<?php

function is_cli() {
    if (defined('STDIN')) {
        return true;
    }
    if (php_sapi_name() === 'cli') {
        return true;
    }
    if (array_key_exists('SHELL', $_ENV)) {
        return true;
    }
    if (empty($_SERVER['REMOTE_ADDR']) and ! isset($_SERVER['HTTP_USER_AGENT']) and count($_SERVER['argv']) > 0) {
        return true;
    }
    if (!array_key_exists('REQUEST_METHOD', $_SERVER)) {
        return true;
    }
    return false;
}

if (is_cli() === false) {
    echo('Unable to Start');
    exit(1);
}

function OS_details() {
    $kernel_version = php_uname('r');
    $system_architecture = php_uname('m');        
    return ['kernel'=>$kernel_version, 'architecture'=>$system_architecture];
}

function get_Windows_version() {
    $os_info = php_uname();
    $pattern = '/Windows\sNT\s(\d+\.\d+).*build\s(\d+)/';
    preg_match($pattern, $os_info, $matches);
    if ($matches && count($matches) >= 3) {
        $version = $matches[1];
        $build_number = $matches[2];
        return ['version' => $version, 'build' => $build_number];
    } else {
        $windows_info = explode(" ", $os_info);
        $windows_version = end($windows_info);
        return ['version' => $windows_version, 'build' => 'unknown'];
    }
}

function get_based_on_distribution($distributionName) {
    $distributions = [
        'ubuntu' => 'debian',
        'debian' => 'unknown',
        'fedora' => 'red hat',
        'centos' => 'red hat',
        'arch' => 'unknown',
        'opensuse' => 'suse',
        'gentoo' => 'unknown',
        'slackware' => 'unknown',
        'mageia' => 'mandriva',
        'manjaro' => 'arch',
        'alpine' => 'unknown',
        'mint' => 'ubuntu',
        'elementary' => 'ubuntu',
        'kali' => 'debian',
        'red hat enterprise linux' => 'red hat',
        'oracle linux' => 'red hat',
        'scientific linux' => 'red hat',
        'clear linux' => 'unknown',
    ];
    $distributionName = strtolower($distributionName);
    if (isset($distributions[$distributionName])) {
        return $distributions[$distributionName];
    } else {
        return 'unknown';
    }
}

function get_Linux_version() {
    $os_info = php_uname();
    $pattern = '/^Linux (.+?)(?:\s+|\()([\d.]+)(?:\).*)?$/';    
    if (preg_match($pattern, $os_info, $matches)) {
        $distribution = $matches[1];
        $version = $matches[2];
        return ['name'=>$distribution,'version_codename'=>null,'version_id'=>$version, 'id_like'=>get_based_on_distribution($distribution),'id'=>strtolower($distribution),'linux'=>true];
    }    
    if (function_exists("exec")) {
        $codename = "unknown";
        exec('lsb_release -sc', $output, $returnCode);
        if ($returnCode === 0 && !empty($output)) {
            $codename = trim($output[0]);
        }
        unset($output);
        $version = "unknown";
        exec('lsb_release -rs', $output, $returnCode);
        if ($returnCode === 0 && !empty($output)) {
            $version = trim($output[0]);
        }
        unset($output);        
        exec('lsb_release -si', $output, $return_code);
        if ($return_code === 0 && !empty($output)) {
            $distribution = trim($output[0]);
            return ['name'=>$distribution, 'version_codename'=>$codename, 'version_id'=>$version, 'id_like'=>get_based_on_distribution($distribution),'id'=> strtolower($distribution),'linux'=>true];
        } 
    }
    return null;
}

function get_OS_information() {
    if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
        $windows_version = get_Windows_version();
        $build = $windows_version['build'] ?? false;
        $version = $windows_version['version'] ?? false;
        return ['name' => 'Windows', 'version_codename'=>$build, 'version_id'=>$version, 'id_like'=>"win"+$version,'id' => $build,'linux'=>false];
    }

    if (function_exists("shell_exec") === false|| is_readable("/etc/os-release") === false) {
        return get_Linux_version();
    }

    $os = shell_exec('cat /etc/os-release');
    $list_ids = preg_match_all('/.*=/', $os, $match_list_ids);
    $list_ids = $match_list_ids[0];

    $list_val = preg_match_all('/=.*/', $os, $match_list_val);
    $list_val = $match_list_val[0];

    array_walk($list_ids, function(&$v, $k) {
        $v = strtolower(str_replace('=', '', $v));
    });

    array_walk($list_val, function(&$v, $k) {
        $v = preg_replace('/=|"/', '', $v);
    });

    $a = array_combine($list_ids, $list_val);
    $a['linux'] = true;
    return $a;
}

function is_string_found(string $data, string $find): bool {
    return (stripos($data, $find) !== false);
}

function get_left(string $str, int $length): string {
    return substr($str, 0, $length);
}

function get_right(string $str, int $length): string {
    return substr($str, -$length);
}

$os = get_OS_information(); 
$details = OS_details();
$os['kernel'] = $details['kernel'] ?? false;
$os['architecture'] = $details['architecture'] ?? false;
$osVer = $os['version_id'] ?? false;
$codeName = $os['version_codename'] ?? false;
$os_like = $os['id_like'] ?? false;

//var_dump($os); exit;