package volume

import (
	"context"
	"fmt"
	"net/http"

	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion"
	iaasUtils "github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/utils"

	"github.com/hashicorp/terraform-plugin-framework/datasource"
	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
	"github.com/hashicorp/terraform-plugin-framework/types"
	"github.com/hashicorp/terraform-plugin-log/tflog"
	"github.com/stackitcloud/stackit-sdk-go/services/iaas"
	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/core"
	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils"
	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/validate"
)

// Ensure the implementation satisfies the expected interfaces.
var (
	_ datasource.DataSource = &volumeDataSource{}
)

// NewVolumeDataSource is a helper function to simplify the provider implementation.
func NewVolumeDataSource() datasource.DataSource {
	return &volumeDataSource{}
}

// volumeDataSource is the data source implementation.
type volumeDataSource struct {
	client *iaas.APIClient
}

// Metadata returns the data source type name.
func (d *volumeDataSource) Metadata(_ context.Context, req datasource.MetadataRequest, resp *datasource.MetadataResponse) {
	resp.TypeName = req.ProviderTypeName + "_volume"
}

func (d *volumeDataSource) Configure(ctx context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
	providerData, ok := conversion.ParseProviderData(ctx, req.ProviderData, &resp.Diagnostics)
	if !ok {
		return
	}

	apiClient := iaasUtils.ConfigureClient(ctx, &providerData, &resp.Diagnostics)
	if resp.Diagnostics.HasError() {
		return
	}
	d.client = apiClient
	tflog.Info(ctx, "iaas client configured")
}

// Schema defines the schema for the resource.
func (r *volumeDataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
	description := "Volume resource schema. Must have a `region` specified in the provider configuration."
	resp.Schema = schema.Schema{
		MarkdownDescription: description,
		Description:         description,
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Description: "Terraform's internal resource ID. It is structured as \"`project_id`,`volume_id`\".",
				Computed:    true,
			},
			"project_id": schema.StringAttribute{
				Description: "STACKIT project ID to which the volume is associated.",
				Required:    true,
				Validators: []validator.String{
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"volume_id": schema.StringAttribute{
				Description: "The volume ID.",
				Required:    true,
				Validators: []validator.String{
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"server_id": schema.StringAttribute{
				Description: "The server ID of the server to which the volume is attached to.",
				Computed:    true,
				Validators: []validator.String{
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"name": schema.StringAttribute{
				Description: "The name of the volume.",
				Computed:    true,
			},
			"description": schema.StringAttribute{
				Description: "The description of the volume.",
				Computed:    true,
			},
			"availability_zone": schema.StringAttribute{
				Description: "The availability zone of the volume.",
				Computed:    true,
			},
			"labels": schema.MapAttribute{
				Description: "Labels are key-value string pairs which can be attached to a resource container",
				ElementType: types.StringType,
				Computed:    true,
			},
			"performance_class": schema.StringAttribute{
				MarkdownDescription: "The performance class of the volume. Possible values are documented in [Service plans BlockStorage](https://docs.stackit.cloud/stackit/en/service-plans-blockstorage-75137974.html#ServiceplansBlockStorage-CurrentlyavailableServicePlans%28performanceclasses%29)",
				Computed:            true,
			},
			"size": schema.Int64Attribute{
				Description: "The size of the volume in GB. It can only be updated to a larger value than the current size",
				Computed:    true,
			},
			"source": schema.SingleNestedAttribute{
				Description: "The source of the volume. It can be either a volume, an image, a snapshot or a backup",
				Computed:    true,
				Attributes: map[string]schema.Attribute{
					"type": schema.StringAttribute{
						Description: "The type of the source. " + utils.SupportedValuesDocumentation(SupportedSourceTypes),
						Computed:    true,
					},
					"id": schema.StringAttribute{
						Description: "The ID of the source, e.g. image ID",
						Computed:    true,
					},
				},
			},
		},
	}
}

// Read refreshes the Terraform state with the latest data.
func (d *volumeDataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) { // nolint:gocritic // function signature required by Terraform
	var model Model
	diags := req.Config.Get(ctx, &model)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}
	projectId := model.ProjectId.ValueString()
	volumeId := model.VolumeId.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectId)
	ctx = tflog.SetField(ctx, "volume_id", volumeId)

	volumeResp, err := d.client.GetVolume(ctx, projectId, volumeId).Execute()
	if err != nil {
		utils.LogError(
			ctx,
			&resp.Diagnostics,
			err,
			"Reading volume",
			fmt.Sprintf("Volume with ID %q does not exist in project %q.", volumeId, projectId),
			map[int]string{
				http.StatusForbidden: fmt.Sprintf("Project with ID %q not found or forbidden access", projectId),
			},
		)
		resp.State.RemoveResource(ctx)
		return
	}

	err = mapFields(ctx, volumeResp, &model)
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading volume", 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, "volume read")
}