package config

import (
	"fmt"
	"github.com/BurntSushi/toml"
	"io/ioutil"
	"os"
	"path"
	"syscall"
)

var loaders = map[string]func([]byte, interface{}) error{
	//".json": LoadConfigFromJsonBytes,
	//".yaml": LoadConfigFromYamlBytes,
	//".yml":  LoadConfigFromYamlBytes,
	".toml": LoadConfigFromTomlBytes,
}

// LoadConfig loads config into v from file, .json, .yaml and .yml are acceptable.
func LoadConfig(file string, v interface{}, opts ...Option) error {
	content, err := ioutil.ReadFile(file)
	if err != nil {
		return err
	}

	loader, ok := loaders[path.Ext(file)]
	if !ok {
		return fmt.Errorf("unrecognized file type: %s", file)
	}

	var opt options
	for _, o := range opts {
		o(&opt)
	}

	if opt.env {
		return loader([]byte(os.ExpandEnv(string(content))), v)
	}

	return loader(content, v)
}

//// LoadConfigFromJsonBytes loads config into v from content json bytes.
//func LoadConfigFromJsonBytes(content []byte, v interface{}) error {
//	return mapping.UnmarshalJsonBytes(content, v)
//}
//
//// LoadConfigFromYamlBytes loads config into v from content yaml bytes.
//func LoadConfigFromYamlBytes(content []byte, v interface{}) error {
//	return mapping.UnmarshalYamlBytes(content, v)
//}
//
//// MustLoad loads config into v from path, exits on error.
//func MustLoad(path string, v interface{}, opts ...Option) {
//	if err := LoadConfig(path, v, opts...); err != nil {
//		log.Fatalf("error: config file %s, %s", path, err.Error())
//	}
//}

// LoadConfigFromTomlBytes loads config into v from content toml bytes.
func LoadConfigFromTomlBytes(content []byte, v interface{}) error {
	_, err := toml.Decode(string(content), v)
	return err
}

func GetEnv(key string, defaultVal string) string {
	val, ok := syscall.Getenv(key)
	if !ok {
		return defaultVal
	}
	return val
}