feat(locale): add locale management functionality

import.lua

@@ -38,6 +38,7 @@ local content <const> = {
         class = true,
         functions = true,
         notify = true,
+        locale = true,
     },
 }
 

shared/locale.lua

@@ -0,0 +1,100 @@
+local CLASS <const> = Import('class').Class
+
+local function loadLangFile(resource, folder, lang)
+    local path <const> = ('%s/%s.lua'):format(folder, lang)
+    local raw <const> = LoadResourceFile(resource, path)
+    if not raw then return nil end
+
+    local fn, err = load(raw)
+    if not fn then
+        print(('[Locale] Error loading %s: %s'):format(path, err))
+        return nil
+    end
+
+    return fn()
+end
+
+local Locale <const> = CLASS:Create({
+    constructor = function(self, data)
+        self._langs = {}
+        self._currentLang = data.default or 'en'
+        self._defaultLang = data.default or 'en'
+        self._fallback = data.fallback ~= false
+        self._folder = data.folder or 'locales'
+        self._resource = data.resource or GetCurrentResourceName()
+
+        local langs <const> = data.langs or { self._defaultLang }
+        for _, lang in ipairs(langs) do
+            local content = loadLangFile(self._resource, self._folder, lang)
+            if content then
+                self._langs[lang] = content
+            end
+        end
+
+        if not self._langs[self._defaultLang] then
+            local content = loadLangFile(self._resource, self._folder, self._defaultLang)
+            if content then
+                self._langs[self._defaultLang] = content
+            end
+        end
+    end,
+
+    set = {
+        SetLang = function(self, lang)
+            if self._langs[lang] then
+                self._currentLang = lang
+            else
+                error(('Language "%s" not loaded'):format(lang))
+            end
+        end
+    },
+
+    get = {
+        GetLang = function(self)
+            return self._currentLang
+        end,
+        GetAvailableLangs = function(self)
+            local langs = {}
+            for lang in pairs(self._langs) do
+                langs[#langs + 1] = lang
+            end
+            return langs
+        end
+    },
+
+    T = function(self, key, vars)
+        local text = nil
+
+        if self._langs[self._currentLang] then
+            text = self._langs[self._currentLang][key]
+        end
+
+        if not text and self._fallback and self._currentLang ~= self._defaultLang then
+            if self._langs[self._defaultLang] then
+                text = self._langs[self._defaultLang][key]
+            end
+        end
+
+        if not text then
+            return key
+        end
+
+        if vars and type(vars) == 'table' then
+            for name, value in pairs(vars) do
+                text = text:gsub('{' .. name .. '}', tostring(value))
+            end
+        end
+
+        return text
+    end
+})
+
+local LocaleAPI <const> = {}
+
+function LocaleAPI:Load(options)
+    return Locale:New(options or {})
+end
+
+return {
+    Locale = LocaleAPI
+}