From 702cdd7fbde99839efbfab350f677c0e24d71ad2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rub=C3=A9n=20Robles?= <me@d8vjork.com>
Date: Mon, 25 Dec 2023 13:12:48 +0100
Subject: [PATCH] add `ByteUnitConverter::nearestUnit` method

---
 src/ByteUnitConverter.php       | 29 +++++++++++++++++++++++++++++
 tests/ByteUnitConverterTest.php | 29 +++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/src/ByteUnitConverter.php b/src/ByteUnitConverter.php
index 85aadca..b8e3db5 100644
--- a/src/ByteUnitConverter.php
+++ b/src/ByteUnitConverter.php
@@ -99,6 +99,35 @@ public function useUnitLabel(bool $value = true): self
         return $this;
     }
 
+    /**
+     * Assign nearest bytes unit by metric system from current bytes value.
+     */
+    public function nearestUnit(?MetricSystem $metric = MetricSystem::Decimal, ByteUnit $stoppingAt = null): self
+    {
+        $nearestUnit = null;
+        $byteUnits = ByteUnit::cases();
+        $i = 0;
+
+        while (! $nearestUnit && $i < count($byteUnits)) {
+            $unit = $byteUnits[$i];
+            $unitMetricSystem = $unit->getMetric();
+
+            $i++;
+
+            if (! $unitMetricSystem || $unitMetricSystem !== $metric) {
+                continue;
+            }
+
+            if ($unit === $stoppingAt || ($this->bytes - $unit->value) >= 0) {
+                $nearestUnit = $unit;
+            }
+        }
+
+        $this->unit = $nearestUnit ?? ByteUnit::B;
+
+        return $this;
+    }
+
     /**
      * Get conversion result numeric value.
      */
diff --git a/tests/ByteUnitConverterTest.php b/tests/ByteUnitConverterTest.php
index e23bc9d..e9e0920 100644
--- a/tests/ByteUnitConverterTest.php
+++ b/tests/ByteUnitConverterTest.php
@@ -6,6 +6,7 @@
 
 use OpenSoutheners\ByteUnitConverter\ByteUnit;
 use OpenSoutheners\ByteUnitConverter\ByteUnitConverter;
+use OpenSoutheners\ByteUnitConverter\MetricSystem;
 use PHPUnit\Framework\TestCase;
 
 enum MyOwnByteUnit: string
@@ -162,4 +163,32 @@ public function testConversionToBytesDoesNotGiveDecimals()
             (string) ByteUnitConverter::new('1000')
         );
     }
+
+    public function testConversionToNearestUnitPrintsConvertedByteUnitAndMetricSystem()
+    {
+        $this->assertEquals(
+            '1.00 KB',
+            (string) ByteUnitConverter::new('1000')->nearestUnit()
+        );
+
+        $this->assertEquals(
+            '1.02 KB',
+            (string) ByteUnitConverter::new('1024')->nearestUnit()
+        );
+
+        $this->assertEquals(
+            '1.00 KiB',
+            (string) ByteUnitConverter::new('1024')->nearestUnit(MetricSystem::Binary)
+        );
+
+        $this->assertEquals(
+            '1000 B',
+            (string) ByteUnitConverter::new('1000')->nearestUnit(MetricSystem::Binary)
+        );
+
+        $this->assertEquals(
+            '0.97 KiB',
+            (string) ByteUnitConverter::new('1000')->nearestUnit(MetricSystem::Binary, ByteUnit::KiB)
+        );
+    }
 }