import { useState } from 'react'
import { useSearchParams, useNavigate } from 'react-router-dom'
import { Hotel, Eye, EyeOff, AlertCircle, CheckCircle2, Moon, Sun } from 'lucide-react'
import { useTheme } from '../contexts/ThemeContext'
import { api } from '../lib/api'
import { cn } from '../lib/utils'

export function ResetPasswordPage() {
  const [searchParams] = useSearchParams()
  const navigate = useNavigate()
  const { theme, toggle } = useTheme()
  const token = searchParams.get('token') ?? ''

  const [password,  setPassword]  = useState('')
  const [password2, setPassword2] = useState('')
  const [showPass,  setShowPass]  = useState(false)
  const [loading,   setLoading]   = useState(false)
  const [error,     setError]     = useState('')
  const [done,      setDone]      = useState(false)

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    if (password.length < 8) { setError('Минимум 8 символов'); return }
    if (!/[a-zA-Zа-яА-ЯёЁ]/.test(password)) { setError('Пароль должен содержать хотя бы одну букву'); return }
    if (password !== password2) { setError('Пароли не совпадают'); return }
    setError('')
    setLoading(true)
    try {
      await api.auth.resetPassword(token, password)
      setDone(true)
    } catch (err) {
      const msg = err instanceof Error ? err.message : 'Ошибка'
      setError(msg)
    } finally {
      setLoading(false)
    }
  }

  return (
    <div className="min-h-screen bg-gradient-to-br from-brand-50 via-white to-slate-100 dark:from-slate-900 dark:via-slate-900 dark:to-brand-950 flex flex-col">
      <div className="flex justify-end p-4">
        <button onClick={toggle} className="btn-ghost p-2">
          {theme === 'light' ? <Moon size={18} /> : <Sun size={18} />}
        </button>
      </div>

      <div className="flex-1 flex items-center justify-center px-6">
        <div className="w-full max-w-sm">
          {/* Logo */}
          <div className="flex items-center gap-2.5 mb-8 justify-center">
            <div className="w-9 h-9 rounded-xl bg-brand-600 flex items-center justify-center">
              <Hotel size={18} className="text-white" />
            </div>
            <span className="text-xl font-bold text-slate-900 dark:text-slate-100">
              Hotel<span className="text-brand-600">Sync</span>
            </span>
          </div>

          {!token ? (
            <div className="text-center py-6">
              <div className="flex items-center gap-2 p-3 rounded-lg bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-300 text-sm mb-6">
                <AlertCircle size={15} /> Ссылка недействительна. Запросите новое письмо.
              </div>
              <button onClick={() => navigate('/login')} className="btn-primary w-full justify-center py-2.5">
                На страницу входа
              </button>
            </div>
          ) : done ? (
            <div className="text-center py-6">
              <div className="w-16 h-16 rounded-full bg-emerald-100 dark:bg-emerald-900/40 flex items-center justify-center mx-auto mb-5">
                <CheckCircle2 size={32} className="text-emerald-600 dark:text-emerald-400" />
              </div>
              <h2 className="text-2xl font-bold text-slate-900 dark:text-slate-100 mb-2">Пароль изменён!</h2>
              <p className="text-slate-500 dark:text-slate-400 mb-8">
                Теперь вы можете войти с новым паролем.
              </p>
              <button onClick={() => navigate('/login')} className="btn-primary w-full justify-center py-2.5">
                Войти
              </button>
            </div>
          ) : (
            <>
              <h2 className="text-2xl font-bold text-slate-900 dark:text-slate-100 mb-1">Новый пароль</h2>
              <p className="text-slate-500 dark:text-slate-400 mb-8">Введите новый пароль для вашего аккаунта</p>

              <form onSubmit={handleSubmit} className="space-y-4">
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1.5">Новый пароль</label>
                  <div className="relative">
                    <input
                      type={showPass ? 'text' : 'password'}
                      className="input pr-10"
                      placeholder="Минимум 8 символов"
                      value={password}
                      onChange={e => { setPassword(e.target.value); setError('') }}
                      required
                    />
                    <button type="button" onClick={() => setShowPass(v => !v)}
                      className="absolute right-3 top-1/2 -translate-y-1/2 text-slate-400 hover:text-slate-600">
                      {showPass ? <EyeOff size={16} /> : <Eye size={16} />}
                    </button>
                  </div>
                  {password && (
                    <div className="mt-2 grid grid-cols-2 gap-x-3 gap-y-1">
                      {[
                        { ok: password.length >= 8,                label: '≥ 8 символов' },
                        { ok: /[a-zA-Zа-яА-ЯёЁ]/.test(password),  label: 'Содержит букву' },
                        { ok: /[A-ZА-ЯЁ]/.test(password),          label: 'Заглавная буква' },
                        { ok: /[0-9]/.test(password),               label: 'Цифра' },
                      ].map(({ ok, label }) => (
                        <div key={label} className="flex items-center gap-1.5 text-xs">
                          <div className={cn('w-1.5 h-1.5 rounded-full shrink-0 transition-colors', ok ? 'bg-emerald-500' : 'bg-slate-300 dark:bg-slate-600')} />
                          <span className={cn('transition-colors', ok ? 'text-emerald-700 dark:text-emerald-400' : 'text-slate-400 dark:text-slate-500')}>{label}</span>
                        </div>
                      ))}
                    </div>
                  )}
                </div>

                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1.5">Повторите пароль</label>
                  <input
                    type={showPass ? 'text' : 'password'}
                    className={cn('input', password2 && password !== password2 && 'border-red-400 focus:ring-red-400')}
                    placeholder="Повторите пароль"
                    value={password2}
                    onChange={e => { setPassword2(e.target.value); setError('') }}
                    required
                  />
                  {password2 && password !== password2 && (
                    <p className="mt-1 text-xs text-red-600 dark:text-red-400">Пароли не совпадают</p>
                  )}
                </div>

                {error && (
                  <div className="flex items-center gap-2 p-3 rounded-lg bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-300 text-sm">
                    <AlertCircle size={15} /> {error}
                  </div>
                )}

                <button type="submit" disabled={loading} className="btn-primary w-full justify-center py-2.5">
                  {loading
                    ? <span className="w-4 h-4 border-2 border-white/30 border-t-white rounded-full animate-spin" />
                    : 'Сохранить пароль'}
                </button>
              </form>

              <p className="mt-5 text-center text-sm text-slate-500 dark:text-slate-400">
                <button onClick={() => navigate('/login')} className="text-brand-600 dark:text-brand-400 font-medium hover:underline">
                  Вернуться к входу
                </button>
              </p>
            </>
          )}
        </div>
      </div>
    </div>
  )
}