Added normalizer to help with concentrates and stones

src/Helper/Normalizer.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace NoccyLabs\Juicer\Helper;
+
+/**
+ * Normalize percentages to a full 100%.
+ *
+ */
+class Normalizer
+{
+
+    protected $inputs = [];
+
+    protected $ratio = 0;
+
+    /**
+     * Normalizer constructor.
+     *
+     * @param array The percentages indexed by a unique key
+     */
+    public function __construct(array $inputPercents=[])
+    {
+        foreach ($inputPercents as $k=>$p)
+            $this->setPart($k, $p);
+    }
+
+    /**
+     * Set the percentage of a component.
+     *
+     * @param mixed The key used to access this part later
+     * @param float The percent of this part
+     */
+    public function setPart($key, float $percent)
+    {
+        $this->inputs[$key] = $percent;
+        $total = array_sum(array_values($this->inputs));
+        $this->ratio = 100 / $total;
+    }
+
+    /**
+     * Get the original percentage of the key.
+     *
+     * @param mixed The key
+     * @return float Original percentage as provided
+     */
+    public function getPercent($key)
+    {
+        if (!array_key_exists($key, $this->inputs))
+            throw new \Exception();
+
+        return floatval($this->inputs[$key]);
+    }
+
+    /**
+     * Get the normalized percentage where the added total equals 100%
+     *
+     * @param mixed The key
+     * @return float Normalized percentage as provided
+     */
+    public function getNormalizedPercent($key)
+    {
+        if (!array_key_exists($key, $this->inputs))
+            throw new \Exception();
+
+        return floatval($this->inputs[$key]) * $this->ratio;
+    }
+
+}

tests/Helper/NormalizerTest.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace NoccyLabs\Juicer\Helper;
+
+
+class NormalizerTest extends \PhpUnit\Framework\TestCase
+{
+
+    public function testThatNormalizedPercentagesAreSane()
+    {
+        $normalizer = new Normalizer([
+            'A' => 10
+        ]);
+
+        $this->assertEquals(10, $normalizer->getPercent("A"));
+        $this->assertEquals(100, $normalizer->getNormalizedPercent("A"));
+
+        $normalizer = new Normalizer([
+            'A' => 10,
+            'B' => 10,
+        ]);
+
+        $this->assertEquals(10, $normalizer->getPercent("A"));
+        $this->assertEquals(50, $normalizer->getNormalizedPercent("A"));
+        $this->assertEquals(10, $normalizer->getPercent("B"));
+        $this->assertEquals(50, $normalizer->getNormalizedPercent("B"));
+
+        $normalizer = new Normalizer([
+            'A' => 2,
+            'B' => 8,
+        ]);
+
+        $this->assertEquals(20, $normalizer->getNormalizedPercent("A"));
+        $this->assertEquals(80, $normalizer->getNormalizedPercent("B"));
+
+    }
+}