package app

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"strings"

	"coopcloud.tech/abra/cli/internal"
	"coopcloud.tech/abra/pkg/app"
	appPkg "coopcloud.tech/abra/pkg/app"
	"coopcloud.tech/abra/pkg/autocomplete"
	"coopcloud.tech/abra/pkg/client"
	containerPkg "coopcloud.tech/abra/pkg/container"
	"coopcloud.tech/abra/pkg/log"
	"coopcloud.tech/abra/pkg/secret"
	"coopcloud.tech/abra/pkg/upstream/stack"
	"github.com/docker/docker/api/types"
	containertypes "github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/filters"
	"github.com/docker/docker/api/types/mount"
	"github.com/docker/docker/api/types/swarm"
	"github.com/docker/docker/api/types/volume"
	dockerclient "github.com/docker/docker/client"
	"github.com/spf13/cobra"
)

var AppMoveCommand = &cobra.Command{
	Use:     "move <domain> <server> [flags]",
	Aliases: []string{"d"},
	Short:   "Moves an app to a different server",
	Long: `Deploy an app.

This command supports chaos operations. Use "--chaos/-C" to deploy your recipe
checkout as-is. Recipe commit hashes are also supported as values for
"[version]". Please note, "upgrade"/"rollback" do not support chaos operations.`,
	Example: `  # standard deployment
  abra app deploy 1312.net

  # chaos deployment
  abra app deploy 1312.net --chaos
  
  # deploy specific version
  abra app deploy 1312.net 2.0.0+1.2.3

  # deploy a specific git hash
  abra app deploy 1312.net 886db76d`,
	Args: cobra.RangeArgs(1, 2),
	ValidArgsFunction: func(
		cmd *cobra.Command,
		args []string,
		toComplete string,
	) ([]string, cobra.ShellCompDirective) {
		switch l := len(args); l {
		case 0:
			return autocomplete.AppNameComplete()
		case 1:
			return autocomplete.ServerNameComplete()
		default:
			return nil, cobra.ShellCompDirectiveDefault
		}
	},
	Run: func(cmd *cobra.Command, args []string) {
		app := internal.ValidateApp(args)
		if len(args) <= 1 {
			log.Fatal("no server provided")
		}
		newServer := args[1]

		if err := app.Recipe.Ensure(internal.GetEnsureContext()); err != nil {
			log.Fatal(err)
		}

		cl, err := client.New(app.Server)
		if err != nil {
			log.Fatal(err)
		}

		resources, err := getAppResources(cl, app)
		if err != nil {
			log.Fatal(err)
		}

		internal.MoveOverview(app, newServer, resources.SecretNames(), resources.VolumeNames())

		if internal.Dry {
			return
		}

		// NOTE: wait timeout will be removed, until it actually is just set it to a high value.
		stack.WaitTimeout = 500
		rmOpts := stack.Remove{
			Namespaces: []string{app.StackName()},
			Detach:     false,
		}
		if err := stack.RunRemove(context.Background(), cl, rmOpts); err != nil {
			log.Fatal(err)
		}

		cl2, err := client.New(newServer)
		if err != nil {
			log.Fatal(err)
		}

		for _, s := range resources.SecretList {
			sname := strings.Split(strings.TrimPrefix(s.Spec.Name, app.StackName()+"_"), "_")
			secretName := strings.Join(sname[:len(sname)-1], "_")
			data := resources.Secrets[secretName]
			if err := client.StoreSecret(cl2, s.Spec.Name, data); err != nil {
				log.Infof("creating secret: %s", s.Spec.Name)
				log.Errorf("failed to store secret on new server: %s", err)
			}
		}

		for _, v := range resources.Volumes {
			log.Infof("moving volume: %s", v.Name)

			// Need to create the volume before copying the data, because when
			// docker creates a new volume it set the folder permissions to
			// root, which might be wrong. This ensures we always have the
			// correct folder permissions inside the volume.
			log.Debug("creating volume: %s", v.Name)
			_, err := cl2.VolumeCreate(context.Background(), volume.CreateOptions{
				Name:   v.Name,
				Driver: v.Driver,
			})
			if err != nil {
				log.Errorf("failed to create volume: %s", err)
			}

			fileName := fmt.Sprintf("%s.tar.gz", v.Name)
			log.Debug("creating %s", fileName)
			cmd := exec.Command("ssh", app.Server, "-tt", fmt.Sprintf("sudo tar --same-owner -czhpf %s -C /var/lib/docker/volumes %s", fileName, v.Name))
			if out, err := cmd.CombinedOutput(); err != nil {
				log.Errorf("failed to tar volume: %s", err)
				fmt.Println(string(out))
			}
			log.Debug("copying %s to local machine", fileName)
			cmd = exec.Command("scp", fmt.Sprintf("%s:%s", app.Server, fileName), fileName)
			if out, err := cmd.CombinedOutput(); err != nil {
				log.Errorf("failed to copy tar to local machine: %s", err)
				fmt.Println(string(out))
			}
			log.Debug("copying %s to %s", fileName, newServer)
			cmd = exec.Command("scp", fileName, fmt.Sprintf("%s:%s", newServer, fileName))
			if out, err := cmd.CombinedOutput(); err != nil {
				log.Errorf("failed to copy tar to new server: %s", err)
				fmt.Println(string(out))
			}
			log.Debug("extracting %s on %s", fileName, newServer)
			cmd = exec.Command("ssh", newServer, "-tt", fmt.Sprintf("sudo tar --same-owner -xzpf %s -C /var/lib/docker/volumes", fileName))
			if out, err := cmd.CombinedOutput(); err != nil {
				log.Errorf("failed to extract tar: %s", err)
				fmt.Println(string(out))
			}

			// Remove tar files
			cmd = exec.Command("ssh", newServer, "-tt", fmt.Sprintf("sudo rm %s", fileName))
			if out, err := cmd.CombinedOutput(); err != nil {
				log.Errorf("failed to remove tar from new server: %s", err)
				fmt.Println(string(out))
			}
			cmd = exec.Command("ssh", app.Server, "-tt", fmt.Sprintf("sudo rm %s", fileName))
			if out, err := cmd.CombinedOutput(); err != nil {
				log.Errorf("failed to remove tar from old server: %s", err)
				fmt.Println(string(out))
			}
			cmd = exec.Command("rm", fileName)
			if out, err := cmd.CombinedOutput(); err != nil {
				log.Errorf("failed to remove tar on local machine: %s", err)
				fmt.Println(string(out))
			}
		}

		log.Debug("moving app config to new server")
		if err := copyFile(app.Path, strings.ReplaceAll(app.Path, app.Server, newServer)); err != nil {
			log.Fatal(err)
		}
		if err := os.Remove(app.Path); err != nil {
			log.Fatal(err)
		}

		fmt.Println("% was succefully moved to %s", app.Name, newServer)
		fmt.Println("Run the following command to deploy the app", app.Name, newServer)
		fmt.Println("  abra app deploy --no-domain-checks", app.Domain)
		fmt.Println()
		fmt.Println("And don't forget to update you DNS record. And don't panic, as it might take a bit for the dust to settle. Traefik for example might fail to obtain the lets encrypt certificate for a while.", app.Domain)
		fmt.Println()
		fmt.Println("If anything goes wrong, you can always move the app config file to the original server and deploy it there again. There was no data removed on the old server")
		return
	},
}

type AppResources struct {
	Secrets    map[string]string
	SecretList []swarm.Secret
	Volumes    map[string]containertypes.MountPoint
}

func (a *AppResources) SecretNames() []string {
	secrets := []string{}
	for name := range a.Secrets {
		secrets = append(secrets, name)
	}
	return secrets
}

func (a *AppResources) VolumeNames() []string {
	volumes := []string{}
	for name := range a.Volumes {
		volumes = append(volumes, name)
	}
	return volumes
}

func getAppResources(cl *dockerclient.Client, app app.App) (*AppResources, error) {
	filter, err := app.Filters(false, false)
	if err != nil {
		return nil, err
	}

	services, err := cl.ServiceList(context.Background(), types.ServiceListOptions{Filters: filter})
	if err != nil {
		return nil, err
	}

	composeFiles, err := app.Recipe.GetComposeFiles(app.Env)
	if err != nil {
		return nil, err
	}

	secretList, err := cl.SecretList(context.Background(), types.SecretListOptions{Filters: filter})
	if err != nil {
		log.Fatal(err)
	}

	secretConfigs, err := secret.ReadSecretsConfig(app.Path, composeFiles, app.StackName())
	if err != nil {
		log.Fatal(err)
	}

	opts := stack.Deploy{Composefiles: composeFiles, Namespace: app.StackName()}
	compose, err := appPkg.GetAppComposeConfig(app.Name, opts, app.Env)
	if err != nil {
		log.Fatal(err)
	}

	resources := &AppResources{
		Secrets:    make(map[string]string),
		SecretList: secretList,
		Volumes:    make(map[string]containertypes.MountPoint),
	}
	for _, s := range services {
		secretNames := map[string]string{}
		for _, serviceCompose := range compose.Services {
			if app.StackName()+"_"+serviceCompose.Name != s.Spec.Name {
				continue
			}

			for _, secret := range serviceCompose.Secrets {
				for _, s := range secretList {
					if s.Spec.Name == app.StackName()+"_"+secret.Source+"_"+secretConfigs[secret.Source].Version {
						secretNames[secret.Source] = s.ID
						break
					}
				}
			}
		}

		f := filters.NewArgs()
		f.Add("name", s.Spec.Name)
		targetContainer, err := containerPkg.GetContainer(context.Background(), cl, f, true)
		if err != nil {
			log.Error(err)
			continue
		}
		for _, m := range targetContainer.Mounts {
			if m.Type == mount.TypeVolume {
				resources.Volumes[m.Name] = m
			}
		}

		for secretName, secretID := range secretNames {
			if _, ok := resources.Secrets[secretName]; ok {
				continue
			}
			log.Debugf("extracting secret %s", secretName)

			out, err := exec.Command("ssh", app.Server, "-tt", fmt.Sprintf("sudo cat /var/lib/docker/containers/%s/mounts/secrets/%s", targetContainer.ID, secretID)).Output()
			if err != nil {
				fmt.Println(string(out))
				fmt.Println(err)
				continue
			}
			resources.Secrets[secretName] = string(out)
		}
	}
	return resources, nil
}

func copyFile(src string, dst string) error {
	// Read all content of src to data, may cause OOM for a large file.
	data, err := os.ReadFile(src)
	if err != nil {
		return err
	}
	// Write data to dst
	err = os.WriteFile(dst, data, 0o644)
	if err != nil {
		return err
	}
	return nil
}

func init() {
	AppMoveCommand.Flags().BoolVarP(
		&internal.Dry,
		"dry-run",
		"r",
		false,
		"report changes that would be made",
	)
}