/*
   Copyright 2014 CoreOS, Inc.

   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 metadata

import (
	"strings"

	"github.com/coreos/coreos-cloudinit/pkg"
)

type MetadataService struct {
	Root         string
	Client       pkg.Getter
	ApiVersion   string
	UserdataPath string
	MetadataPath string
}

func NewDatasource(root, apiVersion, userdataPath, metadataPath string) MetadataService {
	if !strings.HasSuffix(root, "/") {
		root += "/"
	}
	return MetadataService{root, pkg.NewHttpClient(), apiVersion, userdataPath, metadataPath}
}

func (ms MetadataService) IsAvailable() bool {
	_, err := ms.Client.Get(ms.Root + ms.ApiVersion)
	return (err == nil)
}

func (ms MetadataService) AvailabilityChanges() bool {
	return true
}

func (ms MetadataService) ConfigRoot() string {
	return ms.Root
}

func (ms MetadataService) FetchUserdata() ([]byte, error) {
	return ms.FetchData(ms.UserdataUrl())
}

func (ms MetadataService) FetchNetworkConfig(filename string) ([]byte, error) {
	return nil, nil
}

func (ms MetadataService) FetchData(url string) ([]byte, error) {
	if data, err := ms.Client.GetRetry(url); err == nil {
		return data, err
	} else if _, ok := err.(pkg.ErrNotFound); ok {
		return []byte{}, nil
	} else {
		return data, err
	}
}

func (ms MetadataService) MetadataUrl() string {
	return (ms.Root + ms.MetadataPath)
}

func (ms MetadataService) UserdataUrl() string {
	return (ms.Root + ms.UserdataPath)
}