import state from './state.js';
import {
  getServers,
  saveServers,
  getCurrentServer,
  setCurrentServer as persistCurrentServer,
  clearAuth
} from './storage.js';
import { showToast } from './toast.js';

export default class ServerManager {
  constructor() {
    this.serverInput = document.getElementById('serverInput');
    this.addBtn = document.getElementById('addServerBtn');
    this.removeBtn = document.getElementById('removeServerBtn');
    this.selectEl = document.getElementById('serverSelect');
    this.servers = [];
    this.changeHandler = null;
  }

  init() {
    this.servers = getServers();
    this.renderOptions();

    const storedCurrent = getCurrentServer();
    if (storedCurrent) {
      this.setCurrentServer(storedCurrent);
      state.currentServer = storedCurrent;
    }

    if (this.addBtn) {
      this.addBtn.addEventListener('click', () => this.handleAdd());
    }

    if (this.removeBtn) {
      this.removeBtn.addEventListener('click', () => this.handleRemove());
    }

    if (this.selectEl) {
      this.selectEl.addEventListener('change', () => this.handleSelect());
    }
  }

  onChange(handler) {
    this.changeHandler = handler;
  }

  handleAdd() {
    const server = (this.serverInput?.value || '').trim();

    if (!server) {
      showToast('请输入服务器地址', 'error');
      return;
    }

    if (!this.isValidUrl(server)) {
      showToast('无效的服务器地址格式', 'error');
      return;
    }

    if (this.servers.includes(server)) {
      showToast('服务器已存在', 'error');
      return;
    }

    this.servers.push(server);
    saveServers(this.servers);
    this.renderOptions();
    this.setCurrentServer(server);
    persistCurrentServer(server);
    showToast('服务器已添加', 'success');

    if (this.changeHandler) {
      this.changeHandler(server);
    }
    if (this.serverInput) {
      this.serverInput.value = '';
    }
  }

  handleRemove() {
    const server = this.selectEl?.value;
    if (!server) {
      showToast('请选择要删除的服务器', 'error');
      return;
    }

    if (!confirm(`确定要删除服务器 "${server}" 吗？`)) {
      return;
    }

    this.servers = this.servers.filter(item => item !== server);
    saveServers(this.servers);
    clearAuth(server);

    if (state.currentServer === server) {
      state.currentServer = '';
    }

    persistCurrentServer('');
    this.renderOptions();
    showToast('服务器已删除', 'success');

    if (this.changeHandler) {
      this.changeHandler('');
    }
  }

  handleSelect() {
    const server = this.selectEl?.value || '';
    persistCurrentServer(server);
    state.currentServer = server;

    if (this.changeHandler) {
      this.changeHandler(server);
    }
  }

  ensureServerInList(server) {
    if (!server) return;
    if (!this.servers.includes(server)) {
      this.servers.push(server);
      saveServers(this.servers);
      this.renderOptions();
    }
    this.setCurrentServer(server);
  }

  setCurrentServer(server) {
    if (!this.selectEl) return;
    const optionExists = Array.from(this.selectEl.options).some(opt => opt.value === server);
    if (!optionExists && server) {
      const option = document.createElement('option');
      option.value = server;
      option.textContent = server;
      this.selectEl.appendChild(option);
    }
    this.selectEl.value = server || '';
  }

  renderOptions() {
    if (!this.selectEl) return;

    this.selectEl.innerHTML = '';
    const placeholder = document.createElement('option');
    placeholder.value = '';
    placeholder.textContent = '选择服务器';
    this.selectEl.appendChild(placeholder);

    this.servers.forEach(server => {
      const option = document.createElement('option');
      option.value = server;
      option.textContent = server;
      this.selectEl.appendChild(option);
    });
  }

  isValidUrl(value) {
    try {
      new URL(value);
      return true;
    } catch (error) {
      return false;
    }
  }
}