const ModerationAdmin = require('../models/ModerationAdmin');
const User = require('../models/User');
const config = require('../config');

const normalizeUsername = (username = '') => username.replace(/^@/, '').trim().toLowerCase();

const ownerUsernames = new Set(config.moderationOwnerUsernames || []);

const listAdmins = async () => {
  const admins = await ModerationAdmin.find().sort({ username: 1 }).lean();
  return admins.map((admin) => ({
    telegramId: admin.telegramId,
    username: admin.username,
    firstName: admin.firstName,
    lastName: admin.lastName,
    addedBy: admin.addedBy,
    createdAt: admin.createdAt
  }));
};

const isModerationAdmin = async ({ telegramId, username }) => {
  const normalized = normalizeUsername(username);
  if (ownerUsernames.has(normalized)) {
    return true;
  }

  if (telegramId) {
    const byId = await ModerationAdmin.findOne({ telegramId }).lean();
    if (byId) {
      return true;
    }
  }

  if (normalized) {
    const byUsername = await ModerationAdmin.findOne({ username: normalized }).lean();
    if (byUsername) {
      return true;
    }
  }

  return false;
};

const addAdmin = async ({ username, addedBy }) => {
  const normalized = normalizeUsername(username);
  if (!normalized) {
    throw new Error('Укажите username в формате @username');
  }

  const user = await User.findOne({ username: normalized }).lean();
  if (!user) {
    throw new Error(`Пользователь ${normalized} не найден в Nakama`);
  }

  const existing = await ModerationAdmin.findOne({ username: normalized });
  if (existing) {
    return existing;
  }

  const admin = new ModerationAdmin({
    telegramId: user.telegramId,
    username: normalized,
    firstName: user.firstName,
    lastName: user.lastName,
    addedBy: normalizeUsername(addedBy)
  });
  await admin.save();
  return admin;
};

const removeAdmin = async (username) => {
  const normalized = normalizeUsername(username);
  if (!normalized) {
    throw new Error('Укажите username в формате @username');
  }
  if (ownerUsernames.has(normalized)) {
    throw new Error('Нельзя удалить владельца');
  }
  await ModerationAdmin.deleteOne({ username: normalized });
};

module.exports = {
  listAdmins,
  isModerationAdmin,
  addAdmin,
  removeAdmin,
  normalizeUsername
};