From f97c153276af67ec17454c623f383fc4082d4ed8 Mon Sep 17 00:00:00 2001
From: Fatih AYDIN <fatih.aydin@tarfin.com>
Date: Fri, 22 Dec 2023 16:06:03 +0300
Subject: [PATCH] refactor: Updated `context` data

---
 src/Actor/Machine.php | 37 ++++++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 7 deletions(-)

diff --git a/src/Actor/Machine.php b/src/Actor/Machine.php
index c60297c..e146e6d 100644
--- a/src/Actor/Machine.php
+++ b/src/Actor/Machine.php
@@ -217,14 +217,37 @@ public function send(
      */
     public function persist(): ?State
     {
+        // Retrieve the previous context from the definition's config, or set it to an empty array if not set.
+        $incrementalContext = $this->definition->initializeContextFromState()->toArray();
+
+        // Get the last event from the state's history.
+        $lastHistoryEvent = $this->state->history->last();
+
         MachineEvent::upsert(
-            values: $this->state->history->map(fn (MachineEvent $machineEvent) => array_merge($machineEvent->toArray(), [
-                'created_at'    => $machineEvent->created_at->toDateTimeString(),
-                'machine_value' => json_encode($machineEvent->machine_value, JSON_THROW_ON_ERROR),
-                'payload'       => json_encode($machineEvent->payload, JSON_THROW_ON_ERROR),
-                'context'       => json_encode($machineEvent->context, JSON_THROW_ON_ERROR),
-                'meta'          => json_encode($machineEvent->meta, JSON_THROW_ON_ERROR),
-            ]))->toArray(),
+            values: $this->state->history->map(function (MachineEvent $machineEvent, int $index) use (&$incrementalContext, $lastHistoryEvent) {
+                // Get the context of the current machine event.
+                $changes = $machineEvent->context;
+
+                // If the current machine event is not the last one, compare its context with the incremental context and get the differences.
+                if ($machineEvent->id !== $lastHistoryEvent->id && $index > 0) {
+                    $changes = $this->arrayRecursiveDiff($changes, $incrementalContext);
+                }
+
+                // If there are changes, update the incremental context to the current event's context.
+                if (!empty($changes)) {
+                    $incrementalContext = $this->arrayRecursiveMerge($incrementalContext, $machineEvent->context);
+                }
+
+                $machineEvent->context = $changes;
+
+                return array_merge($machineEvent->toArray(), [
+                    'created_at'    => $machineEvent->created_at->toDateTimeString(),
+                    'machine_value' => json_encode($machineEvent->machine_value, JSON_THROW_ON_ERROR),
+                    'payload'       => json_encode($machineEvent->payload, JSON_THROW_ON_ERROR),
+                    'context'       => json_encode($machineEvent->context, JSON_THROW_ON_ERROR),
+                    'meta'          => json_encode($machineEvent->meta, JSON_THROW_ON_ERROR),
+                ]);
+            })->toArray(),
             uniqueBy: ['id']
         );