import { useState, useEffect } from 'react'
import { Link, useSearchParams, useNavigate } from 'react-router-dom'
import { authApi } from '@/api/auth'
import { toast } from '@/lib/toast'
import { BrandLogo } from '@/components/common/BrandLogo'
import { PasswordInput } from '@/components/common/PasswordInput'
import { PageMeta } from '@/components/common/PageMeta'
import { cn } from '@/lib/utils'

export function ResetPasswordPage() {
  const [searchParams] = useSearchParams()
  const navigate = useNavigate()
  const token = searchParams.get('token') || ''

  const [verifying, setVerifying] = useState(true)
  const [valid, setValid] = useState(false)
  const [email, setEmail] = useState<string | null>(null)

  const [newPassword, setNewPassword] = useState('')
  const [confirmPassword, setConfirmPassword] = useState('')
  const [isLoading, setIsLoading] = useState(false)
  const [error, setError] = useState('')

  useEffect(() => {
    if (!token) {
      setVerifying(false)
      return
    }
    authApi.verifyResetToken(token).then((res) => {
      setValid(res.valid)
      setEmail(res.email || null)
    }).catch(() => {
      setValid(false)
    }).finally(() => {
      setVerifying(false)
    })
  }, [token])

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    setError('')

    if (!newPassword || !confirmPassword) {
      setError('Please fill in all fields')
      return
    }

    if (newPassword !== confirmPassword) {
      setError('Passwords do not match')
      return
    }

    if (newPassword.length < 10) {
      setError('Password must be at least 10 characters')
      return
    }

    setIsLoading(true)
    try {
      await authApi.resetPassword(token, newPassword)
      toast.success('Password reset successfully. Please sign in.')
      navigate('/login', { replace: true })
    } catch (err: unknown) {
      if (err && typeof err === 'object' && 'response' in err) {
        const axiosErr = err as { response?: { data?: { detail?: string } } }
        setError(axiosErr.response?.data?.detail || 'Failed to reset password')
      } else {
        setError('Failed to reset password')
      }
    } finally {
      setIsLoading(false)
    }
  }

  return (
    <>
    <PageMeta title="Reset Password" description="Set a new password for your ResolutionFlow account" />
    <div className="flex min-h-screen items-center justify-center bg-black px-4">
      <div className="pointer-events-none fixed inset-0 bg-[radial-gradient(circle_at_50%_0%,rgba(100,100,120,0.03),transparent_50%)]" />

      <div className="relative w-full max-w-md space-y-8">
        <div className="text-center">
          <div className="mb-4 flex justify-center sm:mb-6">
            <div className="w-16 h-16 rounded-2xl bg-white flex items-center justify-center sm:w-20 sm:h-20">
              <BrandLogo size="lg" className="h-10 w-10 invert sm:h-12 sm:w-12" />
            </div>
          </div>
          <h1 className="text-3xl font-bold font-heading text-foreground tracking-tight">
            Reset Password
          </h1>
        </div>

        {verifying ? (
          <div className="bg-card border border-border rounded-xl p-6 text-center">
            <p className="text-muted-foreground">Verifying reset link...</p>
          </div>
        ) : !token || !valid ? (
          <div className="bg-card border border-border rounded-xl p-6 space-y-4">
            <div className="rounded-xl border border-red-400/20 bg-red-400/10 p-4 text-sm text-red-400">
              This reset link is invalid or has expired. Please request a new one.
            </div>
            <div className="text-center">
              <Link
                to="/forgot-password"
                className="text-sm text-muted-foreground hover:text-foreground transition-colors"
              >
                Request new reset link
              </Link>
            </div>
          </div>
        ) : (
          <form onSubmit={handleSubmit} className="mt-8 space-y-6">
            <div className="bg-card border border-border rounded-xl p-6 space-y-4">
              {email && (
                <p className="text-sm text-muted-foreground">
                  Resetting password for <span className="font-medium text-foreground">{email}</span>
                </p>
              )}

              {error && (
                <div className="rounded-xl border border-red-400/20 bg-red-400/10 p-3 text-sm text-red-400">
                  {error}
                </div>
              )}

              <div>
                <label htmlFor="new-password" className="mb-1 block text-sm font-medium text-foreground">
                  New Password
                </label>
                <PasswordInput
                  id="new-password"
                  autoComplete="new-password"
                  required
                  value={newPassword}
                  onChange={(e) => setNewPassword(e.target.value)}
                  className={cn(
                    'block w-full rounded-xl border border-border bg-card px-3 py-2',
                    'text-foreground placeholder:text-muted-foreground',
                    'focus:border-primary focus:outline-hidden focus:ring-1 focus:ring-primary/20',
                    'transition-colors'
                  )}
                  placeholder="At least 10 characters"
                />
                <p className="mt-1 text-xs text-muted-foreground">
                  Must include uppercase, lowercase, and a digit.
                </p>
              </div>

              <div>
                <label htmlFor="confirm-password" className="mb-1 block text-sm font-medium text-foreground">
                  Confirm New Password
                </label>
                <PasswordInput
                  id="confirm-password"
                  autoComplete="new-password"
                  required
                  value={confirmPassword}
                  onChange={(e) => setConfirmPassword(e.target.value)}
                  className={cn(
                    'block w-full rounded-xl border border-border bg-card px-3 py-2',
                    'text-foreground placeholder:text-muted-foreground',
                    'focus:border-primary focus:outline-hidden focus:ring-1 focus:ring-primary/20',
                    'transition-colors'
                  )}
                />
              </div>

              <button
                type="submit"
                disabled={isLoading}
                className={cn(
                  'w-full rounded-xl px-4 py-2.5 text-sm font-semibold btn-press',
                  'bg-gradient-brand text-white shadow-lg shadow-primary/20 hover:opacity-90',
                  'focus:outline-hidden focus:ring-2 focus:ring-primary/30 focus:ring-offset-2 focus:ring-offset-black',
                  'disabled:cursor-not-allowed disabled:opacity-50',
                  'transition-all'
                )}
              >
                {isLoading ? 'Resetting...' : 'Reset Password'}
              </button>
            </div>
          </form>
        )}
      </div>
    </div>
    </>
  )
}

export default ResetPasswordPage
