const path = require('path');
const fs = require('fs');
const { pathToFileURL } = require('url');
const express = require('express');
const { analyzeChatLogsFile, defaultReport, buildHookChatWindows } = require('./lib/analyzeChatLogs');
const { mergeAiEvaluation, loadAiEvaluationFile } = require('./lib/mergeAiEvaluation');
const { loadStudentRepoContext, attachRepoToHeuristicReport } = require('./lib/repoContext.cjs');
const { finalizeTaskAlignedEvidence } = require('./lib/taskAlignedAbility.cjs');
const { ensureStudentRepo } = require('./lib/studentRepo.cjs');
const { resolveChatLogPath } = require('./lib/resolveChatLogPath.cjs');
const { getDefaultPublicStudentGitUrl } = require('./lib/gitCloneUrl.cjs');
const { loadEvaluationDimensions, alignEvaluationAbilityToDimensions } = require('./lib/evaluationDimensions.cjs');

const ROOT = __dirname;
const PORT = Number(process.env.PORT) || 53780;
const CHAT_LOG = resolveChatLogPath(ROOT);

/** 与 report-ui mergeQuestions 一致：跨会话合并提问卡片 */
function mergeHookQuestionsAcrossConversations(conversations) {
  const seen = new Set();
  const out = [];
  for (const c of conversations || []) {
    const cid = String(c.conversation_id || c.id || c.session_id || '').trim();
    for (const q of c.questions || []) {
      const k = q.title || q.detail;
      if (!k) continue;
      const dedupeKey = `${cid}\0${k}\0${String(q.time ?? '')}`;
      if (seen.has(dedupeKey)) continue;
      seen.add(dedupeKey);
      out.push({
        ...q,
        conversation_id: q.conversation_id || cid || null,
      });
    }
  }
  return out;
}

/** 不含密码，用于 API 与页面展示；clone 时在 lib/studentRepo 内按需注入 DEFAULT_STUDENT_GIT_USER / DEFAULT_STUDENT_GIT_PASSWORD */
const DEFAULT_STUDENT_GIT_URL = getDefaultPublicStudentGitUrl();

const app = express();

app.use(express.json({ limit: '2mb' }));

function isSafeHttpUrl(u) {
  try {
    const x = new URL(String(u).trim());
    return x.protocol === 'https:' || x.protocol === 'http:';
  } catch {
    return false;
  }
}

function pickGitUrl(req) {
  const raw = req.query.git;
  if (typeof raw === 'string' && raw.trim()) {
    try {
      const decoded = decodeURIComponent(raw.trim());
      if (isSafeHttpUrl(decoded)) return decoded;
    } catch {
      if (isSafeHttpUrl(raw.trim())) return raw.trim();
    }
  }
  return DEFAULT_STUDENT_GIT_URL;
}

/**
 * 从磁盘 chat_logs 注入：① 各会话完整 Hook 时间线（查看详情）② Hook 原文提问列表（与大模型摘要合并）
 */
function enrichReportWithHookTranscriptMap(report, chatLogPath) {
  if (!report || !report.ok) return;
  report.hook_transcript_source_file = path.basename(chatLogPath);
  if (!fs.existsSync(chatLogPath)) {
    report.hook_transcript_map_error = `未找到「${path.basename(chatLogPath)}」。可设置环境变量 CHAT_LOG_PATH 指向云端落盘路径。`;
    report.hook_transcript_by_conv_id = {};
    report.hook_chat_windows = [];
    return;
  }
  try {
    const raw = JSON.parse(fs.readFileSync(chatLogPath, 'utf8'));
    const analysis = analyzeChatLogsFile(chatLogPath);
    if (!analysis.ok) {
      report.hook_transcript_map_error = analysis.error || 'chat_logs 解析失败';
      report.hook_transcript_by_conv_id = {};
      report.hook_chat_windows = [];
      return;
    }
    report.hook_excerpt_questions = mergeHookQuestionsAcrossConversations(analysis.conversations);
    report.hook_chat_windows = buildHookChatWindows(raw);
    const m = {};
    for (const c of analysis.conversations || []) {
      const t = c.hook_transcript;
      if (typeof t !== 'string' || !t.trim() || !c.id) continue;
      const topId = String(c.id).trim();
      m[topId] = t;
      const events = Array.isArray(raw[topId]) ? raw[topId] : null;
      if (!events) continue;
      for (const ev of events) {
        const hid = ev?.hook_input?.conversation_id;
        if (hid == null) continue;
        const inner = String(hid).trim();
        if (inner && inner !== topId) m[inner] = t;
      }
    }
    report.hook_transcript_by_conv_id = m;
    report.hook_transcript_map_size = Object.keys(m).length;
    if (report.hook_transcript_map_size === 0) {
      report.hook_transcript_map_error =
        '日志已读入但未生成时间线，请确认 JSON 为「会话ID → Hook 事件数组」且事件含 hook_input。';
    } else {
      delete report.hook_transcript_map_error;
    }
  } catch (e) {
    report.hook_transcript_map_error = String(e.message || e);
    report.hook_transcript_by_conv_id = {};
    report.hook_chat_windows = [];
    // eslint-disable-next-line no-console
    console.warn('[api/report] hook_transcript_by_conv_id 构建失败:', e.message || e);
  }
}

function loadReportHeuristicOnly() {
  let report;
  if (!fs.existsSync(CHAT_LOG)) {
    report = defaultReport();
    report.note = `未找到 ${path.basename(CHAT_LOG)}，已返回占位报告。`;
  } else {
    try {
      report = analyzeChatLogsFile(CHAT_LOG);
    } catch (e) {
      return { ok: false, error: String(e.message || e) };
    }
  }
  const heuristicEvalSnapshot =
    report.ok && report.evaluation ? JSON.parse(JSON.stringify(report.evaluation)) : null;
  const ai = loadAiEvaluationFile(ROOT);
  if (report.ok && ai) {
    report.evaluation = mergeAiEvaluation(report.evaluation, ai);
  }
  const dimList = loadEvaluationDimensions(ROOT);
  if (report.ok && report.evaluation && dimList.length) {
    alignEvaluationAbilityToDimensions(report.evaluation, dimList, heuristicEvalSnapshot);
  }
  return report;
}

const MAX_REPO_FILE_BYTES = 200000;

const MIME = {
  '.png': 'image/png',
  '.jpg': 'image/jpeg',
  '.jpeg': 'image/jpeg',
  '.gif': 'image/gif',
  '.webp': 'image/webp',
  '.ico': 'image/x-icon',
  '.svg': 'image/svg+xml',
};

app.get('/api/repo-file', (req, res) => {
  res.setHeader('Cache-Control', 'no-store');
  const gitUrl = pickGitUrl(req);
  const relRaw = req.query.file;
  if (typeof relRaw !== 'string' || !relRaw.trim()) {
    return res.status(400).json({ ok: false, error: '缺少 file 参数（仓库内相对路径）' });
  }
  let rel = relRaw.replace(/\\/g, '/').replace(/^\/+/, '');
  if (rel.includes('..') || path.isAbsolute(rel)) {
    return res.status(400).json({ ok: false, error: '非法路径' });
  }
  try {
    const repoPath = ensureStudentRepo(gitUrl, ROOT);
    const full = path.join(repoPath, rel);
    const resolved = path.resolve(full);
    const rootResolved = path.resolve(repoPath);
    if (!resolved.startsWith(rootResolved + path.sep) && resolved !== rootResolved) {
      return res.status(403).json({ ok: false, error: '禁止越权访问' });
    }
    if (!fs.existsSync(resolved) || !fs.statSync(resolved).isFile()) {
      return res.status(404).json({ ok: false, error: '文件不存在' });
    }
    const ext = path.extname(resolved).toLowerCase();
    const buf = fs.readFileSync(resolved);
    const mime = MIME[ext];
    if (mime && !['.svg'].includes(ext)) {
      return res.json({
        ok: true,
        path: rel,
        mode: 'binary',
        mime,
        base64: buf.toString('base64'),
        size: buf.length,
      });
    }
    const text = buf.toString('utf8');
    const truncated = buf.length > MAX_REPO_FILE_BYTES;
    return res.json({
      ok: true,
      path: rel,
      mode: 'text',
      mime: mime || 'text/plain',
      truncated,
      content: truncated ? text.slice(0, MAX_REPO_FILE_BYTES) : text,
      size: buf.length,
    });
  } catch (e) {
    return res.status(500).json({ ok: false, error: String(e.message || e) });
  }
});

app.get('/api/report', async (req, res) => {
  res.setHeader('Cache-Control', 'no-store');
  const gitUrl = pickGitUrl(req);
  const qFast = String(req.query.fast || req.query.heuristic || req.query.nollm || '').toLowerCase();
  const forceHeuristic = qFast === '1' || qFast === 'true' || qFast === 'yes';
  const useLlm =
    !forceHeuristic &&
    process.env.DISABLE_FULL_LLM_REPORT !== '1' &&
    Boolean(process.env.CURSOR_API_KEY);
  const t0 = Date.now();

  let ctx = null;
  try {
    ctx = loadStudentRepoContext(gitUrl, ROOT, CHAT_LOG);
  } catch (e) {
    console.error('[api/report] git clone/scan failed:', e.message || e);
    if (useLlm) {
      return res.status(502).json({
        ok: false,
        error: `无法拉取或扫描远程仓库：${e.message || e}`,
        git_url: gitUrl,
      });
    }
  }

  if (useLlm && ctx) {
    try {
      const modUrl = pathToFileURL(path.join(ROOT, 'lib/runFullPageAgent.mjs')).href;
      const { generateFullPageReport } = await import(modUrl);
      const data = await generateFullPageReport({
        root: ROOT,
        gitUrl,
        chatLogPath: CHAT_LOG,
        repoContext: ctx,
      });
      enrichReportWithHookTranscriptMap(data, CHAT_LOG);
      if (ctx) finalizeTaskAlignedEvidence(ctx, data);
      data.report_build_ms = Date.now() - t0;
      return res.json(data);
    } catch (e) {
      console.error('[api/report] full LLM report failed:', e.message || e);
      const fallback = loadReportHeuristicOnly();
      if (fallback.ok) {
        fallback.source = 'heuristic_fallback';
        fallback.git_url = gitUrl;
        fallback.llm_error = String(e.message || e);
        fallback.note = (fallback.note ? `${fallback.note} ` : '') + '大模型整页生成失败，已回退到启发式 + lab-eval-ai.json（若存在）。';
        if (ctx) attachRepoToHeuristicReport(fallback, ctx, gitUrl);
      } else {
        fallback.llm_error = String(e.message || e);
      }
      if (fallback.ok) enrichReportWithHookTranscriptMap(fallback, CHAT_LOG);
      if (fallback.ok && ctx) finalizeTaskAlignedEvidence(ctx, fallback);
      fallback.report_build_ms = Date.now() - t0;
      return res.json(fallback);
    }
  }

  const data = loadReportHeuristicOnly();
  if (data.ok) {
    data.source = forceHeuristic ? 'heuristic_fast' : 'heuristic_only';
    data.git_url = gitUrl;
    data.note =
      (data.note ? `${data.note} ` : '') +
      (forceHeuristic
        ? '已使用 ?fast=1 跳过整页大模型生成（仅 git 扫描 + chat_logs 启发式），响应更快。'
        : '未设置 CURSOR_API_KEY 或已 DISABLE_FULL_LLM_REPORT=1，未调用大模型；已尽量从仓库拉取文件列表与评测表。');
    if (ctx) attachRepoToHeuristicReport(data, ctx, gitUrl);
  }
  if (data.ok) enrichReportWithHookTranscriptMap(data, CHAT_LOG);
  if (data.ok && ctx) finalizeTaskAlignedEvidence(ctx, data);
  if (data.ok) data.report_build_ms = Date.now() - t0;
  return res.json(data);
});

app.get('/api/health', (_req, res) => {
  res.json({
    ok: true,
    service: 'chat-lab-report',
    port: PORT,
    default_git: DEFAULT_STUDENT_GIT_URL,
    llm_enabled: Boolean(process.env.CURSOR_API_KEY) && process.env.DISABLE_FULL_LLM_REPORT !== '1',
  });
});

app.get('/', (_req, res) => {
  res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0');
  res.setHeader('Pragma', 'no-cache');
  res.sendFile(path.join(ROOT, 'code.html'));
});

app.get('/report-ui.js', (_req, res) => {
  res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0');
  res.sendFile(path.join(ROOT, 'report-ui.js'));
});

app.use(express.static(ROOT, { index: false }));

const server = app.listen(PORT, () => {
  // eslint-disable-next-line no-console
  console.log(`报告服务已启动: http://127.0.0.1:${PORT}/`);
  console.log(`API: http://127.0.0.1:${PORT}/api/report?git=<可选仓库URL>`);
  console.log(`快速模式（跳过整页大模型，仅 git+chat_logs）: /api/report?fast=1&git=...`);
  console.log(`默认学员仓库: ${DEFAULT_STUDENT_GIT_URL}`);
});

server.timeout = Number(process.env.REPORT_SERVER_TIMEOUT_MS) || 900000;
server.headersTimeout = server.timeout + 10000;