[ADD] Contract Variable Qty Prorated

contract_variable_qty_prorated/models/contract_line.py

@@ -0,0 +1,45 @@
+# Copyright 2018 ACSONE SA/NV
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from odoo import api, models
+
+
+class ContractLine(models.Model):
+    _inherit = "contract.line"
+
+    @api.model
+    def _compute_prorated(
+        self, real_next_date, real_last_date, theoretical_next_date,
+            theoretical_last_date):
+        def _invoiced_days(next_date, last_date):
+            return (next_date - last_date).days + 1
+
+        return _invoiced_days(real_next_date, real_last_date) / _invoiced_days(
+            theoretical_next_date, theoretical_last_date
+        )
+
+    @api.multi
+    def compute_prorated(self, period_first_date, period_last_date,
+                         invoice_date):
+        self.ensure_one()
+        relative_delta = self.get_relative_delta(
+            self.recurring_rule_type, self.recurring_interval
+        )
+        theoretical_next_date = invoice_date
+        if self.recurring_rule_type == "monthlylastday":
+            relative_delta = self.get_relative_delta("monthly",
+                                                     self.recurring_interval)
+            theoretical_next_date += self.get_relative_delta("daily", 1)
+        if (
+            self.recurring_invoicing_type == "pre-paid"
+            and self.recurring_rule_type != "monthlylastday"
+        ):
+            theoretical_next_date += relative_delta
+        theoretical_last_date = theoretical_next_date - relative_delta
+        theoretical_next_date -= self.get_relative_delta("daily", 1)
+        real_last_date = period_first_date
+        real_next_date = period_last_date
+        return self._compute_prorated(
+            real_next_date, real_last_date, theoretical_next_date,
+            theoretical_last_date
+        )