WebHost: use JS to refresh waitSeed if scripting is enabled (#4843)

WebHostLib/templates/waitSeed.html

@@ -4,7 +4,9 @@
 
 {% block head %}
     <title>Generation in Progress</title>
-    <meta http-equiv="refresh" content="1">
+    <noscript>
+        <meta http-equiv="refresh" content="1">
+    </noscript>
     <link rel="stylesheet" type="text/css" href="{{ url_for('static', filename="styles/waitSeed.css") }}"/>
 {% endblock %}
 
@@ -16,4 +18,34 @@
             Waiting for game to generate, this page auto-refreshes to check.
         </div>
     </div>
+    <script>
+        const waitSeedDiv = document.getElementById("wait-seed");
+        async function checkStatus() {
+            try {
+                const response = await fetch("{{ url_for('api.wait_seed_api', seed=seed_id) }}");
+                if (response.status !== 202) {
+                    // Seed is ready; reload page to load seed page.
+                    location.reload();
+                    return;
+                }
+
+                const data = await response.json();
+                waitSeedDiv.innerHTML = `
+                    <h1>Generation in Progress</h1>
+                    <p>${data.text}</p>
+                `;
+
+                setTimeout(checkStatus, 1000); // Continue polling.
+            } catch (error) {
+                waitSeedDiv.innerHTML = `
+                    <h1>Progress Unknown</h1>
+                    <p>${error.message}<br />(Last checked: ${new Date().toLocaleTimeString()})</p>
+                `;
+
+                setTimeout(checkStatus, 1000);
+            }
+        }
+
+        setTimeout(checkStatus, 1000);
+    </script>
 {% endblock %}