'use client';

import { useEffect, useState } from 'react';
import { useParams } from 'next/navigation';
import DOMPurify from 'dompurify';
import { authApi, wishlistsApi, itemsApi, claimingApi, type Wishlist, type Item } from '@/lib/api';
import Header from '@/components/header';
import GuestGuard from '@/components/guest-guard';

export default function PublicWishlistPage() {
  return (
    <GuestGuard>
      <PublicWishlistContent />
    </GuestGuard>
  );
}

function PublicWishlistContent() {
  const params = useParams();
  const [wishlist, setWishlist] = useState<Wishlist | null>(null);
  const [items, setItems] = useState<Item[]>([]);
  const [showClaimed, setShowClaimed] = useState(false);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState('');

  // Current viewer
  const [currentGuestId, setCurrentGuestId] = useState<string | null>(null);
  const [isAdmin, setIsAdmin] = useState(false);

  // Claim form state
  const [claimingItemId, setClaimingItemId] = useState<string | null>(null);
  const [claimNote, setClaimNote] = useState('');
  const [claimQty, setClaimQty] = useState(1);
  const [isClaiming, setIsClaiming] = useState(false);
  const [claimError, setClaimError] = useState('');
  const [justClaimedItemId, setJustClaimedItemId] = useState<string | null>(null);

  // Unclaim state
  const [isUnclaiming, setIsUnclaiming] = useState(false);

  useEffect(() => {
    (async () => {
      try {
        const who = await authApi.whoami();
        if (who.role === 'admin') {
          setIsAdmin(true);
          if (who.guest) setCurrentGuestId(who.guest.id);
        } else if (who.role === 'guest') {
          setCurrentGuestId(who.guest.id);
        }
      } catch {
        /* ignore */
      }
    })();
  }, []);

  useEffect(() => {
    fetchWishlist();
  }, [params.slug]);

  const fetchWishlist = async () => {
    if (!params.slug) return;

    try {
      const wishlistData = await wishlistsApi.getBySlug(params.slug as string);
      setWishlist(wishlistData);

      const itemsData = await itemsApi.getAll(wishlistData.id);
      setItems(itemsData.sort((a, b) => a.sortOrder - b.sortOrder));
    } catch (err: any) {
      setError(err.message || 'Wishlist not found');
    } finally {
      setIsLoading(false);
    }
  };

  const myClaimFor = (item: Item) => item.claims.find((c) => c.guest.id === currentGuestId);

  const handleStartClaim = (item: Item) => {
    const my = myClaimFor(item);
    setClaimingItemId(item.id);
    setClaimError('');
    setClaimNote(my?.note ?? '');
    setClaimQty(my?.quantity ?? 1);
    setJustClaimedItemId(null);
  };

  const handleSubmitClaim = async (e: React.FormEvent, itemId: string) => {
    e.preventDefault();

    setIsClaiming(true);
    setClaimError('');

    try {
      await claimingApi.claim(itemId, { quantity: claimQty, note: claimNote });

      setJustClaimedItemId(itemId);
      setClaimingItemId(null);
      setClaimNote('');
      setClaimQty(1);
      fetchWishlist();
    } catch (err: any) {
      setClaimError(err.message || 'Erro ao reservar item');
    } finally {
      setIsClaiming(false);
    }
  };

  const handleUnclaim = async (itemId: string, guestId?: string) => {
    if (!confirm('Cancelar a reserva?')) return;

    setIsUnclaiming(true);

    try {
      await claimingApi.unclaim(itemId, guestId ? { guestId } : {});
      fetchWishlist();
    } catch (err: any) {
      alert(err.message || 'Erro ao cancelar reserva');
    } finally {
      setIsUnclaiming(false);
    }
  };

  const filteredItems = showClaimed
    ? items
    : items.filter((item) => {
        const my = myClaimFor(item);
        return item.remainingQuantity > 0 || my || item.id === justClaimedItemId;
      });

  const formatPrice = (price: number | null, currency: string) => {
    if (!price) return null;
    return new Intl.NumberFormat('pt-BR', {
      style: 'currency',
      currency: currency || 'BRL',
    }).format(price);
  };

  if (isLoading) {
    return (
      <div className="min-h-screen bg-gray-50 dark:bg-gray-900 flex items-center justify-center">
        <p className="text-gray-600 dark:text-gray-400">Carregando...</p>
      </div>
    );
  }

  if (error || !wishlist) {
    return (
      <div className="min-h-screen bg-gray-50 dark:bg-gray-900 flex items-center justify-center">
        <div className="text-center">
          <h1 className="text-2xl font-bold text-gray-900 dark:text-white mb-2">Lista não encontrada</h1>
          <p className="text-gray-600 dark:text-gray-400">{error || 'Esta lista não existe ou não é pública.'}</p>
        </div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-cosmic">
      <Header
        title={wishlist.name}
        subtitle={wishlist.description || undefined}
        imageUrl={wishlist.imageUrl || undefined}
        maxWidth="max-w-5xl"
      />

      {/* Main Content */}
      <div className="max-w-5xl mx-auto py-12 sm:px-6 lg:px-8">
        <div className="px-4 sm:px-0">
          <a
            href="/"
            className="inline-flex items-center text-indigo-600 dark:text-indigo-400 hover:text-indigo-800 dark:hover:text-indigo-300 mb-6 transition-colors cursor-pointer"
          >
            <svg
              className="w-5 h-5 mr-2"
              fill="none"
              stroke="currentColor"
              viewBox="0 0 24 24"
            >
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M10 19l-7-7m0 0l7-7m-7 7h18"
              />
            </svg>
            Voltar ao início
          </a>

          {/* Preferences Section */}
          {wishlist.preferences && (
            <div className="mb-8 bg-white dark:bg-gray-800 rounded-lg shadow p-6">
              <h2 className="text-xl font-bold text-gray-900 dark:text-white mb-3">
                Interesses e Preferências
              </h2>
              <div
                className="prose prose-indigo dark:prose-invert max-w-none text-gray-700 dark:text-gray-300 [&_a]:text-indigo-600 [&_a]:dark:text-indigo-400 [&_a]:hover:underline"
                dangerouslySetInnerHTML={{ __html: DOMPurify.sanitize(wishlist.preferences) }}
                onClick={(e) => {
                  const target = e.target as HTMLElement;
                  if (target.tagName === 'A') {
                    e.preventDefault();
                    window.open((target as HTMLAnchorElement).href, '_blank', 'noopener,noreferrer');
                  }
                }}
              />
            </div>
          )}

          {/* Controls */}
          <div className="mb-6 flex items-center justify-between">
            <div className="flex items-center space-x-4">
              <label className="flex items-center">
                <input
                  type="checkbox"
                  checked={showClaimed}
                  onChange={(e) => setShowClaimed(e.target.checked)}
                  className="h-4 w-4 text-blue-600 border-gray-300 rounded"
                />
                <span className="ml-2 text-sm text-gray-700 dark:text-gray-300">Mostrar itens esgotados</span>
              </label>
            </div>
            <div className="text-sm text-gray-600 dark:text-gray-400">
              {filteredItems.length} de {items.length} itens
            </div>
          </div>

          {/* Items List */}
          {filteredItems.length === 0 ? (
            <div className="text-center py-12 bg-white dark:bg-gray-800 rounded-lg shadow">
              <p className="text-gray-500 dark:text-gray-400">
                {showClaimed ? 'Nenhum item nesta lista ainda' : 'Todos os itens já foram reservados!'}
              </p>
            </div>
          ) : (
            <div className="space-y-6">
              {filteredItems.map((item) => {
                const myClaim = myClaimFor(item);
                const maxForMe = item.remainingQuantity + (myClaim?.quantity ?? 0);
                const showQuantitySummary = item.quantity > 1;
                const sold = item.remainingQuantity === 0 && !myClaim;

                return (
                  <div
                    key={item.id}
                    className="bg-white dark:bg-gray-800 rounded-lg shadow hover:shadow-lg transition-all duration-300 overflow-hidden"
                  >
                    <div className="flex flex-col md:flex-row">
                      {/* Left: Image */}
                      {item.imageUrl && (
                        <div className="md:w-48 md:flex-shrink-0">
                          <img
                            src={item.imageUrl}
                            alt={item.name}
                            className="w-full h-48 md:h-full object-cover"
                          />
                        </div>
                      )}

                      {/* Middle: Item Details */}
                      <div className="flex-1 p-6">
                        <h3 className="text-2xl font-bold text-gray-900 dark:text-white mb-1">
                          {item.name}
                        </h3>
                        {showQuantitySummary && (
                          <p className="text-sm text-gray-500 dark:text-gray-400 mb-3">
                            {item.claimedQuantity} de {item.quantity} reservados
                          </p>
                        )}
                        {item.description && (
                          <p className="text-base text-gray-600 dark:text-gray-300 mb-4">
                            {item.description}
                          </p>
                        )}

                        {/* Existing claims list */}
                        {item.claims.length > 0 && (
                          <ul className="text-sm text-gray-700 dark:text-gray-300 space-y-1 mt-4 border-t border-gray-200 dark:border-gray-700 pt-3">
                            {item.claims.map((c) => {
                              const isMine = c.guest.id === currentGuestId;
                              const canCancel = isMine || isAdmin;
                              return (
                                <li key={c.id} className="flex items-center justify-between gap-2">
                                  <div>
                                    <span className="font-medium">{c.guest.name}</span>
                                    <span className="text-gray-500"> · {c.quantity} un.</span>
                                    {c.note && (
                                      <span className="block text-xs italic text-gray-500">
                                        &quot;{c.note}&quot;
                                      </span>
                                    )}
                                  </div>
                                  {canCancel && (
                                    <button
                                      onClick={() => handleUnclaim(item.id, isMine ? undefined : c.guest.id)}
                                      disabled={isUnclaiming}
                                      className="text-xs text-red-600 hover:underline disabled:opacity-50 cursor-pointer"
                                    >
                                      Cancelar
                                    </button>
                                  )}
                                </li>
                              );
                            })}
                          </ul>
                        )}
                      </div>

                      {/* Right: Action Area */}
                      <div className="md:w-80 md:flex-shrink-0 p-6 bg-gray-50 dark:bg-gray-900/50 border-t md:border-t-0 md:border-l border-gray-200 dark:border-gray-700 flex flex-col">
                        <div className="mb-4">
                          {item.purchaseUrls && item.purchaseUrls.length > 0 && (
                            <div className="space-y-2">
                              {item.purchaseUrls.map((url, idx) => (
                                <a
                                  key={idx}
                                  href={url.url}
                                  target="_blank"
                                  rel="noopener noreferrer"
                                  className="flex items-center justify-between text-base px-4 py-3 rounded-lg hover:bg-indigo-50 dark:hover:bg-indigo-900/20 transition-colors cursor-pointer border border-gray-200 dark:border-gray-700"
                                >
                                  <span className="text-indigo-600 dark:text-indigo-400 hover:text-indigo-800 dark:hover:text-indigo-300 font-medium">
                                    {url.label}
                                  </span>
                                  <span className="text-gray-900 dark:text-white font-bold text-lg">
                                    {item.price && formatPrice(item.price, item.currency)}
                                  </span>
                                </a>
                              ))}
                            </div>
                          )}
                        </div>

                        <div className="mt-auto">
                          {sold ? (
                            <div className="bg-gray-100 dark:bg-gray-700 rounded p-3 text-center text-sm text-gray-700 dark:text-gray-300">
                              Esgotado
                            </div>
                          ) : claimingItemId === item.id ? (
                            <form onSubmit={(e) => handleSubmitClaim(e, item.id)} className="space-y-3">
                              {claimError && (
                                <div className="p-2 bg-red-50 dark:bg-red-900/20 text-red-800 dark:text-red-400 rounded text-xs">
                                  {claimError}
                                </div>
                              )}

                              {item.quantity > 1 && (
                                <div>
                                  <label htmlFor={`claim-qty-${item.id}`} className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                                    Quantidade (máx {maxForMe}):
                                  </label>
                                  <input
                                    id={`claim-qty-${item.id}`}
                                    type="number"
                                    min={1}
                                    max={maxForMe}
                                    value={claimQty}
                                    onChange={(e) => setClaimQty(Math.max(1, Math.min(maxForMe, Number(e.target.value) || 1)))}
                                    className="w-full px-3 py-2 text-sm border border-gray-300 dark:border-gray-600 rounded-md focus:outline-none focus:ring-2 focus:ring-green-500 dark:bg-gray-700 dark:text-white"
                                  />
                                </div>
                              )}

                              <div>
                                <label htmlFor={`claim-note-${item.id}`} className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                                  Deixe uma nota (opcional):
                                </label>
                                <textarea
                                  id={`claim-note-${item.id}`}
                                  rows={3}
                                  className="w-full px-3 py-2 text-sm border border-gray-300 dark:border-gray-600 rounded-md focus:outline-none focus:ring-2 focus:ring-green-500 dark:bg-gray-700 dark:text-white resize-none"
                                  value={claimNote}
                                  onChange={(e) => setClaimNote(e.target.value)}
                                />
                              </div>

                              <button
                                type="submit"
                                disabled={isClaiming}
                                className="w-full px-4 py-2 bg-green-500 text-white rounded-md hover:bg-green-600 font-medium disabled:opacity-50 transition-colors cursor-pointer"
                              >
                                {isClaiming ? 'Reservando...' : (myClaim ? 'Atualizar reserva' : 'Confirmar reserva')}
                              </button>
                              <button
                                type="button"
                                onClick={() => setClaimingItemId(null)}
                                className="w-full px-4 py-2 text-sm border border-gray-300 dark:border-gray-600 rounded-md text-gray-700 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-gray-700 cursor-pointer"
                              >
                                Cancelar
                              </button>
                            </form>
                          ) : (
                            <button
                              onClick={() => handleStartClaim(item)}
                              className="w-full px-4 py-2 bg-indigo-600 text-white rounded-md hover:bg-indigo-700 font-medium transition-colors cursor-pointer"
                            >
                              {myClaim ? 'Atualizar reserva' : 'Reservar'}
                            </button>
                          )}
                        </div>
                      </div>
                    </div>
                  </div>
                );
              })}
            </div>
          )}
        </div>
      </div>
    </div>
  );
}