package mstrans

import (
	_ "embed"
	"encoding/json"
	"strings"
)

//go:embed all:lang.json
var langJSON []byte

// LangMap maps language codes to names (e.g., "zh-Hans": "Chinese Simplified")
var LangMap map[string]string

func init() {
	// Load language map from embedded JSON (runs once at package init)
	if err := json.Unmarshal(langJSON, &LangMap); err != nil {
		panic("failed to load language map: " + err.Error())
	}
}

// GetLangCode normalizes language input (e.g., "zh" → "zh-Hans", "english" → "en")
func GetLangCode(lang string) string {
	if lang == "" || lang == "auto-detect" {
		return "" // Auto-detect maps to empty from parameter
	}

	// Exact match (e.g., "zh-Hans" → "zh-Hans")
	if _, ok := LangMap[lang]; ok {
		return lang
	}

	// Case-insensitive match (e.g., "ZH" → "zh-Hans", "english" → "en")
	lowerLang := strings.ToLower(lang)
	for code, name := range LangMap {
		if strings.ToLower(code) == lowerLang || strings.ToLower(name) == lowerLang {
			return code
		}
	}

	return "" // Unsupported language
}

// IsLangSupported checks if a language code/name is supported
func IsLangSupported(lang string) bool {
	return GetLangCode(lang) != ""
}