From f5ff0c08030c290e814e7819db64ce89c3bf0900 Mon Sep 17 00:00:00 2001
From: Cristian Magherusan-Stanciu <cristi.magherusan@gmail.com>
Date: Mon, 4 May 2026 19:00:55 +0200
Subject: [PATCH] fix(api): correct async self-invoke payload shape (closes
 #257 followup)
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The async refresh path landed in PR #260 but the Lambda self-invoke
payload didn't match what the receiving Lambda expects. The shipped
payload was:

  {"event": "scheduled_recommendations"}

But internal/server/handler.go::ScheduledEvent has no "event" field —
it has Action, Source, DetailType, Detail. Unmarshalling that JSON
gives Action="", and ParseScheduledEvent rejects every event with:

  unknown scheduled task action: ""

Verified live in /aws/lambda/cudly-dev-426fc8af-api request
3befb380-6d46-47e1-954b-69a2b59ea90a:

  16:49:40 Received unknown event (size: 37 bytes)
  16:49:40 Unknown event type, treating as scheduled event
  16:49:40 {"errorMessage":"failed to parse scheduled event:
              unknown scheduled task action: \"\""}

The 37-byte event = the {"event":"scheduled_recommendations"} string
exactly. The async self-invoke is firing successfully but every
invocation is rejected, so the "Refreshing..." banner never clears
and collection never runs — same user-visible symptom (refresh times
out + no fresh data) as if the env var or IAM grant was missing.

Fix: send the payload shape the dispatcher actually accepts:

  {"source": "aws.events", "action": "collect_recommendations"}

action="collect_recommendations" maps to TaskCollectRecommendations
in the ParseScheduledEvent switch. source="aws.events" makes
detectLambdaEventType in internal/server/lambda.go classify the
invoke consistently with EventBridge cron deliveries that already
exercise this code path.
---
 .../api/handler_recommendations_refresh.go    | 25 ++++++++++++++++---
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/internal/api/handler_recommendations_refresh.go b/internal/api/handler_recommendations_refresh.go
index 5cc0a0d5..ed5fd58e 100644
--- a/internal/api/handler_recommendations_refresh.go
+++ b/internal/api/handler_recommendations_refresh.go
@@ -139,10 +139,27 @@ func (h *Handler) asyncInvokeSelf(ctx context.Context, functionARN string) error
 		return fmt.Errorf("failed to build Lambda client: %w", err)
 	}
 
-	// This payload matches the detectLambdaEventType "scheduled" branch in
-	// internal/server/lambda.go: `scheduledEvent.Action != ""` → "scheduled".
-	// HandleScheduledTask then dispatches to TaskCollectRecommendations.
-	payload, _ := json.Marshal(map[string]string{"event": "scheduled_recommendations"})
+	// Payload shape matches internal/server/handler.go::ScheduledEvent + its
+	// ParseScheduledEvent dispatch table: the Action field selects the
+	// scheduled-task type. "collect_recommendations" maps to
+	// TaskCollectRecommendations, which is what we want to fire.
+	//
+	// The previous payload `{"event":"scheduled_recommendations"}` had no
+	// matching field in ScheduledEvent at all — Action unmarshalled as ""
+	// and ParseScheduledEvent rejected the event with "unknown scheduled
+	// task action: \"\"". Verified in the deployed Lambda log
+	// `/aws/lambda/cudly-dev-426fc8af-api` request 3befb380-6d46-... — the
+	// async self-invoke was firing successfully but the receiving Lambda
+	// was rejecting every invocation, so collection never actually ran.
+	//
+	// Source = "aws.events" so detectLambdaEventType in
+	// internal/server/lambda.go (which checks Source == "aws.events" ||
+	// Action != "") classifies this consistently with EventBridge cron
+	// deliveries that already exercise this code path.
+	payload, _ := json.Marshal(map[string]string{
+		"source": "aws.events",
+		"action": "collect_recommendations",
+	})
 
 	_, err = invoker.Invoke(ctx, &lambda.InvokeInput{
 		FunctionName:   aws.String(functionARN),