fluent-booking / vendor / wpfluent / framework / src / WPFluent / Randomizer / Randomizer.php

Randomizer.php in Fluent Booking – The Ultimate Appointments Scheduling, Events Booking, Events Calendar Solution trunk, at vendor/wpfluent/framework/src/WPFluent/Randomizer/Randomizer.php

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1	<?php
2
3	namespace FluentBooking\Framework\Randomizer;
4
5	use Exception;
6	use FluentBooking\Framework\Support\InvalidArgumentException;
7
8	/**
9	* An implementation of the Randomizer class.
10	* @see https://www.php.net/manual/en/class.random-randomizer.php
11	*/
12	if (class_exists('Random\Randomizer')) {
13	/**
14	* Wrapper around the native PHP 8.2+ Random\Randomizer.
15	*
16	* @method string getBytes(int $length)
17	* @method int getInt(int $min, int $max)
18	* @method float getFloat(float $min, float $max)
19	* @method int nextInt()
20	* @method float nextFloat()
21	* @method array pickArrayKeys(array $array, int $num)
22	* @method array shuffleArray(array $array)
23	* @method string shuffleBytes(string $string)
24	*/
25	final class Randomizer
26	{
27	use GetStringTrait;
28
29	private $randomizer;
30
31	public function __construct()
32	{
33	// @phpstan-ignore-next-line
34	$this->randomizer = new \Random\Randomizer();
35	}
36
37	public function getBytesFromString(string $string, int $length): string
38	{
39	return $this->randomizer->getBytesFromString($string, $length);
40	}
41
42	public function __call($method, $args = [])
43	{
44	return $this->randomizer->{$method}(...$args);
45	}
46	}
47	} else {
48	final class Randomizer
49	{
50	use GetStringTrait;
51
52	private $engine;
53
54	public function __construct()
55	{
56	$this->engine = $this->makeEngine();
57	}
58
59	public function getBytes(int $length)
60	{
61	$result = '';
62
63	while (strlen($result) < $length) {
64	$result .= $this->engine->generate();
65	}
66
67	return substr($result, 0, $length);
68	}
69
70	public function getBytesFromString(string $string, int $length)
71	{
72	if ($length === 0) {
73	throw new InvalidArgumentException('Length cannot be zero.');
74	}
75
76	$sourceLength = strlen($string);
77
78	if ($sourceLength === 0) {
79	throw new InvalidArgumentException(
80	'Source string cannot be empty.'
81	);
82	}
83
84	$result = [];
85
86	for ($i = 0; $i < $length; $i++) {
87	$index = $this->getInt(0, $sourceLength - 1);
88	$result[] = $string[$index];
89	}
90
91	return implode('', $result);
92	}
93
94	public function getFloat(float $min, float $max)
95	{
96	// Match native Random\Randomizer::getFloat — allow $min == $max
97	// (returns $min); only reject $min > $max.
98	if ($min > $max) {
99	$this->throwInvalidRange(
100	'Argument #1 ($min) must be less than or equal to argument #2 ($max).'
101	);
102	}
103
104	// When $min == $max, the formula naturally returns $min
105	// (anything * 0 == 0), so no special case needed.
106	return $min + ($this->nextFloat() * ($max - $min));
107	}
108
109	public function getInt(int $min, int $max)
110	{
111	// Match native Random\Randomizer::getInt — throw on $min > $max
112	// and delegate to random_int (which already handles the range
113	// correctly, rejection-sampled, no manual offset arithmetic).
114	if ($min > $max) {
115	$this->throwInvalidRange(
116	'Argument #1 ($min) must be less than or equal to argument #2 ($max).'
117	);
118	}
119
120	return random_int($min, $max);
121	}
122
123	/**
124	* Throw the same exception type the native Random\Randomizer would
125	* throw on bad range input. \ValueError landed in PHP 8.0; on older
126	* runtimes fall back to InvalidArgumentException so we always raise
127	* something meaningful.
128	*/
129	private function throwInvalidRange(string $message)
130	{
131	if (class_exists('ValueError', false)) {
132	throw new \ValueError($message);
133	}
134
135	throw new InvalidArgumentException($message);
136	}
137
138	public function nextFloat()
139	{
140	return random_int(0, PHP_INT_MAX) / (PHP_INT_MAX + 1);
141	}
142
143	public function nextInt()
144	{
145	return random_int(0, PHP_INT_MAX);
146	}
147
148	public function pickArrayKeys(array $array, int $num)
149	{
150	$count = count($array);
151
152	if ($num < 1 \|\| $num > $count) {
153	throw new InvalidArgumentException(
154	'Argument #2 ($num) must be between 1 and the number of elements in argument #1 ($array).'
155	);
156	}
157
158	// Match native Random\Randomizer::pickArrayKeys — picked keys
159	// are returned in their ORIGINAL position order in the array,
160	// not in pick order. Strategy: build an index list, partial
161	// Fisher-Yates to select $num indices, then sort those indices
162	// and map back to keys. Runs in O(n) time.
163	$keys = array_keys($array);
164	$indices = range(0, $count - 1);
165
166	// Partial Fisher-Yates: only shuffle the first $num positions.
167	for ($i = 0; $i < $num; $i++) {
168	$j = random_int($i, $count - 1);
169	[$indices[$i], $indices[$j]] = [$indices[$j], $indices[$i]];
170	}
171
172	// Take the picked indices, sort to restore original order.
173	$picked = array_slice($indices, 0, $num);
174	sort($picked);
175
176	return array_map(static function ($i) use ($keys) {
177	return $keys[$i];
178	}, $picked);
179	}
180
181	public function shuffleArray(array $array)
182	{
183	$count = count($array);
184
185	if ($count < 2) {
186	return $array;
187	}
188
189	// Match native Random\Randomizer::shuffleArray — a single
190	// unbiased Fisher-Yates pass. Do NOT loop until the result
191	// differs from the input; that biases the distribution and
192	// can infinite-loop on tiny arrays. A fair shuffle MUST be
193	// allowed to occasionally produce the original order.
194	for ($i = $count - 1; $i > 0; $i--) {
195	$j = random_int(0, $i);
196	[$array[$i], $array[$j]] = [$array[$j], $array[$i]];
197	}
198
199	return $array;
200	}
201
202	public function shuffleBytes(string $bytes)
203	{
204	$array = str_split($bytes);
205	$shuffled = $this->shuffleArray($array);
206	return implode('', $shuffled);
207	}
208
209	private function makeEngine()
210	{
211	return new class {
212	public function generate() {
213	$length = 32;
214
215	if (function_exists('random_bytes')) {
216	return random_bytes($length);
217	}
218
219	if (function_exists('openssl_random_pseudo_bytes')) {
220	return openssl_random_pseudo_bytes($length);
221	}
222
223	throw new Exception('No secure random source available.');
224	}
225	};
226	}
227	}
228	}
229