Add i18next framework to enable further contributions (#96)

* prototype

* Update with comments and type safety

src/locales/en/menu.ts

@@ -0,0 +1,13 @@
+/**
+ * The menu namespace holds most miscellaneous text that isn't directly part of the game's
+ * contents or directly related to Pokemon. This includes menu navigation, settings,
+ * account interactions, etc.
+ */
+export const menu = {
+    "cancel": "Cancel",
+    "continue": "Continue",
+    "dailyRun": "Daily Run (Beta)",
+    "loadGame": "Load Game",
+    "newGame": "New Game",
+    "selectGameMode": "Select a game mode."
+} as const;

src/locales/it/menu.ts

@@ -0,0 +1,8 @@
+export const menu = {
+    "cancel": "Annulla",
+    "continue": "Continua",
+    "newGame": "Nuova Partita",
+    "loadGame": "Carica Partita",
+    "dailyRun": "Corsa Giornaliera (Beta)",
+    "selectGameMode": "Seleziona una modalità di gioco."
+} as const;

src/phases.ts

@@ -57,6 +57,7 @@ import { SaveSlotUiMode } from "./ui/save-slot-select-ui-handler";
 import { fetchDailyRunSeed, getDailyRunStarters } from "./data/daily-run";
 import { GameModes, gameModes } from "./game-mode";
 import { getPokemonSpecies, speciesStarters } from "./data/pokemon-species";
+import i18next from './plugins/i18n';
 
 export class LoginPhase extends Phase {
   private showText: boolean;
@@ -173,12 +174,12 @@ export class TitlePhase extends Phase {
     const options: OptionSelectItem[] = [];
     if (loggedInUser.lastSessionSlot > -1) {
       options.push({
-        label: 'Continue',
+        label: i18next.t('menu:continue'),
         handler: () => this.loadSaveSlot(this.lastSessionData ? -1 : loggedInUser.lastSessionSlot)
       });
     }
     options.push({
-      label: 'New Game',
+      label: i18next.t('menu:newGame'),
       handler: () => {
         const setModeAndEnd = (gameMode: GameModes) => {
           this.gameMode = gameMode;
@@ -204,14 +205,14 @@ export class TitlePhase extends Phase {
             });
           }
           options.push({
-            label: 'Cancel',
+            label: i18next.t('menu:cancel'),
             handler: () => {
               this.scene.clearPhaseQueue();
               this.scene.pushPhase(new TitlePhase(this.scene));
               super.end();
             }
           });
-          this.scene.ui.showText('Select a game mode.', null, () => this.scene.ui.setOverlayMode(Mode.OPTION_SELECT, { options: options }));
+          this.scene.ui.showText(i18next.t("menu:selectGameMode"), null, () => this.scene.ui.setOverlayMode(Mode.OPTION_SELECT, { options: options }));
         } else {
           this.gameMode = GameModes.CLASSIC;
           this.scene.ui.setMode(Mode.MESSAGE);
@@ -221,7 +222,7 @@ export class TitlePhase extends Phase {
       }
     },
     {
-      label: 'Load Game',
+      label: i18next.t('menu:loadGame'),
       handler: () => this.scene.ui.setOverlayMode(Mode.SAVE_SLOT, SaveSlotUiMode.LOAD,
         (slotId: integer) => {
           if (slotId === -1)
@@ -231,7 +232,7 @@ export class TitlePhase extends Phase {
       )
     },
     {
-      label: 'Daily Run (Beta)',
+      label: i18next.t('menu:dailyRun'),
       handler: () => this.initDailyRun(),
       keepOpen: true
     });

src/plugins/i18n.ts

@@ -0,0 +1,42 @@
+import i18next from 'i18next';
+import { menu as enMenu } from '../locales/en/menu';
+import { menu as itMenu } from '../locales/it/menu';
+
+const DEFAULT_LANGUAGE_OVERRIDE = '';
+
+/**
+ * i18next is a localization library for maintaining and using translation resources.
+ * 
+ * Q: How do I add a new language?
+ * A: To add a new language, create a new folder in the locales directory with the language code.
+ *    Each language folder should contain a file for each namespace (ex. menu.ts) with the translations.
+ * 
+ * Q: How do I add a new namespace?
+ * A: To add a new namespace, create a new file in each language folder with the translations.
+ *    Then update the `resources` field in the init() call and the CustomTypeOptions interface.
+ */
+
+i18next.init({
+  lng: DEFAULT_LANGUAGE_OVERRIDE ? DEFAULT_LANGUAGE_OVERRIDE : 'en',
+  fallbackLng: 'en',
+  debug: true,
+  resources: {
+    en: {
+      menu: enMenu,
+    },
+    it: {
+      menu: itMenu,
+    }
+  },
+});
+
+// Module declared to make referencing keys in the localization files type-safe.
+declare module 'i18next' {
+  interface CustomTypeOptions {
+    resources: {
+      menu: typeof enMenu;
+    };
+  }
+}
+
+export default i18next;