package schedule

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

	"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/terraform-provider-stackit/stackit/internal/core"
	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/features"
	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/validate"

	"github.com/stackitcloud/stackit-sdk-go/core/config"
	"github.com/stackitcloud/stackit-sdk-go/core/oapierror"
	"github.com/stackitcloud/stackit-sdk-go/services/serverbackup"
)

// scheduleDataSourceBetaCheckDone is used to prevent multiple checks for beta resources.
// This is a workaround for the lack of a global state in the provider and
// needs to exist because the Configure method is called twice.
var scheduleDataSourceBetaCheckDone bool

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

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

// scheduleDataSource is the data source implementation.
type scheduleDataSource struct {
	client *serverbackup.APIClient
}

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

// Configure adds the provider configured client to the data source.
func (r *scheduleDataSource) Configure(ctx context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
	// Prevent panic if the provider has not been configured.
	if req.ProviderData == nil {
		return
	}

	providerData, ok := req.ProviderData.(core.ProviderData)
	if !ok {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error configuring API client", fmt.Sprintf("Expected configure type stackit.ProviderData, got %T", req.ProviderData))
		return
	}

	if !scheduleDataSourceBetaCheckDone {
		features.CheckBetaResourcesEnabled(ctx, &providerData, &resp.Diagnostics, "stackit_server_backup_schedule", "data source")
		if resp.Diagnostics.HasError() {
			return
		}
		scheduleDataSourceBetaCheckDone = true
	}

	var apiClient *serverbackup.APIClient
	var err error
	if providerData.ServerBackupCustomEndpoint != "" {
		ctx = tflog.SetField(ctx, "server_backup_custom_endpoint", providerData.ServerBackupCustomEndpoint)
		apiClient, err = serverbackup.NewAPIClient(
			config.WithCustomAuth(providerData.RoundTripper),
			config.WithEndpoint(providerData.ServerBackupCustomEndpoint),
		)
	} else {
		apiClient, err = serverbackup.NewAPIClient(
			config.WithCustomAuth(providerData.RoundTripper),
			config.WithRegion(providerData.Region),
		)
	}

	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error configuring API client", fmt.Sprintf("Configuring client: %v. This is an error related to the provider configuration, not to the data source configuration", err))
		return
	}

	r.client = apiClient
	tflog.Info(ctx, "Server backup client configured")
}

// Schema defines the schema for the data source.
func (r *scheduleDataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
	resp.Schema = schema.Schema{
		Description:         "Server backup schedule datasource schema. Must have a `region` specified in the provider configuration.",
		MarkdownDescription: features.AddBetaDescription("Server backup schedule datasource schema. Must have a `region` specified in the provider configuration."),
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Description: "Terraform's internal resource identifier. It is structured as \"`project_id`,`server_id`,`backup_schedule_id`\".",
				Computed:    true,
			},
			"name": schema.StringAttribute{
				Description: "The schedule name.",
				Computed:    true,
			},
			"backup_schedule_id": schema.Int64Attribute{
				Description: "Backup schedule ID.",
				Required:    true,
			},
			"project_id": schema.StringAttribute{
				Description: "STACKIT Project ID to which the server is associated.",
				Required:    true,
				Validators: []validator.String{
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"server_id": schema.StringAttribute{
				Description: "Server ID for the backup schedule.",
				Required:    true,
				Validators: []validator.String{
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"rrule": schema.StringAttribute{
				Description: "Backup schedule described in `rrule` (recurrence rule) format.",
				Computed:    true,
			},
			"enabled": schema.BoolAttribute{
				Description: "Is the backup schedule enabled or disabled.",
				Computed:    true,
			},
			"backup_properties": schema.SingleNestedAttribute{
				Description: "Backup schedule details for the backups.",
				Computed:    true,
				Attributes: map[string]schema.Attribute{
					"volume_ids": schema.ListAttribute{
						ElementType: types.StringType,
						Computed:    true,
					},
					"name": schema.StringAttribute{
						Computed: true,
					},
					"retention_period": schema.Int64Attribute{
						Computed: true,
					},
				},
			},
		},
	}
}

// Read refreshes the Terraform state with the latest data.
func (r *scheduleDataSource) 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()
	serverId := model.ServerId.ValueString()
	backupScheduleId := model.BackupScheduleId.ValueInt64()
	ctx = tflog.SetField(ctx, "project_id", projectId)
	ctx = tflog.SetField(ctx, "server_id", serverId)
	ctx = tflog.SetField(ctx, "backup_schedule_id", backupScheduleId)

	scheduleResp, err := r.client.GetBackupSchedule(ctx, projectId, serverId, strconv.FormatInt(backupScheduleId, 10)).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)
		}
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading server backup schedule", fmt.Sprintf("Calling API: %v", err))
		return
	}

	// Map response body to schema
	err = mapFields(ctx, scheduleResp, &model)
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading server backup schedule", fmt.Sprintf("Processing API payload: %v", err))
		return
	}

	// Set refreshed state
	diags = resp.State.Set(ctx, model)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}
	tflog.Info(ctx, "Server backup schedule read")
}