package main

import (
	"context"
	"fmt"
	"io/ioutil"
	"net/url"
	"os"
	"path"
	"time"

	"github.com/spf13/cobra"

	"github.com/fluxcd/toolkit/pkg/git"
)

var bootstrapGitHubCmd = &cobra.Command{
	Use:   "github",
	Short: "Bootstrap GitHub repository",
	Long: `
The bootstrap command creates the GitHub repository if it doesn't exists and
commits the toolkit components manifests to the master branch.
Then it configure the target cluster to synchronize with the repository.
If the toolkit components are present on the cluster,
the bootstrap command will perform an upgrade if needed.`,
	Example: `  # Create a GitHub personal access token and export it as an env var
  export GITHUB_TOKEN=<my-token>

  # Run bootstrap for a private repo owned by a GitHub organization
  bootstrap github --owner=<organization> --repository=<repo name>

  # Run bootstrap for a private repo and assign organization teams to it
  bootstrap github --owner=<organization> --repository=<repo name> --team=<team1 slug> --team=<team2 slug>

  # Run bootstrap for a repository path
  bootstrap github --owner=<organization> --repository=<repo name> --path=dev-cluster

  # Run bootstrap for a public repository on a personal account
  bootstrap github --owner=<user> --repository=<repo name> --private=false --personal=true 

  # Run bootstrap for a private repo hosted on GitHub Enterprise
  bootstrap github --owner=<organization> --repository=<repo name> --hostname=<domain>
`,
	RunE: bootstrapGitHubCmdRun,
}

var (
	ghOwner      string
	ghRepository string
	ghInterval   time.Duration
	ghPersonal   bool
	ghPrivate    bool
	ghHostname   string
	ghPath       string
	ghTeams      []string
)

const (
	ghDefaultPermission = "maintain"
)

func init() {
	bootstrapGitHubCmd.Flags().StringVar(&ghOwner, "owner", "", "GitHub user or organization name")
	bootstrapGitHubCmd.Flags().StringVar(&ghRepository, "repository", "", "GitHub repository name")
	bootstrapGitHubCmd.Flags().StringArrayVar(&ghTeams, "team", []string{}, "GitHub team to be given maintainer access")
	bootstrapGitHubCmd.Flags().BoolVar(&ghPersonal, "personal", false, "is personal repository")
	bootstrapGitHubCmd.Flags().BoolVar(&ghPrivate, "private", true, "is private repository")
	bootstrapGitHubCmd.Flags().DurationVar(&ghInterval, "interval", time.Minute, "sync interval")
	bootstrapGitHubCmd.Flags().StringVar(&ghHostname, "hostname", git.GitHubDefaultHostname, "GitHub hostname")
	bootstrapGitHubCmd.Flags().StringVar(&ghPath, "path", "", "repository path, when specified the cluster sync will be scoped to this path")

	bootstrapCmd.AddCommand(bootstrapGitHubCmd)
}

func bootstrapGitHubCmdRun(cmd *cobra.Command, args []string) error {
	ghToken := os.Getenv(git.GitHubTokenName)
	if ghToken == "" {
		return fmt.Errorf("%s environment variable not found", git.GitHubTokenName)
	}

	repository, err := git.NewRepository(ghRepository, ghOwner, ghHostname, ghToken, "tk", "tk@users.noreply.github.com")
	if err != nil {
		return err
	}

	provider := &git.GithubProvider{
		IsPrivate:  ghPrivate,
		IsPersonal: ghPersonal,
	}

	kubeClient, err := utils.kubeClient(kubeconfig)
	if err != nil {
		return err
	}

	tmpDir, err := ioutil.TempDir("", namespace)
	if err != nil {
		return err
	}
	defer os.RemoveAll(tmpDir)

	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	// create GitHub repository if doesn't exists
	logAction("connecting to %s", ghHostname)
	changed, err := provider.CreateRepository(ctx, repository)
	if err != nil {
		return err
	}
	if changed {
		logSuccess("repository created")
	}

	withErrors := false
	// add teams to org repository
	if !ghPersonal {
		for _, team := range ghTeams {
			if changed, err := provider.AddTeam(ctx, repository, team, ghDefaultPermission); err != nil {
				logFailure(err.Error())
				withErrors = true
			} else if changed {
				logSuccess("%s team access granted", team)
			}
		}
	}

	// clone repository and checkout the master branch
	if err := repository.Checkout(ctx, bootstrapBranch, tmpDir); err != nil {
		return err
	}
	logSuccess("repository cloned")

	// generate install manifests
	logGenerate("generating manifests")
	manifest, err := generateInstallManifests(ghPath, namespace, tmpDir)
	if err != nil {
		return err
	}

	// stage install manifests
	changed, err = repository.Commit(ctx, path.Join(ghPath, namespace), "Add manifests")
	if err != nil {
		return err
	}

	// push install manifests
	if changed {
		if err := repository.Push(ctx); err != nil {
			return err
		}
		logSuccess("components manifests pushed")
	} else {
		logSuccess("components are up to date")
	}

	// determine if repo synchronization is working
	isInstall := shouldInstallManifests(ctx, kubeClient, namespace)

	if isInstall {
		// apply install manifests
		logAction("installing components in %s namespace", namespace)
		if err := applyInstallManifests(ctx, manifest, components); err != nil {
			return err
		}
		logSuccess("install completed")
	}

	// setup SSH deploy key
	if shouldCreateDeployKey(ctx, kubeClient, namespace) {
		logAction("configuring deploy key")
		u, err := url.Parse(repository.GetSSH())
		if err != nil {
			return fmt.Errorf("git URL parse failed: %w", err)
		}

		key, err := generateDeployKey(ctx, kubeClient, u, namespace)
		if err != nil {
			return fmt.Errorf("generating deploy key failed: %w", err)
		}

		keyName := "tk"
		if ghPath != "" {
			keyName = fmt.Sprintf("tk-%s", ghPath)
		}

		if changed, err := provider.AddDeployKey(ctx, repository, key, keyName); err != nil {
			return err
		} else if changed {
			logSuccess("deploy key configured")
		}
	}

	// configure repo synchronization
	if isInstall {
		// generate source and kustomization manifests
		logAction("generating sync manifests")
		if err := generateSyncManifests(repository.GetSSH(), namespace, namespace, ghPath, tmpDir, ghInterval); err != nil {
			return err
		}

		// commit and push manifests
		if changed, err = repository.Commit(ctx, path.Join(ghPath, namespace), "Add manifests"); err != nil {
			return err
		} else if changed {
			if err := repository.Push(ctx); err != nil {
				return err
			}
			logSuccess("sync manifests pushed")
		}

		// apply manifests and waiting for sync
		logAction("applying sync manifests")
		if err := applySyncManifests(ctx, kubeClient, namespace, namespace, ghPath, tmpDir); err != nil {
			return err
		}
	}

	if withErrors {
		return fmt.Errorf("bootstrap completed with errors")
	}

	logSuccess("bootstrap finished")
	return nil
}