import { readFileSync, writeFileSync, mkdirSync } from 'node:fs';
import { resolve } from 'node:path';
import { verifyReview, reviewMarkdown } from './review-content.mjs';
const root = process.cwd();
const catalog = [
  ['api', 'API 服务开发', 16],
  ['database', '数据库开发', 12],
  ['api-database', 'API + 数据库', 12],
  ['tasks', '异步任务开发', 16],
  ['redis', 'Redis 缓存', 10],
  ['docker', 'Docker 容器化', 10],
  ['linux', 'Linux 部署', 10],
  ['troubleshooting', '线上问题排查', 12],
  ['distributed', '分布式系统设计', 12],
  ['review', '复盘与自测', 9],
];
const errors = [];
let total = 0;
const report = [];
const validatedModules = [];
mkdirSync(resolve(root, 'public/downloads'), { recursive: true });
const text = (value) => typeof value === 'string' && value.trim().length > 0;
const list = (value, min = 1) => Array.isArray(value) && value.length >= min;
function verify(l, slug, index) {
  if (slug === 'review') {
    errors.push(
      ...verifyReview(
        l,
        index,
        new Map(
          validatedModules.map((module) => [module.slug, module.lessons]),
        ),
      ),
    );
    return;
  }
  const prefix = `${slug}/${l?.id || index}`;
  const theory = slug === 'distributed';
  if (
    theory &&
    (l.kind !== 'theory' ||
      l.production ||
      l.steps?.some((s) => s.code || s.lang || s.filename))
  )
    errors.push(
      `${prefix}: theory lessons must not contain practical code or production drills`,
    );
  if (
    theory &&
    (!text(l.interview?.question) ||
      !text(l.interview?.answer) ||
      !list(l.interview?.followUps))
  )
    errors.push(`${prefix}: missing interview question, answer or follow-ups`);
  if (l?.id !== String(index + 1).padStart(2, '0'))
    errors.push(`${prefix}: invalid lesson ID`);
  for (const key of ['group', 'title', 'summary'])
    if (!text(l?.[key])) errors.push(`${prefix}: missing ${key}`);
  if (
    !text(l.intro?.scenario) ||
    !text(l.intro?.outcome) ||
    !list(l.intro?.startingPoint) ||
    l.intro.startingPoint.some((item) => !text(item))
  )
    errors.push(
      `${prefix}: missing self-study scenario, starting point or outcome`,
    );
  if ('minutes' in l)
    errors.push(`${prefix}: instructor duration metadata is not allowed`);
  for (const key of [
    'objectives',
    'concepts',
    'steps',
    'checks',
    'pitfalls',
    'refs',
  ])
    if (!list(l?.[key])) errors.push(`${prefix}: missing ${key}`);
  for (const c of l.concepts || [])
    if (!text(c.title) || !text(c.body))
      errors.push(`${prefix}: incomplete concept`);
  for (const [stepIndex, s] of (l.steps || []).entries()) {
    const stepPrefix = `${prefix}/step-${stepIndex + 1}`;
    for (const key of ['title', 'body', 'expected', 'explanation'])
      if (!text(s[key])) errors.push(`${stepPrefix}: missing ${key}`);
    if (
      s.expected === s.body ||
      s.explanation === s.body ||
      s.expected === s.explanation
    )
      errors.push(
        `${stepPrefix}: action, observation and explanation must be distinct`,
      );
  }
  for (const p of l.pitfalls || [])
    if (!text(p.symptom) || !text(p.cause) || !text(p.fix))
      errors.push(`${prefix}: incomplete troubleshooting`);
  for (const key of ['task', 'hint', 'answer'])
    if (!text(l.exercise?.[key]))
      errors.push(`${prefix}: missing exercise ${key}`);
  for (const ref of l.refs || []) {
    try {
      if (!text(ref.label) || new URL(ref.url).protocol !== 'https:')
        throw new Error();
    } catch {
      errors.push(`${prefix}: invalid reference ${ref.url}`);
    }
  }
  if (slug !== 'api') {
    if (
      !list(l.objectives, 3) ||
      !list(l.steps, 4) ||
      !list(l.concepts, 3) ||
      !list(l.checks, 3) ||
      !list(l.pitfalls, 2) ||
      !list(l.refs, 2)
    )
      errors.push(`${prefix}: insufficient lesson detail`);
    if (
      !theory &&
      (!text(l.production?.scenario) ||
        !list(l.production?.decisions) ||
        !text(l.production?.failureDrill) ||
        !list(l.production?.acceptance))
    )
      errors.push(`${prefix}: incomplete production exercise`);
  }
}
const bullets = (items) => items.map((s) => `- ${s}`).join('\n');
function markdown(title, lessons) {
  return (
    `# ${title}\n\n术核 AI · 后端工程课件\n\n` +
    lessons
      .map((l) => {
        const theory = l.kind === 'theory';
        let out = `## ${l.id} ${l.title}\n\n${l.summary}\n\n### 从一个问题开始\n\n${l.intro.scenario}\n\n**这次的终点**\n\n${l.intro.outcome}\n\n#### 开始前，确认你在这里\n\n${bullets(l.intro.startingPoint)}\n\n`;
        out += theory
          ? '先按每一步的问题作出判断，再对照推演结果和解释；完成后用课末回顾整理概念。\n'
          : '每次只做一个步骤，先核对结果，再读原因。结果不一致时，先排查当前步骤，再继续往下。\n';
        out += `\n### 这节课要完成什么\n\n${bullets(l.objectives)}\n`;
        out +=
          `\n### ${theory ? '一步步推演场景' : '一步步完成案例'}\n\n` +
          l.steps
            .map(
              (s, i) =>
                `#### ${i + 1}. ${s.title}\n\n${s.body}\n${s.code ? `\n文件：${s.filename || '终端 / 当前课时'}\n\n\`\`\`\`${s.lang || 'text'}\n${s.code}\n\`\`\`\`\n` : ''}\n**${theory ? '对照你的推演' : '你应该看到什么'}**\n\n${s.expected}\n\n**${theory ? '从这里理解原因' : '刚才发生了什么'}**\n\n${s.explanation}\n`,
            )
            .join('\n');
        out += `\n### ${theory ? '检查推演结果' : '检查学习结果'}\n\n${bullets(l.checks)}\n`;
        if (l.production) {
          const p = l.production;
          out += `\n### 进一步验证：约束与故障\n\n先通过上面的学习结果检查，再做这一组实验。\n\n${p.scenario}\n\n#### 实现决策\n\n${bullets(p.decisions)}\n\n#### 隔离环境演练\n\n${p.failureDrill}\n\n#### 恢复验收\n\n${bullets(p.acceptance)}\n`;
        }
        out +=
          `\n### ${theory ? '常见误区' : '遇到问题时查这里'}\n\n` +
          l.pitfalls
            .map(
              (p) =>
                `#### ${p.symptom}\n\n原因：${p.cause}\n\n处理：${p.fix}\n`,
            )
            .join('\n');
        if (l.interview)
          out += `\n### 面试问答\n\n${l.interview.question}\n\n${l.interview.answer}\n\n追问：\n\n${bullets(l.interview.followUps)}\n`;
        out += `\n### ${theory ? '自己设计一次' : '自己试一次'}\n\n${l.exercise.task}\n\n提示：${l.exercise.hint}\n\n参考答案：\n\n${l.exercise.answer}\n\n### 核心概念回顾\n\n${theory ? '回想刚才每一种选择造成的结果，再用下面的概念解释自己的判断。' : '回想刚才的操作、现象与选择，用下面的概念解释你已经完成的案例。'}\n\n`;
        out += l.concepts
          .map((c) => `#### ${c.title}\n\n${c.body}\n`)
          .join('\n');
        out += `\n### ${theory ? '延伸阅读' : '技术文档'}\n\n${l.refs.map((r) => `- [${r.label}](${r.url})`).join('\n')}\n`;
        return out;
      })
      .join('\n---\n\n')
  );
}
for (const [slug, title, count] of catalog) {
  const path = resolve(
    root,
    slug === 'api' ? 'app/lessons.json' : `public/content/${slug}.json`,
  );
  let lessons;
  try {
    lessons = JSON.parse(readFileSync(path, 'utf8').replace(/^\uFEFF/, ''));
  } catch (error) {
    errors.push(`${slug}: ${error.message}`);
    continue;
  }
  if (!Array.isArray(lessons) || lessons.length !== count) {
    errors.push(`${slug}: expected ${count} lessons`);
    continue;
  }
  lessons.forEach((l, i) => verify(l, slug, i));
  total += lessons.length;
  validatedModules.push({ slug, title, lessons });
  report.push({
    slug,
    lessons: lessons.length,
    steps: lessons.reduce((n, l) => n + (l.steps?.length || 0), 0),
    codeBlocks: lessons.reduce(
      (n, l) => n + (l.steps?.filter((s) => s.code).length || 0),
      0,
    ),
  });
}
if (errors.length) {
  console.error(errors.join('\n'));
  process.exit(1);
}
for (const { slug, title, lessons } of validatedModules) {
  writeFileSync(
    resolve(root, `public/downloads/${slug}-lessons.md`),
    slug === 'review' ? reviewMarkdown(lessons) : markdown(title, lessons),
  );
}
console.log(
  JSON.stringify(
    { modules: report.length, lessons: total, details: report },
    null,
    2,
  ),
);