// Copyright 2015 The Prometheus 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 marathon

import (
	"encoding/json"
	"io/ioutil"
	"net/http"
)

// AppListClient defines a function that can be used to get an application list from marathon.
type AppListClient func(url string) (*AppList, error)

// FetchMarathonApps requests a list of applications from a marathon server.
func FetchMarathonApps(url string) (*AppList, error) {
	resp, err := http.Get(url)
	if err != nil {
		return nil, err
	}

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	return parseAppJSON(body)
}

func parseAppJSON(body []byte) (*AppList, error) {
	apps := &AppList{}
	err := json.Unmarshal(body, apps)
	if err != nil {
		return nil, err
	}
	return apps, nil
}