import { createServer } from 'http';
import { parse } from 'url';
import next from 'next';
import { WebSocketServer } from 'ws';
import { spawn } from 'child_process';
import { join, resolve } from 'path';
import stripAnsi from 'strip-ansi';
import { spawn as ptySpawn } from 'node-pty';

const dev = process.env.NODE_ENV !== 'production';
const hostname = '0.0.0.0';
const port = process.env.PORT || 3000;

const app = next({ dev, hostname, port });
const handle = app.getRequestHandler();

// WebSocket handler for script execution
class ScriptExecutionHandler {
  constructor(server) {
    this.wss = new WebSocketServer({ 
      server,
      path: '/ws/script-execution'
    });
    this.activeExecutions = new Map();
    this.setupWebSocket();
  }

  setupWebSocket() {
    this.wss.on('connection', (ws, request) => {
      console.log('New WebSocket connection for script execution');
      console.log('Client IP:', request.socket.remoteAddress);
      console.log('User-Agent:', request.headers['user-agent']);
      console.log('WebSocket readyState:', ws.readyState);
      console.log('Request URL:', request.url);
      
      // Set connection metadata
      ws.connectionTime = Date.now();
      ws.clientIP = request.socket.remoteAddress;
      
      ws.on('message', (data) => {
        try {
          const message = JSON.parse(data.toString());
          console.log('Received message from client:', message);
          this.handleMessage(ws, message);
        } catch (error) {
          console.error('Error parsing WebSocket message:', error);
          this.sendMessage(ws, {
            type: 'error',
            data: 'Invalid message format',
            timestamp: Date.now()
          });
        }
      });

      ws.on('close', (code, reason) => {
        console.log(`WebSocket connection closed: ${code} - ${reason}`);
        this.cleanupActiveExecutions(ws);
      });

      ws.on('error', (error) => {
        console.error('WebSocket error:', error);
        this.cleanupActiveExecutions(ws);
      });
    });
  }

  async handleMessage(ws, message) {
    const { action, scriptPath, executionId, input } = message;

    switch (action) {
      case 'start':
        if (scriptPath && executionId) {
          await this.startScriptExecution(ws, scriptPath, executionId);
        } else {
          this.sendMessage(ws, {
            type: 'error',
            data: 'Missing scriptPath or executionId',
            timestamp: Date.now()
          });
        }
        break;

      case 'stop':
        if (executionId) {
          this.stopScriptExecution(executionId);
        }
        break;

      case 'input':
        if (executionId && input !== undefined) {
          this.sendInputToProcess(executionId, input);
        }
        break;

      default:
        this.sendMessage(ws, {
          type: 'error',
          data: 'Unknown action',
          timestamp: Date.now()
        });
    }
  }

  async startScriptExecution(ws, scriptPath, executionId) {
    try {
      console.log('Starting script execution...');
      // Basic validation
      const scriptsDir = join(process.cwd(), 'scripts');
      const resolvedPath = resolve(scriptPath);
      
      console.log('Scripts directory:', scriptsDir);
      console.log('Resolved path:', resolvedPath);
      console.log('Is within scripts dir:', resolvedPath.startsWith(resolve(scriptsDir)));
      
      if (!resolvedPath.startsWith(resolve(scriptsDir))) {
        console.log('Script path validation failed');
        this.sendMessage(ws, {
          type: 'error',
          data: 'Script path is not within the allowed scripts directory',
          timestamp: Date.now()
        });
        return;
      }

      // Check if execution is already running
      if (this.activeExecutions.has(executionId)) {
        this.sendMessage(ws, {
          type: 'error',
          data: 'Script execution already running',
          timestamp: Date.now()
        });
        return;
      }

      // Start script execution with pty for proper TTY support
      const childProcess = ptySpawn('bash', [resolvedPath], {
        cwd: scriptsDir,
        name: 'xterm-256color',
        cols: 80,
        rows: 24,
        env: {
          ...process.env,
          TERM: 'xterm-256color', // Enable proper terminal support
          FORCE_ANSI: 'true', // Allow ANSI codes for proper display
          COLUMNS: '80', // Set terminal width
          LINES: '24' // Set terminal height
        }
      });

      // pty handles encoding automatically
      
      // Store the execution
      this.activeExecutions.set(executionId, { process: childProcess, ws });

      // Send start message
      this.sendMessage(ws, {
        type: 'start',
        data: `Starting execution of ${scriptPath}`,
        timestamp: Date.now()
      });

      // Handle pty data (both stdout and stderr combined)
      childProcess.onData((data) => {
        this.sendMessage(ws, {
          type: 'output',
          data: data.toString(),
          timestamp: Date.now()
        });
      });

      // Handle process exit
      childProcess.onExit((exitCode, signal) => {
        this.sendMessage(ws, {
          type: 'end',
          data: `Script execution finished with code: ${exitCode}, signal: ${signal}`,
          timestamp: Date.now()
        });
        
        // Clean up
        this.activeExecutions.delete(executionId);
      });

    } catch (error) {
      this.sendMessage(ws, {
        type: 'error',
        data: `Failed to start script: ${error.message}`,
        timestamp: Date.now()
      });
    }
  }

  stopScriptExecution(executionId) {
    const execution = this.activeExecutions.get(executionId);
    if (execution) {
      execution.process.kill('SIGTERM');
      this.activeExecutions.delete(executionId);
      
      this.sendMessage(execution.ws, {
        type: 'end',
        data: 'Script execution stopped by user',
        timestamp: Date.now()
      });
    }
  }

  sendInputToProcess(executionId, input) {
    const execution = this.activeExecutions.get(executionId);
    if (execution && execution.process.write) {
      console.log('Sending input to process:', JSON.stringify(input), 'Length:', input.length);
      execution.process.write(input);
    } else {
      console.log('No active execution found for input:', executionId);
    }
  }

  sendMessage(ws, message) {
    if (ws.readyState === 1) { // WebSocket.OPEN
      ws.send(JSON.stringify(message));
    }
  }

  cleanupActiveExecutions(ws) {
    for (const [executionId, execution] of this.activeExecutions.entries()) {
      if (execution.ws === ws) {
        execution.process.kill('SIGTERM');
        this.activeExecutions.delete(executionId);
      }
    }
  }
}

// TerminalHandler removed - not used by current application

app.prepare().then(() => {
  const httpServer = createServer(async (req, res) => {
    try {
      // Be sure to pass `true` as the second argument to `url.parse`.
      // This tells it to parse the query portion of the URL.
      const parsedUrl = parse(req.url, true);
      const { pathname, query } = parsedUrl;

      if (pathname === '/ws/script-execution') {
        // WebSocket upgrade will be handled by the WebSocket server
        return;
      }

      await handle(req, res, parsedUrl);
    } catch (err) {
      console.error('Error occurred handling', req.url, err);
      res.statusCode = 500;
      res.end('internal server error');
    }
  });

  // Create WebSocket handlers
  const scriptHandler = new ScriptExecutionHandler(httpServer);
  // Note: TerminalHandler removed as it's not being used by the current application

  httpServer
    .once('error', (err) => {
      console.error(err);
      process.exit(1);
    })
    .listen(port, hostname, () => {
      console.log(`> Ready on http://${hostname}:${port}`);
      console.log(`> WebSocket server running on ws://${hostname}:${port}/ws/script-execution`);
    });
});