const { spawn, exec } = require('child_process');
const fs = require('fs').promises;
const fsSync = require('fs');
const path = require('path');
const EventEmitter = require('events');
const paths = require('./paths');

class ServerManager extends EventEmitter {
  constructor() {
    super();
    this.serverProcess = null;
    this.isRunning = false;
    this.isReady = false; // Track if server is actually ready to accept connections
    this.startTime = null;
    this.logBuffer = [];
    this.maxLogLines = 1000;
    this.serverStats = {
      players: 0,
      uptime: 0,
      memoryUsage: 0,
      cpuUsage: 0
    };
    this.debugFileWatcher = null;
    this.lastDebugFilePosition = 0;
    this.lastStopTime = 0; // Track when we last stopped a server
  }

  async getServerStatus() {
    // Double-check if process is actually running when we think it is
    if (this.isRunning && this.serverProcess && this.serverProcess.pid) {
      try {
        // Use kill(pid, 0) to check if process exists without sending a signal
        process.kill(this.serverProcess.pid, 0);
      } catch (error) {
        // Process doesn't exist anymore - it was killed externally
        this.addLogLine('warning', 'Server process was terminated externally');
        this.isRunning = false;
        this.isReady = false;
        this.serverProcess = null;
        this.startTime = null;
        
        // Reset player stats when server stops
        this.serverStats.players = 0;
        this.serverStats.memoryUsage = 0;
        this.serverStats.cpuUsage = 0;
        
        this.emit('exit', { code: null, signal: 'external' });
        // Emit status change immediately
        this.emit('status', {
          isRunning: this.isRunning,
          isReady: this.isReady,
          uptime: 0,
          startTime: null,
          players: 0,
          memoryUsage: 0,
          cpuUsage: 0,
          processId: null
        });
      }
    }

    // Only check for external servers if we truly have no server process at all
    // This prevents the state confusion that was causing managed servers to be marked as external
    // Also add a cooldown period after stopping a managed server to prevent race conditions
    const timeSinceLastStop = Date.now() - this.lastStopTime;
    const cooldownPeriod = 5000; // 5 seconds cooldown after stopping a server
    
    if (!this.serverProcess && timeSinceLastStop > cooldownPeriod) {
      const externalServer = await this.detectExternalLuantiServer();
      if (externalServer) {
        console.log(`ServerManager: Detected truly external server (PID: ${externalServer.pid})`);
        
        this.isRunning = true;
        this.isReady = true;
        this.startTime = externalServer.startTime;
        
        // Try to get player data from debug log for external servers
        const playerData = await this.getExternalServerPlayerData();
        this.serverStats.players = playerData.count;
        
        this.addLogLine('info', `Detected external Luanti server (PID: ${externalServer.pid}, World: ${externalServer.world})`);
        // Create a mock server process object for tracking
        this.serverProcess = { pid: externalServer.pid, external: true };
        console.log('ServerManager: Set serverProcess.external = true');
        
        // Start monitoring debug file for external server
        this.startDebugFileMonitoring();
      }
    }

    return {
      isRunning: this.isRunning,
      isReady: this.isReady,
      uptime: this.isRunning && this.startTime ? Date.now() - this.startTime : 0,
      startTime: this.startTime,
      players: this.serverStats.players,
      memoryUsage: this.serverStats.memoryUsage,
      cpuUsage: this.serverStats.cpuUsage,
      processId: this.serverProcess?.pid || null
    };
  }

  async startServer(worldName = null) {
    if (this.isRunning) {
      throw new Error('Server is already running');
    }

    try {
      // Ensure minetest directory exists
      paths.ensureDirectories();

      // Build command arguments
      const args = [
        '--server',
        '--config', paths.configFile
      ];

      if (worldName && worldName.trim() !== '') {
        if (!paths.isValidWorldName(worldName)) {
          throw new Error('Invalid world name');
        }
        
        // Check if world exists
        const worldPath = paths.getWorldPath(worldName);
        try {
          await fs.access(worldPath);
        } catch (error) {
          throw new Error(`World "${worldName}" does not exist. Please create it first in the Worlds section.`);
        }
        
        // Read the world's game configuration
        const worldConfigPath = path.join(worldPath, 'world.mt');
        try {
          const worldConfig = await fs.readFile(worldConfigPath, 'utf8');
          const gameMatch = worldConfig.match(/gameid\s*=\s*(.+)/);
          if (gameMatch) {
            const gameId = gameMatch[1].trim();
            
            args.push('--gameid', gameId);
            this.addLogLine('info', `Using game: ${gameId} for world: ${worldName}`);
          }
        } catch (error) {
          this.addLogLine('warning', `Could not read world config, using default game: ${error.message}`);
        }
        
        args.push('--world', worldPath);
      } else {
        // If no world specified, we need to create a default world or let the server create one
        this.addLogLine('info', 'Starting server without specifying a world. Server will use default world settings.');
      }

      // Check if minetest/luanti executable exists
      const executableInfo = await this.findMinetestExecutable();
      
      this.serverProcess = spawn(executableInfo.command, [...executableInfo.args, ...args], {
        cwd: paths.minetestDir,
        stdio: ['pipe', 'pipe', 'pipe']
      });

      this.isRunning = true;
      this.isReady = false; // Server started but not ready yet
      this.startTime = Date.now();

      // Handle process events
      this.serverProcess.on('error', (error) => {
        this.emit('error', error);
        this.isRunning = false;
        this.isReady = false;
        this.serverProcess = null;
      });

      this.serverProcess.on('exit', (code, signal) => {
        this.emit('exit', { code, signal });
        this.isRunning = false;
        this.isReady = false;
        this.serverProcess = null;
        this.startTime = null;
        this.stopDebugFileMonitoring();
      });

      // Handle output streams
      this.serverProcess.stdout.on('data', (data) => {
        const lines = data.toString().split('\n').filter(line => line.trim());
        lines.forEach(line => this.addLogLine('stdout', line));
        this.parseServerStats(data.toString());
      });

      this.serverProcess.stderr.on('data', (data) => {
        const lines = data.toString().split('\n').filter(line => line.trim());
        lines.forEach(line => this.addLogLine('stderr', line));
      });

      this.emit('started', { pid: this.serverProcess.pid });
      
      // Start monitoring debug.txt file for server ready messages
      this.startDebugFileMonitoring();
      
      return {
        success: true,
        pid: this.serverProcess.pid,
        message: `Server started successfully with PID ${this.serverProcess.pid}`
      };

    } catch (error) {
      this.isRunning = false;
      this.isReady = false;
      this.serverProcess = null;
      throw error;
    }
  }

  async stopServer(force = false) {
    if (!this.isRunning || !this.serverProcess) {
      throw new Error('Server is not running');
    }

    const pid = this.serverProcess.pid;
    const isExternal = this.serverProcess.external;
    
    console.log(`ServerManager: Stopping server (PID: ${pid}, External: ${isExternal}, Force: ${force})`);

    return new Promise((resolve, reject) => {
      let timeoutHandle = null;
      let resolved = false;

      const cleanup = (message) => {
        if (resolved) return;
        resolved = true;
        
        if (timeoutHandle) {
          clearTimeout(timeoutHandle);
        }
        
        // Clean up state immediately
        this.cleanupServerState();
        
        // Add a delay to prevent race conditions with external detection
        setTimeout(() => {
          resolve({ success: true, message });
        }, 2000);
      };

      // Set timeout for force kill
      timeoutHandle = setTimeout(() => {
        console.log(`ServerManager: Timeout reached, force-killing process tree for ${pid}`);
        this.killProcessTree(pid, () => {
          console.log(`ServerManager: Process tree killed for PID ${pid} (timeout)`);
          cleanup('Server force-stopped after timeout');
        });
      }, isExternal ? 3000 : 10000);

      // Set up exit handler for managed processes
      if (this.serverProcess.on && !isExternal) {
        this.serverProcess.on('exit', () => {
          console.log('ServerManager: Managed server process exited');
          cleanup('Server stopped gracefully');
        });
      }

      // For external servers or force stop, kill immediately
      if (isExternal || force) {
        console.log(`ServerManager: Killing process tree for PID ${pid}`);
        this.killProcessTree(pid, () => {
          console.log(`ServerManager: Process tree killed for PID ${pid}`);
          cleanup('Server stopped');
        });
      } else {
        // Try graceful shutdown first for managed servers
        try {
          this.serverProcess.stdin.write('/shutdown\n');
          console.log('ServerManager: Sent shutdown command to server');
        } catch (stdinError) {
          console.warn('Failed to send shutdown command, using SIGTERM:', stdinError.message);
          this.killProcessTree(pid, () => {
            console.log(`ServerManager: Process tree killed for PID ${pid} (after stdin failure)`);
            cleanup('Server stopped');
          });
        }
      }
    });
  }

  killProcessTree(pid, callback) {
    console.log(`ServerManager: Attempting to kill process tree for PID ${pid}`);
    
    const { spawn } = require('child_process');
    
    // First, try to kill the process gracefully with SIGTERM
    this.killProcessRecursive(pid, 'TERM', (termSuccess) => {
      if (termSuccess) {
        console.log('ServerManager: Process terminated gracefully');
        callback();
        return;
      }
      
      // If SIGTERM didn't work, wait a moment and try SIGKILL
      console.log('ServerManager: SIGTERM failed, trying SIGKILL...');
      setTimeout(() => {
        this.killProcessRecursive(pid, 'KILL', (killSuccess) => {
          if (killSuccess) {
            console.log('ServerManager: Process force killed');
          } else {
            console.warn('ServerManager: Could not kill process');
          }
          callback();
        });
      }, 2000);
    });
  }
  
  killProcessRecursive(pid, signal, callback) {
    const { spawn } = require('child_process');
    
    // Get all child processes first
    const pstree = spawn('pstree', ['-p', pid.toString()]);
    let pids = [pid];
    
    let pstreeOutput = '';
    pstree.stdout.on('data', (data) => {
      pstreeOutput += data.toString();
    });
    
    pstree.on('close', (code) => {
      // Extract all PIDs from pstree output
      const pidMatches = pstreeOutput.match(/\((\d+)\)/g);
      if (pidMatches) {
        const childPids = pidMatches.map(match => parseInt(match.slice(1, -1)));
        // Add child PIDs to our list, avoiding duplicates
        childPids.forEach(childPid => {
          if (!pids.includes(childPid)) {
            pids.push(childPid);
          }
        });
      }
      
      console.log(`ServerManager: Found ${pids.length} processes to kill:`, pids);
      
      // Kill all processes in reverse order (children first, then parent)
      pids.reverse();
      
      let processesKilled = 0;
      let processesTotal = pids.length;
      
      const killNextProcess = (index) => {
        if (index >= pids.length) {
          // All done
          console.log(`ServerManager: Killed ${processesKilled}/${processesTotal} processes`);
          callback(processesKilled > 0);
          return;
        }
        
        const currentPid = pids[index];
        console.log(`ServerManager: Sending SIG${signal} to PID ${currentPid}`);
        
        try {
          process.kill(currentPid, `SIG${signal}`);
          processesKilled++;
          console.log(`ServerManager: Successfully sent SIG${signal} to PID ${currentPid}`);
        } catch (error) {
          console.log(`ServerManager: Could not kill PID ${currentPid}:`, error.message);
        }
        
        // Move to next process after a short delay
        setTimeout(() => killNextProcess(index + 1), 100);
      };
      
      killNextProcess(0);
    });
    
    pstree.on('error', (error) => {
      console.warn('ServerManager: pstree failed, falling back to simple kill:', error.message);
      
      // Fallback: just try to kill the main PID
      try {
        process.kill(pid, `SIG${signal}`);
        console.log(`ServerManager: Successfully sent SIG${signal} to PID ${pid} (fallback)`);
        callback(true);
      } catch (error) {
        console.log(`ServerManager: Could not kill PID ${pid}:`, error.message);
        callback(false);
      }
    });
  }

  cleanupServerState() {
    console.log('ServerManager: Cleaning up server state');
    this.isRunning = false;
    this.isReady = false;
    this.serverProcess = null;
    this.startTime = null;
    this.lastStopTime = Date.now(); // Record when we stopped the server
    this.stopDebugFileMonitoring();
    
    // Reset player stats when server stops
    this.serverStats.players = 0;
    this.serverStats.memoryUsage = 0;
    this.serverStats.cpuUsage = 0;
  }

  async restartServer(worldName = null) {
    if (this.isRunning) {
      await this.stopServer();
      // Wait a moment for clean shutdown
      await new Promise(resolve => setTimeout(resolve, 2000));
    }
    return await this.startServer(worldName);
  }

  async findGamePath(gameId) {
    try {
      // Use the paths utility to find installed games
      const games = await paths.getInstalledGames();
      const game = games.find(g => g.name === gameId);
      
      if (game) {
        return game.path;
      }
      
      return null;
    } catch (error) {
      this.addLogLine('warning', `Error finding game path for "${gameId}": ${error.message}`);
      return null;
    }
  }

  async findMinetestExecutable() {
    // Check different installation methods for Luanti
    const installationMethods = [
      // System packages
      { command: 'luanti', args: [] },
      { command: 'minetest', args: [] },
      { command: 'minetestserver', args: [] },
      // Flatpak
      { command: 'flatpak', args: ['run', 'org.luanti.luanti'] },
      { command: 'flatpak', args: ['run', 'net.minetest.Minetest'] },
      // Snap
      { command: 'snap', args: ['run', 'luanti'] },
      { command: 'snap', args: ['run', 'minetest'] }
    ];
    
    for (const method of installationMethods) {
      try {
        // Test if the command exists and works
        const testResult = await new Promise((resolve, reject) => {
          const { spawn } = require('child_process');
          const testProcess = spawn(method.command, [...method.args, '--version'], { 
            stdio: ['ignore', 'pipe', 'pipe'],
            timeout: 5000
          });
          
          let stdout = '';
          let stderr = '';
          
          testProcess.stdout.on('data', (data) => {
            stdout += data.toString();
          });
          
          testProcess.stderr.on('data', (data) => {
            stderr += data.toString();
          });
          
          testProcess.on('close', (code) => {
            if ((code === 0 || code === null) && (stdout.includes('Luanti') || stdout.includes('Minetest'))) {
              resolve({ command: method.command, args: method.args, output: stdout });
            } else {
              reject(new Error(`Command failed with code ${code}`));
            }
          });
          
          testProcess.on('error', (error) => {
            reject(error);
          });
        });
        
        const executableInfo = {
          command: testResult.command,
          args: testResult.args,
          fullCommand: testResult.args.length > 0 ? `${testResult.command} ${testResult.args.join(' ')}` : testResult.command
        };
        
        this.addLogLine('info', `Found Luanti: ${executableInfo.fullCommand}`);
        return executableInfo;
        
      } catch (error) {
        // Continue to next method
        continue;
      }
    }
    
    // Provide detailed error message with setup instructions
    const errorMsg = `Luanti/Minetest not found or not working properly.\n\n` +
                    `Please install Luanti using one of these methods:\n` +
                    `• System package: sudo apt install luanti (Ubuntu/Debian)\n` +
                    `• Flatpak: flatpak install flathub org.luanti.luanti\n` +
                    `• Snap: sudo snap install luanti\n` +
                    `• Download from: https://www.luanti.org/downloads/\n\n` +
                    `This web interface requires Luanti to manage worlds and run servers.`;
    
    this.addLogLine('error', errorMsg);
    throw new Error(errorMsg);
  }

  async createWorld(worldName, gameId = 'minetest_game') {
    try {
      const executableInfo = await this.findMinetestExecutable();
      const worldPath = paths.getWorldPath(worldName);
      
      // Create world using Luanti --world command
      // This will initialize the world properly with the correct structure
      const createWorldArgs = [
        '--world', worldPath,
        '--gameid', gameId,
        '--server',
        '--go', // Skip main menu
        '--quiet' // Reduce output
      ];
      
      this.addLogLine('info', `Creating world "${worldName}" with game "${gameId}"`);
      
      return new Promise((resolve, reject) => {
        const createProcess = spawn(executableInfo.command, [...executableInfo.args, ...createWorldArgs], {
          cwd: paths.minetestDir,
          stdio: ['pipe', 'pipe', 'pipe'],
          timeout: 30000 // 30 second timeout
        });
        
        let stdout = '';
        let stderr = '';
        
        createProcess.stdout.on('data', (data) => {
          stdout += data.toString();
        });
        
        createProcess.stderr.on('data', (data) => {
          stderr += data.toString();
        });
        
        // Stop the server after a short time - we just want to initialize the world
        // Complex games like VoxeLibre/MineCLone2 need more time to initialize
        const timeout = gameId === 'mineclone2' || gameId.includes('clone') || gameId.includes('voxel') ? 8000 : 3000;
        this.addLogLine('info', `Using ${timeout}ms timeout for game: ${gameId}`);
        
        setTimeout(() => {
          if (createProcess && !createProcess.killed) {
            createProcess.kill('SIGTERM');
          }
        }, timeout);
        
        createProcess.on('close', (code) => {
          this.addLogLine('info', `World creation process finished with code: ${code}`);
          
          // Check if world directory was created successfully
          if (fsSync.existsSync(worldPath)) {
            this.addLogLine('info', `World "${worldName}" created successfully`);
            resolve({ success: true, worldPath });
          } else {
            this.addLogLine('error', `World directory not created: ${worldPath}`);
            reject(new Error(`Failed to create world directory: ${worldPath}`));
          }
        });
        
        createProcess.on('error', (error) => {
          this.addLogLine('error', `World creation failed: ${error.message}`);
          reject(error);
        });
      });
      
    } catch (error) {
      this.addLogLine('error', `Failed to create world: ${error.message}`);
      throw error;
    }
  }

  addLogLine(type, content) {
    const timestamp = new Date().toISOString();
    const logEntry = {
      timestamp,
      type,
      content: content.trim()
    };

    this.logBuffer.push(logEntry);
    
    // Keep only the last N lines
    if (this.logBuffer.length > this.maxLogLines) {
      this.logBuffer = this.logBuffer.slice(-this.maxLogLines);
    }

    this.emit('log', logEntry);
  }

  parseServerStats(output) {
    // Parse server output for statistics and ready state
    const lines = output.split('\n');
    
    for (const line of lines) {
      // Look for player count
      const playerMatch = line.match(/(\d+) players? online/i);
      if (playerMatch) {
        this.serverStats.players = parseInt(playerMatch[1]);
      }

      // Look for performance stats if available
      const memMatch = line.match(/Memory usage: ([\d.]+)MB/i);
      if (memMatch) {
        this.serverStats.memoryUsage = parseFloat(memMatch[1]);
      }
      
      // Check if server is ready - look for common Luanti server ready messages
      if (!this.isReady && this.isRunning) {
        const readyIndicators = [
          /Server for gameid=".*?" listening on/i,
          /listening on \[::\]:\d+/i,
          /listening on 0\.0\.0\.0:\d+/i,
          /World at \[.*?\]/i,
          /Server started/i,
          /Loading environment/i
        ];
        
        for (const indicator of readyIndicators) {
          if (indicator.test(line)) {
            this.isReady = true;
            this.addLogLine('info', 'Server is now ready to accept connections');
            console.log(`Server ready detected from line: ${line}`); // Debug log
            // Emit status change when server becomes ready
            this.emit('status', {
              isRunning: this.isRunning,
              isReady: this.isReady,
              uptime: this.startTime ? Date.now() - this.startTime : 0,
              startTime: this.startTime,
              players: this.serverStats.players,
              memoryUsage: this.serverStats.memoryUsage,
              cpuUsage: this.serverStats.cpuUsage,
              processId: this.serverProcess?.pid || null
            });
            break;
          }
        }
        
        // Also check for error conditions that indicate startup failure
        const errorIndicators = [
          /ERROR\[Main\]:/i,
          /FATAL ERROR/i,
          /Could not find or load game/i,
          /Failed to/i
        ];
        
        for (const errorIndicator of errorIndicators) {
          if (errorIndicator.test(line)) {
            // Don't mark as ready if we see critical errors
            this.addLogLine('warning', 'Server startup may have failed - check logs for errors');
            break;
          }
        }
      }
    }

    this.emit('stats', this.serverStats);
  }

  getLogs(lines = 100) {
    return this.logBuffer.slice(-lines);
  }

  getRecentLogs(since = null) {
    if (!since) {
      return this.logBuffer.slice(-50);
    }
    
    const sinceTime = new Date(since);
    return this.logBuffer.filter(log => 
      new Date(log.timestamp) > sinceTime
    );
  }

  async sendCommand(command) {
    if (!this.isRunning || !this.serverProcess) {
      throw new Error('Server is not running');
    }

    // Check if this is an external server
    if (this.serverProcess.external) {
      throw new Error('Cannot send commands to external servers. Commands can only be sent to servers started through this dashboard.');
    }

    // Validate and sanitize command
    const sanitizedCommand = this.validateServerCommand(command);
    
    return new Promise((resolve, reject) => {
      try {
        this.serverProcess.stdin.write(sanitizedCommand + '\n');
        this.addLogLine('info', `Command sent: ${sanitizedCommand}`);
        resolve({ success: true, message: 'Command sent successfully' });
      } catch (error) {
        reject(error);
      }
    });
  }

  validateServerCommand(command) {
    if (!command || typeof command !== 'string') {
      throw new Error('Command must be a non-empty string');
    }

    // Remove any control characters and limit length
    const sanitized = command.replace(/[\x00-\x1F\x7F]/g, '').trim();
    
    if (sanitized.length === 0) {
      throw new Error('Command cannot be empty after sanitization');
    }

    if (sanitized.length > 500) {
      throw new Error('Command too long (max 500 characters)');
    }

    // Whitelist of allowed command prefixes for safety
    const allowedCommands = [
      '/say', '/tell', '/kick', '/ban', '/unban', '/status', '/time', '/weather',
      '/give', '/teleport', '/tp', '/spawn', '/help', '/list', '/who', '/shutdown',
      '/stop', '/save-all', '/whitelist', '/op', '/deop', '/gamemode', '/difficulty',
      '/seed', '/defaultgamemode', '/gamerule', '/reload', '/clear', '/experience',
      '/xp', '/effect', '/enchant', '/summon', '/kill', '/scoreboard', '/team',
      '/trigger', '/clone', '/execute', '/fill', '/setblock', '/testforblock',
      '/blockdata', '/entitydata', '/testfor', '/stats', '/worldborder'
    ];

    // Check if command starts with allowed prefix or is a direct server command
    const isAllowed = allowedCommands.some(prefix => 
      sanitized.toLowerCase().startsWith(prefix.toLowerCase())
    ) || /^[a-zA-Z0-9_-]+(\s+[a-zA-Z0-9_.-]+)*$/.test(sanitized);

    if (!isAllowed) {
      throw new Error('Command not allowed or contains invalid characters');
    }

    return sanitized;
  }

  async getServerInfo() {
    try {
      const configExists = await fs.access(paths.configFile).then(() => true).catch(() => false);
      const debugLogExists = await fs.access(paths.debugFile).then(() => true).catch(() => false);
      
      let configMtime = null;
      if (configExists) {
        const stats = await fs.stat(paths.configFile);
        configMtime = stats.mtime;
      }

      return {
        configFile: {
          exists: configExists,
          path: paths.configFile,
          lastModified: configMtime
        },
        debugLog: {
          exists: debugLogExists,
          path: paths.debugFile
        },
        directories: {
          minetest: paths.minetestDir,
          worlds: paths.worldsDir,
          mods: paths.modsDir
        }
      };
    } catch (error) {
      throw new Error(`Failed to get server info: ${error.message}`);
    }
  }

  startDebugFileMonitoring() {
    const debugFilePath = path.join(paths.minetestDir, 'debug.txt');
    
    try {
      // Get initial file size to start monitoring from the end
      const stats = fsSync.existsSync(debugFilePath) ? fsSync.statSync(debugFilePath) : null;
      this.lastDebugFilePosition = stats ? stats.size : 0;
      
      // Watch for changes to debug.txt
      this.debugFileWatcher = fsSync.watchFile(debugFilePath, { interval: 500 }, (current, previous) => {
        if (current.mtime > previous.mtime) {
          this.readDebugFileChanges(debugFilePath);
        }
      });
    } catch (error) {
      this.addLogLine('warning', `Could not monitor debug.txt: ${error.message}`);
    }
  }

  stopDebugFileMonitoring() {
    if (this.debugFileWatcher) {
      const debugFilePath = path.join(paths.minetestDir, 'debug.txt');
      fsSync.unwatchFile(debugFilePath);
      this.debugFileWatcher = null;
    }
  }

  async readDebugFileChanges(debugFilePath) {
    try {
      const stats = fsSync.statSync(debugFilePath);
      if (stats.size > this.lastDebugFilePosition) {
        const stream = fsSync.createReadStream(debugFilePath, {
          start: this.lastDebugFilePosition,
          end: stats.size - 1
        });
        
        let buffer = '';
        stream.on('data', (chunk) => {
          buffer += chunk.toString();
        });
        
        stream.on('end', () => {
          const lines = buffer.split('\n').filter(line => line.trim());
          lines.forEach(line => {
            this.addLogLine('debug-file', line);
            this.parseServerStats(line); // Parse each line for ready indicators
            
            // For external servers, also update player count from new log entries
            if (this.serverProcess?.external) {
              this.updatePlayerCountFromLogLine(line);
            }
          });
        });
        
        this.lastDebugFilePosition = stats.size;
      }
    } catch (error) {
      // Ignore errors when reading debug file changes
    }
  }

  updatePlayerCountFromLogLine(line) {
    // Update player count based on join/leave messages in log
    const joinMatch = line.match(/\[Server\]: (\w+) joined the game/);
    const leaveMatch = line.match(/\[Server\]: (\w+) left the game/);
    
    if (joinMatch || leaveMatch) {
      // Player joined or left - update player data
      this.getExternalServerPlayerData().then(playerData => {
        this.serverStats.players = playerData.count;
      });
    }
  }
  async detectExternalLuantiServer() {
    try {
      const { spawn } = require('child_process');
      
      return new Promise((resolve) => {
        const psProcess = spawn('ps', ['aux'], { stdio: ['ignore', 'pipe', 'pipe'] });
        let stdout = '';
        
        psProcess.stdout.on('data', (data) => {
          stdout += data.toString();
        });
        
        psProcess.on('close', (code) => {
          if (code === 0) {
            const lines = stdout.split('\n');
            for (const line of lines) {
              // Look for luanti or minetest server processes (exclude this dashboard process)
              if ((line.includes('luanti') || line.includes('minetest')) && 
                  (line.includes('--server') || line.includes('--worldname')) &&
                  !line.includes('node app.js')) {
                
                const parts = line.trim().split(/\s+/);
                const pid = parseInt(parts[1]);
                
                if (pid && !isNaN(pid)) {
                  // Extract world name from command line
                  let world = 'unknown';
                  const worldNameMatch = line.match(/--worldname\s+(\S+)/);
                  const worldPathMatch = line.match(/--world\s+(\S+)/);
                  
                  if (worldNameMatch) {
                    world = worldNameMatch[1];
                  } else if (worldPathMatch) {
                    world = path.basename(worldPathMatch[1]);
                  }
                  
                  // Estimate start time (this is rough, but better than nothing)
                  const startTime = Date.now() - 60000; // Assume started 1 minute ago
                  
                  resolve({
                    pid: pid,
                    world: world,
                    startTime: startTime
                  });
                  return;
                }
              }
            }
          }
          resolve(null);
        });
        
        psProcess.on('error', () => {
          resolve(null);
        });
      });
    } catch (error) {
      return null;
    }
  }

  async getExternalServerPlayerData() {
    try {
      const fs = require('fs').promises;
      const debugFilePath = path.join(paths.minetestDir, 'debug.txt');
      
      // Read the last 100 lines of debug.txt to find recent player activity
      const data = await fs.readFile(debugFilePath, 'utf8');
      const lines = data.split('\n').slice(-100);
      
      // Look for recent player actions to determine who's online
      const playerData = new Map(); // Map to store player name -> player info
      const cutoffTime = new Date(Date.now() - 10 * 60 * 1000); // 10 minutes ago (extended from 5)
      
      
      for (const line of lines.reverse()) {
        // Parse timestamp from log line
        const timestampMatch = line.match(/^(\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}):/);
        if (timestampMatch) {
          const logTime = new Date(timestampMatch[1]);
          if (logTime < cutoffTime) break; // Stop looking at older entries
          
          // Look for player actions with more detail
          const actionPatterns = [
            { pattern: /ACTION\[Server\]: (\w+) (.+)/, type: 'action' },
            { pattern: /\[Server\]: (\w+) joined the game/, type: 'joined' },
            { pattern: /\[Server\]: (\w+) left the game/, type: 'left' }
          ];
          
          for (const { pattern, type } of actionPatterns) {
            const match = line.match(pattern);
            if (match && match[1]) {
              const playerName = match[1];
              const actionDescription = match[2] || type;
              
              
              // Filter out obvious non-player names and false positives
              if (!playerName.includes('Entity') && 
                  !playerName.includes('SAO') && 
                  !playerName.includes('Explosion') &&
                  playerName !== 'Player' && // Generic "Player" is not a real username
                  playerName !== 'Server' &&
                  playerName !== 'Main' &&
                  playerName.length > 2 && // Too short usernames are likely false positives
                  playerName.length < 20 && 
                  /^[a-zA-Z0-9_]+$/.test(playerName)) {
                
                
                // Update player data with most recent activity
                if (!playerData.has(playerName) || logTime > playerData.get(playerName).lastSeen) {
                  let lastAction = actionDescription;
                  
                  // Simplify common actions for display
                  if (lastAction.includes('digs ')) {
                    lastAction = 'Mining';
                  } else if (lastAction.includes('places ') || lastAction.includes('puts ')) {
                    lastAction = 'Building';
                  } else if (lastAction.includes('uses ') || lastAction.includes('activates ')) {
                    lastAction = 'Using items';
                  } else if (lastAction.includes('punched ') || lastAction.includes('damage')) {
                    lastAction = 'Combat';
                  } else if (type === 'joined') {
                    lastAction = 'Just joined';
                  } else if (type === 'left') {
                    lastAction = 'Left game';
                  } else {
                    lastAction = 'Active';
                  }
                  
                  // Count activities for this player
                  const existingData = playerData.get(playerName) || { activityCount: 0 };
                  
                  playerData.set(playerName, {
                    name: playerName,
                    lastSeen: logTime,
                    lastAction: lastAction,
                    activityCount: existingData.activityCount + 1,
                    online: type !== 'left' // Mark as offline if they left
                  });
                }
              } else {
              }
            }
          }
        }
      }
      
      // Convert to array of player objects, filtering out players who left
      const players = Array.from(playerData.values())
        .filter(player => player.online)
        .map(player => ({
          name: player.name,
          lastSeen: player.lastSeen,
          lastAction: player.lastAction,
          activityCount: player.activityCount,
          online: true
        }));
      
      return {
        count: players.length,
        players: players
      };
    } catch (error) {
      console.error('Error reading debug file for player data:', error);
      return { count: 0, players: [] };
    }
  }
}

module.exports = ServerManager;