add propagation method to future stock movement valuation

models/stock_inventory_revaluation.py

@@ -119,40 +119,168 @@ class StockInventoryRevaluation(models.Model):
         # Create Stock Valuation Layer
         self._create_valuation_layer(move)
 
-        # AVCO/FIFO Logic: Update Standard Price and Distribute Value to Layers
+        # 1. Common Logic: Calculate Unit Adjustment & Update Standard Price
-        # This fixes the issue where revaluation creates a layer but doesn't update the moving average cost
+        # This applies to Standard Price, AVCO, and FIFO
-        if self.product_id.categ_id.property_cost_method in ['average', 'fifo'] and self.quantity > 0:
+        if self.quantity > 0:
-            # 1. Update Standard Price
+            unit_adjust = self.extra_cost / self.quantity
-            # We use disable_auto_svl to prevent Odoo from creating an extra SVL for this price change
+            new_std_price = self.product_id.standard_price + unit_adjust
-            new_std_price = self.product_id.standard_price + (self.extra_cost / self.quantity)
+            
+            # Update the price on the product
+            # For Standard Price: This sets the new fixed cost.
+            # For AVCO/FIFO: This updates the current running average.
             self.product_id.with_context(disable_auto_svl=True).sudo().write({'standard_price': new_std_price})
         
-            # 2. Distribute Value to Remaining Layers (Crucial for correct COGS later)
+        # 2. AVCO/FIFO Specific Logic: Distribute Value to Layers & Propagate to Sales
+        # Standard Price does not use layers for costing, so we skip this part for it.
+        if self.product_id.categ_id.property_cost_method in ['average', 'fifo'] and self.quantity > 0:
+            
+            # Distribute to Remaining Stock (The "Survivor" Layers)
+            # Track how much we distributed
+            total_distributed = 0.0
+            
             remaining_svls = self.env['stock.valuation.layer'].search([
                 ('product_id', '=', self.product_id.id),
                 ('remaining_qty', '>', 0),
                 ('company_id', '=', self.company_id.id),
+                ('create_date', '<=', self.date), 
             ])
+            remaining_svls = remaining_svls.filtered(lambda l: l.create_date <= self.date)
             
             if remaining_svls:
-                remaining_qty_total = sum(remaining_svls.mapped('remaining_qty'))
-                if remaining_qty_total > 0:
-                    remaining_value_to_distribute = self.extra_cost
-                    remaining_value_unit_cost = remaining_value_to_distribute / remaining_qty_total
-                    
                 for layer in remaining_svls:
-                        if float_compare(layer.remaining_qty, remaining_qty_total, precision_rounding=self.product_id.uom_id.rounding) >= 0:
+                    adjustment_amount = layer.remaining_qty * unit_adjust
-                            taken_remaining_value = remaining_value_to_distribute
+                    adjustment_amount = self.currency_id.round(adjustment_amount)
+                    
+                    if not float_is_zero(adjustment_amount, precision_rounding=self.currency_id.rounding):
+                        layer.sudo().write({
+                            'remaining_value': layer.remaining_value + adjustment_amount,
+                            # 'value': layer.value + adjustment_amount # Leaving value untouched to preserve historic record
+                        })
+                        total_distributed += adjustment_amount
+                        
+            # 3. Distribute to Sold Stock (The "Forward Propagation")
+            # Only distribute what's left! This ensures we don't "correct" sales of NEW stock.
+            remaining_value_to_expense = self.extra_cost - total_distributed
+            remaining_value_to_expense = self.currency_id.round(remaining_value_to_expense)
+            
+            if float_compare(remaining_value_to_expense, 0, precision_rounding=self.currency_id.rounding) > 0:
+                 # Find outgoing moves (sales) that happened AFTER revaluation date
+                outgoing_svls = self.env['stock.valuation.layer'].search([
+                    ('product_id', '=', self.product_id.id),
+                    ('company_id', '=', self.company_id.id),
+                    ('quantity', '<', 0), # Outgoing
+                    ('create_date', '>', self.date), # After revaluation
+                ], order='create_date asc, id asc') # Chronological
+                
+                if outgoing_svls:
+                    for out_layer in outgoing_svls:
+                        if float_compare(remaining_value_to_expense, 0, precision_rounding=self.currency_id.rounding) <= 0:
+                            break # Limit reached
+                            
+                        # How much correction does this move "deserve"?
+                        qty_sold = abs(out_layer.quantity)
+                        theoretical_correction = qty_sold * unit_adjust
+                        theoretical_correction = self.currency_id.round(theoretical_correction)
+                        
+                        # We can only give what we have left
+                        actual_correction = min(theoretical_correction, remaining_value_to_expense) # If positive adjustment
+                        if unit_adjust < 0: # If negative adjustment? 
+                            # If unit_adjust is negative, everything is negative.
+                            # extra_cost is neg, total_dist is neg, remaining_to_exp is neg.
+                            # abs(actual) = min(abs(theo), abs(rem))
+                            # implementation detail: let's handle signs properly?
+                            # Simplify: assume always positive for logic "Cap", but math works.
+                            # Wait, min() with negatives works differently.
+                            # -100 vs -50. min is -100. We want "Closest to zero".
+                            pass
+                        
+                        # Handle Sign-Agnostic Capping
+                        # We want to reduce the magnitude of remaining_to_expense towards zero.
+                        # If remaining is +100, we reduce by positive amounts.
+                        # If remaining is -100, we reduce by negative amounts.
+                        
+                        if remaining_value_to_expense > 0:
+                             actual_correction = min(theoretical_correction, remaining_value_to_expense)
                         else:
-                            taken_remaining_value = remaining_value_unit_cost * layer.remaining_qty
+                             # theoretical is likely negative too because unit_adjust is negative
+                             actual_correction = max(theoretical_correction, remaining_value_to_expense)
 
-                        # Rounding
+                        if float_is_zero(actual_correction, precision_rounding=self.currency_id.rounding):
-                        taken_remaining_value = self.currency_id.round(taken_remaining_value)
+                            continue
                             
-                        layer.sudo().write({'remaining_value': layer.remaining_value + taken_remaining_value})
+                        # Create Correction SVL
+                        stock_val_acc = self.product_id.categ_id.property_stock_valuation_account_id.id
+                        cogs_acc = self.product_id.categ_id.property_stock_account_output_categ_id.id
                         
-                        remaining_value_to_distribute -= taken_remaining_value
+                        if not stock_val_acc or not cogs_acc:
-                        remaining_qty_total -= layer.remaining_qty
+                            continue 
+                            
+                        # Accounting Entries
+                        # If Positive Adjustment (Value Added):
+                        #   Dr COGS -> Increased Cost
+                        #   Cr Stock Asset -> Decreased Asset (Since we put it all in Asset initially)
+                        # Wait, initially we Debited Asset +100.
+                        # Now we say "50 of that was sold".
+                        # So we Credit Asset -50, Debit COGS +50.
+                        # Correct.
+                        
+                        # If Negative Adjustment (Value Removed):
+                        #   Initially Credited Asset -100.
+                        #   "50 of that removal belongs to sales".
+                        #   So we Debit Asset +50, Credit COGS -50 (Reduce Cost).
+                        #   The math: actual_correction is -50.
+                        #   Using same logic: Debit COGS with -50? (Credit 50).
+                        #   Credit Asset with -50? (Debit 50).
+                        #   Logic holds purely with signs.
+                        
+                        move_lines = [
+                            (0, 0, {
+                                'name': _('Revaluation Correction for %s') % out_layer.stock_move_id.name,
+                                'account_id': cogs_acc,
+                                'debit': actual_correction if actual_correction > 0 else 0,
+                                'credit': -actual_correction if actual_correction < 0 else 0,
+                                'product_id': self.product_id.id,
+                            }),
+                            (0, 0, {
+                                'name': _('Revaluation Correction for %s') % out_layer.stock_move_id.name,
+                                'account_id': stock_val_acc,
+                                'debit': -actual_correction if actual_correction < 0 else 0,
+                                'credit': actual_correction if actual_correction > 0 else 0,
+                                'product_id': self.product_id.id,
+                            }),
+                        ]
+                        
+                        am_vals = {
+                            'ref': f"{self.name} - Corr - {out_layer.stock_move_id.name}",
+                            'date': out_layer.create_date.date(),
+                            'journal_id': self.account_journal_id.id,
+                            'line_ids': move_lines,
+                            'move_type': 'entry',
+                            'company_id': self.company_id.id,
+                        }
+                        am = self.env['account.move'].create(am_vals)
+                        am.action_post()
+                        
+                        # Correction SVL
+                        # Value should be negative of correction to reduce Asset
+                        # If correction is +50 (add to COGS), SVL value is -50 (remove from Asset).
+                        svl_value = -actual_correction
+                        
+                        new_svl = self.env['stock.valuation.layer'].create({
+                             'product_id': self.product_id.id,
+                             'value': svl_value,
+                             'quantity': 0,
+                             'unit_cost': 0,
+                             'remaining_qty': 0,
+                             'stock_move_id': out_layer.stock_move_id.id,
+                             'company_id': self.company_id.id,
+                             'description': _('Revaluation Correction (from %s)') % self.name,
+                             'account_move_id': am.id,
+                        })
+                        self.env.cr.execute('UPDATE stock_valuation_layer SET create_date = %s WHERE id = %s', 
+                                          (out_layer.create_date, new_svl.id))
+                                          
+                        remaining_value_to_expense -= actual_correction
         
         self.state = 'done'