/*
Copyright 2020 The Flux authors

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"context"
	"fmt"
	"os"
	"regexp"
	"strings"
	"time"

	"github.com/go-git/go-git/v5/plumbing/transport/http"
	"github.com/spf13/cobra"

	"github.com/fluxcd/flux2/internal/bootstrap"
	"github.com/fluxcd/flux2/internal/bootstrap/git/gogit"
	"github.com/fluxcd/flux2/internal/bootstrap/provider"
	"github.com/fluxcd/flux2/internal/flags"
	"github.com/fluxcd/flux2/internal/utils"
	"github.com/fluxcd/flux2/pkg/manifestgen/install"
	"github.com/fluxcd/flux2/pkg/manifestgen/sourcesecret"
	"github.com/fluxcd/flux2/pkg/manifestgen/sync"
)

var bootstrapGitLabCmd = &cobra.Command{
	Use:   "gitlab",
	Short: "Bootstrap toolkit components in a GitLab repository",
	Long: `The bootstrap gitlab command creates the GitLab repository if it doesn't exists and
commits the toolkit components manifests to the master branch.
Then it configures 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 GitLab API token and export it as an env var
  export GITLAB_TOKEN=<my-token>

  # Run bootstrap for a private repository using HTTPS token authentication
  flux bootstrap gitlab --owner=<group> --repository=<repository name> --token-auth

  # Run bootstrap for a private repository using SSH authentication
  flux bootstrap gitlab --owner=<group> --repository=<repository name>

  # Run bootstrap for a repository path
  flux bootstrap gitlab --owner=<group> --repository=<repository name> --path=dev-cluster

  # Run bootstrap for a public repository on a personal account
  flux bootstrap gitlab --owner=<user> --repository=<repository name> --private=false --personal --token-auth

  # Run bootstrap for a private repository hosted on a GitLab server
  flux bootstrap gitlab --owner=<group> --repository=<repository name> --hostname=<domain> --token-auth

  # Run bootstrap for a an existing repository with a branch named main
  flux bootstrap gitlab --owner=<organization> --repository=<repository name> --branch=main --token-auth`,
	RunE: bootstrapGitLabCmdRun,
}

const (
	glDefaultPermission = "maintain"
	glDefaultDomain     = "gitlab.com"
	glTokenEnvVar       = "GITLAB_TOKEN"
	gitlabProjectRegex  = `\A[[:alnum:]\x{00A9}-\x{1f9ff}_][[:alnum:]\p{Pd}\x{00A9}-\x{1f9ff}_\.]*\z`
)

type gitlabFlags struct {
	owner        string
	repository   string
	interval     time.Duration
	personal     bool
	private      bool
	hostname     string
	path         flags.SafeRelativePath
	teams        []string
	readWriteKey bool
	reconcile    bool
}

var gitlabArgs gitlabFlags

func init() {
	bootstrapGitLabCmd.Flags().StringVar(&gitlabArgs.owner, "owner", "", "GitLab user or group name")
	bootstrapGitLabCmd.Flags().StringVar(&gitlabArgs.repository, "repository", "", "GitLab repository name")
	bootstrapGitLabCmd.Flags().StringSliceVar(&gitlabArgs.teams, "team", []string{}, "GitLab teams to be given maintainer access (also accepts comma-separated values)")
	bootstrapGitLabCmd.Flags().BoolVar(&gitlabArgs.personal, "personal", false, "if true, the owner is assumed to be a GitLab user; otherwise a group")
	bootstrapGitLabCmd.Flags().BoolVar(&gitlabArgs.private, "private", true, "if true, the repository is setup or configured as private")
	bootstrapGitLabCmd.Flags().DurationVar(&gitlabArgs.interval, "interval", time.Minute, "sync interval")
	bootstrapGitLabCmd.Flags().StringVar(&gitlabArgs.hostname, "hostname", glDefaultDomain, "GitLab hostname")
	bootstrapGitLabCmd.Flags().Var(&gitlabArgs.path, "path", "path relative to the repository root, when specified the cluster sync will be scoped to this path")
	bootstrapGitLabCmd.Flags().BoolVar(&gitlabArgs.readWriteKey, "read-write-key", false, "if true, the deploy key is configured with read/write permissions")
	bootstrapGitLabCmd.Flags().BoolVar(&gitlabArgs.reconcile, "reconcile", false, "if true, the configured options are also reconciled if the repository already exists")

	bootstrapCmd.AddCommand(bootstrapGitLabCmd)
}

func bootstrapGitLabCmdRun(cmd *cobra.Command, args []string) error {
	glToken := os.Getenv(glTokenEnvVar)
	if glToken == "" {
		var err error
		glToken, err = readPasswordFromStdin("Please enter your GitLab personal access token (PAT): ")
		if err != nil {
			return fmt.Errorf("could not read token: %w", err)
		}
	}

	if projectNameIsValid, err := regexp.MatchString(gitlabProjectRegex, gitlabArgs.repository); err != nil || !projectNameIsValid {
		if err == nil {
			err = fmt.Errorf("%s is an invalid project name for gitlab.\nIt can contain only letters, digits, emojis, '_', '.', dash, space. It must start with letter, digit, emoji or '_'.", gitlabArgs.repository)
		}
		return err
	}

	if err := bootstrapValidate(); err != nil {
		return err
	}

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

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

	// Manifest base
	if ver, err := getVersion(bootstrapArgs.version); err == nil {
		bootstrapArgs.version = ver
	}
	manifestsBase, err := buildEmbeddedManifestBase()
	if err != nil {
		return err
	}
	defer os.RemoveAll(manifestsBase)

	var caBundle []byte
	if bootstrapArgs.caFile != "" {
		var err error
		caBundle, err = os.ReadFile(bootstrapArgs.caFile)
		if err != nil {
			return fmt.Errorf("unable to read TLS CA file: %w", err)
		}
	}

	// Build GitLab provider
	providerCfg := provider.Config{
		Provider: provider.GitProviderGitLab,
		Hostname: gitlabArgs.hostname,
		Token:    glToken,
		CaBundle: caBundle,
	}
	// Workaround for: https://github.com/fluxcd/go-git-providers/issues/55
	if hostname := providerCfg.Hostname; hostname != glDefaultDomain &&
		!strings.HasPrefix(hostname, "https://") &&
		!strings.HasPrefix(hostname, "http://") {
		providerCfg.Hostname = "https://" + providerCfg.Hostname
	}
	providerClient, err := provider.BuildGitProvider(providerCfg)
	if err != nil {
		return err
	}

	// Lazy go-git repository
	tmpDir, err := os.MkdirTemp("", "flux-bootstrap-")
	if err != nil {
		return fmt.Errorf("failed to create temporary working dir: %w", err)
	}
	defer os.RemoveAll(tmpDir)
	gitClient := gogit.New(tmpDir, &http.BasicAuth{
		Username: gitlabArgs.owner,
		Password: glToken,
	})

	// Install manifest config
	installOptions := install.Options{
		BaseURL:                rootArgs.defaults.BaseURL,
		Version:                bootstrapArgs.version,
		Namespace:              rootArgs.namespace,
		Components:             bootstrapComponents(),
		Registry:               bootstrapArgs.registry,
		ImagePullSecret:        bootstrapArgs.imagePullSecret,
		WatchAllNamespaces:     bootstrapArgs.watchAllNamespaces,
		NetworkPolicy:          bootstrapArgs.networkPolicy,
		LogLevel:               bootstrapArgs.logLevel.String(),
		NotificationController: rootArgs.defaults.NotificationController,
		ManifestFile:           rootArgs.defaults.ManifestFile,
		Timeout:                rootArgs.timeout,
		TargetPath:             gitlabArgs.path.ToSlash(),
		ClusterDomain:          bootstrapArgs.clusterDomain,
		TolerationKeys:         bootstrapArgs.tolerationKeys,
	}
	if customBaseURL := bootstrapArgs.manifestsPath; customBaseURL != "" {
		installOptions.BaseURL = customBaseURL
	}

	// Source generation and secret config
	secretOpts := sourcesecret.Options{
		Name:         bootstrapArgs.secretName,
		Namespace:    rootArgs.namespace,
		TargetPath:   gitlabArgs.path.String(),
		ManifestFile: sourcesecret.MakeDefaultOptions().ManifestFile,
	}
	if bootstrapArgs.tokenAuth {
		secretOpts.Username = "git"
		secretOpts.Password = glToken

		if bootstrapArgs.caFile != "" {
			secretOpts.CAFilePath = bootstrapArgs.caFile
		}
	} else {
		secretOpts.PrivateKeyAlgorithm = sourcesecret.PrivateKeyAlgorithm(bootstrapArgs.keyAlgorithm)
		secretOpts.RSAKeyBits = int(bootstrapArgs.keyRSABits)
		secretOpts.ECDSACurve = bootstrapArgs.keyECDSACurve.Curve
		secretOpts.SSHHostname = gitlabArgs.hostname

		if bootstrapArgs.privateKeyFile != "" {
			secretOpts.PrivateKeyPath = bootstrapArgs.privateKeyFile
		}
		if bootstrapArgs.sshHostname != "" {
			secretOpts.SSHHostname = bootstrapArgs.sshHostname
		}
	}

	// Sync manifest config
	syncOpts := sync.Options{
		Interval:          gitlabArgs.interval,
		Name:              rootArgs.namespace,
		Namespace:         rootArgs.namespace,
		Branch:            bootstrapArgs.branch,
		Secret:            bootstrapArgs.secretName,
		TargetPath:        gitlabArgs.path.ToSlash(),
		ManifestFile:      sync.MakeDefaultOptions().ManifestFile,
		GitImplementation: sourceGitArgs.gitImplementation.String(),
		RecurseSubmodules: bootstrapArgs.recurseSubmodules,
	}

	// Bootstrap config
	bootstrapOpts := []bootstrap.GitProviderOption{
		bootstrap.WithProviderRepository(gitlabArgs.owner, gitlabArgs.repository, gitlabArgs.personal),
		bootstrap.WithBranch(bootstrapArgs.branch),
		bootstrap.WithBootstrapTransportType("https"),
		bootstrap.WithAuthor(bootstrapArgs.authorName, bootstrapArgs.authorEmail),
		bootstrap.WithCommitMessageAppendix(bootstrapArgs.commitMessageAppendix),
		bootstrap.WithProviderTeamPermissions(mapTeamSlice(gitlabArgs.teams, glDefaultPermission)),
		bootstrap.WithReadWriteKeyPermissions(gitlabArgs.readWriteKey),
		bootstrap.WithKubeconfig(rootArgs.kubeconfig, rootArgs.kubecontext),
		bootstrap.WithLogger(logger),
		bootstrap.WithCABundle(caBundle),
	}
	if bootstrapArgs.sshHostname != "" {
		bootstrapOpts = append(bootstrapOpts, bootstrap.WithSSHHostname(bootstrapArgs.sshHostname))
	}
	if bootstrapArgs.tokenAuth {
		bootstrapOpts = append(bootstrapOpts, bootstrap.WithSyncTransportType("https"))
	}
	if !gitlabArgs.private {
		bootstrapOpts = append(bootstrapOpts, bootstrap.WithProviderRepositoryConfig("", "", "public"))
	}
	if gitlabArgs.reconcile {
		bootstrapOpts = append(bootstrapOpts, bootstrap.WithReconcile())
	}

	// Setup bootstrapper with constructed configs
	b, err := bootstrap.NewGitProviderBootstrapper(gitClient, providerClient, kubeClient, bootstrapOpts...)
	if err != nil {
		return err
	}

	// Run
	return bootstrap.Run(ctx, b, manifestsBase, installOptions, secretOpts, syncOpts, rootArgs.pollInterval, rootArgs.timeout)
}