<?php
// System stats endpoint — reads /proc directly, no shell injection risk

function getCpuUsage(): float {
    $s1 = file('/proc/stat')[0];
    preg_match('/cpu\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/', $s1, $m1);
    usleep(200000);
    $s2 = file('/proc/stat')[0];
    preg_match('/cpu\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/', $s2, $m2);
    $idle1  = $m1[4] + $m1[5];
    $total1 = array_sum(array_slice($m1, 1));
    $idle2  = $m2[4] + $m2[5];
    $total2 = array_sum(array_slice($m2, 1));
    $dTotal = $total2 - $total1;
    $dIdle  = $idle2  - $idle1;
    return $dTotal > 0 ? round((($dTotal - $dIdle) / $dTotal) * 100, 1) : 0.0;
}

function getMemory(): array {
    $lines = file('/proc/meminfo');
    $mem = [];
    foreach ($lines as $l) {
        if (preg_match('/^(\w+):\s+(\d+)/', $l, $m)) $mem[$m[1]] = (int)$m[2];
    }
    $total     = $mem['MemTotal']     ?? 0;
    $available = $mem['MemAvailable'] ?? 0;
    $used      = $total - $available;
    return [
        'total_mb' => round($total / 1024),
        'used_mb'  => round($used  / 1024),
        'free_mb'  => round($available / 1024),
        'percent'  => $total > 0 ? round(($used / $total) * 100, 1) : 0,
    ];
}

function getDisk(): array {
    $disks = [];
    foreach (disk_total_space('/') as $dummy) break; // warm up
    $total = disk_total_space('/');
    $free  = disk_free_space('/');
    $used  = $total - $free;
    return [
        'total_gb' => round($total / 1073741824, 1),
        'used_gb'  => round($used  / 1073741824, 1),
        'free_gb'  => round($free  / 1073741824, 1),
        'percent'  => $total > 0 ? round(($used / $total) * 100, 1) : 0,
    ];
}

function getDisk2(): array {
    $total = disk_total_space('/');
    $free  = disk_free_space('/');
    $used  = $total - $free;
    return [
        'total_gb' => round($total / 1073741824, 1),
        'used_gb'  => round($used  / 1073741824, 1),
        'free_gb'  => round($free  / 1073741824, 1),
        'percent'  => $total > 0 ? round(($used / $total) * 100, 1) : 0,
    ];
}

function getUptime(): string {
    $secs = (int)file_get_contents('/proc/uptime');
    $d = intdiv($secs, 86400); $h = intdiv($secs % 86400, 3600);
    $m = intdiv($secs % 3600,  60);
    return "{$d}d {$h}h {$m}m";
}

function getLoadAvg(): array {
    $l = explode(' ', file_get_contents('/proc/loadavg'));
    return ['1m' => (float)$l[0], '5m' => (float)$l[1], '15m' => (float)$l[2]];
}

function getNetworkIO(): array {
    $lines = file('/proc/net/dev');
    $ifaces = [];
    foreach ($lines as $line) {
        if (strpos($line, ':') === false) continue;
        [$name, $stats] = explode(':', $line, 2);
        $name = trim($name);
        if ($name === 'lo') continue;
        $vals = preg_split('/\s+/', trim($stats));
        $ifaces[$name] = [
            'rx_mb' => round($vals[0] / 1048576, 2),
            'tx_mb' => round($vals[8] / 1048576, 2),
        ];
    }
    return $ifaces;
}

function getServices(): array {
    $services = ['apache2', 'mysql'];
    $result = [];
    foreach ($services as $svc) {
        $out = shell_exec('systemctl is-active ' . escapeshellarg($svc) . ' 2>/dev/null');
        $result[$svc] = trim($out ?? '') === 'active';
    }
    return $result;
}

function getTopProcesses(): array {
    $out = shell_exec("ps aux --sort=-%cpu | awk 'NR>1 && NR<=6 {print $11\",\"$3\",\"$4}' 2>/dev/null");
    $procs = [];
    foreach (explode("\n", trim($out ?? '')) as $line) {
        if (!$line) continue;
        [$cmd, $cpu, $mem] = explode(',', $line, 3);
        $procs[] = ['cmd' => basename($cmd), 'cpu' => (float)$cpu, 'mem' => (float)$mem];
    }
    return $procs;
}

$cpu    = getCpuUsage();
$memory = getMemory();
$disk   = getDisk2();

$stats = [
    'cpu'        => $cpu,
    'memory'     => $memory,
    'disk'       => $disk,
    'uptime'     => getUptime(),
    'load'       => getLoadAvg(),
    'network_io' => getNetworkIO(),
    'services'   => getServices(),
    'processes'  => getTopProcesses(),
    'hostname'   => gethostname(),
    'ip'         => JARVIS_IP,
    'timestamp'  => date('c'),
];

// Log to history
JarvisDB::execute(
    'INSERT INTO metrics_history (metric_name, metric_value, host) VALUES (?,?,?),(?,?,?),(?,?,?)',
    ['cpu', $cpu, 'jarvis', 'memory', $memory['percent'], 'jarvis', 'disk', $disk['percent'], 'jarvis']
);

echo json_encode($stats);