdated = types.StringValue(time.Now().Format(time.RFC850))

	// Set state to fully populated data
	resp.Diagnostics.Append(resp.State.Set(ctx, plan)...)
	if resp.Diagnostics.HasError() {
		return
	}
}

// Delete deletes the resource and removes the Terraform state on success.
func (r *resourceDisk) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) {
	// Get current state
	var state models.ResourceDiskModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Delete resourceDisk: Error get state")
		return
	}
	tflog.Info(ctx, "Delete resourceDisk: got state successfully", map[string]any{"disk_id": state.Id.ValueString()})

	// Set timeouts
	deleteTimeout, diags := state.Timeouts.Delete(ctx, constants.Timeout300s)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		tflog.Error(ctx, "Delete resourceDisk: Error set timeout")
		return
	}
	tflog.Info(ctx, "Delete resourceDisk: set timeouts successfully", map[string]any{
		"disk_id":       state.Id.ValueString(),
		"deleteTimeout": deleteTimeout})

	ctx, cancel := context.WithTimeout(ctx, deleteTimeout)
	defer cancel()

	// Delete existing resource group
	delReq := disks.DeleteRequest{
		DiskID:      uint64(state.DiskId.ValueInt64()),
		Detach:      state.Detach.ValueBool(),      // default false
		Permanently: state.Permanently.ValueBool(), // default false
	}

	tflog.Info(ctx, "Delete resourceDisk: before call CloudAPI().Disks().Delete", map[string]any{"req": delReq})
	_, err := r.client.CloudAPI().Disks().Delete(ctx, delReq)
	if err != nil {
		resp.Diagnostics.AddError("Delete resourceDisk: Error deleting disk with error: ", err.Error())
		return
	}

	tflog.Info(ctx, "End delete resourceDisk", map[string]any{"disk_id": state.Id.ValueString()})
}

// Schema defines the schema for the resource.
func (r *resourceDisk) Schema(ctx context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		Attributes: schemas.MakeSchemaResourceDisk(),
		Blocks: map[string]schema.Block{
			"timeouts": timeouts.Block(ctx, timeouts.Opts{Create: true, Read: true, Update: true, Delete: true}),
		},
	}
}

// Metadata returns the resource type name.
func (r *resourceDisk) Metadata(_ context.Context, req resource.MetadataRequest, resp *resource.MetadataResponse) {
	resp.TypeName = req.ProviderTypeName + "_disk"
}

// Configure adds the provider configured client to the resource.
func (r *resourceDisk) Configure(ctx context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
	tflog.Info(ctx, "Get Configure resourceDisk")
	r.client = client.Resource(ctx, &req, resp)
	tflog.Info(ctx, "Getting Configure resourceDisk successfully")
}

func (r *resourceDisk) ImportState(ctx context.Context, req resource.ImportStateRequest, resp *resource.ImportStateResponse) {
	// Retrieve import ID and save to id attribute
	resource.ImportStatePassthroughID(ctx, path.Root("id"), req, resp)
}