<?php

// Simple HTML screening 
function e($string)
{
    return htmlspecialchars($string, ENT_QUOTES, 'UTF-8');
}

function isAdmin()
{
    if (!ipAllowed()) {
        return false;
    } else {
        return isset($_SESSION['user_id']);
    }
}

function ipAllowed()
{
    // If you declared $ALLOWED_IPS in config.php as global or static,
    // retrieve them with "global" or by including them from config
    global $ALLOWED_IPS;

    $clientIp = $_SERVER['REMOTE_ADDR'] ?? 'unknown';

    foreach ($ALLOWED_IPS as $allowed) {
        if (isIpInRange($clientIp, $allowed)) {
            return true;
        }
    }
    return false;
}

function isIpInRange($ip, $allowed)
{
    // If the allowed is an IP with no slash, compare directly
    if (strpos($allowed, '/') === false) {
        return $ip === $allowed;
    } else {
        // It's a CIDR notation, e.g. 192.168.1.0/24
        list($subnet, $mask) = explode('/', $allowed);
        // Convert IPs to their numeric representation
        $ipLong     = ip2long($ip);
        $subnetLong = ip2long($subnet);
        // mask => 24 means 255.255.255.0
        $mask = (int)$mask;
        $maskLong = ~((1 << (32 - $mask)) - 1);

        return ($ipLong & $maskLong) === ($subnetLong & $maskLong);
    }
}

/**
 * Split content at <!--more--> marker.
 * Returns [ 'excerpt' => '...', 'hasMore' => bool ]
 */
function getExcerptWithMore(string $content): array
{
    // Look for the marker
    $parts = explode('<!--more-->', $content, 2);

    if (count($parts) === 2) {
        // We have an excerpt in $parts[0], and the remainder in $parts[1]
        return [
            'excerpt' => $parts[0],
            'hasMore' => true,
        ];
    } else {
        // No marker found, so the entire post is $content
        return [
            'excerpt' => $content,
            'hasMore' => false,
        ];
    }
}