package i18n

import (
	"embed"
	"log"
	"os"

	"github.com/nicksnyder/go-i18n/v2/i18n"
	"golang.org/x/text/language"
	"gopkg.in/yaml.v3"
)

type Language string

const (
	JPN Language = "JPN"
	ENG Language = "ENG"
)

func GetLanguage() Language {
	lang := Language(os.Getenv("LANGUAGE"))
	if lang == "" {
		return JPN
	}
	return lang
}

//go:embed *
var files embed.FS

var loc *i18n.Localizer

func Init() {
	lang := GetLanguage()

	tag := language.Japanese
	if lang == ENG {
		tag = language.English
	}

	bundle := i18n.NewBundle(tag)
	bundle.RegisterUnmarshalFunc("yaml", yaml.Unmarshal)
	if _, err := bundle.LoadMessageFileFS(files, string(lang)+".yaml"); err != nil {
		log.Fatalf("Cannot load message file: %v", err)
	}
	loc = i18n.NewLocalizer(bundle)
}

// ${key}: "MSG001", ...
func GetText(key string) string {
	if loc == nil {
		return ""
	}
	return loc.MustLocalize(&i18n.LocalizeConfig{MessageID: key})
}

MSG001: "こんにちは"

MSG001: "Hello"

i18n
| - i18n.go
| - JPN.yaml
| - ENG.yaml