const { customAlphabet } = require("nanoid");

const codeAlphabet = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789";
const makeCode = customAlphabet(codeAlphabet, 6);
const makeId = customAlphabet(
  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
  21
);

const rooms = new Map();

function genCode() {
  let c;
  do {
    c = makeCode();
  } while (rooms.has(c));
  return c;
}

function getRoom(code) {
  return rooms.get(String(code || "").toUpperCase());
}

function setRoom(code, room) {
  rooms.set(code.toUpperCase(), room);
}

function deleteRoom(code) {
  rooms.delete(String(code || "").toUpperCase());
}

function allRooms() {
  return rooms;
}

// Idle cleanup — drop rooms with no active sockets older than 60min
setInterval(() => {
  const now = Date.now();
  for (const [code, room] of rooms.entries()) {
    const active = room.players.some((p) => p.connected);
    if (!active && now - (room.lastActiveAt || 0) > 60 * 60 * 1000) {
      rooms.delete(code);
    }
  }
}, 60 * 1000);

module.exports = { genCode, getRoom, setRoom, deleteRoom, allRooms, makeId };