/**
 * 本地开发服务器
 * 提供静态文件服务和API代理功能
 */

const express = require('express');
const cors = require('cors');
const path = require('path');
const fs = require('fs');
const helmet = require('helmet');
const morgan = require('morgan');
require('dotenv').config();

if (typeof global.File === 'undefined') {
  global.File = class File {};
}

const Logger = {
  log: (...args) => console.log('[INFO]', ...args),
  warn: (...args) => console.warn('[WARN]', ...args),
  error: (...args) => console.error('[ERROR]', ...args)
};

const app = express();
const PORT = process.env.PORT || 3000;
const STATIC_ROOT = path.join(__dirname, process.env.STATIC_ROOT || 'dist');
const INTERNAL_FUNCTION_KEY = process.env.ACCESS_KEY || '';
const { parseOrigins, isAllowedOrigin: _isAllowedOrigin, resolveCorsOrigin: _resolveCorsOrigin } = require('./netlify/functions/_shared/cors');
const origins = parseOrigins(process.env.ALLOWED_ORIGIN);
const isAllowedOrigin = (origin) => _isAllowedOrigin(origin, origins);
const getCorsOrigin = (origin) => _resolveCorsOrigin(origin, origins);
// 与 src/simyo/js/modules/client-identity.js 保持同步
const DEFAULT_SIMYO_CLIENT_PLATFORM = 'ios';
const DEFAULT_SIMYO_CLIENT_VERSION = '4.28.0';
const DEFAULT_SIMYO_IOS_VERSION = '18.2';
const DEFAULT_SIMYO_DEVICE_MODEL = 'iPhone12,8';
// 版本号与括号之间为两个空格
const DEFAULT_SIMYO_USER_AGENT =
  `MijnSimyoFT/${DEFAULT_SIMYO_CLIENT_VERSION}  (iOS ${DEFAULT_SIMYO_IOS_VERSION}; ${DEFAULT_SIMYO_DEVICE_MODEL})`;
const crypto = require('crypto');
function getDefaultSimyoDeviceId() {
    if (process.env.SIMYO_DEVICE_ID) return process.env.SIMYO_DEVICE_ID;
    // 进程内稳定 ID，避免每次请求换设备身份
    if (!global.__simyoDeviceId) {
        global.__simyoDeviceId = crypto.randomUUID().toUpperCase();
    }
    return global.__simyoDeviceId;
}

// 启动时环境检查
if (!INTERNAL_FUNCTION_KEY) {
    console.error('❌ ACCESS_KEY 未配置');
    console.error('💡 请在 .env 文件或环境变量中设置 ACCESS_KEY');
    console.error('⚠️  Netlify Functions 将无法正常工作，请修复后重启');
}

if (!process.env.SIMYO_CLIENT_TOKEN) {
    console.warn('⚠️  SIMYO_CLIENT_TOKEN 未配置，Simyo 代理请求可能失败');
    console.warn('💡 请在 .env 文件中设置 SIMYO_CLIENT_TOKEN');
}

if (!fs.existsSync(STATIC_ROOT)) {
    console.warn(`⚠️  静态目录 ${STATIC_ROOT} 不存在，请先运行 npm run build`);
    console.warn('💡 运行: npm run build');
}

if (origins.allowAll) {
    Logger.warn('⚠️  ALLOWED_ORIGIN 包含通配符(*)，所有来源均可访问。请勿在生产环境使用');
}

// 中间件配置
app.use(helmet({
    contentSecurityPolicy: {
        directives: {
            defaultSrc: ["'self'"],
            scriptSrc: ["'self'", "'unsafe-inline'", "https://cdn.jsdelivr.net", "https://browser.sentry-cdn.com", "https://sentry.io", "https://*.sentry.io"],
            styleSrc: ["'self'", "'unsafe-inline'", "https://cdn.jsdelivr.net", "https://cdnjs.cloudflare.com", "https://fonts.googleapis.com"],
            imgSrc: ["'self'", "data:", "https:", "http:"],
            // jsdelivr：Bootstrap source map；sentry-cdn：SDK 回退加载
            connectSrc: ["'self'", "https://cdn.jsdelivr.net", "https://cdnjs.cloudflare.com", "https://appapi.simyo.nl", "https://api.giffgaff.com", "https://id.giffgaff.com", "https://publicapi.giffgaff.com", "https://browser.sentry-cdn.com", "https://sentry.io", "https://*.sentry.io"],
            fontSrc: ["'self'", "https://cdn.jsdelivr.net", "https://cdnjs.cloudflare.com", "https://fonts.gstatic.com"],
            frameSrc: ["'self'", "https://*.sentry.io"],
            workerSrc: ["'self'", "blob:"],
            childSrc: ["'self'", "blob:"]
        }
    }
}));

// 仅允许特定来源访问本地API（前端文件本地打开时可能 Origin 为 undefined）
app.use(cors({
    origin: function(origin, callback) {
        if (isAllowedOrigin(origin)) return callback(null, true); // 非浏览器/本地文件放行
        return callback(new Error('Not allowed by CORS'));
    },
    credentials: false
}));
app.use(morgan('combined'));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

const staticMiddleware = express.static(STATIC_ROOT, { fallthrough: true, index: false });

// 全局限流：每 IP 每分钟最多 200 次请求
const { createRateLimiter } = require('./src/js/middleware/validation.js');
app.use(createRateLimiter({ windowMs: 60000, maxRequests: 200 }));
app.use((req, res, next) => {
    if (!['GET', 'HEAD'].includes(req.method)) {
        return next();
    }
    if (/\.html?$/i.test(req.path)) {
        return next();
    }
    return staticMiddleware(req, res, next);
});

// API路由 - 模拟Netlify Functions
const giffgaffMfaChallenge = require('./netlify/functions/giffgaff-mfa-challenge');
const giffgaffMfaValidation = require('./netlify/functions/giffgaff-mfa-validation');
const giffgaffGraphql = require('./netlify/functions/giffgaff-graphql');
const giffgaffTokenExchange = require('./netlify/functions/giffgaff-token-exchange');
const verifyCookie = require('./netlify/functions/verify-cookie');
const giffgaffSmsActivate = require('./netlify/functions/giffgaff-sms-activate');
const autoActivateEsim = require('./netlify/functions/auto-activate-esim');
const publicConfig = require('./netlify/functions/public-config');

// 包装Netlify Functions为Express路由
function wrapNetlifyFunction(handler) {
    return async (req, res) => {
        try {
            const headers = Object.assign({}, req.headers);
            // 仅在客户端未提供密钥时注入内部密钥（避免覆盖）
            if (INTERNAL_FUNCTION_KEY && !headers['x-esim-key'] && !headers['x-app-key']) {
                headers['x-esim-key'] = INTERNAL_FUNCTION_KEY;
            }
            const event = {
                httpMethod: req.method,
                headers,
                body: JSON.stringify(req.body),
                queryStringParameters: req.query
            };

            const context = {};
            const result = await handler.handler(event, context);

            res.status(result.statusCode);

            if (result.headers) {
                Object.entries(result.headers).forEach(([key, value]) => {
                    res.set(key, value);
                });
            }

            if (result.body) {
                const body = typeof result.body === 'string' ? result.body : JSON.stringify(result.body);
                res.send(body);
            } else {
                res.end();
            }
        } catch (error) {
            console.error('API Error:', error);
            res.status(500).json({
                error: 'Internal Server Error',
                message: error.message
            });
        }
    };
}

// API端点（同时挂 /.netlify/functions/* 与 /bff/*，本地模拟 Edge BFF 代理）
const functionRoutes = [
  ['giffgaff-mfa-challenge', giffgaffMfaChallenge],
  ['giffgaff-mfa-validation', giffgaffMfaValidation],
  ['giffgaff-graphql', giffgaffGraphql],
  ['giffgaff-token-exchange', giffgaffTokenExchange],
  ['verify-cookie', verifyCookie],
  ['giffgaff-sms-activate', giffgaffSmsActivate],
  ['auto-activate-esim', autoActivateEsim],
  ['public-config', publicConfig]
];
app.locals.bffRoutes = functionRoutes.map(([name]) => `/bff/${name}`);
app.locals.functionRoutes = functionRoutes.map(([name]) => `/.netlify/functions/${name}`);
functionRoutes.forEach(([name, handler]) => {
  const wrapped = wrapNetlifyFunction(handler);
  app.use(`/.netlify/functions/${name}`, wrapped);
  app.use(`/bff/${name}`, wrapped);
});

// Simyo API代理路由（支持 /api/simyo/v2/* → webapi/api/v2，其余 → webapi/api/v1）
app.use('/api/simyo/*', (req, res) => {
    const [pathPart, queryPart] = req.originalUrl.replace(/^\/api\/simyo/, '').split('?');
    const proxyPath = pathPart || '/';
    const queryString = queryPart ? `?${queryPart}` : '';
    const isV2 = proxyPath === '/v2' || proxyPath.startsWith('/v2/');
    const apiVersionPath = isV2 ? proxyPath.replace(/^\/v2/, '') || '/' : proxyPath;
    const targetUrl = isV2
        ? `https://appapi.simyo.nl/webapi/api/v2${apiVersionPath}${queryString}`
        : `https://appapi.simyo.nl/webapi/api/v1${proxyPath}${queryString}`;
    Logger.log(`[Simyo Proxy] ${req.method} ${req.path} -> ${targetUrl}`);

    // 设置CORS头（仅允许指定域）
    res.header('Access-Control-Allow-Origin', getCorsOrigin(req.headers.origin));
    res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
    res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, Accept, X-Client-Token, X-Client-Platform, X-Client-Version, X-Device-ID, X-Session-Token');
    res.header('Vary', 'Origin');

    if (req.method === 'OPTIONS') {
        return res.status(200).end();
    }

    const simyoClientToken = process.env.SIMYO_CLIENT_TOKEN;
    if (!simyoClientToken) {
        return res.status(500).json({
            error: 'Server Misconfigured',
            message: 'SIMYO_CLIENT_TOKEN 未配置'
        });
    }

    // 代理请求：强制使用客户端身份头（浏览器 UA 不可靠，禁止透传）
    // X-Device-ID 必填，优先使用前端持久化 ID
    const axios = require('axios');
    const config = {
        method: req.method.toLowerCase(),
        url: targetUrl,
        headers: {
            'Content-Type': 'application/json',
            Accept: 'application/json',
            'Accept-Encoding': 'gzip',
            'User-Agent': process.env.SIMYO_USER_AGENT || DEFAULT_SIMYO_USER_AGENT,
            'X-Client-Token': simyoClientToken,
            'X-Client-Platform': process.env.SIMYO_CLIENT_PLATFORM || DEFAULT_SIMYO_CLIENT_PLATFORM,
            'X-Client-Version': process.env.SIMYO_CLIENT_VERSION || DEFAULT_SIMYO_CLIENT_VERSION,
            'X-Device-ID': req.headers['x-device-id'] || process.env.SIMYO_DEVICE_ID || getDefaultSimyoDeviceId(),
            ...(req.headers['x-session-token'] ? { 'X-Session-Token': req.headers['x-session-token'] } : {})
        },
        timeout: 30000
    };

    if (req.body && Object.keys(req.body).length > 0) {
        config.data = req.body;
    }

    axios(config)
        .then(response => {
            res.status(response.status).json(response.data);
        })
        .catch(error => {
            console.error('[Simyo Proxy Error]:', error.message);
            const status = error.response?.status || 500;
            const data = error.response?.data || { error: 'Proxy Error', message: error.message };
            res.status(status).json(data);
        });
});

// 路由配置
const htmlRoutes = [
    { url: '/giffgaff', file: 'src/giffgaff/giffgaff_modular.html' },
    { url: '/simyo', file: 'src/simyo/simyo_modular.html' },
    // 兼容静态路径访问（与 Netlify 重写保持一致）
    { url: '/src/giffgaff/giffgaff_modular.html', file: 'src/giffgaff/giffgaff_modular.html' },
    { url: '/src/simyo/simyo_modular.html', file: 'src/simyo/simyo_modular.html' },
    { url: '/', file: 'index.html' }
];

htmlRoutes.forEach(({ url, file }) => {
    app.get(url, (req, res) => {
        res.sendFile(path.join(STATIC_ROOT, file));
    });
});

// 错误处理
app.use((err, req, res, next) => {
    console.error('Server Error:', err);
    const safeMessage = process.env.NODE_ENV === 'development'
        ? String(err.message || '').replace(/[<>"'&]/g, '')
        : '服务器内部错误';
    res.status(500).json({
        error: 'Internal Server Error',
        message: safeMessage
    });
});

// 404处理
app.use((req, res) => {
    // 优先返回 HTML 404 页面（如果存在）
    const html404Path = path.join(STATIC_ROOT, '404.html');
    if (fs.existsSync(html404Path) && req.accepts('html')) {
        return res.status(404).sendFile(html404Path);
    }

    // API 请求或无 404 页面时返回 JSON
    res.status(404).json({
        error: 'Not Found',
        message: '请求的资源不存在'
    });
});

// 启动服务器。被测试或其他模块 require 时不自动占用端口。
if (require.main === module) {
    app.listen(PORT, () => {
        Logger.log(`🚀 eSIM工具服务器已启动`);
        Logger.log(`📍 本地地址: http://localhost:${PORT}`);
        Logger.log(`🔧 Giffgaff工具: http://localhost:${PORT}/giffgaff`);
        Logger.log(`📱 Simyo工具: http://localhost:${PORT}/simyo`);
        Logger.log(`🌐 环境: ${process.env.NODE_ENV || 'development'}`);
    });
}

module.exports = app;