// xuchao: 校验数学内容 JSON——外层可解析、每课有 md、quiz 块内层可解析且题目字段齐全
// 用法:node scripts/check-math-content.mjs <file.json> [more.json ...](不传则扫 src/content/math/*.json)
import fs from "node:fs";
import path from "node:path";

const TYPE_OK = new Set(["choice", "fill", "judge", "order", "match"]);

function checkQuizBlock(raw, where, errs) {
  let parsed;
  try {
    parsed = JSON.parse(raw);
  } catch (e) {
    errs.push(`${where}: quiz 块 JSON 解析失败 — ${e.message}`);
    return;
  }
  const qs = parsed.questions;
  if (!Array.isArray(qs) || qs.length === 0) {
    errs.push(`${where}: quiz 块没有 questions 数组`);
    return;
  }
  if (qs.length < 8) errs.push(`${where}: 题目只有 ${qs.length} 题(建议 ≥8)`);
  qs.forEach((q, i) => {
    const tag = `${where} 第${i + 1}题`;
    if (!TYPE_OK.has(q.type)) errs.push(`${tag}: 非法 type=${q.type}`);
    if (!q.stem || typeof q.stem !== "string") errs.push(`${tag}: 缺 stem`);
    if (!q.explain) errs.push(`${tag}: 缺 explain`);
    if (q.type === "choice") {
      if (!Array.isArray(q.options) || q.options.length < 2) errs.push(`${tag}: choice 选项不足`);
      if (typeof q.answer !== "number" || q.answer < 0 || q.answer >= (q.options?.length ?? 0))
        errs.push(`${tag}: choice answer 越界`);
    } else if (q.type === "judge") {
      if (q.answer !== 0 && q.answer !== 1) errs.push(`${tag}: judge answer 必须是 0 或 1`);
    } else if (q.type === "fill") {
      if (!Array.isArray(q.answers) || q.answers.length === 0) errs.push(`${tag}: fill 缺 answers 数组`);
    } else if (q.type === "order") {
      if (!Array.isArray(q.words) || !Array.isArray(q.answer)) errs.push(`${tag}: order 缺 words/answer`);
    } else if (q.type === "match") {
      if (!Array.isArray(q.pairs) || q.pairs.length === 0) errs.push(`${tag}: match 缺 pairs`);
    }
  });
}

function checkFile(file) {
  const errs = [];
  let data;
  try {
    data = JSON.parse(fs.readFileSync(file, "utf8"));
  } catch (e) {
    console.log(`❌ ${file}: 外层 JSON 解析失败 — ${e.message}`);
    return 1;
  }
  if (!data.module || !data.moduleName || !Array.isArray(data.points)) {
    console.log(`❌ ${file}: 缺 module / moduleName / points`);
    return 1;
  }
  const ids = new Set();
  let lessons = 0;
  data.points.forEach((p, idx) => {
    const tag = `${file} points[${idx}](${p.id ?? "?"})`;
    if (!p.id) errs.push(`${tag}: 缺 id`);
    else if (ids.has(p.id)) errs.push(`${tag}: id 重复`);
    else ids.add(p.id);
    if (!p.title) errs.push(`${tag}: 缺 title`);
    if (!p.md || typeof p.md !== "string") {
      errs.push(`${tag}: 缺 md`);
      return;
    }
    lessons++;
    const quizRe = /```quiz\s*\n([\s\S]*?)```/g;
    let m, count = 0;
    while ((m = quizRe.exec(p.md))) {
      count++;
      checkQuizBlock(m[1], `${tag} quiz#${count}`, errs);
    }
    if (count === 0) errs.push(`${tag}: md 中没有 quiz 块`);
  });
  if (errs.length) {
    console.log(`❌ ${file}: ${lessons} 课,${errs.length} 处问题`);
    errs.forEach((e) => console.log("   - " + e));
    return 1;
  }
  console.log(`✅ ${file}: ${data.module} / ${lessons} 课,全部通过`);
  return 0;
}

const args = process.argv.slice(2);
const files = args.length
  ? args
  : fs
      .readdirSync(path.join(process.cwd(), "src/content/math"))
      .filter((f) => f.endsWith(".json"))
      .map((f) => path.join(process.cwd(), "src/content/math", f));

let bad = 0;
for (const f of files) bad += checkFile(f);
console.log(bad ? `\n${bad} 个文件有问题` : "\n全部文件校验通过");
process.exit(bad ? 1 : 0);