From c679d39c369eaa3df795c6172e84d7d49d84ea04 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Mudr=C3=A1k?= <david@moodle.com>
Date: Tue, 5 Mar 2019 19:57:52 +0100
Subject: [PATCH] MDL-64996 analytics: Don't mark static model as untrained
 after clearing

Static predictions models (i.e. those using a target based on
assumptions, not facts) are always considered as trained. Clearing them
must not mark them as untrained. Doing so would make them being skipped
by the prediction scheduled task.
---
 analytics/classes/model.php    |  5 ++++-
 analytics/tests/model_test.php | 24 ++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/analytics/classes/model.php b/analytics/classes/model.php
index 3756b907b73..6230b758698 100644
--- a/analytics/classes/model.php
+++ b/analytics/classes/model.php
@@ -1626,7 +1626,10 @@ class model {
         // 1 db read per context.
         $this->purge_insights_cache();
 
-        $this->model->trained = 0;
+        if (!$this->is_static()) {
+            $this->model->trained = 0;
+        }
+
         $this->model->timemodified = time();
         $this->model->usermodified = $USER->id;
         $DB->update_record('analytics_models', $this->model);
diff --git a/analytics/tests/model_test.php b/analytics/tests/model_test.php
index 19ceb6166a0..2fc0fa97c06 100644
--- a/analytics/tests/model_test.php
+++ b/analytics/tests/model_test.php
@@ -169,10 +169,34 @@ class analytics_model_testcase extends advanced_testcase {
         $this->assertEmpty($DB->count_records('analytics_predict_samples'));
         $this->assertEmpty($DB->count_records('analytics_used_files'));
 
+        // Check that the model is marked as not trained after clearing (as it is not a static one).
+        $this->assertEquals(0, $DB->get_field('analytics_models', 'trained', array('id' => $this->modelobj->id)));
+
         set_config('enabled_stores', '', 'tool_log');
         get_log_manager(true);
     }
 
+    /**
+     * Test behaviour of {\core_analytics\model::clear()} for static models.
+     */
+    public function test_clear_static() {
+        global $DB;
+        $this->resetAfterTest();
+
+        $statictarget = new test_static_target_shortname();
+        $indicators['test_indicator_max'] = \core_analytics\manager::get_indicator('test_indicator_max');
+        $model = \core_analytics\model::create($statictarget, $indicators, '\core\analytics\time_splitting\quarters');
+        $modelobj = $model->get_model_obj();
+
+        // Static models are always considered trained.
+        $this->assertEquals(1, $DB->get_field('analytics_models', 'trained', array('id' => $modelobj->id)));
+
+        $model->clear();
+
+        // Check that the model is still marked as trained even after clearing.
+        $this->assertEquals(1, $DB->get_field('analytics_models', 'trained', array('id' => $modelobj->id)));
+    }
+
     public function test_model_manager() {
         $this->resetAfterTest(true);