package utils

import (
	"context"
	"errors"
	"time"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/filters"
	"github.com/docker/docker/api/types/swarm"
	"github.com/docker/docker/api/types/volume"
	"github.com/docker/docker/client"
	"github.com/docker/docker/errdefs"
	"github.com/rs/zerolog/log"
)

var (
	ErrServiceNotFound      = errors.New("unable to found the service")
	ErrServiceCommandFailed = errors.New("command failed on the container")
	ErrServiceUnhealthy     = errors.New("service unhealthy")
)

type FnRetry func(ctx context.Context) error

func Retry(ctx context.Context, fnRetry FnRetry, waitDuration time.Duration, maxRetry int) (err error) {
	for i := 0; i < maxRetry; i++ {
		if err = fnRetry(ctx); err != nil {
			time.Sleep(waitDuration)
			continue
		}
		return nil
	}
	return err
}

func CreateNetwork(ctx context.Context, cli *client.Client, networkName string) error {
	networkSpec := types.NetworkCreate{
		Driver: "overlay",
	}

	_, err := cli.NetworkCreate(ctx, networkName, networkSpec)
	if err != nil {
		return err
	}

	return nil
}

func FilterImagesByName(ctx context.Context, cli *client.Client, name string) ([]types.ImageSummary, error) {
	images, err := cli.ImageList(ctx, types.ImageListOptions{All: true})
	if err != nil {
		return nil, err
	}

	var filteredImages []types.ImageSummary

	for i := range images {
		for _, tag := range images[i].RepoTags {
			if tag == name {
				filteredImages = append(filteredImages, images[i])
				break
			}
		}
	}

	return filteredImages, nil
}

func CreateService(ctx context.Context, cli *client.Client, spec *swarm.ServiceSpec) error {
	serviceName := spec.Annotations.Name
	log.Info().Str("service", serviceName).Msg("creating service...")

	response, err := cli.ServiceCreate(ctx, *spec, types.ServiceCreateOptions{})
	if err != nil {
		if !errdefs.IsConflict(err) {
			return err
		}

		log.Info().Str("service", serviceName).Msg("service already deployed")
		return nil
	}

	log.Info().Str("service", serviceName).Str("id", response.ID).Msg("service deployed")
	return nil
}

func GetServiceByName(ctx context.Context, cli *client.Client, name string) (swarm.Service, error) {
	servicesFilters := filters.NewArgs()
	servicesFilters.Add("name", name)

	options := types.ServiceListOptions{
		Filters: servicesFilters,
		Status:  true,
	}

	services, err := cli.ServiceList(ctx, options)
	if err != nil {
		return swarm.Service{}, err
	}

	if len(services) != 1 {
		return swarm.Service{}, ErrServiceNotFound
	}

	return services[0], nil
}

func CheckServiceHealth(ctx context.Context, cli *client.Client, serviceName string) error {
	log.Info().Str("service", serviceName).Msg("healthchecking...")
	service, err := GetServiceByName(ctx, cli, serviceName)
	if err != nil {
		return err
	}

	if service.ServiceStatus != nil && service.ServiceStatus.RunningTasks != 0 {
		log.Info().Str("service", serviceName).Msg("service is running")
		return nil
	}

	log.Info().Str("service", serviceName).Msg("service not already started, retrying...")
	return errors.New("service unhealthy")
}

func CheckServiceHealthWithRetry(ctx context.Context, cli *client.Client, serviceName string) error {
	fnRetry := func(ctx context.Context) error {
		return CheckServiceHealth(ctx, cli, serviceName)
	}

	waitDuration := 5 * time.Second
	maxRetry := 15
	return Retry(ctx, fnRetry, waitDuration, maxRetry)
}

func CheckAndDeleteCompletedService(ctx context.Context, cli *client.Client, name string) error {
	service, err := GetServiceByName(ctx, cli, name)
	if err != nil {
		return err
	}

	fnRetry := func(ctx context.Context) error {
		taskFilters := filters.NewArgs()
		taskFilters.Add("service", service.ID)

		tasks, err := cli.TaskList(ctx, types.TaskListOptions{
			Filters: taskFilters,
		})
		if err != nil {
			return err
		}

		completeTasks := 0
		for idx := range tasks {
			if tasks[idx].Status.State == swarm.TaskStateComplete {
				completeTasks++
			}
		}

		if completeTasks == 0 {
			return errors.New("no completed tasks")
		}

		return nil
	}

	maxAttempts := 20
	if err := Retry(ctx, fnRetry, time.Second, maxAttempts); err != nil {
		return err
	}

	if err := cli.ServiceRemove(ctx, service.ID); err != nil {
		return err
	}

	return nil
}

// UpdateServiceByName updates force a service by its name. It will remove and recreate the service.
func UpdateServiceByName(ctx context.Context, cli *client.Client, serviceName string) error {
	srv, err := GetServiceByName(ctx, cli, serviceName)
	if err != nil {
		return err
	}

	if err := RemoveService(ctx, cli, srv.ID); err != nil {
		return err
	}

	if err := CreateService(ctx, cli, &srv.Spec); err != nil {
		return err
	}

	return nil
}

func RemoveService(ctx context.Context, cli *client.Client, serviceID string) error {
	fnRetry := func(ctx context.Context) error {
		if err := cli.ServiceRemove(ctx, serviceID); err != nil {
			return err
		}
		return nil
	}

	maxRetry := 10
	if err := Retry(ctx, fnRetry, time.Second, maxRetry); err != nil {
		return err
	}

	return nil
}

func RemoveImage(ctx context.Context, cli *client.Client, imageID string) error {
	fnRetry := func(ctx context.Context) error {
		if _, err := cli.ImageRemove(ctx, imageID, types.ImageRemoveOptions{}); err != nil {
			if errdefs.IsConflict(err) {
				log.Warn().Str("image", imageID).Msg("image is using")
			}
			return err
		}
		return nil
	}

	maxRetry := 10
	if err := Retry(ctx, fnRetry, time.Second, maxRetry); err != nil {
		return err
	}

	return nil
}

func CreateVolume(ctx context.Context, cli *client.Client, volumeName string) error {
	if _, err := cli.VolumeCreate(ctx, volume.CreateOptions{Name: volumeName}); err != nil {
		if !errdefs.IsConflict(err) {
			return err
		}
	}
	return nil
}