/*
Copyright The Helm 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 action

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"path"
	"path/filepath"
	"strings"
	"text/template"
	"time"

	"github.com/Masterminds/sprig"
	"github.com/pkg/errors"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/cli-runtime/pkg/resource"

	"helm.sh/helm/pkg/chart"
	"helm.sh/helm/pkg/chartutil"
	"helm.sh/helm/pkg/cli"
	"helm.sh/helm/pkg/downloader"
	"helm.sh/helm/pkg/engine"
	"helm.sh/helm/pkg/getter"
	kubefake "helm.sh/helm/pkg/kube/fake"
	"helm.sh/helm/pkg/release"
	"helm.sh/helm/pkg/releaseutil"
	"helm.sh/helm/pkg/repo"
	"helm.sh/helm/pkg/storage"
	"helm.sh/helm/pkg/storage/driver"
)

// releaseNameMaxLen is the maximum length of a release name.
//
// As of Kubernetes 1.4, the max limit on a name is 63 chars. We reserve 10 for
// charts to add data. Effectively, that gives us 53 chars.
// See https://github.com/helm/helm/issues/1528
const releaseNameMaxLen = 53

// NOTESFILE_SUFFIX that we want to treat special. It goes through the templating engine
// but it's not a yaml file (resource) hence can't have hooks, etc. And the user actually
// wants to see this file after rendering in the status command. However, it must be a suffix
// since there can be filepath in front of it.
const notesFileSuffix = "NOTES.txt"

const defaultDirectoryPermission = 0755

// Install performs an installation operation.
type Install struct {
	cfg *Configuration

	ChartPathOptions

	ClientOnly       bool
	DryRun           bool
	DisableHooks     bool
	Replace          bool
	Wait             bool
	Devel            bool
	DependencyUpdate bool
	Timeout          time.Duration
	Namespace        string
	ReleaseName      string
	GenerateName     bool
	NameTemplate     string
	OutputDir        string
	Atomic           bool
	SkipCRDs         bool
	OutputFormat     string
	SubNotes         bool
}

// ChartPathOptions captures common options used for controlling chart paths
type ChartPathOptions struct {
	CaFile   string // --ca-file
	CertFile string // --cert-file
	KeyFile  string // --key-file
	Keyring  string // --keyring
	Password string // --password
	RepoURL  string // --repo
	Username string // --username
	Verify   bool   // --verify
	Version  string // --version
}

// NewInstall creates a new Install object with the given configuration.
func NewInstall(cfg *Configuration) *Install {
	return &Install{
		cfg: cfg,
	}
}

func (i *Install) installCRDs(crds []*chart.File) error {
	// We do these one file at a time in the order they were read.
	totalItems := []*resource.Info{}
	for _, obj := range crds {
		// Read in the resources
		res, err := i.cfg.KubeClient.Build(bytes.NewBuffer(obj.Data))
		if err != nil {
			return errors.Wrapf(err, "failed to install CRD %s", obj.Name)
		}

		// Send them to Kube
		if _, err := i.cfg.KubeClient.Create(res); err != nil {
			// If the error is CRD already exists, continue.
			if apierrors.IsAlreadyExists(err) {
				crdName := res[0].Name
				i.cfg.Log("CRD %s is already present. Skipping.", crdName)
				continue
			}
			return errors.Wrapf(err, "failed to instal CRD %s", obj.Name)
		}
		totalItems = append(totalItems, res...)
	}
	// Invalidate the local cache, since it will not have the new CRDs
	// present.
	discoveryClient, err := i.cfg.RESTClientGetter.ToDiscoveryClient()
	if err != nil {
		return err
	}
	i.cfg.Log("Clearing discovery cache")
	discoveryClient.Invalidate()
	// Give time for the CRD to be recognized.
	if err := i.cfg.KubeClient.Wait(totalItems, 60*time.Second); err != nil {
		return err
	}
	// Make sure to force a rebuild of the cache.
	discoveryClient.ServerGroups()
	return nil
}

// Run executes the installation
//
// If DryRun is set to true, this will prepare the release, but not install it
func (i *Install) Run(chrt *chart.Chart, vals map[string]interface{}) (*release.Release, error) {
	// Check reachability of cluster unless in client-only mode (e.g. `helm template` without `--validate`)
	if !i.ClientOnly {
		if err := i.cfg.KubeClient.IsReachable(); err != nil {
			return nil, err
		}
	}

	if err := i.availableName(); err != nil {
		return nil, err
	}

	// Pre-install anything in the crd/ directory. We do this before Helm
	// contacts the upstream server and builds the capabilities object.
	if crds := chrt.CRDs(); !i.ClientOnly && !i.SkipCRDs && len(crds) > 0 {
		// On dry run, bail here
		if i.DryRun {
			i.cfg.Log("WARNING: This chart or one of its subcharts contains CRDs. Rendering may fail or contain inaccuracies.")
		} else if err := i.installCRDs(crds); err != nil {
			return nil, err
		}
	}

	if i.ClientOnly {
		// Add mock objects in here so it doesn't use Kube API server
		// NOTE(bacongobbler): used for `helm template`
		i.cfg.Capabilities = chartutil.DefaultCapabilities
		i.cfg.KubeClient = &kubefake.PrintingKubeClient{Out: ioutil.Discard}
		i.cfg.Releases = storage.Init(driver.NewMemory())
	}

	if err := chartutil.ProcessDependencies(chrt, vals); err != nil {
		return nil, err
	}

	// Make sure if Atomic is set, that wait is set as well. This makes it so
	// the user doesn't have to specify both
	i.Wait = i.Wait || i.Atomic

	caps, err := i.cfg.getCapabilities()
	if err != nil {
		return nil, err
	}

	options := chartutil.ReleaseOptions{
		Name:      i.ReleaseName,
		Namespace: i.Namespace,
		IsInstall: true,
	}
	valuesToRender, err := chartutil.ToRenderValues(chrt, vals, options, caps)
	if err != nil {
		return nil, err
	}

	rel := i.createRelease(chrt, vals)

	var manifestDoc *bytes.Buffer
	rel.Hooks, manifestDoc, rel.Info.Notes, err = i.cfg.renderResources(chrt, valuesToRender, i.OutputDir, i.SubNotes)
	// Even for errors, attach this if available
	if manifestDoc != nil {
		rel.Manifest = manifestDoc.String()
	}
	// Check error from render
	if err != nil {
		rel.SetStatus(release.StatusFailed, fmt.Sprintf("failed to render resource: %s", err.Error()))
		// Return a release with partial data so that the client can show debugging information.
		return rel, err
	}

	// Mark this release as in-progress
	rel.SetStatus(release.StatusPendingInstall, "Initial install underway")

	resources, err := i.cfg.KubeClient.Build(bytes.NewBufferString(rel.Manifest))
	if err != nil {
		return nil, errors.Wrap(err, "unable to build kubernetes objects from release manifest")
	}

	// Bail out here if it is a dry run
	if i.DryRun {
		rel.Info.Description = "Dry run complete"
		return rel, nil
	}

	// Install requires an extra validation step of checking that resources
	// don't already exist before we actually create resources. If we continue
	// forward and create the release object with resources that already exist,
	// we'll end up in a state where we will delete those resources upon
	// deleting the release because the manifest will be pointing at that
	// resource
	if err := existingResourceConflict(resources); err != nil {
		return nil, errors.Wrap(err, "rendered manifests contain a resource that already exists. Unable to continue with install")
	}

	// If Replace is true, we need to supercede the last release.
	if i.Replace {
		if err := i.replaceRelease(rel); err != nil {
			return nil, err
		}
	}

	// Store the release in history before continuing (new in Helm 3). We always know
	// that this is a create operation.
	if err := i.cfg.Releases.Create(rel); err != nil {
		// We could try to recover gracefully here, but since nothing has been installed
		// yet, this is probably safer than trying to continue when we know storage is
		// not working.
		return rel, err
	}

	// pre-install hooks
	if !i.DisableHooks {
		if err := i.cfg.execHook(rel, release.HookPreInstall, i.Timeout); err != nil {
			return i.failRelease(rel, fmt.Errorf("failed pre-install: %s", err))
		}
	}

	// At this point, we can do the install. Note that before we were detecting whether to
	// do an update, but it's not clear whether we WANT to do an update if the re-use is set
	// to true, since that is basically an upgrade operation.
	if _, err := i.cfg.KubeClient.Create(resources); err != nil {
		return i.failRelease(rel, err)
	}

	if i.Wait {
		if err := i.cfg.KubeClient.Wait(resources, i.Timeout); err != nil {
			return i.failRelease(rel, err)
		}

	}

	if !i.DisableHooks {
		if err := i.cfg.execHook(rel, release.HookPostInstall, i.Timeout); err != nil {
			return i.failRelease(rel, fmt.Errorf("failed post-install: %s", err))
		}
	}

	rel.SetStatus(release.StatusDeployed, "Install complete")

	// This is a tricky case. The release has been created, but the result
	// cannot be recorded. The truest thing to tell the user is that the
	// release was created. However, the user will not be able to do anything
	// further with this release.
	//
	// One possible strategy would be to do a timed retry to see if we can get
	// this stored in the future.
	i.recordRelease(rel)

	return rel, nil
}

func (i *Install) failRelease(rel *release.Release, err error) (*release.Release, error) {
	rel.SetStatus(release.StatusFailed, fmt.Sprintf("Release %q failed: %s", i.ReleaseName, err.Error()))
	if i.Atomic {
		i.cfg.Log("Install failed and atomic is set, uninstalling release")
		uninstall := NewUninstall(i.cfg)
		uninstall.DisableHooks = i.DisableHooks
		uninstall.KeepHistory = false
		uninstall.Timeout = i.Timeout
		if _, uninstallErr := uninstall.Run(i.ReleaseName); uninstallErr != nil {
			return rel, errors.Wrapf(uninstallErr, "an error occurred while uninstalling the release. original install error: %s", err)
		}
		return rel, errors.Wrapf(err, "release %s failed, and has been uninstalled due to atomic being set", i.ReleaseName)
	}
	i.recordRelease(rel) // Ignore the error, since we have another error to deal with.
	return rel, err
}

// availableName tests whether a name is available
//
// Roughly, this will return an error if name is
//
//	- empty
//	- too long
//	- already in use, and not deleted
//	- used by a deleted release, and i.Replace is false
func (i *Install) availableName() error {
	start := i.ReleaseName
	if start == "" {
		return errors.New("name is required")
	}

	if len(start) > releaseNameMaxLen {
		return errors.Errorf("release name %q exceeds max length of %d", start, releaseNameMaxLen)
	}

	if i.DryRun {
		return nil
	}

	h, err := i.cfg.Releases.History(start)
	if err != nil || len(h) < 1 {
		return nil
	}
	releaseutil.Reverse(h, releaseutil.SortByRevision)
	rel := h[0]

	if st := rel.Info.Status; i.Replace && (st == release.StatusUninstalled || st == release.StatusFailed) {
		return nil
	}
	return errors.New("cannot re-use a name that is still in use")
}

// createRelease creates a new release object
func (i *Install) createRelease(chrt *chart.Chart, rawVals map[string]interface{}) *release.Release {
	ts := i.cfg.Now()
	return &release.Release{
		Name:      i.ReleaseName,
		Namespace: i.Namespace,
		Chart:     chrt,
		Config:    rawVals,
		Info: &release.Info{
			FirstDeployed: ts,
			LastDeployed:  ts,
			Status:        release.StatusUnknown,
		},
		Version: 1,
	}
}

// recordRelease with an update operation in case reuse has been set.
func (i *Install) recordRelease(r *release.Release) error {
	// This is a legacy function which has been reduced to a oneliner. Could probably
	// refactor it out.
	return i.cfg.Releases.Update(r)
}

// replaceRelease replaces an older release with this one
//
// This allows us to re-use names by superseding an existing release with a new one
func (i *Install) replaceRelease(rel *release.Release) error {
	hist, err := i.cfg.Releases.History(rel.Name)
	if err != nil || len(hist) == 0 {
		// No releases exist for this name, so we can return early
		return nil
	}

	releaseutil.Reverse(hist, releaseutil.SortByRevision)
	last := hist[0]

	// Update version to the next available
	rel.Version = last.Version + 1

	// Do not change the status of a failed release.
	if last.Info.Status == release.StatusFailed {
		return nil
	}

	// For any other status, mark it as superseded and store the old record
	last.SetStatus(release.StatusSuperseded, "superseded by new release")
	return i.recordRelease(last)
}

// renderResources renders the templates in a chart
func (c *Configuration) renderResources(ch *chart.Chart, values chartutil.Values, outputDir string, subNotes bool) ([]*release.Hook, *bytes.Buffer, string, error) {
	hs := []*release.Hook{}
	b := bytes.NewBuffer(nil)

	caps, err := c.getCapabilities()
	if err != nil {
		return hs, b, "", err
	}

	if ch.Metadata.KubeVersion != "" {
		if !chartutil.IsCompatibleRange(ch.Metadata.KubeVersion, caps.KubeVersion.String()) {
			return hs, b, "", errors.Errorf("chart requires kubernetesVersion: %s which is incompatible with Kubernetes %s", ch.Metadata.KubeVersion, caps.KubeVersion.String())
		}
	}

	files, err := engine.Render(ch, values)
	if err != nil {
		return hs, b, "", err
	}

	// NOTES.txt gets rendered like all the other files, but because it's not a hook nor a resource,
	// pull it out of here into a separate file so that we can actually use the output of the rendered
	// text file. We have to spin through this map because the file contains path information, so we
	// look for terminating NOTES.txt. We also remove it from the files so that we don't have to skip
	// it in the sortHooks.
	var notesBuffer bytes.Buffer
	for k, v := range files {
		if strings.HasSuffix(k, notesFileSuffix) {
			if subNotes || (k == path.Join(ch.Name(), "templates", notesFileSuffix)) {
				// If buffer contains data, add newline before adding more
				if notesBuffer.Len() > 0 {
					notesBuffer.WriteString("\n")
				}
				notesBuffer.WriteString(v)
			}
			delete(files, k)
		}
	}
	notes := notesBuffer.String()

	// Sort hooks, manifests, and partials. Only hooks and manifests are returned,
	// as partials are not used after renderer.Render. Empty manifests are also
	// removed here.
	hs, manifests, err := releaseutil.SortManifests(files, caps.APIVersions, releaseutil.InstallOrder)
	if err != nil {
		// By catching parse errors here, we can prevent bogus releases from going
		// to Kubernetes.
		//
		// We return the files as a big blob of data to help the user debug parser
		// errors.
		for name, content := range files {
			if strings.TrimSpace(content) == "" {
				continue
			}
			fmt.Fprintf(b, "---\n# Source: %s\n%s\n", name, content)
		}
		return hs, b, "", err
	}

	// Aggregate all valid manifests into one big doc.
	fileWritten := make(map[string]bool)
	for _, m := range manifests {
		if outputDir == "" {
			fmt.Fprintf(b, "---\n# Source: %s\n%s\n", m.Name, m.Content)
		} else {
			err = writeToFile(outputDir, m.Name, m.Content, fileWritten[m.Name])
			if err != nil {
				return hs, b, "", err
			}
			fileWritten[m.Name] = true
		}
	}

	return hs, b, notes, nil
}

// write the <data> to <output-dir>/<name>. <append> controls if the file is created or content will be appended
func writeToFile(outputDir string, name string, data string, append bool) error {
	outfileName := strings.Join([]string{outputDir, name}, string(filepath.Separator))

	err := ensureDirectoryForFile(outfileName)
	if err != nil {
		return err
	}

	f, err := createOrOpenFile(outfileName, append)
	if err != nil {
		return err
	}

	defer f.Close()

	_, err = f.WriteString(fmt.Sprintf("---\n# Source: %s\n%s\n", name, data))

	if err != nil {
		return err
	}

	fmt.Printf("wrote %s\n", outfileName)
	return nil
}

func createOrOpenFile(filename string, append bool) (*os.File, error) {
	if append {
		return os.OpenFile(filename, os.O_APPEND|os.O_WRONLY, 0600)
	}
	return os.Create(filename)
}

// check if the directory exists to create file. creates if don't exists
func ensureDirectoryForFile(file string) error {
	baseDir := path.Dir(file)
	_, err := os.Stat(baseDir)
	if err != nil && !os.IsNotExist(err) {
		return err
	}

	return os.MkdirAll(baseDir, defaultDirectoryPermission)
}

// NameAndChart returns the name and chart that should be used.
//
// This will read the flags and handle name generation if necessary.
func (i *Install) NameAndChart(args []string) (string, string, error) {
	flagsNotSet := func() error {
		if i.GenerateName {
			return errors.New("cannot set --generate-name and also specify a name")
		}
		if i.NameTemplate != "" {
			return errors.New("cannot set --name-template and also specify a name")
		}
		return nil
	}

	if len(args) == 2 {
		return args[0], args[1], flagsNotSet()
	}

	if i.NameTemplate != "" {
		name, err := TemplateName(i.NameTemplate)
		return name, args[0], err
	}

	if i.ReleaseName != "" {
		return i.ReleaseName, args[0], nil
	}

	if !i.GenerateName {
		return "", args[0], errors.New("must either provide a name or specify --generate-name")
	}

	base := filepath.Base(args[0])
	if base == "." || base == "" {
		base = "chart"
	}

	return fmt.Sprintf("%s-%d", base, time.Now().Unix()), args[0], nil
}

// TemplateName renders a name template, returning the name or an error.
func TemplateName(nameTemplate string) (string, error) {
	if nameTemplate == "" {
		return "", nil
	}

	t, err := template.New("name-template").Funcs(sprig.TxtFuncMap()).Parse(nameTemplate)
	if err != nil {
		return "", err
	}
	var b bytes.Buffer
	if err := t.Execute(&b, nil); err != nil {
		return "", err
	}

	return b.String(), nil
}

// CheckDependencies checks the dependencies for a chart.
func CheckDependencies(ch *chart.Chart, reqs []*chart.Dependency) error {
	var missing []string

OUTER:
	for _, r := range reqs {
		for _, d := range ch.Dependencies() {
			if d.Name() == r.Name {
				continue OUTER
			}
		}
		missing = append(missing, r.Name)
	}

	if len(missing) > 0 {
		return errors.Errorf("found in Chart.yaml, but missing in charts/ directory: %s", strings.Join(missing, ", "))
	}
	return nil
}

// LocateChart looks for a chart directory in known places, and returns either the full path or an error.
//
// This does not ensure that the chart is well-formed; only that the requested filename exists.
//
// Order of resolution:
// - relative to current working directory
// - if path is absolute or begins with '.', error out here
// - URL
//
// If 'verify' was set on ChartPathOptions, this will attempt to also verify the chart.
func (c *ChartPathOptions) LocateChart(name string, settings *cli.EnvSettings) (string, error) {
	name = strings.TrimSpace(name)
	version := strings.TrimSpace(c.Version)

	if _, err := os.Stat(name); err == nil {
		abs, err := filepath.Abs(name)
		if err != nil {
			return abs, err
		}
		if c.Verify {
			if _, err := downloader.VerifyChart(abs, c.Keyring); err != nil {
				return "", err
			}
		}
		return abs, nil
	}
	if filepath.IsAbs(name) || strings.HasPrefix(name, ".") {
		return name, errors.Errorf("path %q not found", name)
	}

	dl := downloader.ChartDownloader{
		Out:     os.Stdout,
		Keyring: c.Keyring,
		Getters: getter.All(settings),
		Options: []getter.Option{
			getter.WithBasicAuth(c.Username, c.Password),
		},
		RepositoryConfig: settings.RepositoryConfig,
		RepositoryCache:  settings.RepositoryCache,
	}
	if c.Verify {
		dl.Verify = downloader.VerifyAlways
	}
	if c.RepoURL != "" {
		chartURL, err := repo.FindChartInAuthRepoURL(c.RepoURL, c.Username, c.Password, name, version,
			c.CertFile, c.KeyFile, c.CaFile, getter.All(settings))
		if err != nil {
			return "", err
		}
		name = chartURL
	}

	if err := os.MkdirAll(settings.RepositoryCache, 0755); err != nil {
		return "", err
	}

	filename, _, err := dl.DownloadTo(name, version, settings.RepositoryCache)
	if err == nil {
		lname, err := filepath.Abs(filename)
		if err != nil {
			return filename, err
		}
		return lname, nil
	} else if settings.Debug {
		return filename, err
	}

	return filename, errors.Errorf("failed to download %q (hint: running `helm repo update` may help)", name)
}