[UPD] Synchronize budget with new quotation lines

By pressing button "Sync missing budget lines", a new budget section
line is created for all the order lines without associated budget line.

account_budget_forecast/models/account_analytic_account.py

@@ -263,6 +263,7 @@ class AccountAnalyticAccount(models.Model):
                 "name": section.product_id.name,
                 "product_uom_qty": 1.0,
                 "price_unit": section.plan_amount_with_coeff,
+                "budget_forecast_id": section.id,
             }
             self.env["sale.order.line"].create(values)
         quotation.analytic_account_id = self.id

account_budget_forecast/models/sale_order.py

@@ -16,6 +16,31 @@ class SaleOrder(models.Model):
             raise Warning(_("Please set the analytic account"))
         return self.analytic_account_id.action_budget_forecast()
 
+    def sync_missing_budget_lines(self):
+        for record in self:
+            for line in self.order_line:
+                if not line.budget_forecast_id:
+                    values = {
+                        "analytic_id": record.analytic_account_id.id,
+                        "product_id": line.product_id.id,
+                        "description": line.name,
+                        "is_summary": True,
+                        "display_type": "line_section",
+                        "sequence": 999,
+                    }
+                    budget_line = self.env["budget.forecast"].create(values)
+                    misc_budget_line = self.env["budget.forecast"].search(
+                        [
+                            ("summary_id", "=", budget_line.id),
+                            ("budget_category", "=", "miscellaneous"),
+                        ]
+                    )
+                    misc_budget_line.plan_qty = 1
+                    misc_budget_line.plan_price = line.price_unit / (
+                        1 + record.analytic_account_id.global_coeff
+                    )
+                    line.budget_forecast_id = budget_line.id
+
     @api.returns("self", lambda value: value.id)
     def copy(self, default=None):
         record = super(SaleOrder, self).copy(default=default)
@@ -28,3 +53,9 @@ class SaleOrder(models.Model):
                 default=dict(name=name)
             )
         return record
+
+
+class SaleOrderLine(models.Model):
+    _inherit = "sale.order.line"
+
+    budget_forecast_id = fields.Many2one("budget.forecast")