'use client'
import { useState } from 'react'

export default function LoginPage() {
  const [username, setUsername] = useState('')
  const [password, setPassword] = useState('')
  const [error, setError] = useState('')
  const [loading, setLoading] = useState(false)
  const [showLdapForm, setShowLdapForm] = useState(false)

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault(); setError(''); setLoading(true)
    try {
      const res = await fetch('/api/auth/login', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ username, password }) })
      const data = await res.json()
      if (!res.ok) { setError(data.error || '登录失败'); return }
      const params = new URLSearchParams(window.location.search)
      const redirect = params.get('redirect')
      const dest = (redirect && redirect.startsWith('/')) ? redirect : '/dashboard'
      window.location.href = dest
    } catch { setError('网络错误') } finally { setLoading(false) }
  }

  function handleSsoLogin() {
    window.location.href = '/api/auth/login/oidc'
  }

  return (
    <div className="min-h-screen flex items-center justify-center bg-slate-50 dark:bg-slate-950 px-4">
      <div className="w-full max-w-sm bg-white dark:bg-slate-900 rounded-lg border border-blue-200/50 dark:border-blue-500/20 shadow-lg p-8">
        <h1 className="text-2xl font-bold text-center mb-6 text-slate-900 dark:text-white">IT 工单跟踪系统</h1>
        {error && <div className="mb-4 p-3 rounded-lg bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 text-red-600 dark:text-red-400 text-sm">{error}</div>}

        {!showLdapForm ? (
          <>
            <button onClick={handleSsoLogin} className="w-full py-2 px-4 rounded-lg bg-blue-600 hover:bg-blue-700 text-white font-medium transition-colors duration-200 mb-3">
              统一认证登录
            </button>
            <p className="text-center text-xs text-slate-400 mb-3">通过 SSO 统一身份认证</p>
            <p className="text-center mb-2">
              <button onClick={() => { window.location.href = '/api/auth/login/oidc?switch=1' }} className="text-xs text-slate-400 hover:text-slate-600 underline">
                使用其他账号登录
              </button>
            </p>
            <p className="text-center">
              <button onClick={() => setShowLdapForm(true)} className="text-xs text-slate-400 hover:text-slate-600 underline">
                使用 LDAP 直接登录
              </button>
            </p>
          </>
        ) : (
          <>
            <form onSubmit={handleSubmit} className="space-y-4">
              <div>
                <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">用户名</label>
                <input type="text" value={username} onChange={(e) => setUsername(e.target.value)} placeholder="请输入用户名"
                  className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-800 text-slate-900 dark:text-white placeholder:text-slate-400 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent" required />
              </div>
              <div>
                <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">密码</label>
                <input type="password" value={password} onChange={(e) => setPassword(e.target.value)} placeholder="请输入密码"
                  className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-800 text-slate-900 dark:text-white placeholder:text-slate-400 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent" required />
              </div>
              <button type="submit" disabled={loading}
                className="w-full py-2 px-4 rounded-lg bg-blue-600 hover:bg-blue-700 disabled:bg-blue-400 text-white font-medium transition-colors duration-200">
                {loading ? '登录中...' : '登录'}
              </button>
            </form>
            <p className="text-center mt-3">
              <button onClick={() => setShowLdapForm(false)} className="text-xs text-slate-400 hover:text-slate-600 underline">
                返回统一认证登录
              </button>
            </p>
          </>
        )}
      </div>
    </div>
  )
}