package app

import (
	"fmt"

	"coopcloud.tech/abra/pkg/autocomplete"
	"coopcloud.tech/abra/pkg/catalogue"
	"coopcloud.tech/abra/pkg/config"
	"coopcloud.tech/abra/pkg/recipe"
	stack "coopcloud.tech/abra/pkg/upstream/stack"
	"coopcloud.tech/tagcmp"

	"coopcloud.tech/abra/cli/internal"
	"coopcloud.tech/abra/pkg/client"
	"github.com/AlecAivazis/survey/v2"
	"github.com/sirupsen/logrus"
	"github.com/urfave/cli/v2"
)

var appRollbackCommand = &cli.Command{
	Name:      "rollback",
	Usage:     "Roll an app back to a previous version",
	Aliases:   []string{"r", "downgrade"},
	ArgsUsage: "<app>",
	Flags: []cli.Flag{
		internal.ForceFlag,
		internal.ChaosFlag,
	},
	Description: `
This command rolls an app back to a previous version if one exists.

You may pass "--force/-f" to downgrade to the same version again. This can be
useful if the container runtime has gotten into a weird state.

This action could be destructive, please ensure you have a copy of your app
data beforehand - see "abra app backup <app>" for more.

Chas mode ("--chaos") will deploy your local checkout of a recipe as-is,
including unstaged changes and can be useful for live hacking and testing new
recipes.
`,
	BashComplete: autocomplete.AppNameComplete,
	Action: func(c *cli.Context) error {
		app := internal.ValidateApp(c)
		stackName := app.StackName()

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

		logrus.Debugf("checking whether '%s' is already deployed", stackName)

		isDeployed, deployedVersion, err := stack.IsDeployed(c.Context, cl, stackName)
		if err != nil {
			logrus.Fatal(err)
		}

		if !isDeployed {
			logrus.Fatalf("'%s' is not deployed?", app.Name)
		}

		catl, err := catalogue.ReadRecipeCatalogue()
		if err != nil {
			logrus.Fatal(err)
		}

		versions, err := catalogue.GetRecipeCatalogueVersions(app.Type, catl)
		if err != nil {
			logrus.Fatal(err)
		}

		var availableDowngrades []string
		if deployedVersion == "" {
			deployedVersion = "unknown"
			availableDowngrades = versions
			logrus.Warnf("failed to determine version of deployed '%s'", app.Name)
		}

		if deployedVersion != "unknown" && !internal.Chaos {
			for _, version := range versions {
				parsedDeployedVersion, err := tagcmp.Parse(deployedVersion)
				if err != nil {
					logrus.Fatal(err)
				}
				parsedVersion, err := tagcmp.Parse(version)
				if err != nil {
					logrus.Fatal(err)
				}
				if parsedVersion != parsedDeployedVersion && parsedVersion.IsLessThan(parsedDeployedVersion) {
					availableDowngrades = append(availableDowngrades, version)
				}
			}

			if len(availableDowngrades) == 0 {
				logrus.Fatal("no available downgrades, you're on latest")
			}
		}

		// FIXME: jeezus golang why do you not have a list reverse function
		for i, j := 0, len(availableDowngrades)-1; i < j; i, j = i+1, j-1 {
			availableDowngrades[i], availableDowngrades[j] = availableDowngrades[j], availableDowngrades[i]
		}

		var chosenDowngrade string
		if !internal.Chaos {
			if internal.Force {
				chosenDowngrade = availableDowngrades[0]
				logrus.Debugf("choosing '%s' as version to downgrade to (--force)", chosenDowngrade)
			} else {
				prompt := &survey.Select{
					Message: fmt.Sprintf("Please select a downgrade (current version: '%s'):", deployedVersion),
					Options: availableDowngrades,
				}
				if err := survey.AskOne(prompt, &chosenDowngrade); err != nil {
					return err
				}
			}
		}

		if !internal.Chaos {
			if err := recipe.EnsureVersion(app.Type, chosenDowngrade); err != nil {
				logrus.Fatal(err)
			}
		}

		if internal.Chaos {
			logrus.Warn("chaos mode engaged")
			var err error
			chosenDowngrade, err = recipe.ChaosVersion(app.Type)
			if err != nil {
				logrus.Fatal(err)
			}
		}

		abraShPath := fmt.Sprintf("%s/%s/%s", config.APPS_DIR, app.Type, "abra.sh")
		abraShEnv, err := config.ReadAbraShEnvVars(abraShPath)
		if err != nil {
			logrus.Fatal(err)
		}
		for k, v := range abraShEnv {
			app.Env[k] = v
		}

		composeFiles, err := config.GetAppComposeFiles(app.Type, app.Env)
		if err != nil {
			logrus.Fatal(err)
		}
		deployOpts := stack.Deploy{
			Composefiles: composeFiles,
			Namespace:    stackName,
			Prune:        false,
			ResolveImage: stack.ResolveImageAlways,
		}
		compose, err := config.GetAppComposeConfig(app.Name, deployOpts, app.Env)
		if err != nil {
			logrus.Fatal(err)
		}

		if !internal.Force {
			if err := internal.NewVersionOverview(app, deployedVersion, chosenDowngrade); err != nil {
				logrus.Fatal(err)
			}
		}

		if err := stack.RunDeploy(cl, deployOpts, compose, app.Type); err != nil {
			logrus.Fatal(err)
		}

		return nil
	},
}