From 7cbad399ed5687671647cafd1eaaf368acee9ceb Mon Sep 17 00:00:00 2001
From: supertorpe <supertorpe@hotmail.com>
Date: Fri, 4 Jul 2025 15:45:45 +0200
Subject: [PATCH] feat : add autoload pgn with a base64 encoded "pgn" query
 param (#57)

---
 src/lib/helpers.ts  | 16 ++++++++++++++++
 src/pages/index.tsx | 18 ++++++++++++++++--
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/lib/helpers.ts b/src/lib/helpers.ts
index f5d6864..a9d832e 100644
--- a/src/lib/helpers.ts
+++ b/src/lib/helpers.ts
@@ -16,3 +16,19 @@ export const isInViewport = (element: HTMLElement) => {
 
 export const sleep = (ms: number) =>
   new Promise((resolve) => setTimeout(resolve, ms));
+
+export const decodeBase64 = (encoded: string | null): string | null => {
+  if (!encoded) return null;
+  try {
+    return atob(encoded);
+  } catch (err) {
+    console.error("Error decoding base64:", err);
+    return null;
+  }
+};
+
+export const decodeBase64Param = (param: string): string | null => {
+  const params = new URLSearchParams(location.search);
+  const encodedParam = params.get(param);
+  return decodeBase64(encodedParam);
+};
diff --git a/src/pages/index.tsx b/src/pages/index.tsx
index 5065dcf..e4fb1ad 100644
--- a/src/pages/index.tsx
+++ b/src/pages/index.tsx
@@ -26,6 +26,7 @@ import { Icon } from "@iconify/react";
 import EngineSettingsButton from "@/sections/engineSettings/engineSettingsButton";
 import GraphTab from "@/sections/analysis/panelBody/graphTab";
 import { PageTitle } from "@/components/pageTitle";
+import { decodeBase64Param } from "@/lib/helpers";
 
 export default function GameAnalysis() {
   const theme = useTheme();
@@ -38,18 +39,31 @@ export default function GameAnalysis() {
   const game = useAtomValue(gameAtom);
   const board = useAtomValue(boardAtom);
   const setBoardOrientation = useSetAtom(boardOrientationAtom);
+  const { setPgn: setGamePgn } = useChessActions(gameAtom);
 
   const router = useRouter();
   const { gameId } = router.query;
+  const pgnParam = decodeBase64Param("pgn");
 
   useEffect(() => {
-    if (!gameId) {
+    if (pgnParam) {
+      setGameEval(undefined);
+      setGamePgn(pgnParam);
+    } else if (!gameId) {
       resetBoard();
       setGameEval(undefined);
       setBoardOrientation(true);
       resetGame({ noHeaders: true });
     }
-  }, [gameId, setGameEval, setBoardOrientation, resetBoard, resetGame]);
+  }, [
+    gameId,
+    pgnParam,
+    setGameEval,
+    setGamePgn,
+    setBoardOrientation,
+    resetBoard,
+    resetGame,
+  ]);
 
   const showMovesTab = game.history().length > 0 || board.history().length > 0;