<?php
class CPUInfo {
    public static function getCpuUsage($samples = 5) {
        $cmd = 'grep cpu /proc/stat';

        exec($cmd, $output1);
        $cpus1 = self::parseCpuStats($output1);

        $data = [];
        for ($i = 0; $i < $samples; $i++) {
            usleep(50000);
            $output2 = [];
            exec($cmd, $output2);
            $cpus2 = self::parseCpuStats($output2);

            foreach ($cpus1 as $cpu => $value) {
                if (!isset($data[$cpu])) $data[$cpu] = 0;

                $total = $cpus2[$cpu]['idle'] - $value['idle'] + $cpus2[$cpu]['work'] - $value['work'];
                $data[$cpu] += ($cpus2[$cpu]['work'] - $value['work']) / $total;
            }
            $cpus1 = $cpus2;
        }

        foreach ($data as $cpu => $value) {
            $data[$cpu] = $data[$cpu] / $samples * 100;
        }


        var_dump($data);

    }

    public static function parseCpuStats($stat_cpuinfo) {
        $cpus = [];
        $first = true;
        foreach ($stat_cpuinfo as $line) {
            $line = preg_replace('!\s+!', ' ', $line);
            $parts = explode(' ', $line);
            $cpu = $parts[0];

            unset($parts[0]);

            $line = implode(' ', $parts);

            sscanf($line,
                "%D %D %D %D %D %D %D %D %D %D",
                $user, $nice, $system, $idle, $iowait, $irq, $softirq, $steal, $guest, $guestnice
            );

            if ($first) {
                $cpus['ALL'] = [
                    'work' => $user + $nice + $system + $irq + $softirq + $steal,
                    'idle' => $idle + $iowait
                ];
            }
            else {
                $cpus[$cpu] = [
                    'work' => $user + $nice + $system + $irq + $softirq + $steal,
                    'idle' => $idle + $iowait
                ];
            }
            $first = false;
        }

        return $cpus;
    }

    public static function getRamUsage() {
        $free = trim(shell_exec('free'));
//        $free = (string)trim($free);
        $free_arr = explode("\n", $free);

        $ret = [
            'hard' => [
                'total' => 0,
                'used' => 0,
                'percent' => 0,
            ],
            'swap' => [
                'total' => 0,
                'used' => 0,
                'percent' => 0,
            ]
        ];
        foreach ($free_arr as $line) {
            if (!preg_match('/(Mem|Swap).*/', $line)) continue;
            $mem_line = explode(" ", $line);
            $mem_clean = array_merge(array_filter($mem_line));

            $memory_usage = $mem_clean[2]/$mem_clean[1]*100;

            if (preg_match('/Mem/', $line)) {
                $ret['hard']['percent'] = $memory_usage;
                $ret['hard']['total'] = (int)$mem_clean[2];
                $ret['hard']['used'] = (int)$mem_clean[1];
            }
            if (preg_match('/Swap/', $line)) {
                $ret['swap']['percent'] = $memory_usage;
                $ret['swap']['total'] = (int)$mem_clean[2];
                $ret['swap']['used'] = (int)$mem_clean[1];
            }
        }

        return $ret;
    }
}