<?php
/**
 * GET /api/hub/vcgateway/invites/get.php
 *
 * Get a single invite link by ID or Token.
 * Requires agent auth (X-Agent-Address header).
 *
 * Query params:
 *   ID      int      optional  Invite link ID
 *   Token   string   optional  Invite link token
 *
 * Response:
 *   OK, Link (object)
 */

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

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

$agentAddress = requireAgentAuth();

$id = (int)($_GET['ID'] ?? 0);
$token = trim($_GET['Token'] ?? '');

if ($id <= 0 && empty($token)) {
    jsonResponse(['OK' => false, 'ERROR' => 'id_or_token_required'], 400);
}

if ($id > 0) {
    $row = queryOne("SELECT * FROM Hub_InviteLinks WHERE ID = ?", [$id]);
} else {
    $row = queryOne("SELECT * FROM Hub_InviteLinks WHERE Token = ?", [$token]);
}

if (!$row) {
    jsonResponse(['OK' => false, 'ERROR' => 'invite_not_found'], 404);
}

// Get visitor count
$vcRow = queryOne(
    "SELECT COUNT(*) AS cnt FROM Hub_Visitors WHERE InviteLinkID = ?",
    [(int)$row['ID']]
);

// Compute 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';
}

// Get visitors using this link
$visitors = queryTimed(
    "SELECT ID, DisplayName, CreatedAt, LastActiveAt
     FROM Hub_Visitors WHERE InviteLinkID = ?
     ORDER BY CreatedAt DESC",
    [(int)$row['ID']]
);

$visitorList = [];
foreach ($visitors as $v) {
    $visitorList[] = [
        'ID' => (int)$v['ID'],
        'DisplayName' => $v['DisplayName'],
        'CreatedAt' => toISO8601($v['CreatedAt']),
        'LastActiveAt' => toISO8601($v['LastActiveAt']),
    ];
}

jsonResponse([
    'OK' => true,
    'Link' => [
        '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)($vcRow['cnt'] ?? 0),
        'Status' => $computedStatus,
        'CreatedBy' => $row['CreatedBy'],
        'CreatedAt' => toISO8601($row['CreatedAt']),
        'Visitors' => $visitorList,
    ],
]);