media-matches.php

<?php
function matches($media, $screen = [])
{
    if (strpos($media, ',') !== false)
        $mql = explode(',', $media);
    else
        $mql = [$media];

    $mqIndex = count($mql) - 1;
    $mqLength = $mqIndex;
    $mq = null;

    $exprList = null;
    $expr = null;
    $match = true;

    if ($media == '')
        return true;

    do {
        $mq = $mql[$mqLength - $mqIndex];
        $exprListStr = $mq;

        if (strpos($exprListStr, ' and ') !== false)
            $exprList = explode(' and ', $exprListStr);
        else
            $exprList = [$exprListStr];

        $exprIndex = count($exprList) - 1;

        if ($match && $exprIndex >= 0 && $exprListStr !== '') {
            do {
                preg_match('/^\s*\(\s*(-[a-z]+-)?(min-|max-)?([a-z\-]+)\s*(:?\s*([0-9]+(\.[0-9]+)?|portrait|landscape)(px|em|dppx|dpcm|rem|%|in|cm|mm|ex|pt|pc|\/([0-9]+(\.[0-9]+)?))?)?\s*\)\s*$/', $exprList[$exprIndex], $expr);

                if (empty($expr) || empty($screen[$expr[3]])) {
                    $match = false;
                    break;
                }

                $prefix = $expr[2];
                $length = $expr[5];
                $value = $length;
                $unit = $expr[7];
                $feature = $screen[$expr[3]];

//                echo 'prefix =' . $prefix . PHP_EOL;
//                echo 'value = ' . $value . PHP_EOL;
//                echo 'unit = ' . $unit . PHP_EOL;
//                echo 'feature = ' . $feature . PHP_EOL;


                if ($unit && $unit === 'px')
                    $value = $length;

                // Test for prefix min or max
                // Test value against feature
                if ($prefix === 'min-' && $value) {
                    $match = $feature >= $value;
                } else if ($prefix === 'max-' && $value) {
                    $match = $feature <= $value;
                } else if ($value) {
                    $match = $feature === $value;
                } else {
                    $match = !!$feature;
                }

                // If 'match' is false, break loop
                // Continue main loop through query list
                if (!$match) {
                    break;
                }
            } while ($exprIndex--);
        }

        // If match is true, break loop
        // Once matched, no need to check other queries
        if ($match) {
            break;
        }
    } while ($mqIndex--);

    return $match;
}

if (matches('', ['width'=>767]) === true)
    echo '1. Ok' . PHP_EOL;
if (matches('(max-width: 767px)', ['width'=>767]) === true)
    echo '2. Ok' . PHP_EOL;
if (matches('(max-width: 400px)', ['width'=>767]) === false)
    echo '3. Ok' . PHP_EOL;
if (matches('(min-width: 767px)', ['width'=>767]) === true)
    echo '4. Ok' . PHP_EOL;
if (matches('(min-width: 768px)', ['width'=>767]) === false)
    echo '5. Ok' . PHP_EOL;