From 9200c554e18ba762715d1360166198a734324f7c Mon Sep 17 00:00:00 2001
From: "christian.vidal" <christianvidalwolf@gmail.com>
Date: Thu, 29 Jan 2026 20:56:19 +0100
Subject: [PATCH] Fix Forecast Seasonality: Process weights using global data
 even when filtered

---
 App.tsx                   | 2 +-
 services/dataProcessor.ts | 9 ++++++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/App.tsx b/App.tsx
index 0ef46ac..09e8590 100644
--- a/App.tsx
+++ b/App.tsx
@@ -246,7 +246,7 @@ const App: React.FC = () => {
         }
       });
 
-      const viewData = calculateForecastViewData(sales, fcRecords, meta, activeFilters, velocityMap);
+      const viewData = calculateForecastViewData(sales, fcRecords, meta, activeFilters, velocityMap, globalSales.length > 0 ? globalSales : undefined);
       setForecastData(viewData);
       console.log('[App] Forecast calculation complete:', viewData.length, 'records');
     } catch (error) {
diff --git a/services/dataProcessor.ts b/services/dataProcessor.ts
index e8124f8..fecf7a9 100644
--- a/services/dataProcessor.ts
+++ b/services/dataProcessor.ts
@@ -1638,10 +1638,13 @@ export const calculateForecastViewData = (
     forecastData: ForecastRecord[],
     asinMetadata: Map<string, { sku: string; title: string; line: string }>,
     filters?: FilterState,
-    velocityMap?: Map<string, number>
+    velocityMap?: Map<string, number>,
+    referenceData?: SalesRecord[] // NEW: Full dataset for global seasonality context
 ): ProductForecastData[] => {
-    const data2025 = rawData.filter(r => r.year === 2025);
-    const data2026 = rawData.filter(r => r.year === 2026);
+    // Use referenceData if provided (for global weights), otherwise fallback to rawData
+    const seasonalitySource = referenceData || rawData;
+    const data2025 = seasonalitySource.filter(r => r.year === 2025);
+    const data2026 = seasonalitySource.filter(r => r.year === 2026);
 
     // Calculate Seasonality weights for 2025
     const getWeightsInfo = (records: SalesRecord[]): { weights: number[]; monthsCount: number } | null => {