import { useEffect, useRef, useState } from 'react';
import { toast, toastAfterReload } from '@/lib/toast';

type Props = {
  material: {
    id: number;
    nombre: string;
    cantidad_disponible: number;
  };
};

export default function SolicitarModal({ material }: Props) {
  const dialogRef = useRef<HTMLDialogElement | null>(null);
  const firstFieldRef = useRef<HTMLInputElement | null>(null);
  const [cantidad, setCantidad] = useState<number>(1);
  const [notas, setNotas] = useState<string>('');
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [ok, setOk] = useState(false);

  const titleId = `solicitar-title-${material.id}`;

  const open = () => {
    setError(null);
    setOk(false);
    setCantidad(1);
    setNotas('');
    dialogRef.current?.showModal();
    queueMicrotask(() => firstFieldRef.current?.focus());
  };

  const close = () => {
    if (loading) return;
    dialogRef.current?.close();
  };

  // Cerrar al click en backdrop
  useEffect(() => {
    const dlg = dialogRef.current;
    if (!dlg) return;
    const onClick = (e: MouseEvent) => {
      if (e.target === dlg) close();
    };
    dlg.addEventListener('click', onClick);
    return () => dlg.removeEventListener('click', onClick);
  });

  const submit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (loading) return;
    setLoading(true);
    setError(null);
    try {
      const res = await fetch('/api/prestamos', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ material_id: material.id, cantidad, notas }),
      });
      const json = await res.json().catch(() => ({}));
      if (!res.ok) {
        throw new Error(json?.error ?? 'No se pudo enviar la solicitud');
      }
      setOk(true);
      toastAfterReload({
        kind: 'success',
        title: 'Solicitud enviada',
        description: `${material.nombre} · pendiente de aprobación`,
      });
      setTimeout(() => {
        dialogRef.current?.close();
        location.reload();
      }, 800);
    } catch (err) {
      const msg = err instanceof Error ? err.message : 'Error inesperado';
      setError(msg);
      toast({ kind: 'error', title: 'No se pudo enviar', description: msg });
    } finally {
      setLoading(false);
    }
  };

  const disabled = material.cantidad_disponible === 0;

  return (
    <>
      <button
        type="button"
        className="btn btn-primary w-full"
        onClick={open}
        disabled={disabled}
      >
        {disabled ? 'Sin stock' : 'Solicitar'}
      </button>

      <dialog
        ref={dialogRef}
        aria-labelledby={titleId}
        className="rounded-lg p-0 bg-white text-[color:var(--color-ink)] border-2 border-[color:var(--color-ink)] shadow-[var(--shadow-hard)] backdrop:bg-black/40 w-[min(92vw,28rem)]"
      >
        <form onSubmit={submit} className="p-5 sm:p-6 flex flex-col gap-4">
          <div className="flex items-start justify-between gap-3">
            <h2 id={titleId} className="text-lg font-semibold">
              Solicitar: {material.nombre}
            </h2>
            <button
              type="button"
              onClick={close}
              aria-label="Cerrar"
              className="rounded-lg p-1.5 hover:bg-black/5 transition-colors"
            >
              <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" aria-hidden="true">
                <path d="M6 18L18 6M6 6l12 12" />
              </svg>
            </button>
          </div>

          <p className="text-sm opacity-70">
            Disponibles: <span style={{ fontVariantNumeric: 'tabular-nums' }}>{material.cantidad_disponible}</span>
          </p>

          <div>
            <label className="label" htmlFor={`cant-${material.id}`}>Cantidad</label>
            <input
              ref={firstFieldRef}
              id={`cant-${material.id}`}
              className="input"
              type="number"
              min={1}
              max={material.cantidad_disponible}
              value={cantidad}
              required
              inputMode="numeric"
              onChange={(e) => setCantidad(Math.max(1, Math.min(material.cantidad_disponible, Number(e.target.value) || 1)))}
              style={{ fontVariantNumeric: 'tabular-nums' }}
            />
          </div>

          <div>
            <label className="label" htmlFor={`notas-${material.id}`}>Motivo del préstamo</label>
            <textarea
              id={`notas-${material.id}`}
              className="input"
              rows={3}
              maxLength={500}
              value={notas}
              required
              onChange={(e) => setNotas(e.target.value)}
              placeholder="¿Para qué clase o proyecto lo necesitas?"
              style={{ minHeight: '96px' }}
              aria-describedby={`notas-hint-${material.id}`}
            />
            <p id={`notas-hint-${material.id}`} className="text-xs opacity-60 mt-1">
              Ejemplo: Clase de Electrónica Analógica · Prof. Gómez · práctica 3.
            </p>
          </div>

          {error && (
            <p role="alert" className="text-sm" style={{ color: 'var(--color-danger-text)' }}>
              {error} · Ajusta la cantidad o intenta de nuevo.
            </p>
          )}
          {ok && (
            <p role="status" className="text-sm" style={{ color: 'var(--color-positive)' }}>
              Solicitud enviada. Actualizando…
            </p>
          )}

          <div className="flex gap-2 justify-end pt-2">
            <button type="button" className="btn btn-ghost" onClick={close} disabled={loading}>
              Cancelar
            </button>
            <button type="submit" className="btn btn-primary" disabled={loading || ok}>
              {loading ? 'Enviando…' : 'Enviar solicitud'}
            </button>
          </div>
        </form>
      </dialog>
    </>
  );
}