feat: add envelopes (#2025)

This PR is handles the changes required to support envelopes. The new
envelope editor/signing page will be hidden during release.

The core changes here is to migrate the documents and templates model to
a centralized envelopes model.

Even though Documents and Templates are removed, from the user
perspective they will still exist as we remap envelopes to documents and
templates.

apps/remix/app/utils/field-signing/signature-field.ts

@@ -0,0 +1,56 @@
+import { FieldType } from '@prisma/client';
+
+import { AppError, AppErrorCode } from '@documenso/lib/errors/app-error';
+import type { TFieldSignature } from '@documenso/lib/types/field';
+import type { TSignEnvelopeFieldValue } from '@documenso/trpc/server/envelope-router/sign-envelope-field.types';
+
+import { SignFieldSignatureDialog } from '~/components/dialogs/sign-field-signature-dialog';
+
+type HandleSignatureFieldClickOptions = {
+  field: TFieldSignature;
+  signature: string | null;
+  typedSignatureEnabled?: boolean;
+  uploadSignatureEnabled?: boolean;
+  drawSignatureEnabled?: boolean;
+};
+
+export const handleSignatureFieldClick = async (
+  options: HandleSignatureFieldClickOptions,
+): Promise<Extract<TSignEnvelopeFieldValue, { type: typeof FieldType.SIGNATURE }> | null> => {
+  const { field, signature, typedSignatureEnabled, uploadSignatureEnabled, drawSignatureEnabled } =
+    options;
+
+  if (field.type !== FieldType.SIGNATURE) {
+    throw new AppError(AppErrorCode.INVALID_REQUEST, {
+      message: 'Invalid field type',
+    });
+  }
+
+  if (field.inserted) {
+    return {
+      type: FieldType.SIGNATURE,
+      value: null,
+      isBase64: false,
+    };
+  }
+
+  let signatureToInsert = signature;
+
+  if (!signatureToInsert) {
+    signatureToInsert = await SignFieldSignatureDialog.call({
+      typedSignatureEnabled,
+      uploadSignatureEnabled,
+      drawSignatureEnabled,
+    });
+  }
+
+  if (!signatureToInsert) {
+    return null;
+  }
+
+  return {
+    type: FieldType.SIGNATURE,
+    value: signatureToInsert,
+    isBase64: signatureToInsert.startsWith('data:image'),
+  };
+};