<?php

error_reporting(-1);
mb_internal_encoding('utf-8');

$correctNumbers = [ 
	  '84951234567',  '+74951234567', '8-495-1-234-567', 
	  ' 8 (8122) 56-56-56', '8-911-1234567', '8 (911) 12 345 67', 
	  '8-911 12 345 67', '8 (911) - 123 - 45 - 67', '+ 7 999 123 4567', 
	  '8 ( 999 ) 1234567', '8 999 123 4567'
	];
	$incorrectNumbers = [
	  '02', '84951234567 позвать люсю', '849512345', '849512345678', 
	  '8 (409) 123-123-123', '7900123467', '5005005001', '8888-8888-88',
	  '84951a234567', '8495123456a', 
	  '+1 234 5678901', /* неверный код страны */
	  '+8 234 5678901', /* либо 8 либо +7 */
	  '7 234 5678901' /* нет + */
	];
function checkValidity($numbers) {
	$regex = '/^(\+\\s?7|\\s?8)(\s|\-|\(|\))*([0-9](\s|\-|\(|\))*){10}$/';
	//$regex2 = ([0-9](\s|\-|\(|\))*){10}
	foreach ($numbers as $number) {
		if (preg_match($regex, $number)) {
			echo "{$number} - is valid\n"; 
		}
		else {
			echo "{$number} - is invalid\n"; 
		}
	}
}

checkValidity($correctNumbers);
echo "_________________________________\n";
checkValidity($incorrectNumbers);