<?php
/**
 * 执行单个升级步骤（代理至后端 API）
 */
header('Content-Type: application/json; charset=utf-8');

require_once __DIR__ . '/../config.php';

// 验证登录和权限
if (!isset($_SESSION['user_id']) || $_SESSION['user_type'] !== 'admin') {
    http_response_code(401);
    echo json_encode(['success' => false, 'error' => '未授权']);
    exit();
}

$role = $_SESSION['role'] ?? '';
if ($role !== '班主任') {
    http_response_code(403);
    echo json_encode(['success' => false, 'error' => '权限不足']);
    exit();
}

// 只接受 POST
if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(400);
    echo json_encode(['success' => false, 'error' => '无效请求']);
    exit();
}

$stepVersion = $_GET['version'] ?? '';
if (empty($stepVersion)) {
    http_response_code(400);
    echo json_encode(['success' => false, 'error' => '缺少版本号参数']);
    exit();
}

// 从 session 获取 JWT token
$token = $_SESSION['jwt_token'] ?? '';
if (empty($token)) {
    http_response_code(401);
    echo json_encode(['success' => false, 'error' => '会话已过期，请重新登录']);
    exit();
}

// 调用后端 API
$apiUrl = API_BASE_URL . '/api/upgrade/step';

$ch = curl_init();
curl_setopt_array($ch, [
    CURLOPT_URL => $apiUrl,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => json_encode(['version' => $stepVersion]),
    CURLOPT_TIMEOUT => API_TIMEOUT,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer ' . $token,
        'Content-Type: application/json'
    ],
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_SSL_VERIFYHOST => 0
]);

$apiResponse = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if (empty($apiResponse)) {
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'version' => $stepVersion,
        'error' => '无法连接升级服务'
    ]);
    exit();
}

$result = json_decode($apiResponse, true);
if (!$result) {
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'version' => $stepVersion,
        'error' => '升级服务返回数据格式错误'
    ]);
    exit();
}

// 后端返回非200或 success=false 时，提取实际错误信息
if ($httpCode !== 200 || !isset($result['success']) || !$result['success']) {
    $errorMsg = $result['message'] ?? ($result['error'] ?? '升级失败');
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'version' => $stepVersion,
        'error' => $errorMsg
    ]);
    exit();
}

// 转发后端返回的数据
$data = $result['data'] ?? [];
echo json_encode($data);