/*
Copyright 2015 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 chart

import (
	"io/ioutil"

	"github.com/Masterminds/semver"
	"gopkg.in/yaml.v2"
)

// Chartfile describes a Helm Chart (e.g. Chart.yaml)
type Chartfile struct {
	Name        string        `yaml:"name"`
	Description string        `yaml:"description"`
	Version     string        `yaml:"version"`
	Keywords    []string      `yaml:"keywords,omitempty"`
	Maintainers []*Maintainer `yaml:"maintainers,omitempty"`
	Source      []string      `yaml:"sources,omitempty"`
	Home        string        `yaml:"home"`
}

// Maintainer describes a chart maintainer.
type Maintainer struct {
	Name  string `yaml:"name"`
	Email string `yaml:"email,omitempty"`
}

// LoadChartfile loads a Chart.yaml file into a *Chart.
func LoadChartfile(filename string) (*Chartfile, error) {
	b, err := ioutil.ReadFile(filename)
	if err != nil {
		return nil, err
	}
	var y Chartfile
	err = yaml.Unmarshal(b, &y)
	if err != nil {
		return nil, err
	}
	// Validate that the Version is actually a valid semver version
	_, err = semver.NewVersion(y.Version)
	if err != nil {
		return nil, err
	}
	return &y, nil
}

// Save saves a Chart.yaml file
func (c *Chartfile) Save(filename string) error {
	b, err := c.Marshal()
	if err != nil {
		return err
	}

	return ioutil.WriteFile(filename, b, 0644)
}

// Marshal encodes the chart file into YAML.
func (c *Chartfile) Marshal() ([]byte, error) {
	return yaml.Marshal(c)
}