import { useEffect, useState } from 'react'
import { useQuery } from '@tanstack/react-query'
import { useNavigate } from '@tanstack/react-router'
import { Loader2 } from 'lucide-react'
import type { ConnectPaymentResult, OnboardingGroupDto } from '@gruperly/shared'
import { Logo, LogoIcon } from '../components/brand'
import {
  ConfirmationStep,
  FirstGroupStep,
  PaymentStep,
  Stepper,
  WelcomeStep,
} from '../components/onboarding'
import { PAYMENT_PROVIDERS } from '../components/onboarding/constants'
import { Button } from '../components/ui'
import { useAuth } from '../context/AuthProvider'
import { getOnboardingStatus } from '../lib/api'

const STEPS = [
  { label: 'Bienvenida' },
  { label: 'Cobros' },
  { label: 'Tu grupo' },
  { label: 'Listo' },
]

export function OnboardingView() {
  const { user, isPending: authPending } = useAuth()
  const navigate = useNavigate()

  const [step, setStep] = useState(0)
  const [paymentResult, setPaymentResult] = useState<ConnectPaymentResult | null>(null)
  const [createdGroup, setCreatedGroup] = useState<OnboardingGroupDto | null>(null)

  const statusQuery = useQuery({
    queryKey: ['onboarding', 'status'],
    queryFn: getOnboardingStatus,
    enabled: !!user,
  })

  useEffect(() => {
    const status = statusQuery.data
    if (!status) return
    if (status.completed) {
      void navigate({ to: '/' })
      return
    }
    // Si interrumpió después de conectar el cobro, retomamos en el paso del grupo.
    if (status.step === 'PAYMENT_CONNECTED') {
      setStep((current) => (current === 0 ? 2 : current))
    }
  }, [statusQuery.data, navigate])

  if (authPending) {
    return (
      <div className="flex min-h-dvh items-center justify-center">
        <Loader2 className="size-6 animate-spin text-foreground/40" />
      </div>
    )
  }

  if (!user) {
    return (
      <div className="flex min-h-dvh items-center justify-center px-4">
        <div className="w-full max-w-sm space-y-4 text-center">
          <span className="mx-auto flex size-14 items-center justify-center rounded-2xl bg-accent-soft">
            <LogoIcon className="size-8" />
          </span>
          <h1 className="text-2xl font-bold text-primary">Tu cuenta, lista</h1>
          <p className="text-sm text-foreground/60">
            Iniciá sesión para configurar tus cobros y crear tu primer grupo.
          </p>
          <Button variant="primary" className="w-full" onClick={() => void navigate({ to: '/login' })}>
            Iniciar sesión
          </Button>
        </div>
      </div>
    )
  }

  if (statusQuery.isPending) {
    return (
      <div className="flex min-h-dvh items-center justify-center">
        <Loader2 className="size-6 animate-spin text-foreground/40" />
      </div>
    )
  }

  const firstName = user.name?.trim().split(/\s+/)[0] ?? 'profesor/a'
  const providerName = paymentResult
    ? PAYMENT_PROVIDERS.find((p) => p.value === paymentResult.provider)?.name
    : undefined

  return (
    <main className="mx-auto flex min-h-dvh w-full max-w-md flex-col px-4 pb-12 pt-8 sm:pt-12">
      <header className="mb-6 flex items-center justify-center">
        <Logo className="h-6" />
      </header>

      <Stepper steps={STEPS} current={step} />

      <div key={step} className="mt-8 animate-step-enter">
        {step === 0 ? (
          <WelcomeStep name={firstName} onNext={() => setStep(1)} />
        ) : null}
        {step === 1 ? (
          <PaymentStep
            initialResult={paymentResult}
            onConnected={(result) => {
              setPaymentResult(result)
              setStep(2)
            }}
            onBack={() => setStep(0)}
          />
        ) : null}
        {step === 2 ? (
          <FirstGroupStep
            onBack={() => setStep(1)}
            onCompleted={(group) => {
              setCreatedGroup(group)
              setStep(3)
            }}
          />
        ) : null}
        {step === 3 && createdGroup ? (
          <ConfirmationStep group={createdGroup} providerName={providerName} />
        ) : null}
      </div>
    </main>
  )
}