<?php
/**
 * GET /api/hub/vcgateway/invites/list.php
 *
 * List invite links. Optionally filter by status.
 * Requires agent auth (X-Agent-Address header).
 *
 * Query params:
 *   Status    string   optional  "active" | "revoked" | "expired" | "all" (default: "all")
 *   Limit     int      optional  Max results (default: 50, max: 200)
 *   Offset    int      optional  Pagination offset (default: 0)
 *
 * Response:
 *   OK, Links[], Total
 */

require_once __DIR__ . '/../helpers.php';

if ($_SERVER['REQUEST_METHOD'] !== 'GET') {
    jsonResponse(['OK' => false, 'ERROR' => 'method_not_allowed'], 405);
}

$agentAddress = requireAgentAuth();

$status = strtolower(trim($_GET['Status'] ?? 'all'));
$limit = min(200, max(1, (int)($_GET['Limit'] ?? 50)));
$offset = max(0, (int)($_GET['Offset'] ?? 0));

// Build WHERE clause
$where = [];
$params = [];

switch ($status) {
    case 'active':
        $where[] = 'il.IsRevoked = 0';
        $where[] = '(il.ExpiresAt IS NULL OR il.ExpiresAt > NOW())';
        $where[] = '(il.MaxUses = 0 OR il.UseCount < il.MaxUses)';
        break;
    case 'revoked':
        $where[] = 'il.IsRevoked = 1';
        break;
    case 'expired':
        $where[] = 'il.IsRevoked = 0';
        $where[] = 'il.ExpiresAt IS NOT NULL AND il.ExpiresAt <= NOW()';
        break;
    case 'all':
    default:
        // No filter
        break;
}

$whereClause = !empty($where) ? 'WHERE ' . implode(' AND ', $where) : '';

// Count total
$countRow = queryOne(
    "SELECT COUNT(*) AS cnt FROM Hub_InviteLinks il $whereClause",
    $params
);
$total = (int)($countRow['cnt'] ?? 0);

// Fetch links
$rows = queryTimed(
    "SELECT il.*,
            (SELECT COUNT(*) FROM Hub_Visitors v WHERE v.InviteLinkID = il.ID) AS VisitorCount
     FROM Hub_InviteLinks il
     $whereClause
     ORDER BY il.CreatedAt DESC
     LIMIT $limit OFFSET $offset",
    $params
);

$links = [];
foreach ($rows as $row) {
    // Determine computed status
    $computedStatus = 'active';
    if ($row['IsRevoked']) {
        $computedStatus = 'revoked';
    } elseif ($row['ExpiresAt'] && strtotime($row['ExpiresAt']) <= time()) {
        $computedStatus = 'expired';
    } elseif ($row['MaxUses'] > 0 && $row['UseCount'] >= $row['MaxUses']) {
        $computedStatus = 'exhausted';
    }

    $links[] = [
        'ID' => (int)$row['ID'],
        'Token' => $row['Token'],
        'Label' => $row['Label'],
        'AllowedChannels' => json_decode($row['AllowedChannels'], true),
        'HostAddress' => $row['HostAddress'],
        'ExpiresAt' => $row['ExpiresAt'] ? toISO8601($row['ExpiresAt']) : null,
        'MaxUses' => (int)$row['MaxUses'],
        'UseCount' => (int)$row['UseCount'],
        'VisitorCount' => (int)$row['VisitorCount'],
        'Status' => $computedStatus,
        'CreatedBy' => $row['CreatedBy'],
        'CreatedAt' => toISO8601($row['CreatedAt']),
    ];
}

jsonResponse([
    'OK' => true,
    'Links' => $links,
    'Total' => $total,
]);