<?php
header('Content-Type: application/json');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type');

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(204);
    exit;
}

if ($_SERVER['REQUEST_METHOD'] !== 'GET') {
    http_response_code(405);
    echo json_encode(['error' => 'Method not allowed']);
    exit;
}

// Connect to SQLite
$db = new PDO('sqlite:/data/db/platform.sqlite');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

// Total users
$totalUsers = $db->query('SELECT COUNT(*) FROM users')->fetchColumn();

// Disk usage of /data
$totalBytes = diskTotalSpace('/data');
$freeBytes  = diskFreeSpace('/data');
$usedBytes  = $totalBytes - $freeBytes;

// Per-user disk usage
$users     = $db->query('SELECT username FROM users ORDER BY username')->fetchAll(PDO::FETCH_COLUMN);
$userStats = [];

foreach ($users as $username) {
    $htdocs = "/data/sites/{$username}/htdocs";
    $size   = is_dir($htdocs) ? directorySize($htdocs) : 0;
    $userStats[] = [
        'username'   => $username,
        'size_bytes' => $size,
        'size_human' => humanSize($size)
    ];
}

echo json_encode([
    'success'      => true,
    'total_users'  => (int)$totalUsers,
    'disk' => [
        'total_bytes' => $totalBytes,
        'used_bytes'  => $usedBytes,
        'free_bytes'  => $freeBytes,
        'total_human' => humanSize($totalBytes),
        'used_human'  => humanSize($usedBytes),
        'free_human'  => humanSize($freeBytes),
        'used_percent'=> $totalBytes > 0 ? round(($usedBytes / $totalBytes) * 100, 2) : 0
    ],
    'users' => $userStats
]);

// ── Helpers ───────────────────────────────────────────────────────────────────
function directorySize(string $dir): int {
    $size  = 0;
    $items = new RecursiveIteratorIterator(
        new RecursiveDirectoryIterator($dir, FilesystemIterator::SKIP_DOTS)
    );
    foreach ($items as $item) {
        $size += $item->getSize();
    }
    return $size;
}

function humanSize(int $bytes): string {
    $units = ['B', 'KB', 'MB', 'GB', 'TB'];
    $i     = 0;
    while ($bytes >= 1024 && $i < count($units) - 1) {
        $bytes /= 1024;
        $i++;
    }
    return round($bytes, 2) . ' ' . $units[$i];
}