chore: disable form on last signer

packages/lib/server-only/recipient/get-is-last-recipient.ts

@@ -0,0 +1,46 @@
+import { prisma } from '@documenso/prisma';
+import { DocumentSigningOrder, RecipientRole, SigningStatus } from '@documenso/prisma/client';
+
+export type GetIsLastRecipientOptions = {
+  token: string;
+};
+
+export async function getIsLastRecipient({ token }: GetIsLastRecipientOptions) {
+  const document = await prisma.document.findFirstOrThrow({
+    where: {
+      recipients: {
+        some: {
+          token,
+        },
+      },
+    },
+    include: {
+      documentMeta: true,
+      recipients: {
+        where: {
+          role: {
+            not: RecipientRole.CC,
+          },
+        },
+        orderBy: [{ signingOrder: { sort: 'asc', nulls: 'last' } }, { id: 'asc' }],
+      },
+    },
+  });
+
+  if (document.documentMeta?.signingOrder !== DocumentSigningOrder.SEQUENTIAL) {
+    const unsignedRecipients = document.recipients.filter(
+      (recipient) => recipient.signingStatus !== SigningStatus.SIGNED,
+    );
+
+    return unsignedRecipients.length <= 1;
+  }
+
+  const { recipients } = document;
+  const currentRecipientIndex = recipients.findIndex((r) => r.token === token);
+
+  if (currentRecipientIndex === -1) {
+    return false;
+  }
+
+  return currentRecipientIndex === recipients.length - 1;
+}