import React, { useState, useEffect } from 'react';
import apiClient from '../../utils/apiClient';
import { buildApiUrl, API_ENDPOINTS } from '../../config/api';
import { Plus, Edit, Trash2, KeyRound, User, Mail, Shield, Search, X } from 'lucide-react';
import ConfirmDialog from '../../components/ConfirmDialog';
import FormModal from '../../components/FormModal';
import Toast from '../../components/Toast';
import './UserManagement.css';

const UserManagement = () => {
  const [users, setUsers] = useState([]);
  const [total, setTotal] = useState(0);
  const [page, setPage] = useState(1);
  const [pageSize, setPageSize] = useState(10);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState('');
  const [showUserModal, setShowUserModal] = useState(false);
  const [isEditing, setIsEditing] = useState(false);
  const [currentUser, setCurrentUser] = useState(null);
  const [deleteConfirmInfo, setDeleteConfirmInfo] = useState(null);
  const [resetConfirmInfo, setResetConfirmInfo] = useState(null);
  const [roles, setRoles] = useState([]);
  const [toasts, setToasts] = useState([]);
  const [searchText, setSearchText] = useState(''); // 搜索文本

  // Toast helper functions
  const showToast = (message, type = 'info') => {
    const id = Date.now();
    setToasts(prev => [...prev, { id, message, type }]);
  };

  const removeToast = (id) => {
    setToasts(prev => prev.filter(toast => toast.id !== id));
  };

  useEffect(() => {
    fetchUsers();
    fetchRoles();
  }, [page, pageSize, searchText]);

  const fetchUsers = async () => {
    setLoading(true);
    try {
      let url = `${API_ENDPOINTS.USERS.LIST}?page=${page}&size=${pageSize}`;
      if (searchText) {
        url += `&search=${encodeURIComponent(searchText)}`;
      }
      const response = await apiClient.get(buildApiUrl(url));
      setUsers(response.data.users);
      setTotal(response.data.total);
    } catch (err) {
      setError('无法加载用户列表');
    } finally {
      setLoading(false);
    }
  };

  const fetchRoles = async () => {
    try {
      const response = await apiClient.get(buildApiUrl(API_ENDPOINTS.USERS.ROLES));
      setRoles(response.data);
    } catch (err) {
      console.error('Error fetching roles:', err);
      // 如果无法获取角色列表，使用默认值
      setRoles([
        { role_id: 1, role_name: '平台管理员' },
        { role_id: 2, role_name: '普通用户' }
      ]);
    }
  };

  const handleAddUser = async (e) => {
    e.preventDefault();
    try {
      await apiClient.post(buildApiUrl(API_ENDPOINTS.USERS.CREATE), currentUser);
      handleCloseModal();
      setError('');
      fetchUsers();
      showToast('用户添加成功', 'success');
    } catch (err) {
      console.error('Error adding user:', err);
      setError(err.response?.data?.message || '新增用户失败');
    }
  };

  const handleUpdateUser = async (e) => {
    e.preventDefault();
    try {
      const updateData = {
        caption: currentUser.caption,
        email: currentUser.email,
        role_id: currentUser.role_id
      };

      if (currentUser.username && currentUser.username.trim()) {
        updateData.username = currentUser.username;
      }

      await apiClient.put(buildApiUrl(API_ENDPOINTS.USERS.UPDATE(currentUser.user_id)), updateData);
      handleCloseModal();
      setError('');
      fetchUsers();
      showToast('用户修改成功', 'success');
    } catch (err) {
      console.error('Error updating user:', err);
      setError(err.response?.data?.message || '修改用户失败');
    }
  };

  const handleDeleteUser = async () => {
    try {
      await apiClient.delete(buildApiUrl(API_ENDPOINTS.USERS.DELETE(deleteConfirmInfo.user_id)));
      setDeleteConfirmInfo(null);
      showToast('用户删除成功', 'success');
      fetchUsers();
    } catch (err) {
      console.error('Error deleting user:', err);
      showToast('删除用户失败，请重试', 'error');
      setDeleteConfirmInfo(null);
    }
  };

  const handleResetPassword = async () => {
    try {
      await apiClient.post(buildApiUrl(API_ENDPOINTS.USERS.RESET_PASSWORD(resetConfirmInfo.user_id)));
      setResetConfirmInfo(null);
      showToast('密码重置成功', 'success');
    } catch (err) {
      console.error('Error resetting password:', err);
      showToast('重置密码失败，请重试', 'error');
      setResetConfirmInfo(null);
    }
  };

  const handleOpenModal = (user = null) => {
    if (user) {
      setIsEditing(true);
      setCurrentUser({ ...user });
    } else {
      setIsEditing(false);
      setCurrentUser({ username: '', caption: '', email: '', role_id: 2 });
    }
    setError('');
    setShowUserModal(true);
  };

  const handleCloseModal = () => {
    setShowUserModal(false);
    setCurrentUser(null);
    setError('');
  };

  const handleSave = async () => {
    if (isEditing) {
      await handleUpdateUser({ preventDefault: () => {} });
    } else {
      await handleAddUser({ preventDefault: () => {} });
    }
  };

  const handleInputChange = (field, value) => {
    setCurrentUser(prev => ({ ...prev, [field]: value }));
  };

  const openDeleteConfirm = (user) => {
    setDeleteConfirmInfo({ user_id: user.user_id, caption: user.caption });
  };

  const openResetConfirm = (user) => {
    setResetConfirmInfo({ user_id: user.user_id, caption: user.caption });
  };

  return (
    <div className="user-management">
      <div className="toolbar">
        <h2>用户列表</h2>
        <div className="toolbar-actions">
          <div className="search-box">
            <Search size={18} />
            <input
              type="text"
              placeholder="搜索用户名或姓名..."
              value={searchText}
              onChange={(e) => {
                setSearchText(e.target.value);
                setPage(1); // 重置到第一页
              }}
            />
            {searchText && (
              <button className="clear-search" onClick={() => setSearchText('')}>
                <X size={16} />
              </button>
            )}
          </div>
          <button className="btn btn-primary" onClick={() => handleOpenModal()}><Plus size={16} /> 新增用户</button>
        </div>
      </div>
      {loading && <p>加载中...</p>}
      {error && <p className="error-message">{error}</p>}
      {!loading && !error && (
        <>
          <table className="users-table">
            <thead>
              <tr>
                <th>ID</th>
                <th>用户名</th>
                <th>姓名</th>
                <th>邮箱</th>
                <th>角色</th>
                <th>创建时间</th>
                <th>操作</th>
              </tr>
            </thead>
            <tbody>
              {users.map(user => (
                <tr key={user.user_id}>
                  <td>{user.user_id}</td>
                  <td>{user.username}</td>
                  <td>{user.caption}</td>
                  <td>{user.email}</td>
                  <td>{user.role_name}</td>
                  <td>{new Date(user.created_at).toLocaleString()}</td>
                  <td className="action-cell">
                    <button className="action-btn" onClick={() => handleOpenModal(user)} title="修改"><Edit size={16} />修改</button>
                    <button className="action-btn btn-danger" onClick={() => openDeleteConfirm(user)} title="删除"><Trash2 size={16} />删除</button>
                    <button className="action-btn btn-warning" onClick={() => openResetConfirm(user)} title="重置密码"><KeyRound size={16} />重置</button>
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
          <div className="pagination">
            <span>总计 {total} 条</span>
            <div>
              <button onClick={() => setPage(p => Math.max(1, p - 1))} disabled={page === 1}>上一页</button>
              <span>第 {page} 页 / {Math.ceil(total / pageSize)}</span>
              <button onClick={() => setPage(p => p + 1)} disabled={page * pageSize >= total}>下一页</button>
            </div>
          </div>
        </>
      )}

      {/* 用户表单模态框 */}
      <FormModal
        isOpen={showUserModal}
        onClose={handleCloseModal}
        title={isEditing ? '编辑用户' : '新增用户'}
        size="medium"
        actions={
          <>
            <button type="button" className="btn btn-secondary" onClick={handleCloseModal}>
              取消
            </button>
            <button type="button" className="btn btn-primary" onClick={handleSave}>
              {isEditing ? '确认修改' : '确认新增'}
            </button>
          </>
        }
      >
        {error && <div className="error-message">{error}</div>}
        {currentUser && (
          <>
            <div className="form-group">
              <label><User size={16} /> 用户名</label>
              <input
                type="text"
                value={currentUser.username}
                onChange={(e) => handleInputChange('username', e.target.value)}
                placeholder="请输入用户名"
                required
              />
            </div>
            <div className="form-group">
              <label><User size={16} /> 姓名</label>
              <input
                type="text"
                value={currentUser.caption}
                onChange={(e) => handleInputChange('caption', e.target.value)}
                placeholder="请输入姓名"
                required
              />
            </div>
            <div className="form-group">
              <label><Mail size={16} /> 邮箱</label>
              <input
                type="email"
                value={currentUser.email}
                onChange={(e) => handleInputChange('email', e.target.value)}
                placeholder="请输入邮箱"
                required
              />
            </div>
            <div className="form-group">
              <label><Shield size={16} /> 角色</label>
              <select
                value={currentUser.role_id}
                onChange={(e) => handleInputChange('role_id', parseInt(e.target.value))}
              >
                {roles.map(role => (
                  <option key={role.role_id} value={role.role_id}>{role.role_name}</option>
                ))}
              </select>
            </div>
            {!isEditing && (
              <div className="info-note">
                <p>注：新用户的默认密码为系统配置的默认密码，用户可登录后自行修改</p>
              </div>
            )}
          </>
        )}
      </FormModal>

      {/* 删除用户确认对话框 */}
      <ConfirmDialog
        isOpen={!!deleteConfirmInfo}
        onClose={() => setDeleteConfirmInfo(null)}
        onConfirm={handleDeleteUser}
        title="删除用户"
        message={`确定要删除用户"${deleteConfirmInfo?.caption}"吗？此操作无法撤销。`}
        confirmText="确定删除"
        cancelText="取消"
        type="danger"
      />

      {/* 重置密码确认对话框 */}
      <ConfirmDialog
        isOpen={!!resetConfirmInfo}
        onClose={() => setResetConfirmInfo(null)}
        onConfirm={handleResetPassword}
        title="重置密码"
        message={`确定要重置用户"${resetConfirmInfo?.caption}"的密码吗？重置后密码将恢复为系统默认密码。`}
        confirmText="确定重置"
        cancelText="取消"
        type="warning"
      />

      {/* Toast notifications */}
      {toasts.map(toast => (
        <Toast
          key={toast.id}
          message={toast.message}
          type={toast.type}
          onClose={() => removeToast(toast.id)}
        />
      ))}
    </div>
  );
};

export default UserManagement;