const test = require('node:test');
const assert = require('node:assert/strict');
const { extractQuestions, create } = require('../src/adapter.js');

const single = () => ({ id: 'q1', quesType: 0, content: '<p>升温时应选择？</p>', choiceItems: [
  { id: 'a1', content: '降低温度', selected: 1, answer: 0 },
  { id: 'a2', content: '提高温度', selected: 0, answer: 1 }
] });

test('extracts confirmed choices atomically and ignores student selection', () => {
  const [q] = extractQuestions({ data: { praId: 'p1', praName: '单选题库', listQues: [single()] } });
  assert.equal(q.bankId, 'p1');
  assert.equal(q.bankName, '单选题库');
  assert.equal(q.stem, '升温时应选择？');
  assert.deepEqual(q.correctOptionIds, ['a2']);
  assert.deepEqual(q.answerTexts, ['提高温度']);
});

test('selected, submitContent, userAnswer and top-level answer/answers are not standard answers', () => {
  const raw = single();
  raw.choiceItems.forEach(o => delete o.answer);
  Object.assign(raw, { answer: 'a1', answers: ['a1'], userAnswer: 'a1', submitQuesAnswers: ['a1'], corrected: true });
  const [q] = extractQuestions({ questionList: [raw] });
  assert.equal(q.answerStatus, 'missing');
  assert.deepEqual(q.answerTexts, []);
});

test('judge zero and string zero mean incorrect, never truthy correct', () => {
  for (const judgeAnswer of [0, '0', 1, '1', null, '-1']) {
    const [q] = extractQuestions({ listQues: [{ id: 'j1', quesType: 2, content: '压力越高越安全。', judgeAnswer }] });
    const valid = judgeAnswer === 0 || judgeAnswer === '0' || judgeAnswer === 1 || judgeAnswer === '1';
    assert.equal(q.answerStatus, valid ? 'confirmed' : 'missing');
    assert.deepEqual(q.answerTexts, valid ? [String(judgeAnswer) === '1' ? '正确' : '错误'] : []);
  }
});

test('multiple answers use ids and follow each response option order without letter assumptions', () => {
  const raw = single(); raw.quesType = 1;
  raw.choiceItems.push({ id: 'a3', content: '保持压力', answer: 1 });
  raw.choiceItems.reverse();
  const [q] = extractQuestions([raw]);
  assert.deepEqual(q.correctOptionIds, ['a3', 'a2']);
  assert.deepEqual(q.answerTexts, ['保持压力', '提高温度']);
  assert.equal(q.options.find(o => o.id === 'a2').label, 'B');
});

test('answer-only responses require an identified known question', () => {
  const raw = single(); raw.choiceItems.forEach(o => delete o.answer);
  const [base] = extractQuestions(raw, { bankId: 'p1' });
  const response = [{ answers: ['a2'], corrected: false, explainText: '<b>标准解释</b>' }];
  assert.deepEqual(extractQuestions(response, { answerResponse: true, questionId: 'other', knownQuestions: [base], bankId: 'p1' }), []);
  const [q] = extractQuestions(response, { answerResponse: true, questionId: 'q1', knownQuestions: [base], bankId: 'p1' });
  assert.equal(q.questionId, 'q1');
  assert.deepEqual(q.answerTexts, ['提高温度']);
  assert.equal(q.explanation, '标准解释');
  assert.deepEqual(extractQuestions([response[0], response[0]], { answerResponse: true, questionId: 'q1', knownQuestions: [base], bankId: 'p1' }), []);
});

test('cross-bank id collisions cannot attach an answer to another bank', () => {
  const [base] = extractQuestions(single(), { bankId: 'p1' });
  assert.deepEqual(extractQuestions([{ answers: ['a2'] }], { answerResponse: true, questionId: 'q1', knownQuestions: [base], bankId: 'p2' }), []);
});

test('known questions support explicit correctAnswers but not invalid option ids', () => {
  const raw = single(); raw.choiceItems.forEach(o => delete o.answer);
  raw.correctAnswers = ['a2'];
  assert.deepEqual(extractQuestions(raw)[0].answerTexts, ['提高温度']);
  raw.correctAnswers = ['a1', 'a2'];
  assert.equal(extractQuestions(raw)[0].answerStatus, 'missing');
  raw.correctAnswers = ['unknown'];
  assert.equal(extractQuestions(raw)[0].answerStatus, 'missing');
});

test('hidden standard answers and unrelated business objects stay unconfirmed', () => {
  const raw = single(); raw.allowViewSingleQuesAnswer = 0;
  assert.equal(extractQuestions(raw)[0].answerStatus, 'missing');
  assert.deepEqual(extractQuestions({ id: 'x', type: 0, content: '普通通知', selected: true }), []);
});

test('resultInfo.answers is explicit standard-answer context on a full question', () => {
  const raw = single(); raw.choiceItems.forEach(o => delete o.answer);
  raw.answers = ['a1']; raw.resultInfo = { answers: ['a2'], explainText: '说明' };
  assert.deepEqual(extractQuestions(raw)[0].answerTexts, ['提高温度']);
});

test('markup and entities preserve comparisons, units and negations', () => {
  const raw = single(); raw.content = '<p>温度&lt;100℃，压力&gt;2MPa时不正确的是？</p>';
  assert.equal(extractQuestions(raw)[0].stem, '温度<100℃，压力>2MPa时不正确的是？');
});

test('malformed/unsupported types, circular and deeply nested payloads are bounded', () => {
  const circular = { data: null }; circular.data = circular;
  assert.deepEqual(extractQuestions(circular), []);
  assert.deepEqual(extractQuestions({ quesType: 3, id: 'x', content: '填空' }), []);
  assert.deepEqual(extractQuestions(null), []);
  assert.deepEqual(extractQuestions('not json'), []);
  assert.deepEqual(extractQuestions({ ...single(), choiceItems: [null, {}] }), []);
  const deeply = {}; let at = deeply; for (let i = 0; i < 30; i++) at = at.data = {};
  at.questionList = [single()];
  assert.deepEqual(extractQuestions(deeply), []);
});

function fakePage(fetchImpl = async () => new Response('{}', { headers: { 'content-type': 'application/json' } })) {
  class XHR extends EventTarget {
    open(method, url) { this.method = method; this.url = url; }
    send(body) { this.sentBody = body; }
    getResponseHeader(name) { return name === 'content-type' ? 'application/json' : null; }
    respond(value) { this.status = 200; this.responseType = ''; this.responseText = JSON.stringify(value); this.dispatchEvent(new Event('load')); }
  }
  const doc = { title: '题库一', querySelector: () => null, querySelectorAll: () => [] };
  const win = { fetch: fetchImpl, XMLHttpRequest: XHR, location: { href: 'https://www.shhuayi-elearning.cn/o2o/' }, setTimeout, clearTimeout };
  const received = [];
  const adapter = create({ window: win, document: doc, onQuestions: values => received.push(...values) });
  return { win, doc, adapter, received };
}
const flush = () => new Promise(resolve => setImmediate(resolve));

test('fetch observation keeps original response, snapshots bank name and restores original fetch', async () => {
  let release;
  const original = () => new Promise(resolve => { release = resolve; });
  const { win, doc, adapter, received } = fakePage(original);
  adapter.start();
  const promise = win.fetch('https://api-ulcd.yunxuetang.cn/v2/upm/start?praId=p1&token=secret');
  doc.title = '题库二';
  const response = new Response(JSON.stringify({ listQues: [single()] }), { headers: { 'content-type': 'application/json' } });
  release(response);
  assert.equal(await promise, response);
  await flush(); await flush();
  assert.equal(received.length, 1);
  assert.equal(received[0].bankName, '题库一');
  assert.equal(received[0].bankId, 'p1');
  assert.equal(received[0].source.url, 'https://api-ulcd.yunxuetang.cn/v2/upm/start');
  assert.equal(response.bodyUsed, false);
  adapter.stop();
  assert.equal(win.fetch, original);
});

test('responses from a previous capture session are ignored after pause and resume', async () => {
  let release;
  const { win, adapter, received } = fakePage(() => new Promise(resolve => { release = resolve; }));
  adapter.start();
  const promise = win.fetch('/upm/start?praId=p1');
  adapter.stop(); adapter.start();
  release(new Response(JSON.stringify({ listQues: [single()] }), { headers: { 'content-type': 'application/json' } }));
  await promise; await flush(); await flush();
  assert.equal(received.length, 0);
  adapter.stop();
});

test('XHR observes standard result by request question id even after another question loads', () => {
  const { win, adapter, received } = fakePage();
  const originalOpen = win.XMLHttpRequest.prototype.open;
  adapter.start();
  const initial = new win.XMLHttpRequest();
  initial.open('GET', '/upm/start?praId=p1'); initial.send();
  const raw = single(); raw.choiceItems.forEach(o => delete o.answer);
  initial.respond({ listQues: [raw, { id: 'q2', quesType: 2, content: '另一题' }] });
  const answer = new win.XMLHttpRequest();
  answer.open('PUT', '/upm/p1/users/u1/answer');
  answer.send(JSON.stringify({ answers: [{ quesId: 'q1', answer: ['a1'] }] }));
  answer.respond([{ answers: ['a2'], corrected: false }]);
  const result = received.at(-1);
  assert.equal(result.questionId, 'q1');
  assert.equal(result.type, 'single');
  assert.deepEqual(result.answerTexts, ['提高温度']);
  adapter.stop();
  assert.equal(win.XMLHttpRequest.prototype.open, originalOpen);
});

test('unrelated API paths and unrelated hosts do not get captured', async () => {
  const { win, adapter, received } = fakePage(async () => new Response(JSON.stringify({ listQues: [single()] }), { headers: { 'content-type': 'application/json' } }));
  adapter.start();
  await win.fetch('https://unknown.example/upm/start?praId=p1');
  await win.fetch('/ordinary/notifications');
  await flush();
  assert.equal(received.length, 0);
  adapter.stop();
});

function bankPage(fetchImpl) {
  const page = fakePage(fetchImpl);
  const events = new EventTarget();
  page.win.addEventListener = events.addEventListener.bind(events);
  page.win.removeEventListener = events.removeEventListener.bind(events);
  page.win.dispatchEvent = events.dispatchEvent.bind(events);
  const state = { sidebar: '判断题库1', player: '判断题库1', exam: '判断题库1', taskId: 'task-a', containerTask: 'task-a', stem: '升温时应选择？', form: true };
  page.win.location.href = 'https://www.shhuayi-elearning.cn/o2o/#/playinfo?taskId=task-a';
  page.doc.title = '不会随切换更新的旧标题';
  const item = { getAttribute: key => key === 'data-task-id' ? state.taskId : null };
  const sidebar = { get textContent() { return state.sidebar; }, closest: () => item };
  const player = { get textContent() { return state.player; } };
  const exam = { get textContent() { return state.exam; } };
  const container = { getAttribute: key => key === 'task-id' ? state.containerTask : null };
  const main = { querySelectorAll: () => [] };
  const stem = { get textContent() { return state.stem; }, matches: selector => selector === '[data-rich-text]' };
  const options = ['降低温度', '提高温度'].map((value, index) => ({
    querySelector: selector => selector === 'input' ? { value: `a${index + 1}` } : selector === '.yxtf-radio__label, .yxtf-checkbox__label' ? { textContent: `${String.fromCharCode(65 + index)}. ${value}`, querySelector: () => null } : null,
    textContent: value
  }));
  const form = {
    get textContent() { return state.stem + options.map(option => option.textContent).join(''); },
    closest: selector => selector === ROOT_SELECTOR_FOR_TEST ? main : null,
    getAttribute: () => null, style: {},
    querySelector: selector => selector === '.yxtulcdsdk-form__content' ? { children: [stem] } : null,
    querySelectorAll: () => options
  };
  page.doc.querySelector = selector => {
    if (selector === '.task-content-active .group-title, .task-content-active .task-content-color-active') return state.sidebar ? sidebar : null;
    if (selector === 'header.o2oPlayFrame-right .title .yxtf-tooltip') return state.player ? player : null;
    if (selector === '.yxtulcdsdk-exam-header .yxtf-tooltip') return state.exam ? exam : null;
    if (selector === '.yxtulcdsdk-exam-container[task-id]') return container;
    return null;
  };
  page.doc.querySelectorAll = selector => selector === '.yxtulcdsdk-pc-marking-main .yxtulcdsdk-form' && state.form ? [form] : [];
  const changes = [];
  page.adapter = create({ window: page.win, document: page.doc, onQuestions: values => page.received.push(...values), onBankChange: bank => changes.push(bank) });
  return { ...page, state, changes, navigate(name, taskId) {
    state.sidebar = name; state.taskId = taskId;
    page.win.location.href = `https://www.shhuayi-elearning.cn/o2o/#/playinfo?taskId=${taskId}`;
    page.win.dispatchEvent(new Event('hashchange'));
  } };
}
const ROOT_SELECTOR_FOR_TEST = '.yxtulcdsdk-pc-marking-main';

test('current bank follows actual active sidebar instead of stale document title, even without questions', () => {
  const { adapter, state, navigate, doc, changes } = bankPage();
  adapter.start();
  assert.equal(adapter.getCurrentBank().bankName, '判断题库1');
  navigate('单选题库1', 'task-b');
  assert.equal(doc.title, '不会随切换更新的旧标题');
  assert.equal(adapter.getCurrentBank().bankName, '单选题库1');
  assert.equal(adapter.getCurrentBank().loading, true);
  assert.equal(adapter.getCurrentQuestion(), null, '旧判断题DOM仍在时不能采到新的单选库');
  state.player = state.exam = '单选题库1'; state.containerTask = 'task-b';
  assert.equal(adapter.getCurrentQuestion(), null, '只更新标题和task-id也不能把旧正文移入新库');
  state.stem = '新的单选题目？';
  const question = adapter.getCurrentQuestion();
  assert.equal(question.bankName, '单选题库1');
  assert.equal(question.stem, '新的单选题目？');
  assert.equal(adapter.getCurrentBank().loading, false);
  state.form = false;
  assert.equal(adapter.getCurrentBank().bankName, '单选题库1', '未出现题目时仍能识别库名用于导出');
  assert.ok(changes.some(bank => bank.bankName === '单选题库1'));
  adapter.stop();
});

test('late old-bank response retains source name and cannot change the new active bank', async () => {
  const pending = new Map();
  const page = bankPage(url => new Promise(resolve => pending.set(url, resolve)));
  page.adapter.start();
  const first = page.win.fetch('/upm/start?praId=bank-a');
  page.navigate('单选题库1', 'task-b');
  page.state.player = page.state.exam = '单选题库1'; page.state.containerTask = 'task-b'; page.state.stem = '新的单选题目？';
  const second = page.win.fetch('/upm/start?praId=bank-b');
  const response = raw => new Response(JSON.stringify({ listQues: [raw] }), { headers: { 'content-type': 'application/json' } });
  pending.get('/upm/start?praId=bank-b')(response({ ...single(), id: 'q-b', content: '新的单选题目？' }));
  await second; await flush(); await flush();
  assert.equal(page.adapter.getCurrentBank().bankId, 'bank-b');
  pending.get('/upm/start?praId=bank-a')(response(single()));
  await first; await flush(); await flush();
  assert.equal(page.adapter.getCurrentBank().bankName, '单选题库1');
  assert.equal(page.adapter.getCurrentBank().bankId, 'bank-b');
  assert.equal(page.received.find(record => record.bankId === 'bank-a').bankName, '判断题库1');
  page.adapter.stop();
});

test('returning A to B to A does not adopt late B results or stale document title', async () => {
  let releaseB;
  const page = bankPage(url => String(url).includes('bank-b') ? new Promise(resolve => { releaseB = resolve; }) : Promise.resolve(new Response(JSON.stringify({ listQues: [single()] }), { headers: { 'content-type': 'application/json' } })));
  page.adapter.start();
  await page.win.fetch('/upm/start?praId=bank-a'); await flush(); await flush();
  page.navigate('单选题库1', 'task-b');
  page.state.player = page.state.exam = '单选题库1'; page.state.containerTask = 'task-b'; page.state.stem = '新的单选题目？';
  const pending = page.win.fetch('/upm/start?praId=bank-b');
  page.navigate('判断题库1', 'task-a');
  page.state.player = page.state.exam = '判断题库1'; page.state.containerTask = 'task-a'; page.state.stem = '升温时应选择？';
  releaseB(new Response(JSON.stringify({ listQues: [{ ...single(), content: '新的单选题目？' }] }), { headers: { 'content-type': 'application/json' } }));
  await pending; await flush(); await flush();
  assert.equal(page.adapter.getCurrentBank().bankName, '判断题库1');
  assert.equal(page.adapter.getCurrentBank().bankId, 'bank-a');
  assert.equal(page.received.find(record => record.bankId === 'bank-b').bankName, '单选题库1');
  page.adapter.stop();
});

test('different named response in same task never changes selected bank name or id', async () => {
  let payload = { praName: '判断题库1', listQues: [single()] };
  const page = bankPage(async () => new Response(JSON.stringify(payload), { headers: { 'content-type': 'application/json' } }));
  page.adapter.start();
  await page.win.fetch('/upm/start?praId=bank-a'); await flush(); await flush();
  assert.equal(page.adapter.getCurrentBank().bankId, 'bank-a');
  payload = { praName: '接口验收库', listQues: [single()] };
  await page.win.fetch('/upm/start?praId=unrelated-bank'); await flush(); await flush();
  assert.equal(page.adapter.getCurrentBank().bankName, '判断题库1');
  assert.equal(page.adapter.getCurrentBank().bankId, 'bank-a');
  page.adapter.stop();
});

test('bank identity keeps updating while capture and copy are both paused', () => {
  const page = bankPage();
  page.adapter.start(); page.adapter.stop(); page.adapter.setCopyEnabled(false);
  const before = page.received.length;
  page.navigate('多选题库', 'task-c');
  assert.equal(page.changes.at(-1).bankName, '多选题库');
  assert.equal(page.received.length, before);
});

test('initial HTML parsing and atomic full SPA render do not block a new form', () => {
  const page = bankPage();
  page.state.sidebar = page.state.player = page.state.exam = ''; page.state.form = false;
  page.adapter.start();
  page.state.sidebar = page.state.player = page.state.exam = '判断题库1'; page.state.form = true;
  assert.ok(page.adapter.getCurrentQuestion(), '首次解析出正文不能当成上一题残留');
  page.state.sidebar = page.state.player = page.state.exam = '单选题库1';
  page.state.taskId = page.state.containerTask = 'task-b'; page.state.stem = '同步渲染的新题目？';
  page.win.location.href = 'https://www.shhuayi-elearning.cn/o2o/#/playinfo?taskId=task-b';
  const question = page.adapter.getCurrentQuestion();
  assert.equal(question.bankName, '单选题库1');
  assert.equal(question.stem, '同步渲染的新题目？');
  page.adapter.stop();
});

test('ordinary pages do not observe requests, capture questions or intercept copy events', async () => {
  const page = fakePage(async () => new Response(JSON.stringify({ listQues: [single()] }), { headers: { 'content-type': 'application/json' } }));
  page.win.location.href = 'https://ordinary.example/account';
  page.doc.title = '普通网页标题不应成为题库';
  const originalFetch = page.win.fetch;
  const originalOpen = page.win.XMLHttpRequest.prototype.open;
  const originalSend = page.win.XMLHttpRequest.prototype.send;
  const listeners = [];
  const observers = [];
  page.win.addEventListener = type => listeners.push(type);
  page.win.removeEventListener = () => {};
  page.win.MutationObserver = class {
    constructor(callback) { observers.push(callback); }
    observe() {}
  };
  page.doc.createElement = () => assert.fail('普通网页不能注入复制恢复样式');
  const changes = [];
  const adapter = create({ window: page.win, document: page.doc, observeNetwork: false,
    onQuestions: values => page.received.push(...values), onBankChange: bank => changes.push(bank) });
  adapter.start();
  adapter.setCopyEnabled(true);
  assert.equal(adapter.isSupportedPage(), false);
  assert.equal(adapter.getCurrentQuestion(), null);
  assert.equal(adapter.captureCurrent(), null);
  assert.deepEqual(adapter.getCurrentBank(), { bankId: '', bankName: '', taskId: '', loading: false });
  await page.win.fetch('/upm/start?praId=not-a-bank');
  const xhr = new page.win.XMLHttpRequest();
  xhr.open('GET', '/upm/start?praId=not-a-bank'); xhr.send(); xhr.respond({ listQues: [single()] });
  await flush();
  adapter.stop();
  assert.equal(page.win.fetch, originalFetch);
  assert.equal(page.win.XMLHttpRequest.prototype.open, originalOpen);
  assert.equal(page.win.XMLHttpRequest.prototype.send, originalSend);
  assert.deepEqual(page.received, [], '普通页响应即使碰巧形似练习数据也不能写入题库');
  assert.deepEqual(listeners, [], '普通页无需安装copy、selection或导航监听');
  assert.deepEqual(observers, [], '普通页不需要观察整个DOM');
  assert.ok(changes.every(bank => bank.bankName === '' && bank.bankId === ''));
});

test('network observation can be disabled independently on a supported exercise page', async () => {
  const page = bankPage();
  const originalFetch = page.win.fetch;
  const originalOpen = page.win.XMLHttpRequest.prototype.open;
  const adapter = create({ window: page.win, document: page.doc, observeNetwork: false,
    onQuestions: values => page.received.push(...values) });
  adapter.start();
  assert.equal(adapter.isSupportedPage(), true);
  assert.equal(page.received.length, 1, '已知站点的页面采集不依赖网络钩子');
  assert.equal(page.received[0].stem, '升温时应选择？');
  assert.equal(page.received[0].bankName, '判断题库1');
  assert.equal(page.received[0].answerStatus, 'missing');
  assert.equal(page.win.fetch, originalFetch);
  assert.equal(page.win.XMLHttpRequest.prototype.open, originalOpen);
  adapter.stop();
});

test('a known root appearing later is detectable without automatically enabling network observation', () => {
  const page = fakePage();
  page.win.location.href = 'https://ordinary.example/demo';
  page.doc.title = '显式题目结构演示';
  let exerciseRoot = null;
  page.doc.querySelector = selector => selector === ROOT_SELECTOR_FOR_TEST ? exerciseRoot : null;
  const originalFetch = page.win.fetch;
  const originalOpen = page.win.XMLHttpRequest.prototype.open;
  const adapter = create({ window: page.win, document: page.doc, observeNetwork: false,
    onQuestions: values => page.received.push(...values) });
  adapter.start();
  assert.equal(adapter.isSupportedPage(), false);
  assert.equal(adapter.getCurrentBank().bankName, '');
  exerciseRoot = {};
  assert.equal(adapter.isSupportedPage(), true);
  assert.equal(adapter.getCurrentBank().bankName, '显式题目结构演示');
  assert.equal(page.win.fetch, originalFetch);
  assert.equal(page.win.XMLHttpRequest.prototype.open, originalOpen);
  assert.deepEqual(page.received, []);
  adapter.stop();
});

test('a lookalike hostname is not treated as the supported learning platform', () => {
  const page = fakePage();
  page.win.location.href = 'https://www.shhuayi-elearning.cn.ordinary.example/';
  page.doc.title = '页面标题不是题库';
  const adapter = create({ window: page.win, document: page.doc, observeNetwork: false });
  adapter.start();
  assert.equal(adapter.isSupportedPage(), false);
  assert.equal(adapter.getCurrentBank().bankName, '');
  assert.equal(adapter.getCurrentQuestion(), null);
  adapter.stop();
});