<?php

header('Content-Type: application/json');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST'); 
header("Access-Control-Allow-Headers: X-Requested-With");
echo json_encode(getSystemInfo());

// Main function to get all system info
function getSystemInfo() {
    return [
        "cpu" => getCpuInfo(),
        "memory" => getMemoryInfo(),
        "storage" => getStorageInfo(),
    ];
}

// Get CPU load and history
function getCpuInfo() {
    $os = getOS();
    $load = [];

    if ($os === 'Windows') {
        // Windows: Use WMIC for CPU load
        $output = shell_exec("wmic cpu get loadpercentage");
        preg_match_all('/\d+/', $output, $matches);
        $load = array_map('floatval', $matches[0]);
    } else {
        // Linux and macOS: Use sys_getloadavg
        $load = sys_getloadavg();
    }

    return [
        "load" => isset($load[0]) ? number_format($load[0], 2) . " %" : "N/A",
        "history" => array_map(function($value) {
            return number_format($value, 2);
        }, $load)
    ];
}

// Get memory usage
function getMemoryInfo() {
    $os = getOS();

    if ($os === 'Windows') {
        // Windows: Use WMIC for memory stats
        $totalMemory = shell_exec("wmic os get totalvisiblememorysize /value");
        $freeMemory = shell_exec("wmic os get freephysicalmemory /value");

        preg_match('/\d+/', $totalMemory, $totalMatch);
        preg_match('/\d+/', $freeMemory, $freeMatch);

        $totalMemoryKB = isset($totalMatch[0]) ? intval($totalMatch[0]) : 0;
        $freeMemoryKB = isset($freeMatch[0]) ? intval($freeMatch[0]) : 0;

    } else {
        // Linux and macOS: Use /proc/meminfo or vm_stat
        if ($os === 'Linux') {
            $totalMemory = shell_exec("grep MemTotal /proc/meminfo | awk '{print $2}'") * 1024;
            $freeMemory = shell_exec("grep MemAvailable /proc/meminfo | awk '{print $2}'") * 1024;
        } else {
            // macOS: Use vm_stat for memory stats
            $totalMemory = shell_exec("sysctl hw.memsize | awk '{print $2}'");
            $freeMemory = shell_exec("vm_stat | grep 'free' | awk '{print $3}' | sed 's/\\.$//'");
            $freeMemory = $freeMemory * 4096; // Convert to bytes
        }

        $totalMemoryKB = intval($totalMemory) / 1024;
        $freeMemoryKB = intval($freeMemory) / 1024;
    }

    $totalMemoryGB = $totalMemoryKB / 1024 / 1024; // Convert to GB
    $freeMemoryGB = $freeMemoryKB / 1024 / 1024;   // Convert to GB
    $usedMemoryGB = $totalMemoryGB - $freeMemoryGB;

    $usagePercentage = $totalMemoryGB > 0 ? ($usedMemoryGB / $totalMemoryGB) * 100 : 0;

    return [
        "total" => number_format($totalMemoryGB, 2) . " GB",
        "used" => number_format($usedMemoryGB, 2) . " GB",
        "usage" => number_format($usagePercentage, 2) . " %"
    ];
}

// Get storage info
function getStorageInfo() {
    $os = getOS();
    $output = [];

    if ($os === 'Windows') {
        // Windows: Use WMIC for disk stats
        $rawOutput = shell_exec("wmic logicaldisk get name, size, freespace");
        $lines = array_slice(explode("\n", $rawOutput), 1);
        foreach ($lines as $line) {
            $columns = preg_split('/\s+/', trim($line));
            if (count($columns) === 3) {
                $filesystem = $columns[0];
                $size = intval($columns[1]) / 1024 / 1024 / 1024; // Convert to GB
                $free = intval($columns[2]) / 1024 / 1024 / 1024; // Convert to GB
                $used = $size - $free;
                $usage = $size > 0 ? ($used / $size) * 100 : 0;

                $output[] = [
                    "filesystem" => $filesystem,
                    "size" => number_format($size, 2) . " GB",
                    "used" => number_format($used, 2) . " GB",
                    "usage" => number_format($usage, 2) . " %"
                ];
            }
        }
    } else {
        // Linux and macOS: Use df command
        $rawOutput = shell_exec("df -h --output=source,size,used,pcent | grep -v 'tmpfs' | grep -v 'Filesystem'");
        $lines = explode("\n", trim($rawOutput));
        foreach ($lines as $line) {
            $columns = preg_split('/\s+/', $line);
            if (count($columns) >= 4) {
                $output[] = [
                    "filesystem" => $columns[0],
                    "size" => $columns[1],
                    "used" => $columns[2],
                    "usage" => trim($columns[3])
                ];
            }
        }
    }

    return $output;
}

// Detect the operating system
function getOS() {
    if (stristr(PHP_OS, 'WIN')) {
        return 'Windows';
    } elseif (stristr(PHP_OS, 'DAR')) {
        return 'macOS';
    } elseif (stristr(PHP_OS, 'LINUX')) {
        return 'Linux';
    }
    return 'Unknown';
}