account_usability: reversal wizard: check the move hasn't already been reversed

account_usability/wizard/account_move_reversal.py

@@ -2,21 +2,28 @@
 # @author: Alexis de Lattre <alexis.delattre@akretion.com>
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
-from odoo import api, fields, models
+from odoo import api, models, _
 from dateutil.relativedelta import relativedelta
+from odoo.exceptions import UserError
 
 
 class AccountMoveReversal(models.TransientModel):
     _inherit = 'account.move.reversal'
 
+    # Set default reversal date to original move + 1 day
+    # and raise error if original move has already been reversed
     @api.model
-    def _default_date(self):
-        date_dt = None
-        if (
-                self._context.get('active_model') == 'account.move' and
-                self._context.get('active_id')):
-            move = self.env['account.move'].browse(self._context['active_id'])
-            date_dt = move.date + relativedelta(days=1)
-        return date_dt
-
-    date = fields.Date(default=_default_date)
+    def default_get(self, fields_list):
+        res = super().default_get(fields_list)
+        assert self._context.get('active_model') == 'account.move'
+        amo = self.env['account.move']
+        moves = amo.browse(self._context['active_ids'])
+        if len(moves) == 1:
+            res['date'] = moves.date + relativedelta(days=1)
+        reversed_move = amo.search([('reversed_entry_id', 'in', moves.ids)], limit=1)
+        if reversed_move:
+            raise UserError(_(
+                "Move '%s' has already been reversed by move '%s'.") % (
+                    reversed_move.reversed_entry_id.display_name,
+                    reversed_move.display_name))
+        return res