// ==UserScript==
// @name         不智慧教室
// @version      1.0
// @description  Bypass CORS in private
// @author       singledog
// @match        https://duaa.singledog233.top/*
// @grant        GM_xmlhttpRequest
// @connect      iclass.buaa.edu.cn
// @run-at       document-start
// @license MIT
// @namespace https://greasyfork.org/users/1226768
// @downloadURL none
// ==/UserScript==

(function () {
    'use strict';

    const DEBUG = false;
    const dlog = (...args) => { if (DEBUG) console.log('[iClass-Userscript]', ...args); };
    dlog('Userscript loaded at', location.href);

    // 简单的内存缓存：按 studentId 存最近一次查询到的课程数组
    // 形如 { [studentId]: [{ id, classBeginTime, classEndTime, ...}, ...] }
    const scheduleCache = new Map();

    function cacheSchedule(studentId, scheduleRes) {
        try {
            const list = Array.isArray(scheduleRes?.result) ? scheduleRes.result : [];
            if (studentId && list.length) {
                scheduleCache.set(String(studentId), list);
                dlog('cacheSchedule:stored', { studentId, count: list.length });
            }
        } catch (_) { /* ignore */ }
    }

    function findCourseTimes(studentId, courseSchedId) {
        try {
            const list = scheduleCache.get(String(studentId));
            if (!list || !list.length) return null;
            const item = list.find(it => String(it?.id) === String(courseSchedId));
            if (!item) return null;
            const beginStr = item.classBeginTime; // 例如: "2025-10-21 09:50:00"
            const endStr = item.classEndTime;     // 例如: "2025-10-21 11:25:00"
            if (!beginStr || !endStr) return null;
            const begin = new Date(beginStr);
            const end = new Date(endStr);
            if (isNaN(begin.getTime()) || isNaN(end.getTime())) return null;
            return { begin, end };
        } catch (_) { return null; }
    }

    function randomTimestampBetween(begin, end) {
        // 在上课过程中选一个更自然的时间：开始+5分钟 ~ 结束-1分钟
        const marginStartMs = 5 * 60 * 1000;
        const marginEndMs = 1 * 60 * 1000;
        const startMs = begin.getTime() + marginStartMs;
        const endMs = end.getTime() - marginEndMs;
        if (endMs <= startMs) return null; // 边界异常时放弃
        const rnd = startMs + Math.floor(Math.random() * (endMs - startMs + 1));
        return rnd;
    }

    function httpRequest(method, url, { headers = {}, data = null, timeout = 8000 } = {}) {
        dlog('httpRequest:start', { method, url, headers, dataPreview: (typeof data === 'string' ? data.slice(0, 128) : data), timeout });
        return new Promise((resolve, reject) => {
            const t0 = performance.now();
            GM_xmlhttpRequest({
                method,
                url,
                headers,
                data,
                timeout,
                onload: (res) => {
                    const dt = (performance.now() - t0).toFixed(1);
                    dlog('httpRequest:onload', { url, status: res.status, timeMs: dt, length: (res.responseText || '').length });
                    try {
                        const json = JSON.parse(res.responseText || '{}');
                        dlog('httpRequest:json', json);
                        resolve(json);
                    } catch (e) {
                        dlog('httpRequest:parse-error', e);
                        resolve({ STATUS: '1', message: '响应非JSON', raw: res.responseText });
                    }
                },
                onerror: (e) => {
                    dlog('httpRequest:onerror', e);
                    reject(new Error('网络错误'));
                },
                ontimeout: () => {
                    dlog('httpRequest:timeout', { url, timeout });
                    reject(new Error('请求超时'));
                },
            });
        });
    }

    function toQuery(params) {
        const usp = new URLSearchParams();
        Object.entries(params).forEach(([k, v]) => usp.append(k, v));
        return usp.toString();
    }

    // 登录
    async function login(studentId) {
        dlog('login:start', { studentId });
        const url = `https://iclass.buaa.edu.cn:8346/app/user/login.action?` + toQuery({
            password: '',
            phone: studentId,
            userLevel: '1',
            verificationType: '2',
            verificationUrl: '',
        });
        const res = await httpRequest('GET', url);
        dlog('login:done', res);
        return res;
    }

    // 课表查询
    async function getSchedule(userId, sessionId, dateStr) {
        dlog('getSchedule:start', { userId, sessionIdPreview: (sessionId || '').slice(0, 6) + '...', dateStr });
        const url = `https://iclass.buaa.edu.cn:8346/app/course/get_stu_course_sched.action?` + toQuery({
            dateStr,
            id: userId,
        });
        const res = await httpRequest('GET', url, { headers: { sessionId } });
        dlog('getSchedule:done', res);
        return res;
    }

    // 签到
    async function sign(userId, courseSchedId, tsOverride) {
        dlog('sign:start', { userId, courseSchedId });
        const tsMs = (typeof tsOverride === 'number' && tsOverride > 0) ? tsOverride : Date.now();
        const url = `http://iclass.buaa.edu.cn:8081/app/course/stu_scan_sign.action?courseSchedId=${encodeURIComponent(courseSchedId)}&timestamp=${tsMs}`;
        const body = toQuery({ id: userId }); // 表单方式
        const res = await httpRequest('POST', url, {
            headers: {
                'Content-Type': 'application/x-www-form-urlencoded',
            },
            data: body,
        });
        dlog('sign:done', res);
        return res;
    }

    // 使用 postMessage 监听来自页面的请求，并回传处理结果
    window.addEventListener('message', async (ev) => {
        try {
            const data = ev.data || {};
            if (!data.__ICLASS_MSG__) return;
            const { type, id, payload } = data;
            dlog('message:received', { type, id, payload });

            if (type === 'iclass:intranet:query') {
                const { studentId, dateStr } = payload || {};
                try {
                    const loginRes = await login(studentId);
                    if (loginRes.STATUS !== '0') {
                        dlog('query:login-failed', loginRes);
                        window.postMessage({ __ICLASS_MSG__: true, type: 'iclass:intranet:query:result', id, payload: { login: loginRes, schedule: { STATUS: '1', message: '登录失败' } } }, '*');
                        return;
                    }
                    const userId = loginRes.result?.id;
                    const sessionId = loginRes.result?.sessionId;
                    const scheduleRes = await getSchedule(userId, sessionId, dateStr);
                    // 缓存课表，供后续签到时生成课程内随机时间戳使用
                    cacheSchedule(studentId, scheduleRes);
                    dlog('query:success');
                    window.postMessage({ __ICLASS_MSG__: true, type: 'iclass:intranet:query:result', id, payload: { login: loginRes, schedule: scheduleRes } }, '*');
                } catch (e) {
                    dlog('query:error', e);
                    window.postMessage({ __ICLASS_MSG__: true, type: 'iclass:intranet:query:result', id, payload: { login: { STATUS: '1', message: e.message }, schedule: { STATUS: '1', message: e.message } } }, '*');
                }
            }

            if (type === 'iclass:intranet:signin') {
                const { studentId, courseSchedId } = payload || {};
                try {
                    const loginRes = await login(studentId);
                    if (loginRes.STATUS !== '0') {
                        dlog('signin:login-failed', loginRes);
                        window.postMessage({ __ICLASS_MSG__: true, type: 'iclass:intranet:signin:result', id, payload: { STATUS: '1', message: '登录失败' } }, '*');
                        return;
                    }
                    const userId = loginRes.result?.id;

                    // 若能从缓存课表中找到对应课程时间，则将 URL 的 timestamp 改为课程进行中的随机时间；否则不改动
                    let tsOverride = undefined;
                    const times = findCourseTimes(studentId, courseSchedId);
                    if (times) {
                        const rnd = randomTimestampBetween(times.begin, times.end);
                        if (typeof rnd === 'number' && rnd > 0) {
                            tsOverride = rnd;
                            dlog('signin:timestamp-override', { begin: times.begin.toISOString(), end: times.end.toISOString(), ts: tsOverride });
                        }
                    }

                    const signRes = await sign(userId, courseSchedId, tsOverride);
                    dlog('signin:success');
                    window.postMessage({ __ICLASS_MSG__: true, type: 'iclass:intranet:signin:result', id, payload: signRes }, '*');
                } catch (e) {
                    dlog('signin:error', e);
                    window.postMessage({ __ICLASS_MSG__: true, type: 'iclass:intranet:signin:result', id, payload: { STATUS: '1', message: e.message } }, '*');
                }
            }
        } catch (err) {
            dlog('message:handler-error', err);
        }
    });

})();