import state from './state.js';
import {
  getToken,
  setToken,
  getUser,
  setUser,
  getCurrentServer,
  setCurrentServer as persistCurrentServer,
  clearAuth
} from './storage.js';
import { showToast } from './toast.js';
import { login, register, ApiError } from './api.js';

export default class AuthManager {
  constructor(calendarView, serverManager) {
    this.calendarView = calendarView;
    this.serverManager = serverManager;

    this.authModal = document.getElementById('authModal');
    this.mainContainer = document.getElementById('mainContainer');
    this.authTitle = document.getElementById('authTitle');
    this.authUsername = document.getElementById('authUsername');
    this.authPassword = document.getElementById('authPassword');
    this.authServer = document.getElementById('authServer');
    this.authMessage = document.getElementById('authMessage');
    this.loginBtn = document.getElementById('loginBtn');
    this.registerBtn = document.getElementById('registerBtn');
    this.switchToRegister = document.getElementById('switchToRegister');
    this.switchToLogin = document.getElementById('switchToLogin');
    this.closeModalBtn = document.getElementById('closeAuthModal');
    this.logoutBtn = document.getElementById('logoutBtn');
    this.userDisplay = document.getElementById('userDisplay');
  }

  init() {
    this.bindEvents();
    this.updateAuthUI();
  }

  bindEvents() {
    if (this.loginBtn) {
      this.loginBtn.addEventListener('click', () => this.handleLogin());
    }

    if (this.registerBtn) {
      this.registerBtn.addEventListener('click', () => this.handleRegister());
    }

    if (this.switchToRegister) {
      this.switchToRegister.addEventListener('click', () => {
        state.isLoginMode = false;
        this.updateAuthUI();
      });
    }

    if (this.switchToLogin) {
      this.switchToLogin.addEventListener('click', () => {
        state.isLoginMode = true;
        this.updateAuthUI();
      });
    }

    if (this.closeModalBtn) {
      this.closeModalBtn.addEventListener('click', () => {
        // Allow closing modal even without login
        this.hideAuthModal();
      });
    }

    if (this.logoutBtn) {
      this.logoutBtn.addEventListener('click', () => {
        if (state.user) {
          this.logout();
        } else {
          this.showAuthModal(state.currentServer || window.location.origin);
        }
      });
    }

    if (this.authPassword) {
      this.authPassword.addEventListener('keypress', (event) => {
        if (event.key === 'Enter') {
          state.isLoginMode ? this.handleLogin() : this.handleRegister();
        }
      });
    }
  }

  async handleLogin() {
    const server = this.getServerInput();
    const username = (this.authUsername?.value || '').trim();
    const password = this.authPassword?.value || '';

    if (!server || !username || !password) {
      this.showAuthMessage('请输入服务器、用户名和密码');
      return;
    }

    try {
      this.showAuthMessage('正在登录...', 'info');
      const result = await login(server, username, password);
      this.afterAuthSuccess(server, result.token, {
        username: result.username,
        userId: result.userId
      });
      showToast('登录成功', 'success');
    } catch (error) {
      this.handleAuthError(error);
    }
  }

  async handleRegister() {
    const server = this.getServerInput();
    const username = (this.authUsername?.value || '').trim();
    const password = this.authPassword?.value || '';

    if (!server || !username || !password) {
      this.showAuthMessage('请输入服务器、用户名和密码');
      return;
    }

    if (username.length < 3) {
      this.showAuthMessage('用户名至少需要3个字符');
      return;
    }

    if (password.length < 6) {
      this.showAuthMessage('密码至少需要6个字符');
      return;
    }

    try {
      this.showAuthMessage('正在注册...', 'info');
      const result = await register(server, username, password);
      this.afterAuthSuccess(server, result.token, {
        username: result.username,
        userId: result.userId
      });
      showToast('注册成功', 'success');
    } catch (error) {
      this.handleAuthError(error);
    }
  }

  getServerInput() {
    const value = this.authServer?.value.trim();
    if (!value) {
      this.showAuthMessage('请输入服务器地址');
      return '';
    }

    try {
      new URL(value);
      return value;
    } catch (error) {
      this.showAuthMessage('无效的服务器地址格式');
      return '';
    }
  }

  afterAuthSuccess(server, token, user) {
    state.currentServer = server;
    state.token = token;
    state.user = user;

    persistCurrentServer(server);
    setToken(server, token);
    setUser(server, user);

    if (this.serverManager) {
      this.serverManager.ensureServerInList(server);
    }

    this.hideAuthModal();
    this.showMainContainer();
    this.updateUserDisplay();

    if (this.serverManager) {
      this.serverManager.setCurrentServer(server);
    }

    this.calendarView.loadData();
    this.clearAuthForm();
    this.clearAuthMessage();
  }

  handleAuthError(error) {
    if (error instanceof ApiError) {
      this.showAuthMessage(error.message || '操作失败');
      return;
    }
    this.showAuthMessage('操作失败，请稍后再试');
  }

  clearAuthForm() {
    if (this.authPassword) this.authPassword.value = '';
  }

  showAuthMessage(message, type = 'error') {
    if (!this.authMessage) return;
    this.authMessage.textContent = message;
    this.authMessage.className = `auth-message ${type}`;
  }

  clearAuthMessage() {
    if (!this.authMessage) return;
    this.authMessage.textContent = '';
    this.authMessage.className = 'auth-message';
  }

  updateAuthUI() {
    if (!this.authTitle || !this.loginBtn || !this.registerBtn || !this.switchToLogin || !this.switchToRegister) {
      return;
    }

    if (state.isLoginMode) {
      this.authTitle.textContent = '登录';
      this.loginBtn.style.display = 'block';
      this.registerBtn.style.display = 'none';
      this.switchToRegister.style.display = 'block';
      this.switchToLogin.style.display = 'none';
    } else {
      this.authTitle.textContent = '注册';
      this.loginBtn.style.display = 'none';
      this.registerBtn.style.display = 'block';
      this.switchToRegister.style.display = 'none';
      this.switchToLogin.style.display = 'block';
    }
  }

  showAuthModal(prefillServer) {
    if (this.authModal) {
      this.authModal.style.display = 'flex';
    }
    // Don't hide main container anymore

    const serverValue = prefillServer || state.currentServer || window.location.origin;
    if (this.authServer) {
      this.authServer.value = serverValue;
    }

    state.isLoginMode = true;
    this.updateAuthUI();
    this.clearAuthMessage();
  }

  hideAuthModal() {
    if (this.authModal) {
      this.authModal.style.display = 'none';
    }
  }

  showMainContainer() {
    if (this.mainContainer) {
      this.mainContainer.style.display = 'block';
    }
    this.hideAuthModal();
  }

  hideMainContainer() {
    if (this.mainContainer) {
      this.mainContainer.style.display = 'none';
    }
  }

  updateUserDisplay() {
    if (this.userDisplay) {
      this.userDisplay.textContent = state.user ? `用户: ${state.user.username}` : '未登录';
    }
    // Update logout button text based on login state
    if (this.logoutBtn) {
      this.logoutBtn.textContent = state.user ? '退出' : '登录';
    }
  }

  async handleServerSelection(server) {
    if (!server) {
      persistCurrentServer('');
      state.currentServer = '';
      state.token = '';
      state.user = null;
      this.calendarView.clearData();
      this.updateUserDisplay();
      // Keep main container visible
      return;
    }

    persistCurrentServer(server);
    state.currentServer = server;

    const storedToken = getToken(server);
    const storedUser = getUser(server);

    if (storedToken && storedUser) {
      state.token = storedToken;
      state.user = storedUser;
      this.showMainContainer();
      this.updateUserDisplay();
      this.calendarView.loadData();
      this.hideAuthModal();
    } else {
      state.token = '';
      state.user = null;
      this.calendarView.clearData();
      this.updateUserDisplay();
      // Show main container and auth modal together
      this.showMainContainer();
      this.showAuthModal(server);
    }
  }

  logout() {
    if (state.currentServer) {
      clearAuth(state.currentServer);
    }
    state.token = '';
    state.user = null;
    this.calendarView.clearData();
    this.updateUserDisplay();
    showToast('已退出登录', 'success');
    // Keep main container visible, just show auth modal
    this.showAuthModal(state.currentServer || window.location.origin);
  }

  checkExistingSession() {
    const storedServer = getCurrentServer();
    if (storedServer) {
      state.currentServer = storedServer;
      if (this.serverManager) {
        this.serverManager.ensureServerInList(storedServer);
        this.serverManager.setCurrentServer(storedServer);
      }
    }

    const storedToken = storedServer ? getToken(storedServer) : '';
    const storedUser = storedServer ? getUser(storedServer) : null;

    // Always show main container first
    this.showMainContainer();
    if (storedServer && storedToken && storedUser) {
      state.token = storedToken;
      state.user = storedUser;
      this.updateUserDisplay();
      // Try to load data, will show login if it fails
      this.calendarView.loadData();
    } else {
      // Render empty calendar
      this.updateUserDisplay();
      this.calendarView.renderCalendar();
    }
  }
}