// src/pages/LoginPage/LoginPage.jsx

import React, { useState, useEffect } from 'react'
import { useNavigate, Link } from 'react-router-dom'
import { Input, Checkbox, Modal, Alert } from 'antd'
import {
  MailOutlined,
  LockOutlined,
  ExclamationCircleOutlined,
  CheckCircleOutlined
} from '@ant-design/icons'
import {
  getRememberedLoginInfo,
  saveRememberedLoginInfo,
  saveAuthInfo,
  isLoggedIn,
  clearAuthInfo           // ← 新增
} from '../../utils/auth'
import { hashPassword } from '../../utils/crypto'
import './LoginPage.css'

const baseURL = 'http://10.126.59.25:8082'

export default function LoginPage() {
  const navigate = useNavigate()

  // —— 登录页加载时先清除旧的认证信息 —— 
  useEffect(() => {
    clearAuthInfo(/* clearRemembered= */ false)
  }, [])

  const [formData, setFormData] = useState({
    email: '',
    password: ''
  })
  const [rememberMe, setRememberMe] = useState(false)
  const [isLoading, setIsLoading] = useState(false)
  const [errors, setErrors] = useState({ email: '', password: '' })
  const [errorModal, setErrorModal] = useState({
    visible: false,
    title: '',
    content: ''
  })
  const [successAlert, setSuccessAlert] = useState({
    visible: false,
    message: ''
  })

  // 显示错误弹窗
  const showErrorModal = (title, content) => {
    setErrorModal({ visible: true, title, content })
  }
  // 关闭错误弹窗
  const closeErrorModal = () => {
    setErrorModal({ visible: false, title: '', content: '' })
  }
  // 显示成功提示
  const showSuccessAlert = (message) => {
    setSuccessAlert({ visible: true, message })
    setTimeout(() => {
      setSuccessAlert({ visible: false, message: '' })
    }, 3000)
  }

  // 初始化：检查登录 & 填充“记住我”
  useEffect(() => {
    if (isLoggedIn()) {
      console.log('用户已登录')
      // 如果想自动跳转： navigate('/home', { replace: true })
    }
    const { email, password, rememberMe } = getRememberedLoginInfo()
    if (rememberMe && email) {
      setFormData({ email, password })
      setRememberMe(true)
    }
  }, [])

  const handleEmailChange = (e) => {
    setFormData(f => ({ ...f, email: e.target.value }))
    if (errors.email) setErrors(e => ({ ...e, email: '' }))
  }
  const handlePasswordChange = (e) => {
    setFormData(f => ({ ...f, password: e.target.value }))
    if (errors.password) setErrors(e => ({ ...e, password: '' }))
  }
  const handleRememberMeChange = (e) => {
    const checked = e.target.checked
    setRememberMe(checked)
    if (!checked) {
      saveRememberedLoginInfo('', '', false)
    }
  }

  const validateForm = () => {
    const newErr = { email: '', password: '' }
    let hasError = false
    if (!formData.email.trim() || !/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(formData.email)) {
      newErr.email = '请输入有效的邮箱地址'
      hasError = true
    }
    if (!formData.password.trim() || formData.password.length < 6) {
      newErr.password = '密码长度至少6位'
      hasError = true
    }
    setErrors(newErr)
    return !hasError
  }

  const handleSubmit = async (e) => {
    e.preventDefault()
    if (!validateForm()) return

    setIsLoading(true)
    try {
      const res = await fetch(baseURL + '/login', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          email: formData.email,
          password: hashPassword(formData.password)
        })
      })
      const result = await res.json()
      if (result.success) {
        showSuccessAlert('登录成功！正在跳转...')
        saveAuthInfo(result.token, result.user, rememberMe)
        saveRememberedLoginInfo(formData.email, formData.password, rememberMe)
        setTimeout(() => {
          const uid = result.user.id
          switch (result.user.role) {
            case 'admin':
              navigate(`/admin/${uid}`, { replace: true })
              break
            case 'superadmin':
              navigate(`/superadmin/${uid}/users`, { replace: true })
              break
            default:
              navigate('/home', { replace: true })
          }
        }, 1500)
      } else {
        let title = '登录失败'
        let content = result.message || '登录失败，请检查您的邮箱和密码'
        if (result.message) {
          if (/邮箱|email/.test(result.message)) {
            title = '邮箱验证失败'
            content = '请输入正确的邮箱地址'
          } else if (/密码|password/.test(result.message)) {
            title = '密码验证失败'
            content = '密码不正确，请重试'
          }
        }
        showErrorModal(title, content)
      }
    } catch (err) {
      console.error(err)
      showErrorModal('网络异常', '无法连接到服务器，请稍后重试')
    } finally {
      setIsLoading(false)
    }
  }

  return (
    <div className="login-container">
      <div className="login-background" />
      {isLoading && (
        <div className="loading-overlay">
          <div className="loading-content">
            <div className="loading-spinner-large" />
            <p className="loading-text">正在登录...</p>
          </div>
        </div>
      )}
      <div className="login-content">
        <div className="login-card">
          {successAlert.visible && (
            <Alert
              message={successAlert.message}
              type="success"
              icon={<CheckCircleOutlined />}
              closable
              style={{ marginBottom: 16, borderRadius: 8 }}
            />
          )}
          <div className="login-header">
            <h1>欢迎来到小红书</h1>
            <p>标记我的生活</p>
          </div>
          <form className="login-form" onSubmit={handleSubmit}>
            <div className="form-group">
              <Input
                type="email"
                placeholder="邮箱"
                value={formData.email}
                onChange={handleEmailChange}
                prefix={<MailOutlined />}
                status={errors.email ? 'error' : ''}
              />
              {errors.email && <div className="error-message">{errors.email}</div>}
            </div>
            <div className="form-group">
              <Input.Password
                placeholder="密码"
                value={formData.password}
                onChange={handlePasswordChange}
                prefix={<LockOutlined />}
                status={errors.password ? 'error' : ''}
              />
              {errors.password && <div className="error-message">{errors.password}</div>}
            </div>
            <div className="form-options">
              <Checkbox checked={rememberMe} onChange={handleRememberMeChange}>
                记住我
              </Checkbox>
              <Link to="/forgot-password">忘记密码？</Link>
            </div>
            <button
              type="submit"
              className={`login-button ${isLoading ? 'loading' : ''}`}
              disabled={isLoading}
            >
              {isLoading ? '登录中...' : '登录'}
            </button>
          </form>
          <div className="signup-link">
            <p>还没有账户？<Link to="/register">立即注册</Link></p>
          </div>
        </div>
      </div>
      <Modal
        title={<><ExclamationCircleOutlined style={{ color: '#ff4d4f' }} /> {errorModal.title}</>}
        open={errorModal.visible}
        onOk={closeErrorModal}
        cancelButtonProps={{ style: { display: 'none' } }}
      >
        <p>{errorModal.content}</p>
      </Modal>
    </div>
  )
}