From 1b48e659a88f29adc02db834405bca1ca303626b Mon Sep 17 00:00:00 2001
From: Christian <christian@blaahund.dk>
Date: Mon, 26 Jan 2026 17:17:14 +0100
Subject: [PATCH] feat: Show 12-month matrix with empty cells for missing
 invoices

- Generate all 12 months automatically (last 12 months from today)
- Display empty cells with 'missing' status for months without invoices
- Makes it easy to spot billing gaps
- Empty cells show 0 kr and null invoice_number
---
 app/services/subscription_matrix.py | 85 ++++++++++++++++++++++-------
 1 file changed, 66 insertions(+), 19 deletions(-)

diff --git a/app/services/subscription_matrix.py b/app/services/subscription_matrix.py
index 2c63cbd..da8a8ae 100644
--- a/app/services/subscription_matrix.py
+++ b/app/services/subscription_matrix.py
@@ -140,13 +140,39 @@ class SubscriptionMatrixService:
             months: Number of months to include
             
         Returns:
-            List of product records with aggregated monthly data
+            List of product records with aggregated monthly data (including empty months)
         """
+        # Generate list of all months to display (last N months from today)
+        all_months = self._generate_month_range(months)
+        
         # Structure: {product_number: {year_month: {amount, status, invoice_number, period_from, period_to}}}
         product_matrix = defaultdict(dict)
         product_names = {}  # Cache product names
         
+        # Initialize all products with empty cells for all months
         try:
+            for invoice in invoices:
+                lines = invoice.get('lines', [])
+                for line in lines:
+                    product_number = line.get('product', {}).get('productNumber')
+                    product_name = line.get('product', {}).get('name') or line.get('description')
+                    
+                    if product_number and product_number not in product_names:
+                        product_names[product_number] = product_name or f"Product {product_number}"
+            
+            # Initialize all products with all months (empty)
+            for product_number in product_names.keys():
+                for year_month in all_months:
+                    product_matrix[product_number][year_month] = {
+                        "amount": 0.0,
+                        "status": "missing",
+                        "invoice_number": None,
+                        "period_from": None,
+                        "period_to": None,
+                        "period_label": None
+                    }
+            
+            # Now fill in data from invoices
             for invoice in invoices:
                 invoice_number = invoice.get('bookedInvoiceNumber') or invoice.get('draftInvoiceNumber')
                 # Determine status based on invoice type/endpoint it came from
@@ -214,24 +240,15 @@ class SubscriptionMatrixService:
                     # Calculate period label
                     period_label = self._format_period_label(period_from, period_to)
                     
-                    # Initialize cell if doesn't exist
-                    if year_month not in product_matrix[product_number]:
-                        product_matrix[product_number][year_month] = {
-                            "amount": 0.0,
-                            "status": "missing",
-                            "invoice_number": None,
-                            "period_from": None,
-                            "period_to": None
-                        }
-                    
-                    # Update cell
-                    cell = product_matrix[product_number][year_month]
-                    cell["amount"] = amount  # Take last amount (or sum if multiple?)
-                    cell["status"] = self._determine_status(invoice_status)
-                    cell["invoice_number"] = invoice_number
-                    cell["period_from"] = period_from.isoformat().split('T')[0]
-                    cell["period_to"] = period_to.isoformat().split('T')[0]
-                    cell["period_label"] = period_label
+                    # Update cell (it should already exist from initialization)
+                    if year_month in product_matrix.get(product_number, {}):
+                        cell = product_matrix[product_number][year_month]
+                        cell["amount"] = amount  # Take last amount (or sum if multiple?)
+                        cell["status"] = self._determine_status(invoice_status)
+                        cell["invoice_number"] = invoice_number
+                        cell["period_from"] = period_from.isoformat().split('T')[0]
+                        cell["period_to"] = period_to.isoformat().split('T')[0]
+                        cell["period_label"] = period_label
         
         except Exception as e:
             logger.error(f"❌ Error aggregating data: {e}")
@@ -268,6 +285,36 @@ class SubscriptionMatrixService:
         
         return products
     
+    @staticmethod
+    def _generate_month_range(num_months: int) -> List[str]:
+        """
+        Generate list of month keys for the last N months
+        
+        Args:
+            num_months: Number of months to generate (e.g., 12)
+            
+        Returns:
+            Sorted list of 'YYYY-MM' strings going back from today
+        """
+        months = []
+        today = datetime.now()
+        
+        for i in range(num_months):
+            # Go back i months from today using calendar arithmetic
+            year = today.year
+            month = today.month - i
+            
+            # Adjust year and month if month goes negative
+            while month <= 0:
+                month += 12
+                year -= 1
+            
+            month_key = f"{year:04d}-{month:02d}"
+            months.append(month_key)
+        
+        # Return sorted chronologically (oldest first)
+        return sorted(months)
+    
     @staticmethod
     def _format_period_label(period_from: datetime, period_to: datetime) -> str:
         """Format period as readable label (e.g., 'Jan', 'Jan-Mar', etc)"""