/*
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 installer // import "k8s.io/helm/cmd/helm/installer"

import (
	"fmt"
	"io"
	"os"

	"k8s.io/helm/pkg/getter"
	helm_env "k8s.io/helm/pkg/helm/environment"
	"k8s.io/helm/pkg/helm/helmpath"
	"k8s.io/helm/pkg/repo"
)

const (
	stableRepository = "stable"

	// LocalRepository is the standard name of the local repository
	LocalRepository = "local"

	// LocalRepositoryIndexFile is the standard name of the local repository index file
	LocalRepositoryIndexFile = "index.yaml"
)

// Initialize initializes local config
//
// Returns an error if the command failed.
func Initialize(home helmpath.Home, out io.Writer, skipRefresh bool, settings helm_env.EnvSettings, stableRepositoryURL, localRepositoryURL string) error {
	if err := ensureDirectories(home, out); err != nil {
		return err
	}
	if err := ensureDefaultRepos(home, out, skipRefresh, settings, stableRepositoryURL, localRepositoryURL); err != nil {
		return err
	}

	return ensureRepoFileFormat(home.RepositoryFile(), out)
}

// InitializeWithoutRepos initializes local config without adding repos
//
// Returns an error if the command failed.
func InitializeWithoutRepos(home helmpath.Home, out io.Writer) error {
	if err := ensureDirectories(home, out); err != nil {
		return err
	}

	// Adding an empty repositories file
	repoFile := home.RepositoryFile()
	if fi, err := os.Stat(repoFile); err != nil {
		fmt.Fprintf(out, "Creating %s \n", repoFile)
		f := repo.NewRepoFile()
		if err := f.WriteFile(repoFile, 0644); err != nil {
			return err
		}
	} else if fi.IsDir() {
		return fmt.Errorf("%s must be a file, not a directory", repoFile)
	}

	return ensureRepoFileFormat(home.RepositoryFile(), out)
}

// ensureDirectories checks to see if $HELM_HOME exists.
//
// If $HELM_HOME does not exist, this function will create it.
func ensureDirectories(home helmpath.Home, out io.Writer) error {
	configDirectories := []string{
		home.String(),
		home.Repository(),
		home.Cache(),
		home.LocalRepository(),
		home.Plugins(),
		home.Starters(),
		home.Archive(),
	}
	for _, p := range configDirectories {
		if fi, err := os.Stat(p); err != nil {
			fmt.Fprintf(out, "Creating %s \n", p)
			if err := os.MkdirAll(p, 0755); err != nil {
				return fmt.Errorf("Could not create %s: %s", p, err)
			}
		} else if !fi.IsDir() {
			return fmt.Errorf("%s must be a directory", p)
		}
	}

	return nil
}

func ensureDefaultRepos(home helmpath.Home, out io.Writer, skipRefresh bool, settings helm_env.EnvSettings, stableRepositoryURL, localRepositoryURL string) error {
	repoFile := home.RepositoryFile()
	if fi, err := os.Stat(repoFile); err != nil {
		fmt.Fprintf(out, "Creating %s \n", repoFile)
		f := repo.NewRepoFile()
		sr, err := initStableRepo(home.CacheIndex(stableRepository), home, out, skipRefresh, settings, stableRepositoryURL)
		if err != nil {
			return err
		}
		lr, err := initLocalRepo(home.LocalRepository(LocalRepositoryIndexFile), home.CacheIndex("local"), home, out, settings, localRepositoryURL)
		if err != nil {
			return err
		}
		f.Add(sr)
		f.Add(lr)
		if err := f.WriteFile(repoFile, 0644); err != nil {
			return err
		}
	} else if fi.IsDir() {
		return fmt.Errorf("%s must be a file, not a directory", repoFile)
	}
	return nil
}

func initStableRepo(cacheFile string, home helmpath.Home, out io.Writer, skipRefresh bool, settings helm_env.EnvSettings, stableRepositoryURL string) (*repo.Entry, error) {
	fmt.Fprintf(out, "Adding %s repo with URL: %s \n", stableRepository, stableRepositoryURL)
	c := repo.Entry{
		Name:  stableRepository,
		URL:   stableRepositoryURL,
		Cache: cacheFile,
	}
	r, err := repo.NewChartRepository(&c, getter.All(settings))
	if err != nil {
		return nil, err
	}

	if skipRefresh {
		return &c, nil
	}

	// In this case, the cacheFile is always absolute. So passing empty string
	// is safe.
	if err := r.DownloadIndexFile(""); err != nil {
		return nil, fmt.Errorf("Looks like %q is not a valid chart repository or cannot be reached: %s", stableRepositoryURL, err.Error())
	}

	return &c, nil
}

func initLocalRepo(indexFile, cacheFile string, home helmpath.Home, out io.Writer, settings helm_env.EnvSettings, localRepositoryURL string) (*repo.Entry, error) {
	if fi, err := os.Stat(indexFile); err != nil {
		fmt.Fprintf(out, "Adding %s repo with URL: %s \n", LocalRepository, localRepositoryURL)
		i := repo.NewIndexFile()
		if err := i.WriteFile(indexFile, 0644); err != nil {
			return nil, err
		}

		//TODO: take this out and replace with helm update functionality
		if err := createLink(indexFile, cacheFile, home); err != nil {
			return nil, err
		}
	} else if fi.IsDir() {
		return nil, fmt.Errorf("%s must be a file, not a directory", indexFile)
	}

	return &repo.Entry{
		Name:  LocalRepository,
		URL:   localRepositoryURL,
		Cache: cacheFile,
	}, nil
}

func ensureRepoFileFormat(file string, out io.Writer) error {
	r, err := repo.LoadRepositoriesFile(file)
	if err == repo.ErrRepoOutOfDate {
		fmt.Fprintln(out, "Updating repository file format...")
		if err := r.WriteFile(file, 0644); err != nil {
			return err
		}
	}

	return nil
}