'use strict';

const fs = require('node:fs');
const path = require('node:path');
const net = require('node:net');

const configPath = path.join(__dirname, 'config.json');
const defaultConfig = {
  host: '0.0.0.0',
  port: 24469,
  token: ''
};

if (!fs.existsSync(configPath)) {
  fs.writeFileSync(configPath, JSON.stringify(defaultConfig, null, 2));
}

const config = {
  ...defaultConfig,
  ...JSON.parse(fs.readFileSync(configPath, 'utf8'))
};

const clients = new Set();

function sendJson(socket, payload) {
  socket.write(JSON.stringify(payload) + '\n');
}

function broadcast(payload) {
  const line = JSON.stringify(payload) + '\n';
  for (const socket of clients) {
    if (!socket.destroyed) {
      socket.write(line);
    }
  }
}

function systemMessage(message) {
  return {
    type: 'system',
    message,
    timestamp: Date.now()
  };
}

const server = net.createServer((socket) => {
  socket.setEncoding('utf8');
  clients.add(socket);
  let buffer = '';

  sendJson(socket, systemMessage('Connected to IRC server.'));
  console.log(`[connect] ${socket.remoteAddress}:${socket.remotePort}`);

  socket.on('data', (chunk) => {
    buffer += chunk;

    let separatorIndex = buffer.indexOf('\n');
    while (separatorIndex !== -1) {
      const rawLine = buffer.slice(0, separatorIndex).trim();
      buffer = buffer.slice(separatorIndex + 1);
      separatorIndex = buffer.indexOf('\n');

      if (!rawLine) {
        continue;
      }

      let payload;
      try {
        payload = JSON.parse(rawLine);
      } catch (error) {
        sendJson(socket, systemMessage(`Bad JSON: ${error.message}`));
        continue;
      }

      if (config.token && payload.token !== config.token) {
        sendJson(socket, systemMessage('Invalid token.'));
        continue;
      }

      if (payload.type === 'hello') {
        const name = payload.player || 'unknown';
        sendJson(socket, systemMessage(`Hello, ${name}.`));
        continue;
      }

      if (payload.type === 'chat') {
        const clientName = String(payload.client || 'UNKNOWN-CLIENT').trim();
        const playerName = String(payload.player || 'unknown').trim();
        const message = String(payload.message || '').trim();

        if (!message) {
          sendJson(socket, systemMessage('Empty chat message ignored.'));
          continue;
        }

        const outgoing = {
          type: 'chat',
          client: clientName,
          player: playerName,
          message,
          timestamp: Date.now()
        };

        console.log(`[chat] ${clientName} >> ${playerName}: ${message}`);
        broadcast(outgoing);
        continue;
      }

      if (payload.type === 'marker_set') {
        const clientName = String(payload.client || 'UNKNOWN-CLIENT').trim();
        const playerName = String(payload.player || 'unknown').trim();
        const dimensionId = String(payload.dimensionId || 'minecraft:overworld').trim();
        const x = Number(payload.x);
        const y = Number(payload.y);
        const z = Number(payload.z);
        if (!Number.isFinite(x) || !Number.isFinite(y) || !Number.isFinite(z)) {
          sendJson(socket, systemMessage('Bad marker_set coords.'));
          continue;
        }
        const outgoing = {
          type: 'marker_set',
          client: clientName,
          player: playerName,
          dimensionId,
          x,
          y,
          z,
          timestamp: Date.now()
        };
        console.log(`[marker_set] ${clientName} >> ${playerName} @ ${dimensionId} ${x.toFixed(1)},${y.toFixed(1)},${z.toFixed(1)}`);
        broadcast(outgoing);
        continue;
      }

      if (payload.type === 'marker_remove') {
        const clientName = String(payload.client || 'UNKNOWN-CLIENT').trim();
        const playerName = String(payload.player || 'unknown').trim();
        const outgoing = {
          type: 'marker_remove',
          client: clientName,
          player: playerName,
          timestamp: Date.now()
        };
        console.log(`[marker_remove] ${clientName} >> ${playerName}`);
        broadcast(outgoing);
        continue;
      }

      sendJson(socket, systemMessage(`Unknown packet type: ${payload.type}`));
    }
  });

  socket.on('close', () => {
    clients.delete(socket);
    console.log(`[disconnect] ${socket.remoteAddress}:${socket.remotePort}`);
  });

  socket.on('error', (error) => {
    clients.delete(socket);
    console.error(`[socket-error] ${socket.remoteAddress}:${socket.remotePort} ${error.message}`);
  });
});

server.on('error', (error) => {
  console.error(`[server-error] ${error.message}`);
  process.exitCode = 1;
});

server.listen(config.port, config.host, () => {
  console.log(`IRC server listening on ${config.host}:${config.port}`);
});