package locale

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

//go:embed *.yaml
var locales embed.FS

var localizers = map[string]Localizer{}

func init() {
	entries, err := locales.ReadDir(".")
	if err != nil {
		panic(err)
	}

	tags := []language.Tag{}
	bundle := i18n.NewBundle(language.English)
	bundle.RegisterUnmarshalFunc("yaml", yaml.Unmarshal)

	for _, entry := range entries {
		_, err := bundle.LoadMessageFileFS(locales, entry.Name())
		if err != nil {
			panic(err)
		}
		tags = append(tags, extractTagFromPath(entry.Name()))
	}

	for _, tag := range tags {
		localizers[tag.String()] = &localizer{loc: i18n.NewLocalizer(bundle, tag.String()), tag: tag}
	}
}

func extractTagFromPath(path string) language.Tag {
	var langTag string
	formatStartIdx := -1
	for i := len(path) - 1; i >= 0; i-- {
		c := path[i]
		if os.IsPathSeparator(c) {
			if formatStartIdx != -1 {
				langTag = path[i+1 : formatStartIdx]
			}
			return language.Make(langTag)
		}
		if path[i] == '.' {
			if formatStartIdx != -1 {
				langTag = path[i+1 : formatStartIdx]
				return language.Make(langTag)
			}
			formatStartIdx = i
		}
	}
	if formatStartIdx != -1 {
		return language.Make(path[:formatStartIdx])
	}
	return language.English
}

func For(lang string) Localizer {
	return localizers[lang]
}