/*
Copyright 2017 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 commands

import (
	"errors"

	"github.com/spf13/cobra"

	"github.com/kubernetes-sigs/kustomize/pkg/constants"
	"github.com/kubernetes-sigs/kustomize/pkg/fs"
)

type setNamePrefixOptions struct {
	prefix string
}

// newCmdSetNamePrefix sets the value of the namePrefix field in the kustomization.
func newCmdSetNamePrefix(fsys fs.FileSystem) *cobra.Command {
	var o setNamePrefixOptions

	cmd := &cobra.Command{
		Use:   "nameprefix",
		Short: "Sets the value of the namePrefix field in the kustomization file.",
		Example: `
The command
  set nameprefix acme-
will add the field "namePrefix: acme-" to the kustomization file if it doesn't exist,
and overwrite the value with "acme-" if the field does exist.
`,
		RunE: func(cmd *cobra.Command, args []string) error {
			err := o.Validate(args)
			if err != nil {
				return err
			}
			err = o.Complete(cmd, args)
			if err != nil {
				return err
			}
			return o.RunSetNamePrefix(fsys)
		},
	}
	return cmd
}

// Validate validates setNamePrefix command.
func (o *setNamePrefixOptions) Validate(args []string) error {
	if len(args) != 1 {
		return errors.New("must specify exactly one prefix value")
	}
	// TODO: add further validation on the value.
	o.prefix = args[0]
	return nil
}

// Complete completes setNamePrefix command.
func (o *setNamePrefixOptions) Complete(cmd *cobra.Command, args []string) error {
	return nil
}

// RunSetNamePrefix runs setNamePrefix command (does real work).
func (o *setNamePrefixOptions) RunSetNamePrefix(fsys fs.FileSystem) error {
	mf, err := newKustomizationFile(constants.KustomizationFileName, fsys)
	if err != nil {
		return err
	}
	m, err := mf.read()
	if err != nil {
		return err
	}
	m.NamePrefix = o.prefix
	return mf.write(m)
}
