[FIX] event_registration_partner_unique: avoid constraint on merge

When a user merges two contacts an error will raise if there are event
with a unique partner constraint when both partner were atendees. With
these changes, we let the user get rid of those duplicated attendees.

TT45921

event_registration_partner_unique/README.rst

@@ -7,7 +7,7 @@ Unique Partner per Event
    !! This file is generated by oca-gen-addon-readme !!
    !! changes will be overwritten.                   !!
    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-   !! source digest: sha256:fa39a5416b9a53ff743d770b11ab214277fe38d04077dfa770174e259f481c29
+   !! source digest: sha256:3d53fec9f6993c3a355d0cac4a4fc844e5290c7466ea731d4f6174c8486d9249
    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
 .. |badge1| image:: https://img.shields.io/badge/maturity-Beta-yellow.png

event_registration_partner_unique/__init__.py

@@ -1,3 +1,4 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 
 from . import models
+from . import wizards

event_registration_partner_unique/__manifest__.py

@@ -14,5 +14,5 @@
     "application": False,
     "installable": True,
     "depends": ["event", "partner_event"],
-    "data": ["views/event_event_view.xml"],
+    "data": ["views/event_event_view.xml", "wizards/base_partner_merge_views.xml"],
 }

event_registration_partner_unique/models/event.py

@@ -18,6 +18,8 @@ class EventEvent(models.Model):
     @api.constrains("forbid_duplicates", "registration_ids")
     def _check_forbid_duplicates(self):
         """Ensure no duplicated attendee are found in the event."""
+        if self.env.context.get("skip_registration_partner_unique"):
+            return
         return self.filtered(
             "forbid_duplicates"
         ).registration_ids._check_forbid_duplicates()
@@ -29,9 +31,22 @@ class EventRegistration(models.Model):
     @api.constrains("event_id", "attendee_partner_id")
     def _check_forbid_duplicates(self):
         """Ensure no duplicated attendees are found in the event."""
+        if self.env.context.get("skip_registration_partner_unique"):
+            return
+        dupes_to_unlink = self.browse()
+        # From the contact merge dialog we could choose to get rid of duplicated
+        # attendees linked to the merged partners.
+        unlink_dupes = self.env.context.get("merge_duplicated_registrations")
         for event_reg in self.filtered("event_id.forbid_duplicates"):
-            dupes = self.search(event_reg._duplicate_search_domain())
-            if dupes:
+            dupes = self.search(
+                event_reg._duplicate_search_domain(), order="create_date desc"
+            )
+            if not dupes:
+                continue
+            if unlink_dupes:
+                # Only the oldest one is kept
+                dupes_to_unlink += dupes[:-1]
+            else:
                 raise ValidationError(
                     _("Duplicated partners found in event %(name)s: %(partners)s.")
                     % {
@@ -42,6 +57,8 @@ def _check_forbid_duplicates(self):
                         ),
                     }
                 )
+        # Call with skipping context to avoid triggering the constraint again
+        dupes_to_unlink.with_context(skip_registration_partner_unique=True).unlink()
 
     def _duplicate_search_domain(self):
         """What to look for when searching duplicates."""

event_registration_partner_unique/static/description/index.html

@@ -367,7 +367,7 @@ <h1 class="title">Unique Partner per Event</h1>
 !! This file is generated by oca-gen-addon-readme !!
 !! changes will be overwritten.                   !!
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-!! source digest: sha256:fa39a5416b9a53ff743d770b11ab214277fe38d04077dfa770174e259f481c29
+!! source digest: sha256:3d53fec9f6993c3a355d0cac4a4fc844e5290c7466ea731d4f6174c8486d9249
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
 <p><a class="reference external image-reference" href="https://odoo-community.org/page/development-status"><img alt="Beta" src="https://img.shields.io/badge/maturity-Beta-yellow.png" /></a> <a class="reference external image-reference" href="http://www.gnu.org/licenses/agpl-3.0-standalone.html"><img alt="License: AGPL-3" src="https://img.shields.io/badge/licence-AGPL--3-blue.png" /></a> <a class="reference external image-reference" href="https://github.com/OCA/event/tree/15.0/event_registration_partner_unique"><img alt="OCA/event" src="https://img.shields.io/badge/github-OCA%2Fevent-lightgray.png?logo=github" /></a> <a class="reference external image-reference" href="https://translation.odoo-community.org/projects/event-15-0/event-15-0-event_registration_partner_unique"><img alt="Translate me on Weblate" src="https://img.shields.io/badge/weblate-Translate%20me-F47D42.png" /></a> <a class="reference external image-reference" href="https://runboat.odoo-community.org/builds?repo=OCA/event&amp;target_branch=15.0"><img alt="Try me on Runboat" src="https://img.shields.io/badge/runboat-Try%20me-875A7B.png" /></a></p>
 <p>This module is intended for backend use only, and extends the functionality

event_registration_partner_unique/wizards/__init__.py

@@ -0,0 +1 @@
+from . import base_partner_merge

event_registration_partner_unique/wizards/base_partner_merge.py

@@ -0,0 +1,21 @@
+# Copyright 2023 Tecnativa - David Vidal
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+from odoo import fields, models
+
+
+class BasePartnerMergeAutomaticWizard(models.TransientModel):
+    _inherit = "base.partner.merge.automatic.wizard"
+
+    merge_duplicated_registrations = fields.Boolean(
+        help="If the merged partners were linked to registrations in an event that had "
+        "unique attendees flag we'll take only the oldest one",
+    )
+
+    def action_merge(self):
+        """Inject context so we can deal with duplicates when merging"""
+        if self.merge_duplicated_registrations:
+            return super(
+                BasePartnerMergeAutomaticWizard,
+                self.with_context(merge_registration_partner_unique=True),
+            ).action_merge()
+        return super().action_merge()

event_registration_partner_unique/wizards/base_partner_merge_views.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<odoo>
+<record id="base_partner_merge_automatic_wizard_form" model="ir.ui.view">
+    <field name="inherit_id" ref="base.base_partner_merge_automatic_wizard_form" />
+    <field name='model'>base.partner.merge.automatic.wizard</field>
+    <field name='arch' type='xml'>
+        <field name="dst_partner_id" position="after">
+            <field name="merge_duplicated_registrations" />
+        </field>
+    </field>
+</record>
+</odoo>