const express = require('express');
const http = require('http');
const { Server } = require('socket.io');
const cors = require('cors');
const Database = require('better-sqlite3');
const { claude, ConsoleLogger, LogLevel } = require('@instantlyeasy/claude-code-sdk-ts');
const path = require('path');
const { exec } = require('child_process');

// 补充 PATH
const cliDir = 'C:\\Users\\MerCry\\AppData\\Roaming\\npm';
process.env.PATH = `${cliDir};${process.env.PATH || ''}`;

// 启动时自检
exec('claude --version', { env: process.env }, (error, stdout, stderr) => {
  if (error) {
    console.error('[ERROR] 无法在 Node 进程中执行 claude CLI:', error.message);
  } else {
    console.log('[INFO] claude CLI 检测通过:', (stdout || stderr || '').trim());
  }
});

const app = express();
const server = http.createServer(app);
const io = new Server(server, {
  cors: { origin: "*" }
});

app.use(cors());
app.use(express.json());

// 数据库初始化
const dbPath = path.resolve(__dirname, '..', 'claude_web.db');
const db = new Database(dbPath);
db.exec(`
  CREATE TABLE IF NOT EXISTS tabs (
    id TEXT PRIMARY KEY,
    name TEXT,
    layout_config TEXT
  );
  CREATE TABLE IF NOT EXISTS sessions (
    id TEXT PRIMARY KEY,
    name TEXT,
    tab_id TEXT,
    mode TEXT DEFAULT 'ask',
    cwd TEXT,
    allowed_tools TEXT,
    denied_tools TEXT,
    claude_session_id TEXT,
    layout_config TEXT
  );
  CREATE TABLE IF NOT EXISTS messages (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id TEXT,
    role TEXT,
    content TEXT,
    type TEXT DEFAULT 'text',
    metadata TEXT,
    timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
  );
`);

const activeAborts = new Map();

// 辅助函数：保存全量状态
function saveState(tabs, sessions) {
  const transaction = db.transaction(() => {
    db.prepare('DELETE FROM tabs').run();
    db.prepare('DELETE FROM sessions').run();
    
    for (const tab of tabs) {
      db.prepare('INSERT INTO tabs (id, name, layout_config) VALUES (?, ?, ?)')
        .run(tab.id, tab.name, JSON.stringify(tab.layoutConfig || {}));
      
      for (const pane of tab.panes) {
        const session = sessions[pane.i] || { mode: 'ask', cwd: '', allowedTools: [], deniedTools: [] };
        db.prepare('INSERT INTO sessions (id, name, tab_id, mode, cwd, allowed_tools, denied_tools, claude_session_id, layout_config) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)')
          .run(
            pane.i, 
            pane.i, 
            tab.id, 
            session.mode, 
            session.cwd, 
            JSON.stringify(session.allowedTools || []), 
            JSON.stringify(session.deniedTools || []),
            session.claudeSessionId || null,
            JSON.stringify(pane)
          );
      }
    }
  });
  transaction();
}

io.on('connection', (socket) => {
  socket.on('join_session', (sessionId) => {
    socket.join(sessionId);
    console.log(`[Socket] Client ${socket.id} joined session ${sessionId}`);
  });

  socket.on('save_state', ({ tabs, sessions }) => {
    try {
      saveState(tabs, sessions);
    } catch (err) {
      console.error('Failed to save state:', err);
    }
  });

  socket.on('stop_session', ({ sessionId }) => {
    const controller = activeAborts.get(sessionId);
    if (controller) {
      controller.abort();
      activeAborts.delete(sessionId);
      console.log(`Session ${sessionId} stop requested`);
    }
  });

  socket.on('stop_all', () => {
    for (const [sessionId, controller] of activeAborts.entries()) {
      controller.abort();
    }
    activeAborts.clear();
    console.log('All sessions stop requested');
  });

  socket.on('close_session', ({ sessionId }) => {
    const controller = activeAborts.get(sessionId);
    if (controller) {
      controller.abort();
      activeAborts.delete(sessionId);
    }
    socket.leave(sessionId);
  });

  socket.on('send_message', async ({ sessionId, prompt, mode, cwd, allowedTools, deniedTools }) => {
    try {
      console.log('[send_message] received', { sessionId, mode, cwd, promptPreview: String(prompt).slice(0, 50) });
      
      if (activeAborts.has(sessionId)) {
        activeAborts.get(sessionId).abort();
      }

      // 记录用户消息
      db.prepare('INSERT INTO messages (session_id, role, content) VALUES (?, ?, ?)').run(sessionId, 'user', prompt);
      
      const abortController = new AbortController();
      activeAborts.set(sessionId, abortController);

      // 从 DB 获取已有的 claude_session_id 实现 resume
      const sessionData = db.prepare('SELECT claude_session_id FROM sessions WHERE id = ?').get(sessionId);
      const claudeSessionId = sessionData?.claude_session_id;

      const sdkLogger = new ConsoleLogger(LogLevel.INFO);
      
      let queryBuilder = claude()
        .withLogger(sdkLogger)
        .withSignal(abortController.signal)
        .inDirectory(cwd || process.cwd());

      if (claudeSessionId) {
        queryBuilder = queryBuilder.withSessionId(claudeSessionId);
      }

      if (mode === 'plan') {
        queryBuilder = queryBuilder.denyTools(['*']);
      } else if (mode === 'auto') {
        queryBuilder = queryBuilder.skipPermissions();
      }

      const effectiveAllowedTools = (allowedTools && allowedTools.length > 0)
        ? allowedTools
        : ['Read', 'Bash', 'Write', 'Grep', 'Glob'];
      
      queryBuilder = queryBuilder.allowTools(...effectiveAllowedTools);
      
      if (deniedTools && deniedTools.length > 0) {
        queryBuilder = queryBuilder.denyTools(...deniedTools);
      }

      const parser = queryBuilder.query(prompt);
      
      let fullAssistantContent = '';
      let gotAnyMessage = false;
      const watchdog = setTimeout(() => {
        if (!gotAnyMessage) {
          io.to(sessionId).emit('error', { sessionId, error: 'Claude 响应超时，请检查本地 CLI 状态。' });
          abortController.abort();
        }
      }, 30000);

      // 获取并持久化真实 Claude Session ID
      parser.getSessionId().then(id => {
        if (id && id !== claudeSessionId) {
          db.prepare('UPDATE sessions SET claude_session_id = ? WHERE id = ?').run(id, sessionId);
          console.log(`[Session ${sessionId}] Updated Claude Session ID: ${id}`);
        }
      }).catch(() => {});

      await parser.stream(async (message) => {
        gotAnyMessage = true;
        clearTimeout(watchdog);

        // 转发所有原始消息给前端，以便前端进行复杂渲染（thinking, tool_use 等）
        io.to(sessionId).emit('claude_event', { sessionId, message });

        // 提取纯文本用于简单兼容和拼接
        const text = extractTextFromMessage(message);
        if (text) {
          fullAssistantContent += text;
          io.to(sessionId).emit('text', { sessionId, token: text });
        }
      });

      // 保存完整的助手回复到数据库
      if (fullAssistantContent) {
        db.prepare('INSERT INTO messages (session_id, role, content) VALUES (?, ?, ?)').run(sessionId, 'assistant', fullAssistantContent);
      }

      clearTimeout(watchdog);
      io.to(sessionId).emit('done', { sessionId });
      activeAborts.delete(sessionId);

    } catch (err) {
      if (err.name === 'AbortError') {
        console.log(`[Session ${sessionId}] Aborted`);
      } else {
        console.error(`[Session ${sessionId}] Error:`, err);
        io.to(sessionId).emit('error', { sessionId, error: err.message });
      }
      activeAborts.delete(sessionId);
    }
  });
});

function extractTextFromMessage(message) {
  if (typeof message === 'string') return message;
  if (!message || typeof message !== 'object') return null;
  if (message.type === 'text' && typeof message.text === 'string') return message.text;
  if (message.delta && typeof message.delta.text === 'string') return message.delta.text;
  if (Array.isArray(message.content)) {
    return message.content.map(p => p.text || (p.delta ? p.delta.text : '')).join('');
  }
  return null;
}

// REST API
app.get('/api/state', (req, res) => {
  try {
    const tabs = db.prepare('SELECT * FROM tabs').all();
    const sessions = db.prepare('SELECT * FROM sessions').all();
    
    const resultTabs = tabs.map(t => {
      const tabPanes = sessions
        .filter(s => s.tab_id === t.id)
        .map(s => JSON.parse(s.layout_config));
      return {
        id: t.id,
        name: t.name,
        panes: tabPanes,
        layoutConfig: JSON.parse(t.layout_config || '{}')
      };
    });

    const resultSessions = {};
    sessions.forEach(s => {
      const messages = db.prepare('SELECT role, content, type, metadata, timestamp FROM messages WHERE session_id = ? ORDER BY timestamp ASC').all(s.id);
      resultSessions[s.id] = {
        mode: s.mode,
        cwd: s.cwd,
        allowedTools: JSON.parse(s.allowed_tools || '[]'),
        deniedTools: JSON.parse(s.denied_tools || '[]'),
        claudeSessionId: s.claude_session_id,
        messages,
        status: 'idle'
      };
    });

    res.json({ tabs: resultTabs, sessions: resultSessions });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.get('/api/config', (req, res) => {
  res.json({ status: 'ok', tools: ['Read', 'Edit', 'Write', 'Bash', 'Grep', 'Glob', 'WebSearch'] });
});

app.get('/api/logs/search', (req, res) => {
  const { sessionId, query: q } = req.query;
  try {
    let sql = 'SELECT * FROM messages WHERE 1=1';
    const params = [];
    if (sessionId) { sql += ' AND session_id = ?'; params.push(sessionId); }
    if (q) { sql += ' AND content LIKE ?'; params.push(`%${q}%`); }
    sql += ' ORDER BY timestamp DESC';
    res.json(db.prepare(sql).all(...params));
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.get('/api/logs/export', (req, res) => {
  const { sessionId, format } = req.query;
  try {
    let sql = 'SELECT * FROM messages';
    if (sessionId) sql += ' WHERE session_id = ?';
    sql += ' ORDER BY timestamp ASC';
    const logs = db.prepare(sql).all(sessionId ? [sessionId] : []);
    
    if (format === 'markdown') {
      let md = `# Claude Web Logs\n\n`;
      logs.forEach(l => {
        md += `### ${l.role.toUpperCase()} (${l.timestamp})\n${l.content}\n\n---\n\n`;
      });
      res.setHeader('Content-Type', 'text/markdown');
      return res.send(md);
    }
    res.json(logs);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

const PORT = 3001;
server.listen(PORT, () => console.log(`Backend running on http://localhost:${PORT}`));