'use client';

import React, { useState, useEffect } from 'react';
import Link from 'next/link';
import { ArrowLeft, CheckCircle2, ShieldCheck, Truck, Zap, QrCode, Phone, MapPin, User, MessageCircle, ExternalLink, CreditCard } from 'lucide-react';
import { City, PaymentMethod, Order, StoreSettings } from '@/types';
import { INITIAL_CITIES, INITIAL_PAYMENT_METHODS, INITIAL_PRODUCTS } from '@/lib/data-service';
import { formatCOP } from '@/lib/pricing-engine';
import { useBrand } from '@/context/BrandContext';
import { useAuth } from '@/context/AuthContext';
import { renderClientTemplate } from '@/lib/templates-client';
import confetti from 'canvas-confetti';
import { OptimizedImage } from '@/components/ui/OptimizedImage';

export default function CheckoutPage() {
  const { currentBrand } = useBrand();
  const { user } = useAuth();

  const [customerName, setCustomerName] = useState('');
  const [customerPhone, setCustomerPhone] = useState('');
  const [address, setAddress] = useState('');
  const [neighborhood, setNeighborhood] = useState('');
  const [notes, setNotes] = useState('');

  const [cities, setCities] = useState<City[]>(INITIAL_CITIES);
  const [paymentMethods, setPaymentMethods] = useState<PaymentMethod[]>(INITIAL_PAYMENT_METHODS);
  const [selectedCityId, setSelectedCityId] = useState<string>('city-cali');
  const [selectedPaymentId, setSelectedPaymentId] = useState<string>('pay-deposit-10k');
  const [storeSettings, setStoreSettings] = useState<StoreSettings | null>(null);

  const [checkoutItems] = useState<Array<{
    productId: string;
    productName: string;
    brand: string;
    size: string;
    quantity: number;
    price: number;
    image: string;
  }>>(
    INITIAL_PRODUCTS.length > 0
      ? [
          {
            productId: INITIAL_PRODUCTS[0].id,
            productName: INITIAL_PRODUCTS[0].name,
            brand: INITIAL_PRODUCTS[0].brand,
            size: '39',
            quantity: 1,
            price: INITIAL_PRODUCTS[0].retailPrice,
            image: INITIAL_PRODUCTS[0].images[0],
          },
        ]
      : []
  );

  const [isSubmitting, setIsSubmitting] = useState(false);
  const [orderCompleted, setOrderCompleted] = useState<Order | null>(null);
  const [userRequiresDeposit, setUserRequiresDeposit] = useState<boolean>(false);
  const [userDepositReason, setUserDepositReason] = useState<string>('');

  useEffect(() => {
    fetch('/api/cities')
      .then((r) => r.json())
      .then((d) => d.success && setCities(d.cities))
      .catch(() => {});

    fetch('/api/payment-methods')
      .then((r) => r.json())
      .then((d) => d.success && setPaymentMethods(d.paymentMethods))
      .catch(() => {});

    fetch('/api/settings')
      .then((r) => r.json())
      .then((d) => d.success && setStoreSettings(d.settings))
      .catch(() => {});
  }, []);

  useEffect(() => {
    if (user) {
      setUserRequiresDeposit(user.requiresShippingDeposit === true);
      setUserDepositReason(user.depositReason || '');
    }
  }, [user]);

  useEffect(() => {
    const clean = customerPhone.replace(/\D/g, '');
    if (clean.length >= 10) {
      fetch(`/api/users?phone=${clean}`)
        .then((r) => r.json())
        .then((data) => {
          if (data.success) {
            setUserRequiresDeposit(data.requiresShippingDeposit === true);
            setUserDepositReason(data.depositReason || '');
          }
        })
        .catch(() => {});
    }
  }, [customerPhone]);

  const activeCity = cities.find((c) => c.id === selectedCityId) || cities[0];
  const activePayment = paymentMethods.find((p) => p.id === selectedPaymentId) || paymentMethods[0];

  const subtotal = checkoutItems.reduce((acc, it) => acc + it.price * it.quantity, 0);
  const shippingCost = activeCity.shippingCost;
  const totalAmount = subtotal + shippingCost;

  // Valor de garantía por flete según la ciudad seleccionada (o $10.000 COP si flete local es 0)
  const cityShippingFee = activeCity.shippingCost > 0 ? activeCity.shippingCost : 10000;
  
  // Por defecto NO se cobra anticipo a clientes nuevos
  // Solo se activa si el cliente tiene un pedido rechazado previo o si un admin lo activó
  const isMandatoryDeposit = userRequiresDeposit;
  const depositAmount = isMandatoryDeposit
    ? cityShippingFee
    : (activePayment.requiresDeposit ? activePayment.depositAmount : 0);
  const balanceDue = Math.max(0, totalAmount - depositAmount);

  const officialWhatsapp = storeSettings?.whatsappNumber || '573167455877';
  const boldLink = storeSettings?.boldPaymentLink || 'https://bold.co/p/carlos-lasso';

  const handleSubmitOrder = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!customerName || !customerPhone || !address) {
      alert('Por favor completa tu nombre, celular y dirección para el despacho.');
      return;
    }

    setIsSubmitting(true);

    try {
      const orderPayload = {
        customerName,
        customerPhone,
        address: `${address} - Barrio: ${neighborhood || 'Centro'}`,
        cityId: activeCity.id,
        cityName: activeCity.name,
        items: checkoutItems,
        subtotal,
        shippingCost,
        totalAmount,
        depositAmount,
        balanceDue,
        paymentMethodId: activePayment.id,
        paymentMethodName: activePayment.name,
        notes,
      };

      const res = await fetch('/api/orders', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(orderPayload),
      });

      const data = await res.json();
      if (data.success) {
        setOrderCompleted(data.order);
        confetti({
          particleCount: 100,
          spread: 70,
          origin: { y: 0.6 },
        });
      }
    } catch (err) {
      console.error('Error creando orden:', err);
    } finally {
      setIsSubmitting(false);
    }
  };

  const handleOpenWhatsAppOrder = (order: Order) => {
    const itemsSummary = order.items
      .map((i) => `• ${i.productName} (Talla ${i.size}) x${i.quantity} = ${formatCOP(i.price * i.quantity)}`)
      .join('\n');

    const paymentCondition = order.depositAmount > 0
      ? `⚡ *Separación:* ${formatCOP(order.depositAmount)}\n🤝 *Saldo Contraentrega:* ${formatCOP(order.balanceDue)}`
      : '🤝 *Pago 100% Contraentrega.*';

    const rawText = renderClientTemplate('order_checkout_wa', {
      tienda_nombre: currentBrand.name,
      orden_id: order.id,
      cliente_nombre: order.customerName,
      cliente_telefono: order.customerPhone,
      cliente_direccion: order.address,
      cliente_ciudad: order.cityName,
      articulos_resumen: itemsSummary,
      total: formatCOP(order.totalAmount),
      condicion_pago_resumen: paymentCondition,
      metodo_pago: order.paymentMethodName,
      saldo_contraentrega: formatCOP(order.balanceDue),
    });

    window.open(`https://wa.me/${officialWhatsapp}?text=${encodeURIComponent(rawText)}`, '_blank');
  };


  if (orderCompleted) {
    return (
      <div className={`min-h-screen ${currentBrand.colors.bodyBg} flex items-center justify-center p-4`}>
        <div className={`bg-neutral-900 border ${currentBrand.colors.border} rounded-3xl max-w-lg w-full p-6 sm:p-8 shadow-2xl text-center space-y-5 animate-in zoom-in-95 duration-300`}>
          <div className={`w-16 h-16 rounded-full bg-gradient-to-r ${currentBrand.colors.primaryGradient} text-white flex items-center justify-center mx-auto shadow-md`}>
            <CheckCircle2 className="w-10 h-10" />
          </div>

          <div>
            <span className={`text-xs font-bold bg-white/10 text-white px-3 py-1 rounded-full uppercase tracking-wider border border-white/10`}>
              ¡Pedido Registrado con Éxito!
            </span>
            <h2 className="text-2xl font-black text-white mt-2">Orden #{orderCompleted.id}</h2>
            <p className="text-xs text-neutral-400 mt-1">
              Hemos recibido tu solicitud para entrega en <strong>{orderCompleted.cityName}</strong> con <strong>{currentBrand.name}</strong>.
            </p>
          </div>

          {/* Bold.co or Nequi Separation Box */}
          {orderCompleted.depositAmount > 0 ? (
            <div className="bg-neutral-950 border border-white/10 rounded-2xl p-4 text-left space-y-2.5">
              <div className="flex items-center space-x-2 text-white font-bold text-xs uppercase">
                <QrCode className="w-4 h-4 text-white" />
                <span>Paso 2: Realiza la separación de $10.000 COP</span>
              </div>
              <p className="text-xs text-neutral-300">
                Paga de inmediato con <strong>Link de Pago Bold.co</strong> (PSE / Tarjeta / Nequi) o transfiere a nuestra cuenta oficial:
              </p>

              {boldLink && (
                <a
                  href={boldLink}
                  target="_blank"
                  rel="noopener noreferrer"
                  className="w-full bg-indigo-600 hover:bg-indigo-500 text-white font-black text-xs py-2.5 px-3 rounded-xl flex items-center justify-center gap-1.5 shadow-md transition-all"
                >
                  <CreditCard className="w-4 h-4" />
                  <span>Pagar $10.000 COP con Bold.co (PSE / Tarjetas)</span>
                  <ExternalLink className="w-3.5 h-3.5" />
                </a>
              )}

              <div className="bg-neutral-900 p-2.5 rounded-xl border border-neutral-700 text-xs font-mono font-bold text-white">
                📱 Nequi / Daviplata: <strong>{storeSettings?.nequiAccount || '316 745 5877'}</strong> ({storeSettings?.accountHolder || 'Carlos Andrés Lasso'})
              </div>
              <p className="text-[11px] text-emerald-400 font-semibold">
                🤝 Cancelas el saldo de <strong>{formatCOP(orderCompleted.balanceDue)}</strong> al recibir el paquete en tu casa.
              </p>
            </div>
          ) : (
            <div className="bg-neutral-950 border border-white/10 rounded-2xl p-4 text-left space-y-2">
              <p className="text-xs text-neutral-300 font-semibold">
                Tu pedido quedó programado para entrega contraentrega en 24 horas. ¡Nos pondremos en contacto contigo por WhatsApp!
              </p>
            </div>
          )}

          <div className="flex flex-col gap-2 pt-2">
            <button
              onClick={() => handleOpenWhatsAppOrder(orderCompleted)}
              className="w-full bg-emerald-600 hover:bg-emerald-700 text-white font-bold text-sm py-3 px-4 rounded-xl flex items-center justify-center space-x-2 shadow-lg shadow-emerald-600/20 active:scale-95 transition-all cursor-pointer"
            >
              <MessageCircle className="w-4 h-4 fill-white" />
              <span>Confirmar y Enviar Comprobante por WhatsApp</span>
            </button>

            <Link
              href="/"
              className="w-full bg-neutral-800 hover:bg-neutral-700 text-neutral-300 font-bold text-xs py-2.5 px-4 rounded-xl text-center transition-all border border-neutral-700"
            >
              Volver a la Tienda
            </Link>
          </div>
        </div>
      </div>
    );
  }

  return (
    <div className={`min-h-screen ${currentBrand.colors.bodyBg} py-8 px-4 font-sans`}>
      <div className="max-w-4xl mx-auto space-y-6">
        {/* Header */}
        <div className="flex items-center justify-between">
          <Link
            href="/"
            className="flex items-center space-x-2 text-xs font-bold text-neutral-400 hover:text-white transition-colors"
          >
            <ArrowLeft className="w-4 h-4" />
            <span>Regresar a {currentBrand.name}</span>
          </Link>
          <div className="flex items-center space-x-1.5 text-xs font-bold text-white bg-white/10 border border-white/10 px-3 py-1 rounded-full shadow-sm">
            <ShieldCheck className="w-4 h-4" />
            <span>Compra Segura & Garantizada</span>
          </div>
        </div>

        <form onSubmit={handleSubmitOrder} className="grid grid-cols-1 md:grid-cols-12 gap-6">
          {/* Left Column: Shipping & Payment Details (7 cols) */}
          <div className="md:col-span-7 space-y-5">
            {/* 1. Datos del Cliente */}
            <div className="bg-neutral-900 border border-neutral-800 rounded-3xl p-5 sm:p-6 shadow-sm space-y-4">
              <h3 className="font-black text-white text-base flex items-center gap-2">
                <User className="w-5 h-5 text-white" />
                <span>1. Datos de Entrega</span>
              </h3>

              <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
                <div>
                  <label className="block text-xs font-bold text-neutral-300 mb-1">Nombre Completo *</label>
                  <input
                    type="text"
                    required
                    placeholder="Ej: Juan Pérez"
                    value={customerName}
                    onChange={(e) => setCustomerName(e.target.value)}
                    className="w-full bg-neutral-950 border border-neutral-800 rounded-xl px-3 py-2 text-sm text-white focus:border-purple-400 outline-hidden"
                  />
                </div>
                <div>
                  <label className="block text-xs font-bold text-neutral-300 mb-1">Celular / WhatsApp *</label>
                  <input
                    type="tel"
                    required
                    placeholder="Ej: 3XX XXX XXXX"
                    value={customerPhone}
                    onChange={(e) => setCustomerPhone(e.target.value)}
                    className="w-full bg-neutral-950 border border-neutral-800 rounded-xl px-3 py-2 text-sm text-white focus:border-purple-400 outline-hidden"
                  />
                </div>
              </div>

              {/* City Selection */}
              <div>
                <label className="block text-xs font-bold text-neutral-300 mb-1">Ciudad de Despacho *</label>
                <select
                  value={selectedCityId}
                  onChange={(e) => setSelectedCityId(e.target.value)}
                  className="w-full bg-neutral-950 border border-neutral-800 rounded-xl px-3 py-2.5 text-sm text-white focus:border-purple-400 font-semibold outline-hidden"
                >
                  {cities.map((city) => (
                    <option key={city.id} value={city.id} className="bg-neutral-900">
                      {city.name} — {city.shippingCost === 0 ? 'Envío Gratis' : formatCOP(city.shippingCost)} ({city.deliveryTime})
                    </option>
                  ))}
                </select>
              </div>

              <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
                <div>
                  <label className="block text-xs font-bold text-neutral-300 mb-1">Dirección de Entrega *</label>
                  <input
                    type="text"
                    required
                    placeholder="Ej: Calle 123 # 45 - 67, Apto 201"
                    value={address}
                    onChange={(e) => setAddress(e.target.value)}
                    className="w-full bg-neutral-950 border border-neutral-800 rounded-xl px-3 py-2 text-sm text-white focus:border-purple-400 outline-hidden"
                  />
                </div>
                <div>
                  <label className="block text-xs font-bold text-neutral-300 mb-1">Barrio / Sector</label>
                  <input
                    type="text"
                    placeholder="Ej: Barrio San Fernando / Casa blanca"
                    value={neighborhood}
                    onChange={(e) => setNeighborhood(e.target.value)}
                    className="w-full bg-neutral-950 border border-neutral-800 rounded-xl px-3 py-2 text-sm text-white focus:border-purple-400 outline-hidden"
                  />
                </div>
              </div>

            </div>

            {/* 2. Método de Pago */}
            <div className="bg-neutral-900 border border-neutral-800 rounded-3xl p-5 sm:p-6 shadow-sm space-y-4">
              <h3 className="font-black text-white text-base flex items-center gap-2">
                <Zap className="w-5 h-5 text-white" />
                <span>2. Selecciona tu Método de Pago</span>
              </h3>

              <div className="space-y-2.5">
                {paymentMethods.map((method) => {
                  const isSelected = selectedPaymentId === method.id;
                  return (
                    <div
                      key={method.id}
                      onClick={() => setSelectedPaymentId(method.id)}
                      className={`p-4 rounded-2xl border transition-all cursor-pointer space-y-1.5 ${
                        isSelected
                          ? `border-purple-400 bg-purple-950/20 shadow-md`
                          : 'border-neutral-800 hover:border-neutral-700 bg-neutral-950'
                      }`}
                    >
                      <div className="flex items-center justify-between">
                        <div className="flex items-center space-x-2">
                          <div
                            className={`w-4 h-4 rounded-full border-2 flex items-center justify-center ${
                              isSelected ? 'border-purple-400' : 'border-neutral-600'
                            }`}
                          >
                            {isSelected && <div className="w-2 h-2 rounded-full bg-purple-400" />}
                          </div>
                          <span className="font-black text-white text-sm">{method.name}</span>
                        </div>

                        {method.requiresDeposit && (
                          <span className="bg-white/10 text-white border border-white/20 text-[10px] font-black px-2 py-0.5 rounded-full uppercase">
                            Separa con $10.000
                          </span>
                        )}
                      </div>

                      <p className="text-xs text-neutral-400 pl-6">{method.description}</p>

                      {isSelected && (method.accountInfo || (method.type === 'bold' && boldLink)) && (
                        <div className="ml-6 mt-2 bg-neutral-900 p-3 rounded-xl border border-white/10 text-xs space-y-2 text-white">
                          {method.accountInfo && <p className="font-semibold">{method.accountInfo}</p>}
                          {method.type === 'bold' && boldLink && (
                            <a
                              href={boldLink}
                              target="_blank"
                              rel="noopener noreferrer"
                              className="inline-flex items-center gap-1.5 bg-indigo-600 hover:bg-indigo-500 text-white text-xs font-bold px-3 py-1.5 rounded-lg shadow-sm"
                            >
                              <ExternalLink className="w-3.5 h-3.5" />
                              <span>Abrir Link de Pago Bold.co</span>
                            </a>
                          )}
                        </div>
                      )}
                    </div>
                  );
                })}
              </div>
            </div>
          </div>

          {/* Right Column: Summary (5 cols) */}
          <div className="md:col-span-5 space-y-5">
            <div className="bg-neutral-900 border border-neutral-800 rounded-3xl p-5 sm:p-6 shadow-sm space-y-4 sticky top-20">
              <h3 className="font-black text-white text-base">Resumen del Pedido</h3>

              {/* Items */}
              <div className="space-y-3 max-h-60 overflow-y-auto pr-1">
                {checkoutItems.map((item, i) => (
                  <div key={i} className="flex gap-3 bg-neutral-950 p-2.5 rounded-2xl border border-neutral-800">
                    <OptimizedImage
                      src={item.image}
                      alt={item.productName}
                      width={120}
                      height={120}
                      quality={75}
                      className="w-14 h-14 rounded-xl object-cover bg-neutral-900 border border-neutral-700 shrink-0"
                      containerClassName="w-14 h-14 rounded-xl shrink-0"
                    />
                    <div className="flex-1 text-xs">
                      <h4 className="font-bold text-white line-clamp-1">{item.productName}</h4>
                      <p className="text-neutral-400">Talla: <strong className="text-white">{item.size}</strong> | Cant: {item.quantity}</p>
                      <p className={`font-black mt-0.5 text-transparent bg-clip-text bg-gradient-to-r ${currentBrand.colors.primaryGradient}`}>
                        {formatCOP(item.price * item.quantity)}
                      </p>
                    </div>
                  </div>
                ))}
              </div>

              {/* Breakdown */}
              <div className="border-t border-neutral-800 pt-3 space-y-2 text-xs text-neutral-400">
                <div className="flex justify-between">
                  <span>Subtotal:</span>
                  <span className="font-bold text-white">{formatCOP(subtotal)}</span>
                </div>
                <div className="flex justify-between">
                  <span>Envío ({activeCity.name}):</span>
                  <span className="font-bold text-white">
                    {shippingCost === 0 ? <span className="text-emerald-400 font-bold uppercase">Gratis</span> : formatCOP(shippingCost)}
                  </span>
                </div>
                <div className="flex justify-between text-base font-black text-white pt-2 border-t border-neutral-800">
                  <span>Total a Pagar:</span>
                  <span className={`text-transparent bg-clip-text bg-gradient-to-r ${currentBrand.colors.primaryGradient} text-lg`}>
                    {formatCOP(totalAmount)}
                  </span>
                </div>

                {/* Garantía de Flete / Despacho (Solo visible si está activo para el usuario) */}
                {isMandatoryDeposit ? (
                  <div className="bg-amber-500/10 border border-amber-500/30 rounded-2xl p-3.5 space-y-2 text-xs">
                    <div className="flex items-center space-x-2 text-amber-300 font-bold">
                      <ShieldCheck className="w-4 h-4 text-amber-400 shrink-0" />
                      <span>Garantía de Despacho & Reserva ({activeCity.name})</span>
                    </div>
                    <p className="text-neutral-300 text-[11px] leading-relaxed">
                      Para asegurar tu turno prioritario de entrega con la transportadora en <strong>{activeCity.name}</strong>, se realiza un anticipo de <strong>{formatCOP(depositAmount)}</strong> por concepto de flete, el cual es <strong>100% descontable</strong> del valor total al recibir tu calzado en tu domicilio.
                    </p>
                    <div className="flex justify-between items-center pt-1.5 border-t border-amber-500/20 text-[11px]">
                      <span className="text-amber-200">Saldo a pagar en efectivo al recibir:</span>
                      <span className="font-mono font-black text-white text-xs">{formatCOP(balanceDue)}</span>
                    </div>
                  </div>
                ) : depositAmount > 0 ? (
                  <div className="bg-white/5 border border-white/10 rounded-xl p-2.5 text-xs text-white space-y-1">
                    <div className="flex justify-between font-bold text-white">
                      <span>Anticipo de Separación:</span>
                      <span>{formatCOP(depositAmount)}</span>
                    </div>
                    <div className="flex justify-between font-black text-white pt-1 border-t border-white/10">
                      <span>Saldo a pagar al recibir:</span>
                      <span>{formatCOP(balanceDue)}</span>
                    </div>
                  </div>
                ) : null}

                <div className="bg-white/5 border border-white/10 rounded-xl p-2.5 text-xs text-neutral-300 space-y-1">
                  <div className="flex items-center space-x-1.5 font-bold text-white">
                    <ShieldCheck className={`w-3.5 h-3.5 ${activeCity.firstExchangeFree ? 'text-emerald-400' : 'text-purple-400'}`} />
                    <span>Garantía en {activeCity.name}:</span>
                  </div>
                  <p className="text-[11px] text-neutral-300">
                    {activeCity.firstExchangeFree
                      ? '1er Cambio de Talla 100% GRATIS (cambios posteriores con flete estándar).'
                      : 'Cambios de talla 100% garantizados (los costos de envío son asumidos por el cliente).'}
                  </p>
                </div>
              </div>

              <button
                type="submit"
                disabled={isSubmitting}
                className={`w-full bg-gradient-to-r ${currentBrand.colors.primaryGradient} hover:opacity-95 text-white font-black text-sm py-3.5 px-4 rounded-2xl shadow-lg active:scale-95 transition-all cursor-pointer flex items-center justify-center space-x-2`}
              >
                {isSubmitting ? (
                  <span>Procesando Pedido...</span>
                ) : (
                  <>
                    <span>Confirmar Pedido Contraentrega</span>
                    <Truck className="w-4 h-4" />
                  </>
                )}
              </button>

              <p className="text-[11px] text-neutral-500 text-center leading-tight">
                Al confirmar, se guardará tu pedido y recibirás asistencia inmediata por WhatsApp oficial ({officialWhatsapp}) para el seguimiento de tu entrega en 24 horas.
              </p>
            </div>
          </div>
        </form>
      </div>
    </div>
  );
}