package main

import (
    "fmt"
    "net/url"
    "time"

    "github.com/miladabc/gonfig"
)

// Unexported struct fields are ignored
type Config struct {
	Host     string
	Log      bool
	Expiry   int
	Port     uint
	Pi       float64
	Com      complex128
	Byte     byte
	Rune     rune
	Duration time.Duration
	Time     time.Time
	url      url.URL
	Redis    struct {
		Hosts []string
		Ports []int
	}
}

func main() {
	var c Config

	// Input argument must be a pointer to struct
	err := gonfig.Load().FromEnv().Into(&c)
	if err != nil {
		fmt.Println(err)
	}
}

type Config struct {
	HostName string `config:"HOST"`
}

func main() {
	var c Config

	os.Setenv("HOST", "golang.org")
	gonfig.Load().FromEnv().Into(&c)
}

type Config struct {
	HostName string `json:"host" yaml:"host" toml:"host"`
}

func main() {
	var c Config

	gonfig.Load().FromFile("config.json").Into(&c)
}

type Config struct {
	Host url.URL `default:"golang.org"`
}

type Config struct {
	Host url.URL `required:"true"`
}

type Config struct {
	Ignored     int `ignore:"true"`
	AlsoIgnored int `config:"-"`
}

type Config struct {
	Expanded int `expand:"true" default:"${ENV_VALUE}"`
}

func main() {
	var c Config

	os.Setenv("ENV_VALUE", "123")
	gonfig.Load().FromEnv().Into(&c)
	fmt.Println(c.Expanded) // 123
}

type Config struct {
	List []int `separator:"," default:"1, 2, 3"`
}

type Config struct {
	Time time.Time `format:"2006-01-02T15:04:05.999999999Z07:00"`
}

func main() {
	var c Config

	gonfig.
		Load().
		FromEnv().
		FromFile("config.json").
		FromFile("config.yaml").
		FromFile("config.toml").
		FromFile(".env").
		AddProvider(CustomProvider).
		Into(&c)
}

type Config struct {
	PrettyLog bool
	Redis     struct {
		Host string
		Port int
	}
}

func main() {
	var c Config

	gonfig.
		Load().
		FromEnv().
		Into(&c)
}

type Config struct {
	PrettyLog bool
	Redis     struct {
		Host string
		Port int
	}
}

func main() {
	var c Config

	ep := gonfig.EnvProvider{
		Prefix:         "APP_", // Default to ""
		SnakeCase:      false,  // Defaults to true
		UpperCase:      false,  // Defaults to true
		FieldSeparator: "__",   // Defaults to "_"
		Source:         ".env", // Defaults to OS env vars
		Required:       true,   // Defaults to false
	}

	gonfig.
		Load().
		AddProvider(&ep).
		Into(&c)
}

type CustomProvider struct{}

func (cp *CustomProvider) Name() string {
	return "custom provider"
}

func (cp *CustomProvider) UnmarshalStruct(i interface{}) error {
	// UnmarshalStruct receives a struct pointer and unmarshalls values into it.
	return nil
}

func (cp *CustomProvider) Fill(in *gonfig.Input) error {
	// Fill receives struct fields and set their values.
	return nil
}

func main() {
	var c Config

	gonfig.
		Load().
		AddProvider(new(CustomProvider)).
		Into(&c)
}