feat: detect fields

apps/remix/app/utils/detect-document-fields.ts

@@ -0,0 +1,39 @@
+import { AppError, AppErrorCode } from '@documenso/lib/errors/app-error';
+import type { TDetectedFormField } from '@documenso/lib/types/document-analysis';
+
+export const detectFieldsInDocument = async (envelopeId: string): Promise<TDetectedFormField[]> => {
+  const response = await fetch('/api/ai/detect-fields', {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify({ envelopeId }),
+    credentials: 'include',
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+
+    console.error('Field detection failed:', {
+      status: response.status,
+      statusText: response.statusText,
+      error: errorText,
+    });
+
+    throw new AppError(AppErrorCode.UNKNOWN_ERROR, {
+      message: `Field detection failed: ${response.statusText}`,
+      userMessage: 'Failed to detect fields in the document. Please try adding fields manually.',
+    });
+  }
+
+  const data = await response.json();
+
+  if (!Array.isArray(data)) {
+    throw new AppError(AppErrorCode.UNKNOWN_ERROR, {
+      message: 'Invalid response from field detection API - expected array',
+      userMessage: 'Failed to detect fields in the document. Please try again.',
+    });
+  }
+
+  return data;
+};