/**
* Generate a set of random codes based on Paggern pattern.
* Codes are guaranteed to be unique within the set.
*
* @param string $pattern Paggern pattern.
* @param int $amount Number of codes to generate.
* @param int $safeguard Number of additional codes generated in case there are duplicates that need to be replaced.
* @return array
*/
public function generateFromPattern($pattern, $amount = 1, $safeguard = 100)
{
$lexer = new \Gajus\Paggern\Lexer();
$tokens = $lexer->tokenise($pattern, true);
$codes = array_fill(0, $amount + $safeguard, '');
foreach ($tokens as &$token) {
if ($token['type'] !== 'literal') {
// Use RandomLib\Generator to populate token pool with random characters matching the pattern.
// Pool is pre-generated for each token use. This is done to reduce the number of generator invocations.
$token['pool'] = $this->generator->generateString($token['repetition'] * ($amount + $safeguard), $token['haystack']);
}
unset($token);
}
// Itterate through each code appending the value derived from the token.
// In case of the range or class token, offset the value from the pre-generated pattern matching pool.
foreach ($codes as $i => &$code) {
foreach ($tokens as $token) {
if ($token['type'] === 'literal') {
$code .= $token['string'];
} else {
$code .= mb_substr($token['pool'], $token['repetition'] * $i, $token['repetition']);
}
}
unset($code);
}
$codes = array_slice(array_unique($codes), 0, $amount);
if (count($codes) < $amount) {
throw new Exception\RuntimeException('Unique combination pool exhausted.');
}
return $codes;
}
public function testCombined()
{
$lexer = new \Gajus\Paggern\Lexer();
$tokens = $lexer->tokenise('abc[a-z]{2}[0-9]\\U\\U{3}');
$this->assertCount(5, $tokens);
$this->assertSame(['type' => 'literal', 'string' => 'abc'], $tokens[0]);
$this->assertSame(['type' => 'range', 'token' => 'a-z', 'repetition' => 2], $tokens[1]);
$this->assertSame(['type' => 'range', 'token' => '0-9', 'repetition' => 1], $tokens[2]);
$this->assertSame(['type' => 'class', 'class' => \Gajus\Paggern\Lexer::CLASS_UPPERCASE_UNAMBIGUOUS, 'repetition' => 1], $tokens[3]);
$this->assertSame(['type' => 'class', 'class' => \Gajus\Paggern\Lexer::CLASS_UPPERCASE_UNAMBIGUOUS, 'repetition' => 3], $tokens[4]);
}
