[IMP] mass_mailing: use cron trigger to send "now"

The "launch" button of an email campaign mark the current campaign ready
to be processed. As sending all the mails is a pretty heavy operation,
it is done asynchronously in a cron. The cron was running every hour, it
means the cron was running even if there was no active campaign and it
has a best precision of 1 hour.

We now use the new mechanism of cron triggers (4b28f11) to schedule the
con execution at the time the campaign is configured to be sent. It
achieves a better precision and ensures the cron only runs when there are
stuff to process.

We still let the cron run once a day as a security until the cron
mechanisme proves reliable.

closes odoo/odoo#65124

Task: 2416741
Signed-off-by: Julien Castiaux <Julien00859@users.noreply.github.com>

addons/mass_mailing/data/mass_mailing_data.xml

@@ -8,8 +8,8 @@
             <field name="state">code</field>
             <field name="code">model._process_mass_mailing_queue()</field>
             <field name="user_id" ref="base.user_root" />
-            <field name="interval_number">60</field>
-            <field name="interval_type">minutes</field>
+            <field name="interval_number">1</field>
+            <field name="interval_type">days</field>
             <field name="numbercall">-1</field>
             <field eval="False" name="doall" />
         </record>

addons/mass_mailing/models/mailing.py

@@ -358,6 +358,11 @@ class MassMailing(models.Model):
 
     def action_put_in_queue(self):
         self.write({'state': 'in_queue'})
+        cron = self.env.ref('mass_mailing.ir_cron_mass_mailing_queue')
+        cron._trigger(
+            schedule_date or fields.Datetime.now()
+            for schedule_date in self.mapped('schedule_date')
+        )
 
     def action_cancel(self):
         self.write({'state': 'draft', 'schedule_date': False, 'schedule_type': 'now', 'next_departure': False})

addons/mass_mailing/tests/test_mailing_internals.py

@@ -2,6 +2,9 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 from ast import literal_eval
+from datetime import datetime
+
+from freezegun import freeze_time
 
 from odoo.addons.mass_mailing.tests.common import MassMailCommon
 from odoo.tests.common import users, Form
@@ -173,6 +176,44 @@ class TestMassMailFeatures(MassMailCommon):
                 'email_to incorrect. Should be equal to "%s"' % (
                     formataddr((test_partner.name, test_partner.email))))
 
+    @users('user_marketing')
+    @mute_logger('odoo.addons.mail.models.mail_mail')
+    def test_mailing_cron_trigger(self):
+        """ Technical test to ensure the cron is triggered at the correct
+        time """
+
+        ir_cron_triggers = self.env['ir.cron.trigger'].sudo()
+        partner = self.env['res.partner'].create({
+            'name': 'Jean-Alphonce',
+            'email': 'jeanalph@example.com',
+        })
+        common_mailing_values = {
+            'name': 'Knock knock',
+            'subject': "Who's there?",
+            'mailing_model_id': self.env['ir.model']._get('res.partner').id,
+            'mailing_domain': [('id', '=', partner.id)],
+            'body_html': 'The marketing mailing test.',
+            'schedule_type': 'scheduled',
+        }
+
+        now = datetime(2021, 2, 5, 16, 43, 20)
+        then = datetime(2021, 2, 7, 12, 0, 0)
+
+        with freeze_time(now):
+            for (test, truth) in [(False, now), (then, then)]:
+                with self.subTest(schedule_date=test):
+                    triggers_before = ir_cron_triggers.search([])
+                    mailing = self.env['mailing.mailing'].create({
+                        **common_mailing_values,
+                        'schedule_date': test,
+                    })
+                    mailing.action_put_in_queue()
+
+                    triggers_after = ir_cron_triggers.search([])
+                    new_triggers = triggers_after - triggers_before
+                    new_triggers.ensure_one()
+                    self.assertLessEqual(new_triggers.call_at, truth)
+
     @users('user_marketing')
     @mute_logger('odoo.addons.mail.models.mail_mail')
     def test_mailing_on_res_partner(self):