package i18n

import (
	"context"
	_ "embed"
	"encoding/json"
	"fmt"
	"sync"

	"git.dmitriygnatenko.ru/dima/go-common/logger"
)

//go:embed ru.json
var ruJsonContent []byte

//go:embed en.json
var enJsonContent []byte

type Language string

const (
	Ru        Language = "ru"
	En        Language = "en"
	Default   Language = Ru
	LangParam          = "lang"
)

var (
	once sync.Once
	i18n *I18n
)

type I18n struct {
	translations map[Language]map[string]string
}

func Init() error {
	var err error

	once.Do(func() {
		ruTranslations := make(map[string]string)
		enTranslations := make(map[string]string)

		err = json.Unmarshal(ruJsonContent, &ruTranslations)
		if err != nil {
			return
		}

		err = json.Unmarshal(enJsonContent, &enTranslations)
		if err != nil {
			return
		}

		i18n = &I18n{translations: map[Language]map[string]string{
			Ru: ruTranslations,
			En: enTranslations,
		}}
	})

	return err
}

func T(lang Language, key string, args ...any) string {
	if i18n == nil {
		logger.Error(context.Background(), "i18n not initialized")
		return ""
	}

	if i18n.translations[lang] == nil {
		logger.Warnf(context.Background(), "i18n: language %s not initialized", lang)
		return ""
	}

	var translated string

	if len(args) == 0 {
		translated = i18n.translations[lang][key]
	} else {
		translated = fmt.Sprintf(i18n.translations[lang][key], args...)
	}

	if len(translated) == 0 {
		logger.Warnf(
			context.Background(),
			"i18n: language %s translation %s is not found", lang, key,
		)
	}

	return translated
}