/*
Copyright 2018 The Kubernetes 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 misc

import (
	"fmt"
	"path/filepath"

	"github.com/spf13/cobra"

	"sigs.k8s.io/kustomize/pkg/fs"
	"sigs.k8s.io/kustomize/pkg/transformers/config/defaultconfig"
)

// NewCmdConfig returns an instance of 'config' subcommand.
func NewCmdConfig(fsys fs.FileSystem) *cobra.Command {
	c := &cobra.Command{
		Use:   "config",
		Short: "Config Kustomize transformers",
		Long:  "",
		Example: `
	# Save the default transformer configurations to a local directory
	kustomize config save -d ~/.kustomize/config
`,
		Args: cobra.MinimumNArgs(1),
	}
	c.AddCommand(
		newCmdSave(fsys),
	)
	return c
}

type saveOptions struct {
	saveDirectory string
}

func newCmdSave(fsys fs.FileSystem) *cobra.Command {
	var o saveOptions

	c := &cobra.Command{
		Use:   "save",
		Short: "Save default kustomize transformer configurations to a local directory",
		Long:  "",
		Example: `
	# Save the default transformer configurations to a local directory
	save -d ~/.kustomize/config

`,
		RunE: func(cmd *cobra.Command, args []string) error {
			err := o.Validate()
			if err != nil {
				return err
			}
			err = o.Complete(fsys)
			if err != nil {
				return err
			}
			return o.RunSave(fsys)
		},
	}
	c.Flags().StringVarP(
		&o.saveDirectory,
		"directory", "d", "",
		"Directory to save the default transformer configurations")

	return c

}

// Validate validates the saveOptions is not empty
func (o *saveOptions) Validate() error {
	if o.saveDirectory == "" {
		return fmt.Errorf("must specify one local directory to save the default transformer configurations")
	}
	return nil
}

// Complete creates the save directory when the directory doesn't exist
func (o *saveOptions) Complete(fsys fs.FileSystem) error {
	if !fsys.Exists(o.saveDirectory) {
		return fsys.MkdirAll(o.saveDirectory)
	}
	if fsys.IsDir(o.saveDirectory) {
		return nil
	}
	return fmt.Errorf("%s is not a directory", o.saveDirectory)
}

// RunSave saves the default transformer configurations local directory
func (o *saveOptions) RunSave(fsys fs.FileSystem) error {
	m := defaultconfig.GetDefaultFieldSpecsAsMap()
	for tname, tcfg := range m {
		filename := filepath.Join(o.saveDirectory, tname+".yaml")
		err := fsys.WriteFile(filename, []byte(tcfg))
		if err != nil {
			return err
		}
	}
	return nil
}