/**
 * 点名系统后端API服务器
 * 使用Node.js原生HTTP模块实现
 */

const http = require('http');
const fs = require('fs');
const path = require('path');
const url = require('url');

// 数据存储（实际应用中应使用数据库）
let rollCallLists = [];
let rollCallRecords = [];

// 从文件加载数据
function loadData() {
    try {
        const listsData = fs.readFileSync('data_lists.json', 'utf8');
        rollCallLists = JSON.parse(listsData);
    } catch (e) {
        rollCallLists = [];
    }
    
    try {
        const recordsData = fs.readFileSync('data_records.json', 'utf8');
        rollCallRecords = JSON.parse(recordsData);
    } catch (e) {
        rollCallRecords = [];
    }
}

// 保存数据到文件
function saveData() {
    fs.writeFileSync('data_lists.json', JSON.stringify(rollCallLists, null, 2));
    fs.writeFileSync('data_records.json', JSON.stringify(rollCallRecords, null, 2));
}

// 生成随机编号
function generateCode() {
    const length = Math.floor(Math.random() * 7) + 6; // 6-12位
    let code = '';
    for (let i = 0; i < length; i++) {
        code += Math.floor(Math.random() * 10);
    }
    return code;
}

// 创建HTTP服务器
const server = http.createServer((req, res) => {
    // 设置CORS头
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
    
    // 处理OPTIONS请求
    if (req.method === 'OPTIONS') {
        res.writeHead(200);
        res.end();
        return;
    }
    
    const parsedUrl = url.parse(req.url, true);
    const pathname = parsedUrl.pathname;
    
    // API路由
    if (pathname.startsWith('/api/')) {
        handleAPI(req, res, pathname, parsedUrl.query);
        return;
    }
    
    // 静态文件服务
    serveStatic(req, res, pathname);
});

// 处理API请求
function handleAPI(req, res, pathname, query) {
    let body = '';
    
    req.on('data', chunk => {
        body += chunk.toString();
    });
    
    req.on('end', () => {
        let data = {};
        if (body) {
            try {
                data = JSON.parse(body);
            } catch (e) {
                sendError(res, '无效的JSON数据');
                return;
            }
        }
        
        // 路由处理
        switch (pathname) {
            case '/api/login':
                handleLogin(res, data);
                break;
            case '/api/create-list':
                handleCreateList(res, data);
                break;
            case '/api/get-lists':
                handleGetLists(res);
                break;
            case '/api/get-list':
                handleGetList(res, query);
                break;
            case '/api/update-list':
                handleUpdateList(res, data);
                break;
            case '/api/delete-list':
                handleDeleteList(res, data);
                break;
            case '/api/roll-call':
                handleRollCall(res, data);
                break;
            case '/api/get-records':
                handleGetRecords(res);
                break;
            default:
                sendError(res, '未知的API路径', 404);
        }
    });
}

// 登录处理
function handleLogin(res, data) {
    const { username, password } = data;
    
    if (username === 'admin' && password === 'admin123') {
        sendSuccess(res, { token: 'admin-token-' + Date.now() });
    } else {
        sendError(res, '用户名或密码错误', 401);
    }
}

// 创建点名名单
function handleCreateList(res, data) {
    const { name, members } = data;
    
    if (!name || !members || !Array.isArray(members)) {
        sendError(res, '参数错误');
        return;
    }
    
    const newList = {
        id: Date.now(),
        name: name,
        code: generateCode(),
        members: members.map(memberName => ({
            name: memberName,
            completed: false,
            timestamp: null
        })),
        createdAt: new Date().toLocaleString()
    };
    
    rollCallLists.push(newList);
    saveData();
    
    sendSuccess(res, newList);
}

// 获取所有名单
function handleGetLists(res) {
    sendSuccess(res, rollCallLists);
}

// 获取单个名单
function handleGetList(res, query) {
    const code = query.code;
    const list = rollCallLists.find(l => l.code === code);
    
    if (list) {
        sendSuccess(res, list);
    } else {
        sendError(res, '名单不存在', 404);
    }
}

// 更新名单
function handleUpdateList(res, data) {
    const { id, name, members } = data;
    const list = rollCallLists.find(l => l.id === id);
    
    if (!list) {
        sendError(res, '名单不存在', 404);
        return;
    }
    
    if (name) list.name = name;
    if (members && Array.isArray(members)) {
        list.members = members.map(memberName => {
            const existing = list.members.find(m => m.name === memberName);
            return existing || { name: memberName, completed: false, timestamp: null };
        });
    }
    
    saveData();
    sendSuccess(res, list);
}

// 删除名单
function handleDeleteList(res, data) {
    const { id } = data;
    const index = rollCallLists.findIndex(l => l.id === id);
    
    if (index === -1) {
        sendError(res, '名单不存在', 404);
        return;
    }
    
    rollCallLists.splice(index, 1);
    saveData();
    sendSuccess(res, { message: '删除成功' });
}

// 点名
function handleRollCall(res, data) {
    const { code, name } = data;
    const list = rollCallLists.find(l => l.code === code);
    
    if (!list) {
        sendError(res, '名单不存在', 404);
        return;
    }
    
    const member = list.members.find(m => m.name === name);
    if (!member) {
        sendError(res, '成员不存在', 404);
        return;
    }
    
    if (member.completed) {
        sendError(res, '该成员已点名');
        return;
    }
    
    member.completed = true;
    member.timestamp = new Date().toLocaleString();
    
    // 添加记录
    rollCallRecords.push({
        name: name,
        listName: list.name,
        code: code,
        timestamp: member.timestamp
    });
    
    saveData();
    sendSuccess(res, { message: '点名成功', member: member });
}

// 获取点名记录
function handleGetRecords(res) {
    sendSuccess(res, rollCallRecords);
}

// 静态文件服务
function serveStatic(req, res, pathname) {
    let filePath = pathname === '/' ? '/index.html' : pathname;
    filePath = path.join(__dirname, filePath);
    
    const extname = path.extname(filePath);
    const contentTypes = {
        '.html': 'text/html',
        '.js': 'text/javascript',
        '.css': 'text/css',
        '.json': 'application/json',
        '.png': 'image/png',
        '.jpg': 'image/jpeg',
        '.gif': 'image/gif'
    };
    
    const contentType = contentTypes[extname] || 'text/plain';
    
    fs.readFile(filePath, (err, content) => {
        if (err) {
            if (err.code === 'ENOENT') {
                res.writeHead(404);
                res.end('文件未找到');
            } else {
                res.writeHead(500);
                res.end('服务器错误');
            }
        } else {
            res.writeHead(200, { 'Content-Type': contentType });
            res.end(content);
        }
    });
}

// 发送成功响应
function sendSuccess(res, data) {
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ success: true, data: data }));
}

// 发送错误响应
function sendError(res, message, code = 400) {
    res.writeHead(code, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ success: false, error: message }));
}

// 启动服务器
const PORT = 3000;
loadData();

server.listen(PORT, () => {
    console.log(`点名系统服务器已启动`);
    console.log(`访问地址: http://localhost:${PORT}`);
    console.log(`后台管理: http://localhost:${PORT}/admin.html`);
    console.log(`用户点名: http://localhost:${PORT}/index.html`);
});