/*
Copyright 2016 The Kubernetes Authors All rights reserved.

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 (
	"bytes"
	"errors"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"

	"text/template"

	"github.com/Masterminds/sprig"
	"github.com/ghodss/yaml"
	"github.com/spf13/cobra"

	"k8s.io/helm/pkg/chartutil"
	"k8s.io/helm/pkg/downloader"
	"k8s.io/helm/pkg/getter/defaultgetters"
	"k8s.io/helm/pkg/helm"
	"k8s.io/helm/pkg/kube"
	"k8s.io/helm/pkg/proto/hapi/chart"
	"k8s.io/helm/pkg/proto/hapi/release"
	"k8s.io/helm/pkg/strvals"
)

const installDesc = `
This command installs a chart archive.

The install argument must be either a relative path to a chart directory or the
name of a chart in the current working directory.

To override values in a chart, use either the '--values' flag and pass in a file
or use the '--set' flag and pass configuration from the command line.

	$ helm install -f myvalues.yaml ./redis

or

	$ helm install --set name=prod ./redis

You can specify the '--values'/'-f' flag multiple times. The priority will be given to the
last (right-most) file specified. For example, if both myvalues.yaml and override.yaml
contained a key called 'Test', the value set in override.yaml would take precedence:

	$ helm install -f myvalues.yaml -f override.yaml ./redis

You can specify the '--set' flag multiple times. The priority will be given to the
last (right-most) set specified. For example, if both 'bar' and 'newbar' values are
set for a key called 'foo', the 'newbar' value would take precedence:

	$ helm install --set foo=bar --set foo=newbar ./redis


To check the generated manifests of a release without installing the chart,
the '--debug' and '--dry-run' flags can be combined. This will still require a
round-trip to the Tiller server.

If --verify is set, the chart MUST have a provenance file, and the provenenace
fall MUST pass all verification steps.

There are four different ways you can express the chart you want to install:

1. By chart reference: helm install stable/mariadb
2. By path to a packaged chart: helm install ./nginx-1.2.3.tgz
3. By path to an unpacked chart directory: helm install ./nginx
4. By absolute URL: helm install https://example.com/charts/nginx-1.2.3.tgz

CHART REFERENCES

A chart reference is a convenient way of reference a chart in a chart repository.

When you use a chart reference ('stable/mariadb'), Helm will look in the local
configuration for a chart repository named 'stable', and will then look for a
chart in that repository whose name is 'mariadb'. It will install the latest
version of that chart unless you also supply a version number with the
'--version' flag.

To see the list of chart repositories, use 'helm repo list'. To search for
charts in a repository, use 'helm search'.
`

type installCmd struct {
	name         string
	namespace    string
	valueFiles   valueFiles
	chartPath    string
	dryRun       bool
	disableHooks bool
	replace      bool
	verify       bool
	keyring      string
	out          io.Writer
	client       helm.Interface
	values       []string
	nameTemplate string
	version      string
	timeout      int64
	wait         bool
}

type valueFiles []string

func (v *valueFiles) String() string {
	return fmt.Sprint(*v)
}

func (v *valueFiles) Type() string {
	return "valueFiles"
}

func (v *valueFiles) Set(value string) error {
	for _, filePath := range strings.Split(value, ",") {
		*v = append(*v, filePath)
	}
	return nil
}

func newInstallCmd(c helm.Interface, out io.Writer) *cobra.Command {
	inst := &installCmd{
		out:    out,
		client: c,
	}

	cmd := &cobra.Command{
		Use:               "install [CHART]",
		Short:             "install a chart archive",
		Long:              installDesc,
		PersistentPreRunE: setupConnection,
		RunE: func(cmd *cobra.Command, args []string) error {
			if err := checkArgsLength(len(args), "chart name"); err != nil {
				return err
			}
			cp, err := locateChartPath(args[0], inst.version, inst.verify, inst.keyring)
			if err != nil {
				return err
			}
			inst.chartPath = cp
			inst.client = ensureHelmClient(inst.client)
			return inst.run()
		},
	}

	f := cmd.Flags()
	f.VarP(&inst.valueFiles, "values", "f", "specify values in a YAML file (can specify multiple)")
	f.StringVarP(&inst.name, "name", "n", "", "release name. If unspecified, it will autogenerate one for you")
	f.StringVar(&inst.namespace, "namespace", "", "namespace to install the release into")
	f.BoolVar(&inst.dryRun, "dry-run", false, "simulate an install")
	f.BoolVar(&inst.disableHooks, "no-hooks", false, "prevent hooks from running during install")
	f.BoolVar(&inst.replace, "replace", false, "re-use the given name, even if that name is already used. This is unsafe in production")
	f.StringArrayVar(&inst.values, "set", []string{}, "set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)")
	f.StringVar(&inst.nameTemplate, "name-template", "", "specify template used to name the release")
	f.BoolVar(&inst.verify, "verify", false, "verify the package before installing it")
	f.StringVar(&inst.keyring, "keyring", defaultKeyring(), "location of public keys used for verification")
	f.StringVar(&inst.version, "version", "", "specify the exact chart version to install. If this is not specified, the latest version is installed")
	f.Int64Var(&inst.timeout, "timeout", 300, "time in seconds to wait for any individual kubernetes operation (like Jobs for hooks)")
	f.BoolVar(&inst.wait, "wait", false, "if set, will wait until all Pods, PVCs, Services, and minimum number of Pods of a Deployment are in a ready state before marking the release as successful. It will wait for as long as --timeout")

	return cmd
}

func (i *installCmd) run() error {
	if settings.FlagDebug {
		fmt.Fprintf(i.out, "CHART PATH: %s\n", i.chartPath)
	}

	if i.namespace == "" {
		i.namespace = defaultNamespace()
	}

	rawVals, err := i.vals()
	if err != nil {
		return err
	}

	// If template is specified, try to run the template.
	if i.nameTemplate != "" {
		i.name, err = generateName(i.nameTemplate)
		if err != nil {
			return err
		}
		// Print the final name so the user knows what the final name of the release is.
		fmt.Printf("FINAL NAME: %s\n", i.name)
	}

	// Check chart requirements to make sure all dependencies are present in /charts
	chartRequested, err := chartutil.Load(i.chartPath)
	if err != nil {
		return prettyError(err)
	}

	if req, err := chartutil.LoadRequirements(chartRequested); err == nil {
		checkDependencies(chartRequested, req, i.out)
	}

	res, err := i.client.InstallReleaseFromChart(
		chartRequested,
		i.namespace,
		helm.ValueOverrides(rawVals),
		helm.ReleaseName(i.name),
		helm.InstallDryRun(i.dryRun),
		helm.InstallReuseName(i.replace),
		helm.InstallDisableHooks(i.disableHooks),
		helm.InstallTimeout(i.timeout),
		helm.InstallWait(i.wait))
	if err != nil {
		return prettyError(err)
	}

	rel := res.GetRelease()
	if rel == nil {
		return nil
	}
	i.printRelease(rel)

	// If this is a dry run, we can't display status.
	if i.dryRun {
		return nil
	}

	// Print the status like status command does
	status, err := i.client.ReleaseStatus(rel.Name)
	if err != nil {
		return prettyError(err)
	}
	PrintStatus(i.out, status)
	return nil
}

// Merges source and destination map, preferring values from the source map
func mergeValues(dest map[string]interface{}, src map[string]interface{}) map[string]interface{} {
	for k, v := range src {
		// If the key doesn't exist already, then just set the key to that value
		if _, exists := dest[k]; !exists {
			dest[k] = v
			continue
		}
		nextMap, ok := v.(map[string]interface{})
		// If it isn't another map, overwrite the value
		if !ok {
			dest[k] = v
			continue
		}
		// If the key doesn't exist already, then just set the key to that value
		if _, exists := dest[k]; !exists {
			dest[k] = nextMap
			continue
		}
		// Edge case: If the key exists in the destination, but isn't a map
		destMap, isMap := dest[k].(map[string]interface{})
		// If the source map has a map for this key, prefer it
		if !isMap {
			dest[k] = v
			continue
		}
		// If we got to this point, it is a map in both, so merge them
		dest[k] = mergeValues(destMap, nextMap)
	}
	return dest
}

func (i *installCmd) vals() ([]byte, error) {
	base := map[string]interface{}{}

	// User specified a values files via -f/--values
	for _, filePath := range i.valueFiles {
		currentMap := map[string]interface{}{}
		bytes, err := ioutil.ReadFile(filePath)
		if err != nil {
			return []byte{}, err
		}

		if err := yaml.Unmarshal(bytes, &currentMap); err != nil {
			return []byte{}, fmt.Errorf("failed to parse %s: %s", filePath, err)
		}
		// Merge with the previous map
		base = mergeValues(base, currentMap)
	}

	// User specified a value via --set
	for _, value := range i.values {
		if err := strvals.ParseInto(value, base); err != nil {
			return []byte{}, fmt.Errorf("failed parsing --set data: %s", err)
		}
	}

	return yaml.Marshal(base)
}

// printRelease prints info about a release if the flagDebug is true.
func (i *installCmd) printRelease(rel *release.Release) {
	if rel == nil {
		return
	}
	// TODO: Switch to text/template like everything else.
	fmt.Fprintf(i.out, "NAME:   %s\n", rel.Name)
	if settings.FlagDebug {
		printRelease(i.out, rel)
	}
}

// locateChartPath 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:
// - current working directory
// - if path is absolute or begins with '.', error out here
// - chart repos in $HELM_HOME
// - URL
//
// If 'verify' is true, this will attempt to also verify the chart.
func locateChartPath(name, version string, verify bool, keyring string) (string, error) {
	name = strings.TrimSpace(name)
	version = strings.TrimSpace(version)
	if fi, err := os.Stat(name); err == nil {
		abs, err := filepath.Abs(name)
		if err != nil {
			return abs, err
		}
		if verify {
			if fi.IsDir() {
				return "", errors.New("cannot verify a directory")
			}
			if _, err := downloader.VerifyChart(abs, keyring); err != nil {
				return "", err
			}
		}
		return abs, nil
	}
	if filepath.IsAbs(name) || strings.HasPrefix(name, ".") {
		return name, fmt.Errorf("path %q not found", name)
	}

	crepo := filepath.Join(settings.Home.Repository(), name)
	if _, err := os.Stat(crepo); err == nil {
		return filepath.Abs(crepo)
	}

	dl := downloader.ChartDownloader{
		HelmHome: settings.Home,
		Out:      os.Stdout,
		Keyring:  keyring,
		Getters:  defaultgetters.Get(settings),
	}
	if verify {
		dl.Verify = downloader.VerifyAlways
	}

	filename, _, err := dl.DownloadTo(name, version, ".")
	if err == nil {
		lname, err := filepath.Abs(filename)
		if err != nil {
			return filename, err
		}
		if settings.FlagDebug {
			fmt.Printf("Fetched %s to %s\n", name, filename)
		}
		return lname, nil
	} else if settings.FlagDebug {
		return filename, err
	}

	return filename, fmt.Errorf("file %q not found", name)
}

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

func defaultNamespace() string {
	if ns, _, err := kube.GetConfig(kubeContext).Namespace(); err == nil {
		return ns
	}
	return "default"
}

func checkDependencies(ch *chart.Chart, reqs *chartutil.Requirements, out io.Writer) {
	deps := ch.GetDependencies()
	for _, r := range reqs.Dependencies {
		found := false
		for _, d := range deps {
			if d.Metadata.Name == r.Name {
				found = true
				break
			}
		}
		if !found {
			fmt.Fprintf(out, "Warning: %s is in requirements.yaml but not in the charts/ directory!\n", r.Name)
		}
	}
}