import express, { Request, Response, NextFunction } from 'express';
import cors from 'cors';
import cookieParser from 'cookie-parser';
import WebSocket from 'ws';
import jwt from 'jsonwebtoken';
import DockerController from './services/DockerController';
import { FileSystemService } from './services/FileSystemService';
import { ComposeService } from './services/ComposeService';
import { ConfigService } from './services/ConfigService';
import composerize from 'composerize';
import si from 'systeminformation';
import http from 'http';

const app = express();
const PORT = 3000;

// Environment variables
const JWT_SECRET = process.env.JWT_SECRET || 'your-secret-key-change-in-production';

// ConfigService for persistent auth storage
const configService = new ConfigService();

// Cookie settings
const COOKIE_NAME = 'sencho_token';
const COOKIE_OPTIONS = {
  httpOnly: true,
  secure: process.env.NODE_ENV === 'production',
  sameSite: 'strict' as const,
  maxAge: 24 * 60 * 60 * 1000, // 24 hours
};

// Middleware
app.use(cors({
  origin: true,
  credentials: true,
}));
app.use(express.json());
app.use(cookieParser());

// Extend Express Request type for user
declare module 'express' {
  interface Request {
    user?: { username: string };
  }
}

// Authentication Middleware
const authMiddleware = (req: Request, res: Response, next: NextFunction): void => {
  const token = req.cookies[COOKIE_NAME];
  
  if (!token) {
    res.status(401).json({ error: 'Authentication required' });
    return;
  }
  
  try {
    const decoded = jwt.verify(token, JWT_SECRET) as { username: string };
    req.user = { username: decoded.username };
    next();
  } catch {
    res.status(401).json({ error: 'Invalid or expired token' });
    return;
  }
};

// Auth Routes (no authentication required)

// Check if setup is needed
app.get('/api/auth/status', async (req: Request, res: Response): Promise<void> => {
  try {
    const needsSetup = await configService.needsSetup();
    res.json({ needsSetup });
  } catch (error) {
    console.error('Error checking setup status:', error);
    res.json({ needsSetup: true });
  }
});

// Initial setup endpoint
app.post('/api/auth/setup', async (req: Request, res: Response): Promise<void> => {
  try {
    // Check if setup is still needed
    const needsSetup = await configService.needsSetup();
    if (!needsSetup) {
      res.status(400).json({ error: 'Setup has already been completed' });
      return;
    }

    const { username, password, confirmPassword } = req.body;
    
    // Validation
    if (!username || !password || !confirmPassword) {
      res.status(400).json({ error: 'All fields are required' });
      return;
    }
    
    if (username.length < 3) {
      res.status(400).json({ error: 'Username must be at least 3 characters' });
      return;
    }
    
    if (password.length < 6) {
      res.status(400).json({ error: 'Password must be at least 6 characters' });
      return;
    }
    
    if (password !== confirmPassword) {
      res.status(400).json({ error: 'Passwords do not match' });
      return;
    }

    // Save credentials
    await configService.saveConfig(username, password);
    
    // Issue JWT and log user in
    const token = jwt.sign({ username }, JWT_SECRET, { expiresIn: '24h' });
    res.cookie(COOKIE_NAME, token, COOKIE_OPTIONS);
    res.json({ success: true, message: 'Setup completed successfully' });
  } catch (error) {
    console.error('Setup error:', error);
    res.status(500).json({ error: 'Failed to complete setup' });
  }
});

// Login endpoint
app.post('/api/auth/login', async (req: Request, res: Response): Promise<void> => {
  const { username, password } = req.body;
  
  if (!username || !password) {
    res.status(400).json({ error: 'Username and password are required' });
    return;
  }
  
  try {
    const isValid = await configService.validateCredentials(username, password);
    
    if (isValid) {
      const token = jwt.sign({ username }, JWT_SECRET, { expiresIn: '24h' });
      res.cookie(COOKIE_NAME, token, COOKIE_OPTIONS);
      res.json({ success: true, message: 'Login successful' });
      return;
    }
    
    res.status(401).json({ error: 'Invalid credentials' });
  } catch (error) {
    console.error('Login error:', error);
    res.status(500).json({ error: 'Login failed' });
  }
});

app.post('/api/auth/logout', (req: Request, res: Response): void => {
  res.clearCookie(COOKIE_NAME, {
    httpOnly: true,
    secure: process.env.NODE_ENV === 'production',
    sameSite: 'strict',
  });
  res.json({ success: true, message: 'Logged out successfully' });
});

// Check authentication status
app.get('/api/auth/check', authMiddleware, (req: Request, res: Response): void => {
  res.json({ authenticated: true, user: req.user });
});

// Apply authentication middleware to all /api/* routes except /api/auth/*
app.use('/api', (req: Request, res: Response, next: NextFunction): void => {
  if (req.path.startsWith('/auth/')) {
    next();
    return;
  }
  authMiddleware(req, res, next);
});

// Create HTTP server for WebSocket upgrade handling
const server = http.createServer(app);

// WebSocket server with authentication
const wss = new WebSocket.Server({ noServer: true });

let terminalWs: WebSocket | null = null;

// Handle WebSocket upgrade with JWT authentication
server.on('upgrade', (req, socket, head) => {
  // Parse cookies from the upgrade request
  const cookieHeader = req.headers.cookie || '';
  const cookies = Object.fromEntries(
    cookieHeader.split(';').map(c => c.trim().split('=')).filter(([k, v]) => k && v)
  );
  
  const token = cookies[COOKIE_NAME];
  
  if (!token) {
    socket.write('HTTP/1.1 401 Unauthorized\r\n\r\n');
    socket.destroy();
    return;
  }
  
  try {
    jwt.verify(token, JWT_SECRET);
    // Authentication successful, proceed with WebSocket connection
    wss.handleUpgrade(req, socket, head, (ws) => {
      wss.emit('connection', ws, req);
    });
  } catch (error) {
    socket.write('HTTP/1.1 401 Unauthorized\r\n\r\n');
    socket.destroy();
    return;
  }
});

wss.on('connection', (ws) => {
  console.log('WebSocket connected');

  ws.on('message', (message) => {
    try {
      const data = JSON.parse(message.toString());
      if (data.action === 'connectTerminal') {
        terminalWs = ws;
      } else if (data.action === 'streamStats') {
        const dockerController = DockerController.getInstance();
        dockerController.streamStats(data.containerId, ws);
      } else if (data.action === 'execContainer') {
        // Handle container exec for bash access
        const dockerController = DockerController.getInstance();
        dockerController.execContainer(data.containerId, ws);
      } else if (data.action === 'input') {
        // Forward input to exec stream
        const dockerController = DockerController.getInstance();
        dockerController.sendExecInput(data.data);
      } else if (data.action === 'resize') {
        const dockerController = DockerController.getInstance();
        dockerController.resizeExec(data.cols, data.rows);
      }
    } catch (error) {
      ws.send(JSON.stringify({ error: 'Invalid message' }));
    }
  });
});

// API Routes (all protected by authMiddleware)

app.get('/api/containers', async (req: Request, res: Response) => {
  try {
    const dockerController = DockerController.getInstance();
    const containers = await dockerController.getRunningContainers();
    res.json(containers);
  } catch (error) {
    res.status(500).json({ error: 'Failed to fetch containers' });
  }
});

const fileSystemService = new FileSystemService();

app.get('/api/stacks', async (req: Request, res: Response) => {
  try {
    const files = await fileSystemService.getStackFiles();
    res.json(files);
  } catch (error) {
    res.status(500).json({ error: 'Failed to fetch stack files' });
  }
});

app.get('/api/stacks/:filename', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    const content = await fileSystemService.getStackContent(filename);
    res.send(content);
  } catch (error) {
    res.status(500).json({ error: 'Failed to read file' });
  }
});

app.put('/api/stacks/:filename', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    const { content } = req.body;
    console.log('PUT /api/stacks/:filename', { filename, contentType: typeof content, contentLength: content?.length });
    if (typeof content !== 'string') {
      console.error('Content is not a string:', content);
      return res.status(400).json({ error: 'Content must be a string' });
    }
    await fileSystemService.saveStackContent(filename, content);
    console.log('File saved successfully:', filename);
    res.json({ message: 'File saved successfully' });
  } catch (error) {
    console.error('Failed to save file:', error);
    res.status(500).json({ error: 'Failed to save file' });
  }
});

app.get('/api/stacks/:filename/env', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    const exists = await fileSystemService.envExists(filename);
    if (!exists) {
      return res.status(404).json({ error: 'Env file not found' });
    }
    const content = await fileSystemService.getEnvContent(filename);
    res.send(content);
  } catch (error) {
    res.status(500).json({ error: 'Failed to read env file' });
  }
});

app.put('/api/stacks/:filename/env', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    const { content } = req.body;
    if (typeof content !== 'string') {
      return res.status(400).json({ error: 'Content must be a string' });
    }
    await fileSystemService.saveEnvContent(filename, content);
    res.json({ message: 'Env file saved successfully' });
  } catch (error) {
    console.error('Failed to save env file:', error);
    res.status(500).json({ error: 'Failed to save env file' });
  }
});

app.post('/api/stacks', async (req: Request, res: Response) => {
  try {
    const { filename } = req.body;
    if (!filename || typeof filename !== 'string') {
      return res.status(400).json({ error: 'Filename is required and must be a string' });
    }
    await fileSystemService.createStack(filename);
    res.json({ message: 'Stack created successfully' });
  } catch (error) {
    console.error('Failed to create stack:', error);
    res.status(500).json({ error: 'Failed to create stack' });
  }
});

app.delete('/api/stacks/:filename', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    await fileSystemService.deleteStack(filename);
    res.json({ message: 'Stack deleted successfully' });
  } catch (error) {
    console.error('Failed to delete stack:', error);
    res.status(500).json({ error: 'Failed to delete stack' });
  }
});

app.get('/api/stacks/:filename/containers', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    const stackName = filename.replace(/\.yml$/, '');
    const dockerController = DockerController.getInstance();
    const containers = await dockerController.getContainersByStack(stackName);
    res.json(containers);
  } catch (error) {
    res.status(500).json({ error: 'Failed to fetch containers' });
  }
});

app.post('/api/containers/:id/start', async (req: Request, res: Response) => {
  try {
    const id = req.params.id as string;
    const dockerController = DockerController.getInstance();
    await dockerController.startContainer(id);
    res.json({ message: 'Container started' });
  } catch (error) {
    res.status(500).json({ error: 'Failed to start container' });
  }
});

app.post('/api/containers/:id/stop', async (req: Request, res: Response) => {
  try {
    const id = req.params.id as string;
    const dockerController = DockerController.getInstance();
    await dockerController.stopContainer(id);
    res.json({ message: 'Container stopped' });
  } catch (error) {
    res.status(500).json({ error: 'Failed to stop container' });
  }
});

app.post('/api/containers/:id/restart', async (req: Request, res: Response) => {
  try {
    const id = req.params.id as string;
    const dockerController = DockerController.getInstance();
    await dockerController.restartContainer(id);
    res.json({ message: 'Container restarted' });
  } catch (error) {
    res.status(500).json({ error: 'Failed to restart container' });
  }
});

const composeService = new ComposeService();

app.post('/api/stacks/:filename/up', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    composeService.runCommand(filename, 'up', terminalWs || undefined);
    res.json({ status: 'Command started' });
  } catch (error) {
    res.status(500).json({ error: 'Failed to start command' });
  }
});

app.post('/api/stacks/:filename/down', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    composeService.runCommand(filename, 'down', terminalWs || undefined);
    res.json({ status: 'Command started' });
  } catch (error) {
    res.status(500).json({ error: 'Failed to start command' });
  }
});

// Update stack: pull images and recreate containers
app.post('/api/stacks/:filename/update', async (req: Request, res: Response) => {
  try {
    const filename = req.params.filename as string;
    // Run update asynchronously, don't wait for completion
    composeService.updateStack(filename, terminalWs || undefined).catch(error => {
      console.error('Update stack error:', error);
    });
    res.json({ status: 'Update started' });
  } catch (error) {
    res.status(500).json({ error: 'Failed to start update' });
  }
});

// Docker Run to Compose converter endpoint
app.post('/api/convert', async (req: Request, res: Response) => {
  try {
    const { dockerRun } = req.body;
    if (!dockerRun || typeof dockerRun !== 'string') {
      return res.status(400).json({ error: 'dockerRun command is required' });
    }
    const yaml = composerize(dockerRun);
    res.json({ yaml });
  } catch (error) {
    console.error('Conversion error:', error);
    res.status(500).json({ error: 'Failed to convert docker run command' });
  }
});

// Get all containers stats for dashboard
app.get('/api/stats', async (req: Request, res: Response) => {
  try {
    const dockerController = DockerController.getInstance();
    const containers = await dockerController.getRunningContainers();
    const allContainers = await dockerController.getAllContainers();
    
    const active = containers.length;
    const exited = allContainers.filter((c: { State: string }) => c.State === 'exited').length;
    const total = allContainers.length;
    
    res.json({ active, exited, total, inactive: total - active - exited });
  } catch (error) {
    res.status(500).json({ error: 'Failed to fetch stats' });
  }
});

// Get host system stats
app.get('/api/system/stats', async (req: Request, res: Response) => {
  try {
    const [currentLoad, mem, fsSize] = await Promise.all([
      si.currentLoad(),
      si.mem(),
      si.fsSize(),
    ]);
    
    // Find the main mount (usually the largest or root mount)
    const mainDisk = fsSize.find(fs => fs.mount === '/' || fs.mount === 'C:') || fsSize[0];
    
    res.json({
      cpu: {
        usage: currentLoad.currentLoad.toFixed(1),
        cores: currentLoad.cpus.length,
      },
      memory: {
        total: mem.total,
        used: mem.used,
        free: mem.free,
        usagePercent: ((mem.used / mem.total) * 100).toFixed(1),
      },
      disk: mainDisk ? {
        fs: mainDisk.fs,
        mount: mainDisk.mount,
        total: mainDisk.size,
        used: mainDisk.used,
        free: mainDisk.available,
        usagePercent: mainDisk.use ? mainDisk.use.toFixed(1) : '0',
      } : null,
    });
  } catch (error) {
    console.error('Failed to fetch system stats:', error);
    res.status(500).json({ error: 'Failed to fetch system stats' });
  }
});

// Serve static files in production (for Docker deployment)
if (process.env.NODE_ENV === 'production') {
  app.use(express.static('public'));
  
  // Handle SPA routing - serve index.html for non-API routes
  app.get('*', (req: Request, res: Response) => {
    if (!req.path.startsWith('/api')) {
      res.sendFile('index.html', { root: 'public' });
    }
  });
}

server.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});