package stack

import (
	"fmt"
	"strings"

	"github.com/spf13/cobra"
	"golang.org/x/net/context"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/swarm"
	"github.com/docker/docker/cli"
	"github.com/docker/docker/cli/command"
	"github.com/docker/docker/cli/command/bundlefile"
)

const (
	defaultNetworkDriver = "overlay"
)

type deployOptions struct {
	bundlefile       string
	namespace        string
	sendRegistryAuth bool
}

func newDeployCommand(dockerCli *command.DockerCli) *cobra.Command {
	var opts deployOptions

	cmd := &cobra.Command{
		Use:     "deploy [OPTIONS] STACK",
		Aliases: []string{"up"},
		Short:   "Create and update a stack from a Distributed Application Bundle (DAB)",
		Args:    cli.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			opts.namespace = strings.TrimSuffix(args[0], ".dab")
			return runDeploy(dockerCli, opts)
		},
		Tags: map[string]string{"experimental": ""},
	}

	flags := cmd.Flags()
	addBundlefileFlag(&opts.bundlefile, flags)
	addRegistryAuthFlag(&opts.sendRegistryAuth, flags)
	return cmd
}

func runDeploy(dockerCli *command.DockerCli, opts deployOptions) error {
	bundle, err := loadBundlefile(dockerCli.Err(), opts.namespace, opts.bundlefile)
	if err != nil {
		return err
	}

	info, err := dockerCli.Client().Info(context.Background())
	if err != nil {
		return err
	}
	if !info.Swarm.ControlAvailable {
		return fmt.Errorf("This node is not a swarm manager. Use \"docker swarm init\" or \"docker swarm join\" to connect this node to swarm and try again.")
	}

	networks := getUniqueNetworkNames(bundle.Services)
	ctx := context.Background()

	if err := updateNetworks(ctx, dockerCli, networks, opts.namespace); err != nil {
		return err
	}
	return deployServices(ctx, dockerCli, bundle.Services, opts.namespace, opts.sendRegistryAuth)
}

func getUniqueNetworkNames(services map[string]bundlefile.Service) []string {
	networkSet := make(map[string]bool)
	for _, service := range services {
		for _, network := range service.Networks {
			networkSet[network] = true
		}
	}

	networks := []string{}
	for network := range networkSet {
		networks = append(networks, network)
	}
	return networks
}

func updateNetworks(
	ctx context.Context,
	dockerCli *command.DockerCli,
	networks []string,
	namespace string,
) error {
	client := dockerCli.Client()

	existingNetworks, err := getNetworks(ctx, client, namespace)
	if err != nil {
		return err
	}

	existingNetworkMap := make(map[string]types.NetworkResource)
	for _, network := range existingNetworks {
		existingNetworkMap[network.Name] = network
	}

	createOpts := types.NetworkCreate{
		Labels: getStackLabels(namespace, nil),
		Driver: defaultNetworkDriver,
	}

	for _, internalName := range networks {
		name := fmt.Sprintf("%s_%s", namespace, internalName)

		if _, exists := existingNetworkMap[name]; exists {
			continue
		}
		fmt.Fprintf(dockerCli.Out(), "Creating network %s\n", name)
		if _, err := client.NetworkCreate(ctx, name, createOpts); err != nil {
			return err
		}
	}
	return nil
}

func convertNetworks(networks []string, namespace string, name string) []swarm.NetworkAttachmentConfig {
	nets := []swarm.NetworkAttachmentConfig{}
	for _, network := range networks {
		nets = append(nets, swarm.NetworkAttachmentConfig{
			Target:  namespace + "_" + network,
			Aliases: []string{name},
		})
	}
	return nets
}

func deployServices(
	ctx context.Context,
	dockerCli *command.DockerCli,
	services map[string]bundlefile.Service,
	namespace string,
	sendAuth bool,
) error {
	apiClient := dockerCli.Client()
	out := dockerCli.Out()

	existingServices, err := getServices(ctx, apiClient, namespace)
	if err != nil {
		return err
	}

	existingServiceMap := make(map[string]swarm.Service)
	for _, service := range existingServices {
		existingServiceMap[service.Spec.Name] = service
	}

	for internalName, service := range services {
		name := fmt.Sprintf("%s_%s", namespace, internalName)

		var ports []swarm.PortConfig
		for _, portSpec := range service.Ports {
			ports = append(ports, swarm.PortConfig{
				Protocol:   swarm.PortConfigProtocol(portSpec.Protocol),
				TargetPort: portSpec.Port,
			})
		}

		serviceSpec := swarm.ServiceSpec{
			Annotations: swarm.Annotations{
				Name:   name,
				Labels: getStackLabels(namespace, service.Labels),
			},
			TaskTemplate: swarm.TaskSpec{
				ContainerSpec: swarm.ContainerSpec{
					Image:   service.Image,
					Command: service.Command,
					Args:    service.Args,
					Env:     service.Env,
					// Service Labels will not be copied to Containers
					// automatically during the deployment so we apply
					// it here.
					Labels: getStackLabels(namespace, nil),
				},
			},
			EndpointSpec: &swarm.EndpointSpec{
				Ports: ports,
			},
			Networks: convertNetworks(service.Networks, namespace, internalName),
		}

		cspec := &serviceSpec.TaskTemplate.ContainerSpec
		if service.WorkingDir != nil {
			cspec.Dir = *service.WorkingDir
		}
		if service.User != nil {
			cspec.User = *service.User
		}

		encodedAuth := ""
		if sendAuth {
			// Retrieve encoded auth token from the image reference
			image := serviceSpec.TaskTemplate.ContainerSpec.Image
			encodedAuth, err = command.RetrieveAuthTokenFromImage(ctx, dockerCli, image)
			if err != nil {
				return err
			}
		}

		if service, exists := existingServiceMap[name]; exists {
			fmt.Fprintf(out, "Updating service %s (id: %s)\n", name, service.ID)

			updateOpts := types.ServiceUpdateOptions{}
			if sendAuth {
				updateOpts.EncodedRegistryAuth = encodedAuth
			}
			if err := apiClient.ServiceUpdate(
				ctx,
				service.ID,
				service.Version,
				serviceSpec,
				updateOpts,
			); err != nil {
				return err
			}
		} else {
			fmt.Fprintf(out, "Creating service %s\n", name)

			createOpts := types.ServiceCreateOptions{}
			if sendAuth {
				createOpts.EncodedRegistryAuth = encodedAuth
			}
			if _, err := apiClient.ServiceCreate(ctx, serviceSpec, createOpts); err != nil {
				return err
			}
		}
	}

	return nil
}