<?php
$handle = fopen('input.txt', 'r');
$lines = array();

while (($line = fgets($handle)) !== false) {
    $lines[] = $line;
}
fclose($handle);

sort($lines);

$start_minute = 0;
$guard_id = 0;
$guards = array();

foreach ($lines as $line) {
    if (stripos($line, 'guard') !== false) {
        preg_match('/.*?#(\d+).*?/', $line, $gn);
        $guard_id = (int)$gn[1];
    } elseif (stripos($line, 'fall') !== false) {
        preg_match('/.*?:(\d+)/', $line, $minutes);
        $start_minute = (int)$minutes[1];
    } elseif (stripos($line, 'wakes') !== false) {
        preg_match('/.*?:(\d+)/', $line, $minutes);
        $end_minute = (int)$minutes[1];

        if (!isset($guards[$guard_id])) {
            $guards[$guard_id] = array_fill(0, 60, 0);
        }

        $sleep = array_fill($start_minute, $end_minute - $start_minute, 1);
        $sleep += array_fill_keys(range(0, 59), 0);

        ksort($sleep);

        $guards[$guard_id] = array_map(function (...$arrays) {return array_sum($arrays);}, $guards[$guard_id], $sleep);
    }
}

//Part 1:

uasort($guards, function($a, $b){ return array_sum($a)>array_sum($b)?-1:1;});

$sleepiest_guard = array_keys($guards)[0];
$best_minute = array_search(max($guards[$sleepiest_guard]), $guards[$sleepiest_guard], true);

echo 'Part 1:' . PHP_EOL;
echo 'The sleepiest guard is #' . $sleepiest_guard . ', the minute he slept the most is ' . $best_minute . PHP_EOL;
echo 'The solution is: ' . ($sleepiest_guard * $best_minute) . PHP_EOL;
echo PHP_EOL;

//Part2:

uasort($guards, function($a, $b){ return max($a)>max($b)?-1:1;});

$sleepiest_guard = array_keys($guards)[0];
$best_minute = array_search(max($guards[$sleepiest_guard]), $guards[$sleepiest_guard], true);

echo 'Part 2:' . PHP_EOL;
echo 'The sleepiest guard is #' . $sleepiest_guard  . ' he slept the most in minute ' . $best_minute . PHP_EOL;
echo 'The solution is: ' . ($sleepiest_guard * $best_minute) . PHP_EOL;