const express = require('express');
const http = require('http');
const { Server } = require('socket.io');
const Convert = require('ansi-to-html');
const { exec } = require('child_process');
const path = require('path');

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

const PORT = 7860;

// ANSI → HTML
const convert = new Convert({
  fg: '#e2e8f0',
  bg: '#0b1020',
  newline: true,
  escapeXML: true
});

// logs memory
let logs = [];
const MAX_LOGS = 10000;

function formatLog(data) {
  return {
    html: convert.toHtml(data.message || ''),
    level: data.level || 'info',
    timestamp: new Date()
  };
}

function addLog(log) {
  logs.push(log);
  if (logs.length > MAX_LOGS) logs.shift();
}

// STATIC
app.use(express.static(path.join(__dirname, 'public')));

// ✅ PAGINATED API
app.get('/api/logs', (req, res) => {
  const limit = parseInt(req.query.limit) || 50;
  const offset = parseInt(req.query.offset) || 0;

  const start = Math.max(logs.length - offset - limit, 0);
  const end = logs.length - offset;

  const slice = logs.slice(start, end);

  res.json({
    logs: slice,
    hasMore: start > 0
  });
});

// SOCKET
io.on('connection', (socket) => {
  console.log('Client connected:', socket.id);

  socket.on('log', (data) => {
    const log = formatLog(data);
    addLog(log);
    io.emit('log', log);
  });

  socket.on('command', (data) => {
    const cmd = data.command.trim();
    if (!cmd) return;

    if (cmd === "clear") {
      logs = [];
      return;
    }

    const blocked = ['rm', 'shutdown', 'reboot', 'mkfs'];
    if (blocked.some(b => cmd.includes(b))) {
      const log = formatLog({
        message: "\x1b[31mBlocked command!\x1b[0m",
        level: "error"
      });
      addLog(log);
      return io.emit('log', log);
    }

    const cmdLog = formatLog({
      message: "\x1b[32m$ " + cmd + "\x1b[0m"
    });

    addLog(cmdLog);
    io.emit('log', cmdLog);

    exec(cmd, { timeout: 20000 }, (error, stdout, stderr) => {

      if (stdout) {
        const outLog = formatLog({ message: stdout });
        addLog(outLog);
        io.emit('log', outLog);
      }

      if (stderr) {
        const errLog = formatLog({
          message: "\x1b[31m" + stderr + "\x1b[0m",
          level: "error"
        });
        addLog(errLog);
        io.emit('log', errLog);
      }

      if (error) {
        const errLog = formatLog({
          message: "\x1b[31m" + error.message + "\x1b[0m",
          level: "error"
        });
        addLog(errLog);
        io.emit('log', errLog);
      }
    });
  });
});

server.listen(PORT, () => {
  console.log('🚀 Server running on http://localhost:' + PORT);
});