// Copyright 2015 clair 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"
	"os"
	"time"

	"gopkg.in/yaml.v2"
)

// Config is the global configuration for an instance of Clair.
type Config struct {
	Database *DatabaseConfig
	Updater  *UpdaterConfig
	Notifier *NotifierConfig
	API      *APIConfig
}

// DatabaseConfig is the configuration used to specify how Clair connects
// to a database.
type DatabaseConfig struct {
	Type string
	Path string
}

// UpdaterConfig is the configuration for the Updater service.
type UpdaterConfig struct {
	Interval time.Duration
}

// NotifierConfig is the configuration for the Notifier service.
type NotifierConfig struct {
	Endpoint   string
	ServerName string
	CertFile   string
	KeyFile    string
	CAFile     string
}

// APIConfig is the configuration for the API service.
type APIConfig struct {
	Port                      int
	HealthPort                int
	Timeout                   time.Duration
	CertFile, KeyFile, CAFile string
}

// DefaultConfig is a configuration that can be used as a fallback value.
var DefaultConfig = Config{
	Database: &DatabaseConfig{
		Type: "memstore",
	},
	Updater: &UpdaterConfig{
		Interval: 1 * time.Hour,
	},
	API: &APIConfig{
		Port:       6060,
		HealthPort: 6061,
		Timeout:    900 * time.Second,
	},
}

// Load is a shortcut to open a file, read it, and generate a Config.
// It supports relative and absolute paths. Given "", it returns DefaultConfig.
func Load(path string) (config *Config, err error) {
	config = &DefaultConfig
	if path == "" {
		return
	}

	f, err := os.Open(os.ExpandEnv(path))
	if err != nil {
		return
	}
	defer f.Close()

	d, err := ioutil.ReadAll(f)
	if err != nil {
		return
	}

	err = yaml.Unmarshal(d, config)
	return
}