#!/usr/bin/env node
/**
 * Session Pin - 钉住已命名(renamed)的会话，防止 auto-cleanup 清理
 * 创建: 2026-04-15 | 部署: deploy-session-pin.js
 */
'use strict';

const fs = require('fs');
const path = require('path');

let ROOT;
try { ROOT = require('../hooks/lib/root.js'); }
catch { ROOT = path.join(process.env.USERPROFILE || process.env.HOME || '', '.claude'); }

const PIN_FILE = path.join(ROOT, 'pinned-sessions.json');
const SESSIONS_DIR = path.join(ROOT, 'sessions');
const ARCHIVES_DIR = path.join(ROOT, 'archives');
const PIN_TTL_DAYS = 90;

function readPins() {
  try {
    if (!fs.existsSync(PIN_FILE)) return { version: 1, pins: {} };
    const raw = fs.readFileSync(PIN_FILE, 'utf8');
    const data = JSON.parse(raw);
    if (!data || typeof data.pins !== 'object') throw new Error('invalid schema');
    return data;
  } catch {
    // 备份损坏文件而非静默丢弃，防止覆盖导致数据丢失
    try { fs.copyFileSync(PIN_FILE, PIN_FILE + '.corrupt.' + Date.now()); } catch {}
    return { version: 1, pins: {} };
  }
}

function writePins(data) {
  const tmp = PIN_FILE + '.tmp.' + process.pid;
  fs.writeFileSync(tmp, JSON.stringify(data, null, 2), 'utf8');
  fs.renameSync(tmp, PIN_FILE);
}

function findSessionMeta(sessionId) {
  if (!fs.existsSync(SESSIONS_DIR)) return null;
  try {
    const files = fs.readdirSync(SESSIONS_DIR).filter(f => f.endsWith('.json'));
    for (const file of files) {
      try {
        const meta = JSON.parse(fs.readFileSync(path.join(SESSIONS_DIR, file), 'utf8'));
        if (meta.sessionId === sessionId && meta.name) {
          return { name: meta.name, startedAt: meta.startedAt, pid: meta.pid };
        }
      } catch {}
    }
  } catch {}
  return null;
}

function extractSummary(transcriptPath) {
  const result = { messageCount: 0, firstPrompt: '', lastPrompt: '' };
  try {
    if (!transcriptPath || !fs.existsSync(transcriptPath)) return result;
    const content = fs.readFileSync(transcriptPath, 'utf8');
    const lines = content.split('\n').filter(l => l.trim());
    result.messageCount = lines.length;
    const userMessages = [];
    for (const line of lines) {
      try {
        const obj = JSON.parse(line);
        const isHuman = (obj.type === 'human') ||
          (obj.message && obj.message.role === 'human') ||
          (obj.role === 'human');
        if (isHuman) {
          let text = '';
          if (typeof obj.message === 'string') text = obj.message;
          else if (obj.message && obj.message.content) {
            if (typeof obj.message.content === 'string') text = obj.message.content;
            else if (Array.isArray(obj.message.content)) {
              text = obj.message.content.filter(c => c.type === 'text').map(c => c.text).join(' ');
            }
          } else if (obj.content && typeof obj.content === 'string') text = obj.content;
          if (text.trim()) userMessages.push(text.trim().slice(0, 200));
        }
      } catch {}
    }
    if (userMessages.length > 0) {
      result.firstPrompt = userMessages[0];
      result.lastPrompt = userMessages[userMessages.length - 1];
    }
  } catch {}
  return result;
}

function saveArchive(sessionId, name, summary, startedAt) {
  try {
    if (!fs.existsSync(ARCHIVES_DIR)) fs.mkdirSync(ARCHIVES_DIR, { recursive: true });
    const date = new Date().toISOString().slice(0, 10);
    const safeName = (name
      .replace(/[\x00-\x1f<>:"\/\\|?*\[\]]/g, '_')
      .replace(/^(CON|PRN|AUX|NUL|COM\d|LPT\d)$/i, '_$1')
      .trim()
      .slice(0, 50)) || 'unnamed';
    const archiveFile = path.join(ARCHIVES_DIR, date + '_' + safeName + '.json');
    const archive = {
      sessionId, name,
      archivedAt: new Date().toISOString(),
      startedAt: startedAt ? new Date(startedAt).toISOString() : null,
      messageCount: summary.messageCount,
      firstPrompt: summary.firstPrompt,
      lastPrompt: summary.lastPrompt,
    };
    fs.writeFileSync(archiveFile, JSON.stringify(archive, null, 2), 'utf8');
    return archiveFile;
  } catch { return null; }
}

function cleanExpiredPins() {
  const data = readPins();
  const now = Date.now();
  let cleaned = 0;
  for (const [sid, entry] of Object.entries(data.pins)) {
    const expiry = entry.expiresAt ? new Date(entry.expiresAt).getTime() : 0;
    if (!entry.expiresAt || isNaN(expiry) || expiry < now) {
      delete data.pins[sid]; cleaned++;
    }
  }
  if (cleaned > 0) writePins(data);
  return cleaned;
}

function pinSession(input) {
  const sessionId = input && input.session_id;
  if (!sessionId) return;
  const meta = findSessionMeta(sessionId);
  if (!meta || !meta.name) return;
  const data = readPins();
  if (data.pins[sessionId]) {
    data.pins[sessionId].name = meta.name;
    writePins(data);
    return;
  }
  const now = new Date();
  const expiresAt = new Date(now.getTime() + PIN_TTL_DAYS * 24 * 60 * 60 * 1000);
  let transcriptRel = '';
  if (input.transcript_path) {
    const normalized = input.transcript_path.replace(/\\/g, '/');
    const idx = normalized.indexOf('projects/');
    transcriptRel = idx >= 0 ? normalized.slice(idx) : normalized;
  }
  data.pins[sessionId] = {
    name: meta.name,
    pinnedAt: now.toISOString(),
    expiresAt: expiresAt.toISOString(),
    ttlDays: PIN_TTL_DAYS,
    transcriptRel,
  };
  // 内联过期清理，避免双重写盘 [P2-1 fixed]
  const _now = Date.now();
  for (const [_sid, _entry] of Object.entries(data.pins)) {
    if (_sid === sessionId) continue; // 刚添加的不清理
    const _exp = _entry.expiresAt ? new Date(_entry.expiresAt).getTime() : 0;
    if (!_entry.expiresAt || isNaN(_exp) || _exp < _now) delete data.pins[_sid];
  }
  writePins(data);
  const summary = extractSummary(input.transcript_path);
  saveArchive(sessionId, meta.name, summary, meta.startedAt);
}

module.exports = { pinSession, readPins, cleanExpiredPins, PIN_FILE, ARCHIVES_DIR };