const express = require('express');
const multer = require('multer');
const xlsx = require('xlsx');
const cors = require('cors');
const bodyParser = require('body-parser');
const path = require('path');

const app = express();
const PORT = 3000;

app.use(cors());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(express.static(path.join(__dirname, 'public')));

let students = []; // 存储学生名单
let studentScores = {}; // 存储学生积分
let calledStudents = []; // 存储已点名学生的 ID

// 设置 multer 以处理文件上传
const upload = multer({ dest: 'uploads/' });

// 导入 Excel 文件中的学生名单
app.post('/upload', upload.single('file'), (req, res) => {
    const workbook = xlsx.readFile(req.file.path);
    const sheetName = workbook.SheetNames[0];
    const sheet = workbook.Sheets[sheetName];

    const data = xlsx.utils.sheet_to_json(sheet);
    students = data.map(student => ({
        id: student['学号'],
        name: student['姓名'],
        score: 0 // 初始积分为 0
    }));

    // 初始化学生积分
    students.forEach(student => {
        studentScores[student.id] = student.score;
    });

    // 清空已点名的学生列表
    calledStudents = [];

    res.send({ message: '学生名单已导入', students });
});

// 随机点名
app.get('/rollcall', (req, res) => {
    if (students.length === 0) {
        return res.status(400).send({ message: '学生名单为空，请先导入名单' });
    }

    // 从所有学生中随机选择
    const randomIndex = Math.floor(Math.random() * students.length);
    const chosenStudent = students[randomIndex];

    // 将选中的学生加入已点名列表
    calledStudents.push(chosenStudent.id);
    res.send(chosenStudent);
});

// 更新学生积分
app.post('/update-score', (req, res) => {
    const { id, isInClass, isQuestionCorrect, isAnswerCorrect, score } = req.body;

    // 检查学生 ID 是否存在
    if (!studentScores.hasOwnProperty(id)) {
        return res.status(400).send({ message: '学生不存在' });
    }

    let scoreChange = 0;

    if (isInClass) {
        scoreChange += 1; // 到达课堂
    }
    if (isQuestionCorrect) {
        scoreChange += 0.5; // 准确重复问题
    } else if (isQuestionCorrect === false) {
        scoreChange -= 1; // 未准确重复问题
    }
    if (isAnswerCorrect && score) {
        scoreChange += score; // 根据情况加分
    }

    studentScores[id] += scoreChange;

    res.send({ message: '积分已更新', score: studentScores[id] });
});

// 幸运抽奖
app.post('/lottery', (req, res) => {
    const { id } = req.body;

    // 检查学生 ID 是否存在
    if (!studentScores.hasOwnProperty(id)) {
        return res.status(400).send({ message: '学生不存在' });
    }

    // 随机选择一个操作
    const randomAction = Math.random();
    let scoreChange = 0;

    if (randomAction < 0.33) {
        scoreChange = -0.5; // 扣0.5分
        studentScores[id] += scoreChange;
        return res.send({ message: '真无语,扣0.5分', score: studentScores[id] });
    } else if (randomAction < 0.66) {
        scoreChange = 1; // 加1分
        studentScores[id] += scoreChange;
        return res.send({ message: '不错不错,加1分', score: studentScores[id] });
    } else {
        scoreChange = 10; // 加10分
        studentScores[id] += scoreChange;
        return res.send({ message: '孩子你无敌了,加10分', score: studentScores[id] });
    }
});

// 重置点名状态
app.post('/reset', (req, res) => {
    calledStudents = []; // 清空已点名学生列表
    res.send({ message: '点名状态已重置' });
});

app.listen(PORT, () => {
    console.log(`服务器正在运行在 http://localhost:${PORT}`);
});