From 364cda772e64bee7d546af32e26c62139e2a72a8 Mon Sep 17 00:00:00 2001
From: Jay Knight <jay.knight@stjude.org>
Date: Fri, 6 Dec 2024 11:23:24 -0600
Subject: [PATCH] Function to reindex all segments in a message

---
 src/HL7/Message.php   | 20 ++++++++++++++++++++
 tests/MessageTest.php | 28 ++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/src/HL7/Message.php b/src/HL7/Message.php
index ee41ccf..950407f 100644
--- a/src/HL7/Message.php
+++ b/src/HL7/Message.php
@@ -5,6 +5,7 @@
 namespace Aranyasen\HL7;
 
 use Aranyasen\Exceptions\HL7Exception;
+use Aranyasen\HL7\Segments\MSH;
 use InvalidArgumentException;
 
 /**
@@ -325,6 +326,25 @@ public function getSegments(): array
         return $this->segments;
     }
 
+    /**
+     * Reindex all of the segments in the message
+     */
+    public function reindexSegments(): void
+    {
+        $indexes = [];
+        foreach ($this->segments as $segment) {
+            if (is_a($segment, MSH::class)) {
+                continue;
+            }
+
+            if (!array_key_exists(get_class($segment), $indexes)) {
+                $indexes[get_class($segment)] = 1;
+            }
+
+            $segment->setId($indexes[get_class($segment)]++);
+        }
+    }
+
     /**
      * Return a string representation of this message.
      *
diff --git a/tests/MessageTest.php b/tests/MessageTest.php
index cfcfbfd..754f58f 100644
--- a/tests/MessageTest.php
+++ b/tests/MessageTest.php
@@ -635,4 +635,32 @@ public function segments_can_be_retrieved_by_class(): void
         $OBRs = $message->getSegmentsByClass(OBR::class);
         self::assertCount(0, $OBRs);
     }
+
+    /** @test */
+    public function reindex_message_segments(): void
+    {
+        $message = new Message(autoIncrementIndices: false);
+        $pid = new PID();
+        $pid->setId(2);
+        $message->addSegment($pid);
+
+        $obx1 = new OBX();
+        $obx1->setId(3);
+        $obx1->setValueType("ST");
+        $message->addSegment($obx1);
+
+        $obx2 = new OBX();
+        $obx2->setId(1);
+        $obx2->setValueType("CWE");
+        $message->addSegment($obx2);
+
+        $message->reindexSegments();
+        $PIDs = $message->getSegmentsByClass(PID::class);
+        self::assertSame(1, $PIDs[0]->getId());
+        $OBXs = $message->getSegmentsByClass(OBX::class);
+        self::assertSame(1, $OBXs[0]->getId());
+        self::assertSame("ST", $OBXs[0]->getValueType());
+        self::assertSame(2, $OBXs[1]->getId());
+        self::assertSame("CWE", $OBXs[1]->getValueType());
+    }
 }