// Copyright 2013 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 config

import (
	"io/ioutil"

	"github.com/golang/protobuf/proto"

	pb "github.com/prometheus/prometheus/config/generated"
)

// LoadFromString returns a config parsed from the provided string.
func LoadFromString(configStr string) (*Config, error) {
	configProto := pb.PrometheusConfig{}
	if err := proto.UnmarshalText(configStr, &configProto); err != nil {
		return nil, err
	}
	if configProto.Global == nil {
		configProto.Global = &pb.GlobalConfig{}
	}
	for _, scfg := range configProto.GetScrapeConfig() {
		if scfg.ScrapeInterval == nil {
			scfg.ScrapeInterval = proto.String(configProto.Global.GetScrapeInterval())
		}
	}

	config := &Config{configProto}
	err := config.Validate()

	return config, err
}

// LoadFromFile returns a config parsed from the file of the provided name.
func LoadFromFile(fileName string) (*Config, error) {
	configStr, err := ioutil.ReadFile(fileName)
	if err != nil {
		return nil, err
	}

	return LoadFromString(string(configStr))
}