From a467b280c1d408eb861dafadd5914d67de3af485 Mon Sep 17 00:00:00 2001
From: SammyBits <samuelbeato7@gmail.com>
Date: Sat, 29 Aug 2026 17:25:06 -0400
Subject: [PATCH] feat(faseF2): DELTIX_ENABLE_GRPC_TRANSFER flag gates the
 legacy gRPC pull

Native commit-based pull (Fase C) is now the default. To allow a safe rollback
while it is confirmed in production, the old whole-file gRPC pull is kept behind
an opt-in feature flag:

- env: DELTIX_ENABLE_GRPC_TRANSFER (default false).
- 'deltix pull <repo> <file>' uses the legacy gRPC DataflowService.pull only
  when the flag is on AND a destination file is passed; otherwise the native
  REST pull runs. Dataflow is a lazy import so it only loads when used.

Marked transitional: the gRPC pull path is removed in a later phase once the
native path is confirmed. 113 unit tests pass, build + lint clean.
---
 src/cli/index.ts  | 23 ++++++++++++++++++++++-
 src/shared/env.ts |  9 +++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/cli/index.ts b/src/cli/index.ts
index 04d7c62..78813d6 100644
--- a/src/cli/index.ts
+++ b/src/cli/index.ts
@@ -208,7 +208,28 @@ function handleSyncError(err: unknown, action: string): number {
 
 async function runPull(args: string[]): Promise<number> {
   const abort = args.includes('--abort');
-  const repoArg = args.find((a) => !a.startsWith('--'));
+  const positional = args.filter((a) => !a.startsWith('--'));
+  const repoArg = positional[0];
+  const destFile = positional[1];
+
+  // Transitional legacy path: whole-file gRPC pull, behind
+  // DELTIX_ENABLE_GRPC_TRANSFER. Removed once the native commit-based pull is
+  // confirmed in production.
+  if (loadEnv().DELTIX_ENABLE_GRPC_TRANSFER && repoArg && destFile) {
+    const { createDataflowService } = await import('../contexts/dataflow');
+    try {
+      const result = await createDataflowService().pull(repoArg, destFile);
+      printSuccess(`[legacy gRPC] Pull completed for ${repoArg}`, {
+        bytesReceived: result.bytesReceived,
+        checksum: result.checksum,
+      });
+      return 0;
+    } catch (err) {
+      printError(`Pull failed (legacy gRPC): ${String(err)}`);
+      return 1;
+    }
+  }
+
   const identity = await resolveServerIdentity(repoArg);
   if (!identity) {
     return 1;
diff --git a/src/shared/env.ts b/src/shared/env.ts
index 04d904f..261d037 100644
--- a/src/shared/env.ts
+++ b/src/shared/env.ts
@@ -61,6 +61,15 @@ const envSchema = z.object({
   // when the host already runs a real MySQL service.
   DELTIX_LOCAL_HOST: z.string().min(1).default('127.0.0.1'),
   DELTIX_LOCAL_PORT: z.coerce.number().int().positive().default(3306),
+  // Transitional feature flag (Fase 5.9). `deltix pull` is now commit-based
+  // over REST (native, git-like). When this is enabled AND a destination file
+  // is passed, `deltix pull` falls back to the legacy whole-file gRPC transfer
+  // instead. Off by default; kept only to allow an easy rollback/comparison
+  // until the native path is fully confirmed, then the gRPC pull path is removed.
+  DELTIX_ENABLE_GRPC_TRANSFER: z
+    .enum(['true', 'false', '1', '0'])
+    .default('false')
+    .transform((v) => v === 'true' || v === '1'),
 });
 
 export type Env = z.infer<typeof envSchema>;