import { useEffect, useRef } from 'react'
import { useForm } from 'react-hook-form'
import { zodResolver } from '@hookform/resolvers/zod'
import { z } from 'zod'
import type { Pago } from '../types'
import { fechaISOHoy, formatoMoneda } from '../lib/formatters'
import { round2 } from '../lib/cobranza'

function esquemaAbono(restante: number) {
  return z.object({
    monto: z
      .number({ invalid_type_error: 'Captura un monto válido' })
      .positive('El monto debe ser mayor a 0')
      .max(restante, `No puede exceder el restante (${formatoMoneda(restante)})`),
    fechaPago: z.string().min(1, 'La fecha es requerida'),
    referencia: z.string().trim().min(3, 'Referencia requerida (mín. 3 caracteres)'),
  })
}

type AbonoForm = z.infer<ReturnType<typeof esquemaAbono>>

interface Props {
  pago: Pago
  onCancelar: () => void
  onGuardar: (datos: AbonoForm) => void
}

const claseLabel = 'block text-xs font-bold uppercase tracking-widest text-neutral-500'

/** Modal para registrar un abono (total o parcial) a un pago del plan */
export default function ModalAbono({ pago, onCancelar, onGuardar }: Props) {
  const restante = round2(pago.monto - pago.montoPagado)
  const {
    register,
    handleSubmit,
    formState: { errors },
  } = useForm<AbonoForm>({
    resolver: zodResolver(esquemaAbono(restante)),
    defaultValues: { monto: restante, fechaPago: fechaISOHoy(), referencia: '' },
  })

  // Foco al primer input al abrir
  const refMonto = useRef<HTMLInputElement | null>(null)
  useEffect(() => {
    refMonto.current?.focus()
  }, [])

  // Escape cierra el modal
  useEffect(() => {
    const alTeclar = (e: KeyboardEvent) => {
      if (e.key === 'Escape') onCancelar()
    }
    window.addEventListener('keydown', alTeclar)
    return () => window.removeEventListener('keydown', alTeclar)
  }, [onCancelar])

  const regMonto = register('monto', { valueAsNumber: true })

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/40 p-4">
      <div
        role="dialog"
        aria-modal="true"
        aria-labelledby="titulo-abono"
        className="w-full max-w-md border border-neutral-900 bg-white p-8"
      >
        <h2 id="titulo-abono" className="text-xl font-light text-neutral-900">
          Registrar abono — Pago #{pago.numPago}
        </h2>
        <p className="mt-2 text-sm text-neutral-500">
          Restante: <span className="font-bold text-neutral-900">{formatoMoneda(restante)}</span>
        </p>
        <form
          className="mt-8 space-y-6"
          onSubmit={(e) => {
            void handleSubmit(onGuardar)(e)
          }}
        >
          <div>
            <label htmlFor="abono-monto" className={claseLabel}>
              Monto (MXN)
            </label>
            <input
              id="abono-monto"
              type="number"
              step="0.01"
              className={`mt-1 w-full border bg-white px-3 py-2.5 text-sm focus:border-neutral-900 focus:outline-none ${errors.monto ? 'border-red-400' : 'border-neutral-300'}`}
              {...regMonto}
              ref={(el) => {
                regMonto.ref(el)
                refMonto.current = el
              }}
            />
            {errors.monto && <p className="mt-1 text-xs text-red-700">{errors.monto.message}</p>}
          </div>
          <div>
            <label htmlFor="abono-fecha" className={claseLabel}>
              Fecha de pago
            </label>
            <input
              id="abono-fecha"
              type="date"
              className={`mt-1 w-full border bg-white px-3 py-2.5 text-sm focus:border-neutral-900 focus:outline-none ${errors.fechaPago ? 'border-red-400' : 'border-neutral-300'}`}
              {...register('fechaPago')}
            />
            {errors.fechaPago && <p className="mt-1 text-xs text-red-700">{errors.fechaPago.message}</p>}
          </div>
          <div>
            <label htmlFor="abono-referencia" className={claseLabel}>
              Referencia bancaria / folio
            </label>
            <input
              id="abono-referencia"
              type="text"
              className={`mt-1 w-full border bg-white px-3 py-2.5 text-sm focus:border-neutral-900 focus:outline-none ${errors.referencia ? 'border-red-400' : 'border-neutral-300'}`}
              placeholder="SPEI-000123"
              {...register('referencia')}
            />
            {errors.referencia && <p className="mt-1 text-xs text-red-700">{errors.referencia.message}</p>}
          </div>
          <div className="flex justify-end gap-3 pt-2">
            <button
              type="button"
              onClick={onCancelar}
              aria-label="Cancelar y cerrar el registro de abono"
              className="border border-neutral-900 bg-transparent px-5 py-2.5 text-xs font-bold uppercase tracking-widest text-neutral-900 transition-colors duration-150 hover:bg-neutral-900 hover:text-white"
            >
              Cancelar
            </button>
            <button
              type="submit"
              className="bg-accent px-5 py-2.5 text-xs font-bold uppercase tracking-widest text-white transition-colors duration-150 hover:opacity-90 disabled:opacity-40"
            >
              Guardar abono
            </button>
          </div>
        </form>
      </div>
    </div>
  )
}