Convert to the superior language system. (pt. 1)

src/main/java/emu/grasscutter/utils/Language.java

@@ -0,0 +1,82 @@
+package emu.grasscutter.utils;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import emu.grasscutter.Grasscutter;
+
+import javax.annotation.Nullable;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
+
+public final class Language {
+    private final JsonObject languageData;
+    private final Map<String, String> cachedTranslations = new HashMap<>();
+
+    /**
+     * Creates a language instance from a code.
+     * @param langCode The language code.
+     * @return A language instance.
+     */
+    public static Language getLanguage(String langCode) {
+        return new Language(langCode + ".json");
+    }
+
+    /**
+     * Returns the translated value from the key while substituting arguments.
+     * @param key The key of the translated value to return.
+     * @param args The arguments to substitute.
+     * @return A translated value with arguments substituted.
+     */
+    public static String translate(String key, Object... args) {
+        return Grasscutter.getLanguage().get(key).formatted(args);
+    }
+
+    /**
+     * Reads a file and creates a language instance.
+     * @param fileName The name of the language file.
+     */
+    private Language(String fileName) {
+        @Nullable JsonObject languageData = null;
+        
+        try {
+            InputStream file = Grasscutter.class.getResourceAsStream("/lang/" + fileName);
+            languageData = Grasscutter.getGsonFactory().fromJson(Utils.readFromInputStream(file), JsonObject.class);
+        } catch (Exception exception) {
+            Grasscutter.getLogger().error("Failed to load language file: " + fileName, exception);
+        } this.languageData = languageData;
+    }
+
+    /**
+     * Returns the value (as a string) from a nested key.
+     * @param key The key to look for.
+     * @return The value (as a string) from a nested key.
+     */
+    public String get(String key) {
+        if(this.cachedTranslations.containsKey(key)) {
+            return this.cachedTranslations.get(key);
+        }
+        
+        String[] keys = key.split("\\.");
+        JsonObject object = this.languageData;
+
+        int index = 0;
+        String result = "";
+
+        while (true) {
+            if(index == keys.length) break;
+            
+            String currentKey = keys[index++];
+            if(object.has(currentKey)) {
+                JsonElement element = object.get(currentKey);
+                if(element.isJsonObject())
+                    object = element.getAsJsonObject();
+                else {
+                    result = element.getAsString(); break;
+                }
+            } else break;
+        }
+        
+        this.cachedTranslations.put(key, result); return result;
+    }
+}