Add signin.ejs for single-sign-on

scenarios/single-sign-on/signin.ejs

@@ -0,0 +1,26 @@
+<%- include(commonPath + '/header.ejs') %>
+
+<div class="container mx-auto py-8">
+    <h1 class="text-3xl font-bold mb-4 text-center">🚧 Single Sign-On Demo</h1>
+    <div class="text-center">
+        <button id="signInButton" class="bg-blue-500 text-white font-bold py-2 px-4 rounded-full inline-block">Sign In</button>
+    </div>
+</div>
+
+<script>
+	document.getElementById('signInButton').addEventListener('click', function() {
+		const win = window.open('<%= protocol %>://<%= domainC %>/single-sign-on/login', 'Login to SSO', 'width=500,height=500');
+		window.addEventListener('message', function(event) {
+			if (event.origin !== '<%= protocol %>://<%= domainC %>') return;
+			// Expected structure of event.data: { action: 'login', email: '[email protected]' }
+			if (event.data.action === 'login') {
+				// Set the cookie for domainC here using fetch or other methods.
+				// Redirect to profile or another route as needed.
+				document.cookie = `email=${event.data.email}; max-age=900000`;
+				window.location.href = '/single-sign-on/profile';
+			}
+		}, false);
+	});
+</script>
+
+<%- include(commonPath + '/footer.ejs') %>