From 0cadd9af2424cd0db2ca8e34211a1e4a27dd0dd1 Mon Sep 17 00:00:00 2001
From: Nepster <nepsterxxx@mail.ru>
Date: Wed, 20 Oct 2021 16:37:48 +0300
Subject: [PATCH] add doc ShiftedNumber

---
 docs/guide/ShiftedNumber.md | 11 +++++--
 src/ShiftedNumber.php       | 44 +++++++++++++++++--------
 tests/ShiftedNumberTest.php | 66 +++++++++++++++++++++++++++++++++++++
 3 files changed, 105 insertions(+), 16 deletions(-)
 create mode 100644 tests/ShiftedNumberTest.php

diff --git a/docs/guide/ShiftedNumber.md b/docs/guide/ShiftedNumber.md
index 557830d..d60fd30 100644
--- a/docs/guide/ShiftedNumber.md
+++ b/docs/guide/ShiftedNumber.md
@@ -1,11 +1,16 @@
 Shifted number
 ==============
 
-------------------
+Shifts the specified number using a hash.
 
+**Example:**
 
-----
-
+```php
+$number = ((new ShiftedNumber())
+    ->setMin(0)
+    ->setMax(100))
+    (42, 'my_hash');
+```
 
 <br>
 
diff --git a/src/ShiftedNumber.php b/src/ShiftedNumber.php
index 2cfad8d..9f6faa3 100644
--- a/src/ShiftedNumber.php
+++ b/src/ShiftedNumber.php
@@ -4,14 +4,17 @@
 
 namespace Gambling\Tech;
 
+use ErrorException;
+use Exception;
+
 /**
  * Base value shifting by hash
  */
 class ShiftedNumber
 {
-    private float $min = 0;
+    private int $min = 0;
 
-    private float $max = 100;
+    private int $max = 100;
 
     /**
      * @param float $number
@@ -22,14 +25,14 @@ public function __invoke(float $number, string $hash): int
     {
         $shiftValue = $this->getShiftValue($hash);
 
-        return $this->shift($number, $shiftValue);
+        return (int)$this->shift($number, $shiftValue);
     }
 
     /**
-     * @param float $min
+     * @param int $min
      * @return $this
      */
-    public function setMin(float $min): self
+    public function setMin(int $min): self
     {
         $this->min = $min;
 
@@ -37,10 +40,10 @@ public function setMin(float $min): self
     }
 
     /**
-     * @param float $max
+     * @param int $max
      * @return $this
      */
-    public function setMax(float $max): self
+    public function setMax(int $max): self
     {
         $this->max = $max;
 
@@ -50,25 +53,40 @@ public function setMax(float $max): self
     /**
      * @param float $number
      * @param int $shift
-     * @return int
+     * @return float
      */
-    protected function shift(float $number, int $shift): int
+    protected function shift(float $number, int $shift): float
     {
         if ($shift > $this->max) {
             $shift %= ($this->max - $this->min + 1);
         }
 
-        return $number + $shift <= $this->max ?
+        $shift = $shift === 0 ? (int)(7 / 100 * $this->max) : $shift;
+
+        $result = $number + $shift <= $this->max ?
             $number + $shift :
             $this->min + ($number + $shift - $this->max) - 1;
+
+        if ($result < $this->min || $result > $this->max) {
+            $float = round(($this->min / ($this->max + 1)) + M_PI, 5);
+            $percent = (int)mb_substr((string)$float, -2, 2);
+            $result = ($this->min === 0 ? $this->max / 2 : $this->min) + ($percent / 100 * $this->min);
+            $result = $result > $this->max ? $this->max : $result;
+        }
+
+        return $result;
     }
 
     /**
-     * @param string $clientHash
+     * @param string $hash
      * @return int
      */
-    protected function getShiftValue(string $clientHash): int
+    protected function getShiftValue(string $hash): int
     {
-        return (int)hexdec(substr($clientHash, -5));
+        if (preg_match("/^([a-f0-9])$/", $hash) === 0) {
+            $hash = sha1($hash);
+        }
+
+        return (int)hexdec(mb_substr($hash, -5));
     }
 }
diff --git a/tests/ShiftedNumberTest.php b/tests/ShiftedNumberTest.php
new file mode 100644
index 0000000..13e99dd
--- /dev/null
+++ b/tests/ShiftedNumberTest.php
@@ -0,0 +1,66 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Gambling\TechTest;
+
+use Gambling\Tech\ShiftedNumber;
+use PHPUnit\Framework\TestCase;
+
+class ShiftedNumberTest extends TestCase
+{
+    public function testShiftedNumber(): void
+    {
+        $hash = sha1('hash');
+        $number = (new ShiftedNumber())(7, $hash);
+
+        self::assertNotEquals(7, $number);
+    }
+
+    public function testReproduceShiftedNumber(): void
+    {
+        $hash = sha1('hash');
+        $number = (new ShiftedNumber())(7, $hash);
+
+        self::assertEquals(1, $number);
+    }
+
+    public function testMinLimit(): void
+    {
+        $min = 100;
+        $pinpoint = false;
+
+        for ($i = 0; $i < 100; ++$i) {
+            $number = ((new ShiftedNumber())
+                ->setMin($min)->setMax(1000))($i, sha1(uniqid('', true)));
+            if ($min > $number) { echo $number . ' ';
+                $pinpoint = true;
+            }
+        }
+
+        self::assertFalse($pinpoint);
+    }
+
+    public function testMaxLimit(): void
+    {
+        $max = 1000;
+        $pinpoint = false;
+
+        for ($i = 0; $i < 100; ++$i) {
+            $number = ((new ShiftedNumber())
+                ->setMin(100)->setMax($max))($i, sha1(uniqid('', true)));
+            if ($number > $max) {
+                $pinpoint = true;
+            }
+        }
+
+        self::assertFalse($pinpoint);
+    }
+
+    public function testShiftedNumberByRandomString(): void
+    {
+        $number = (new ShiftedNumber())(7, 'my_random_string');
+
+        self::assertNotEquals(7, $number);
+    }
+}