PasswordGenerator.php

<?php

class PasswordGenerator {
	var $pwdMinLength = 12;
	var $pwdMaxLength = 20;
	var $pwdMap = [
		[
			'chars' => 'abcdefghijklmnopqrstuvwxyz',
			'weight' => 30,
		],
		[
			'chars' => 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
			'weight' => 30,
		],
		[
			'chars' => '0123456789',
			'weight' => 30,
		],
		[
			'chars' => ',._-+',
			'weight' => 10,
		],
	];

	var $pwdMapSets = [];
	var $pwdMapWeights = [];
	var $pwdMapTotalWeight = 0;

	function __construct() {
		$prevWeight = 0;
		foreach ($this->pwdMap as $pwdMap){
			$this->pwdMapSets[] = str_split($pwdMap['chars']);
			$weight = $pwdMap['weight'];
			$this->pwdMapWeights[] = [$prevWeight, $prevWeight + $weight-1];
			$prevWeight += $weight;
		}
		$this->pwdMapTotalWeight = $prevWeight;
	}

	public function generatePassword($minLength = -1, $maxLength = -1){
		if ($minLength<0) $minLength = $this->pwdMinLength;
		if ($maxLength<0) $maxLength = $this->pwdMaxLength;

		$original_bytes = str_split(random_bytes(random_int($minLength, $maxLength)));

		$mapSelector = function(): int{
			$selection = random_int(0, $this->pwdMapTotalWeight);

			foreach ($this->pwdMapWeights as $index => $weights){
				if (($selection >= $weights[0]) && ($selection <= $weights[1])){
					return $index;
				}
			}
			return 0;
		};

		$pwd = array_map(function($n) use ($mapSelector) {
			$charIndex = ord($n);
			$currentMap = $this->pwdMapSets[$mapSelector()];
			$index = $charIndex % count($currentMap);
			return $currentMap[$index];
		}, $original_bytes);

		return implode($pwd);
	}
}