Implement daily game logic

src/lib/game.ts

···
 
   return grouped;
 }
+
+export function generateSeedForDay(day: Date) {
+  return `${day.getFullYear()}${day.getMonth().toString().padStart(2, "0")}${day.getDate().toString().padStart(2, "0")}`;
+}

src/lib/hash.ts

···
+const encoder = new TextEncoder();
+
+export async function sha256(input: string) {
+  const digest = await crypto.subtle.digest(
+    { name: "SHA-256" },
+    encoder.encode(input),
+  );
+  return new Uint8Array(digest);
+}

src/pages/index.tsx

···
-import { arrayOfSize } from "@/lib/game";
+import { arrayOfSize, generateSeedForDay } from "@/lib/game";
 import { Game } from "../components/game";
 import { HydrationProvider } from "@/components/providers/hydration-provider";
 import { defaultHeight, defaultVariants, defaultWidth } from "@/lib/state";
+import { sha256 } from "@/lib/hash";
 
-const board = arrayOfSize(defaultWidth * defaultHeight).map(() =>
-  Math.floor(Math.random() * defaultVariants.length),
-);
+async function board(seed: string) {
+  const bytes = Array.from(await sha256(seed));
+  return arrayOfSize(defaultWidth * defaultHeight).map((_, i) =>
+    Math.floor(bytes[i]! % defaultVariants.length),
+  );
+}
 
 export default async function HomePage() {
+  const seed = generateSeedForDay(new Date());
   const props = {
     width: defaultWidth,
     height: defaultHeight,
     variants: defaultVariants,
-    board,
+    board: await board(seed),
   };
   return (
     <HydrationProvider {...props}>