From a1548adc5347077d7d545f0f109341cfaf7d9e97 Mon Sep 17 00:00:00 2001
From: mokaddem <sami.mokaddem@circl.lu>
Date: Fri, 29 May 2020 14:40:13 +0200
Subject: [PATCH] chg: [decaying] `last_seen` takes precedence over `timestamp`

If `last_seen` is set, it will take precedence over the timestamp if no
sightings have been recorded.
By doing so, we prevent the score to be refreshed if the attribute is
slightly modified (a tag is added/removed)
---
 app/Model/DecayingModel.php               | 25 +++++++++++++++++++----
 app/Model/DecayingModelsFormulas/Base.php | 10 +++++++--
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/app/Model/DecayingModel.php b/app/Model/DecayingModel.php
index 7e52037c4..2c95658b1 100644
--- a/app/Model/DecayingModel.php
+++ b/app/Model/DecayingModel.php
@@ -489,27 +489,44 @@ class DecayingModel extends AppModel
         $this->Sighting = ClassRegistry::init('Sighting');
         $sightings = $this->Sighting->listSightings($user, $attribute_id, 'attribute', false, 0, false);
         if (empty($sightings)) {
-            $sightings = array(array('Sighting' => array('date_sighting' => $attribute['Attribute']['timestamp']))); // simulate a Sighting nonetheless
+            if (!is_null($attribute['Attribute']['last_seen'])) {
+                $falseSighting = (new DateTime($attribute['Attribute']['last_seen']))->format('U');
+            } else {
+                $falseSighting = $attribute['Attribute']['timestamp'];
+            }
+            $sightings = array(array('Sighting' => array('date_sighting' => $falseSighting))); // simulate a Sighting nonetheless
         }
         foreach ($sightings as $i => $sighting) {
             $sightings[$i]['Sighting']['rounded_timestamp'] = $this->round_timestamp_to_hour($sighting['Sighting']['date_sighting']);
         }
         // get start time
         $start_time = $attribute['Attribute']['timestamp'];
+        if (!is_null($attribute['Attribute']['last_seen'])) {
+            $start_time = (new DateTime($attribute['Attribute']['last_seen']))->format('U');
+        }
         $start_time = $sightings[0]['Sighting']['date_sighting'] < $start_time ? $sightings[0]['Sighting']['date_sighting'] : $start_time;
         $start_time = intval($start_time);
         $start_time = $this->round_timestamp_to_hour($start_time);
         // get end time
         $last_sighting_timestamp = $sightings[count($sightings)-1]['Sighting']['date_sighting'];
         if ($attribute['Attribute']['timestamp'] > $last_sighting_timestamp) { // The attribute was modified after the last sighting, simulate a Sighting
+            if (!is_null($attribute['Attribute']['timestamp'])) {
+                $falseSighting = (new DateTime($attribute['Attribute']['last_seen']))->format('U');
+            } else {
+                $falseSighting = $attribute['timestamp'];
+            }
             $sightings[count($sightings)] = array(
                 'Sighting' => array(
-                    'date_sighting' => $attribute['Attribute']['timestamp'],
+                    'date_sighting' => $falseSighting,
                     'type' => 0, 
-                    'rounded_timestamp' => $this->round_timestamp_to_hour($attribute['Attribute']['timestamp'])
+                    'rounded_timestamp' => $this->round_timestamp_to_hour($falseSighting)
                 )
             );
-            $last_sighting_timestamp = $attribute['Attribute']['timestamp'];
+            if (!is_null($attribute['Attribute']['timestamp'])) {
+                $last_sighting_timestamp = (new DateTime($attribute['Attribute']['last_seen']))->format('U');
+            } else {
+                $last_sighting_timestamp = $attribute['Attribute']['timestamp'];
+            }
         }
         $end_time = $last_sighting_timestamp + $model['DecayingModel']['parameters']['lifetime']*24*60*60;
         $end_time = $this->round_timestamp_to_hour($end_time);
diff --git a/app/Model/DecayingModelsFormulas/Base.php b/app/Model/DecayingModelsFormulas/Base.php
index 3cf879506..98d2bc175 100644
--- a/app/Model/DecayingModelsFormulas/Base.php
+++ b/app/Model/DecayingModelsFormulas/Base.php
@@ -136,12 +136,18 @@ abstract class DecayingModelBase
             $all_sightings = $this->Sighting->listSightings($user, $attribute['id'], 'attribute', false, 0, true);
             if (!empty($all_sightings)) {
                 $last_sighting_timestamp = $all_sightings[0]['Sighting']['date_sighting'];
+            } elseif (!is_null($attribute['last_seen'])) {
+                $last_sighting_timestamp = (new DateTime($attribute['last_seen']))->format('U');
             } else {
-                $last_sighting_timestamp = $attribute['timestamp']; // if no sighting, take the last update time
+                $last_sighting_timestamp = $attribute['timestamp']; // if no sighting nor valid last_seen, take the last update time
             }
         }
         if ($attribute['timestamp'] > $last_sighting_timestamp) { // The attribute was modified after the last sighting
-            $last_sighting_timestamp = $attribute['timestamp'];
+            if (!is_null($attribute['last_seen'])) {
+                $last_sighting_timestamp = (new DateTime($attribute['last_seen']))->format('U');
+            } else {
+                $last_sighting_timestamp = $attribute['timestamp'];
+            }
         }
         $timestamp = time();
         $scores = array(