package setting

import (
	"encoding/json"
	"fyne.io/fyne/v2"
	fyneLang "fyne.io/fyne/v2/lang"
	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/resources"
)

var supportedLanguages = map[string]Lang{
	"ru": {Code: "ru", Title: "Русский"},
	"kk": {Code: "kk", Title: "Қазақ Тілі"},
	"en": {Code: "en", Title: "English"},
}

type Lang struct {
	Code  string
	Title string
}

func ChangeLang(lang Lang) error {
	translationsData, err := getTranslations(lang)
	if err != nil {
		return err
	}

	name := fyneLang.SystemLocale().LanguageString()
	return fyneLang.AddTranslations(fyne.NewStaticResource(name+".json", translationsData))
}

func defaultLang() Lang {
	return supportedLanguages["ru"]
}

func getTranslations(language Lang) ([]byte, error) {
	translations := resources.GetTranslations()

	baseJson, err := translations.ReadFile("translations/base." + language.Code + ".json")
	if err != nil {
		return nil, err
	}
	appJson, err := translations.ReadFile("translations/app." + language.Code + ".json")
	if err != nil {
		return nil, err
	}

	return mergeTranslations(baseJson, appJson)
}

func mergeTranslations(baseJson []byte, appJson []byte) ([]byte, error) {
	base := map[string]interface{}{}
	custom := map[string]interface{}{}
	err := json.Unmarshal(baseJson, &base)
	if err != nil {
		return nil, err
	}
	err = json.Unmarshal(appJson, &custom)
	if err != nil {
		return nil, err
	}

	for k, v := range custom {
		base[k] = v
	}
	return json.Marshal(base)
}