Subrscribe partner to company channel when added to a company

If the company doesn't have a channel and the partner has an active
contract we create the channel.
When a partner is removed from a company, he is also removed from the
channel.

commown_b2b_mail_channel/models/contract.py

@@ -8,6 +8,12 @@
 class Contract(models.Model):
     _inherit = "contract.contract"
 
+    def is_active_contract(self):
+        if self.date_start and self.date_start <= date.today():
+            return not self.date_end or self.date_end > date.today()
+        else:
+            return False
+
     @api.constrains("date_start")
     def on_contract_start_create_channel(self):
         """Trigger support channel creation if contract is about to start"""

commown_b2b_mail_channel/models/res_partner.py

@@ -28,6 +28,23 @@ def write(self, vals):
                 self.env["mail.channel"].browse(new_chan_id).channel_invite(
                     partners_to_add.ids
                 )
+        if not self.is_company and "parent_id" in vals.keys():
+            new_parent_id = vals["parent_id"]
+            if new_parent_id:
+                new_parent = self.env["res.partner"].browse(new_parent_id)
+                if new_parent.mail_channel_id:
+                    new_parent.mail_channel_id.channel_invite(self.id)
+
+                elif not new_parent.mail_channel_id and self.contract_ids.filtered(
+                    lambda c: c.is_active_contract()
+                ):
+                    new_parent.sudo().create_mail_channel()
+
+            if not new_parent_id:
+                old_parent = self.parent_id
+                if old_parent and old_parent.mail_channel_id:
+                    self.remove_partners_from_channel(old_parent.mail_channel_id, self)
+
         return super().write(vals)
 
     def remove_partners_from_channel(self, channel, partners):

commown_b2b_mail_channel/tests/test_res_partner.py

@@ -39,3 +39,32 @@ def test_support_channel_creation_on_contract_start(self):
             self.part1 + self.part2 + self.user_support.partner_id,
         )
         self.assertEqual(company_chan.group_ids, expected_groups)
+
+    def test_partner_is_added_when_parent_has_channel(self):
+        self.company.create_mail_channel()
+        mail_channel = self.company.mail_channel_id
+        self.assertTrue(mail_channel)
+
+        initial_parts = mail_channel.channel_last_seen_partner_ids.mapped("partner_id")
+
+        self.part1.parent_id = self.company
+        self.assertEqual(
+            mail_channel.channel_last_seen_partner_ids.mapped("partner_id"),
+            initial_parts + self.part1,
+        )
+
+        self.part1.parent_id = False
+        self.assertEqual(
+            mail_channel.channel_last_seen_partner_ids.mapped("partner_id"),
+            initial_parts,
+        )
+
+    def test_channel_creation_on_active_contract_join_company(self):
+        """Test if channel is created when a partner with an active contract join
+        company"""
+        self.part2.parent_id = self.company
+        self.contract.date_start = date.today()
+        self.assertFalse(self.company.mail_channel_id)
+
+        self.part1.parent_id = self.company
+        self.assertTrue(self.company.mail_channel_id)