// Package miot provides MIoT core client for Xiaomi Home devices.
// This file is a direct port of py-miot/miot_i18n.py.
package miot

import (
	"strings"

	"github.com/sirupsen/logrus"
)

// MIoTI18n provides internationalization translation.
// Translate by Copilot, which does not guarantee the accuracy of the
// translation. If there is a problem with the translation, please submit
// the ISSUE feedback. After the review, we will modify it as soon as possible.
type MIoTI18n struct {
	lang string
	data map[string]interface{}
}

// NewMIoTI18n creates a new MIoTI18n instance.
func NewMIoTI18n(lang string) *MIoTI18n {
	return &MIoTI18n{
		lang: lang,
		data: make(map[string]interface{}),
	}
}

// Init loads the i18n JSON file for the configured language.
func (i *MIoTI18n) Init() {
	if len(i.data) > 0 {
		return
	}
	i.data = make(map[string]interface{})

	data, err := LoadJSONFile(GenAbsolutePath("i18n/" + i.lang + ".json"))
	if err != nil {
		logrus.Errorf("load i18n file error: %v", err)
		return
	}
	if data == nil {
		logrus.Errorf("invalid i18n file: nil data")
		return
	}
	i.data = data
}

// Deinit clears the loaded translation data.
func (i *MIoTI18n) Deinit() {
	i.data = make(map[string]interface{})
}

// Translate looks up a translation by dot-separated key.
// It traverses nested JSON objects, e.g. "device.light.name"
// -> data["device"]["light"]["name"].
// If the key is not found, returns an empty string.
// Optional replace map performs placeholder substitution: {key} -> value.
func (i *MIoTI18n) Translate(key string, replace map[string]string) string {
	result := i.lookup(strings.Split(key, "."))
	s, ok := result.(string)
	if !ok {
		return ""
	}
	if replace != nil {
		for k, v := range replace {
			s = strings.ReplaceAll(s, "{"+k+"}", v)
		}
	}
	return s
}

// lookup traverses the nested map using the given key segments.
func (i *MIoTI18n) lookup(keys []string) interface{} {
	var cur interface{} = i.data
	for _, k := range keys {
		m, ok := cur.(map[string]interface{})
		if !ok {
			return nil
		}
		cur = m[k]
		if cur == nil {
			return nil
		}
	}
	return cur
}