import React, { useState } from 'react';
import { Elements } from '@stripe/react-stripe-js';
import { loadStripe } from '@stripe/stripe-js';
import type { StripeElementsOptions } from '@stripe/stripe-js';
import { format } from 'date-fns';
import { GlassCard } from '../../../shared-minimal/components/mobile/GlassCard';
import { MobileContainer } from '../../../shared-minimal/components/mobile/MobileContainer';
import { PaymentMethodForm } from '../components/PaymentMethodForm';
import { DonationSectionMobile } from '../components/DonationSectionMobile';
import {
  useSubscription,
  useCheckout,
  useCancelSubscription,
  useReactivateSubscription,
  useInvoices,
} from '../hooks/useSubscription';
import { PLANS } from '../constants/plans';
import type { BillingCycle, SubscriptionTier, SubscriptionPlan } from '../types/subscription.types';

const stripePromise = loadStripe(import.meta.env.VITE_STRIPE_PUBLISHABLE_KEY || '');

const paymentElementsOptions: StripeElementsOptions = {
  mode: 'setup',
  currency: 'usd',
  paymentMethodCreation: 'manual',
};

interface MobileTierCardProps {
  plan: SubscriptionPlan;
  billingCycle: BillingCycle;
  currentTier?: string;
  isLoading?: boolean;
  onUpgrade: () => void;
}

const MobileTierCard: React.FC<MobileTierCardProps> = ({
  plan,
  billingCycle,
  currentTier,
  isLoading = false,
  onUpgrade,
}) => {
  const isCurrent = currentTier === plan.tier;
  const price = billingCycle === 'monthly' ? plan.monthlyPrice : plan.yearlyPrice;
  const priceLabel = billingCycle === 'monthly' ? '/month' : '/year';

  return (
    <GlassCard className={`${isCurrent ? 'border-2 border-rose-500' : ''}`}>
      {isCurrent && (
        <div className="mb-3">
          <span className="inline-block bg-rose-500 text-white text-xs font-semibold px-3 py-1 rounded-full">
            Current Plan
          </span>
        </div>
      )}

      <h3 className="text-xl font-bold text-slate-800 dark:text-avus mb-2">
        {plan.name}
      </h3>

      <div className="my-4">
        <div className="text-3xl font-bold text-slate-900 dark:text-white">
          ${price.toFixed(2)}
        </div>
        <div className="text-sm text-slate-600 dark:text-titanio">
          {priceLabel}
        </div>
      </div>

      <ul className="space-y-2 mb-4">
        {plan.features.map((feature, index) => (
          <li key={index} className="flex items-start gap-2 text-sm">
            <span className="text-rose-500 mt-0.5">✓</span>
            <span className="text-slate-700 dark:text-avus">{feature}</span>
          </li>
        ))}
      </ul>

      {isCurrent ? (
        <button
          disabled
          className="w-full py-3 px-4 bg-gray-200 dark:bg-gray-700 text-gray-500 dark:text-gray-400 rounded-xl font-semibold"
        >
          Current Plan
        </button>
      ) : (
        <button
          onClick={onUpgrade}
          disabled={isLoading}
          className={`w-full py-3 px-4 rounded-xl font-semibold min-h-[44px] ${
            plan.tier === 'enterprise'
              ? 'bg-rose-500 text-white hover:bg-rose-600 disabled:bg-gray-300'
              : 'border-2 border-rose-500 text-rose-500 hover:bg-rose-50 dark:hover:bg-rose-900/20 disabled:border-gray-300 disabled:text-gray-400'
          }`}
        >
          {plan.tier === 'free' ? 'Downgrade' : 'Upgrade'}
        </button>
      )}
    </GlassCard>
  );
};

interface MobileModalProps {
  isOpen: boolean;
  onClose: () => void;
  title: string;
  children: React.ReactNode;
}

const MobileModal: React.FC<MobileModalProps> = ({ isOpen, onClose, title, children }) => {
  if (!isOpen) return null;

  return (
    <div className="fixed inset-0 bg-black bg-opacity-50 dark:bg-black/50 flex items-center justify-center z-50 p-4">
      <div className="bg-white dark:bg-scuro rounded-3xl p-6 max-w-md w-full">
        <h3 className="text-lg font-semibold text-slate-800 dark:text-avus mb-4">{title}</h3>
        {children}
        <div className="flex justify-end mt-4">
          <button
            onClick={onClose}
            className="px-6 py-2 bg-gray-200 dark:bg-gray-700 text-gray-700 dark:text-gray-200 rounded-xl font-medium min-h-[44px]"
          >
            Close
          </button>
        </div>
      </div>
    </div>
  );
};

export const SubscriptionMobileScreen: React.FC = () => {
  const [billingCycle, setBillingCycle] = useState<BillingCycle>('monthly');
  const [selectedTier, setSelectedTier] = useState<SubscriptionTier | null>(null);
  const [showPaymentDialog, setShowPaymentDialog] = useState(false);

  const { data: subscriptionData, isLoading: isLoadingSubscription } = useSubscription();
  const { data: invoicesData, isLoading: isLoadingInvoices } = useInvoices();
  const checkoutMutation = useCheckout();
  const cancelMutation = useCancelSubscription();
  const reactivateMutation = useReactivateSubscription();

  const subscription = subscriptionData?.data;
  const invoices = invoicesData?.data || [];

  const handleUpgradeClick = (tier: SubscriptionTier) => {
    setSelectedTier(tier);
    setShowPaymentDialog(true);
  };

  const handlePaymentSubmit = (paymentMethodId: string) => {
    if (!selectedTier) return;

    checkoutMutation.mutate(
      {
        tier: selectedTier,
        billingCycle,
        paymentMethodId,
      },
      {
        onSuccess: () => {
          setShowPaymentDialog(false);
          setSelectedTier(null);
        },
      }
    );
  };

  const handleCancel = () => {
    if (window.confirm('Are you sure you want to cancel your subscription? Your plan will remain active until the end of the current billing period.')) {
      cancelMutation.mutate();
    }
  };

  const handleReactivate = () => {
    reactivateMutation.mutate();
  };

  const getStatusColor = (status: string) => {
    switch (status) {
      case 'active':
        return 'bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-400';
      case 'past_due':
        return 'bg-yellow-100 text-yellow-800 dark:bg-yellow-900/30 dark:text-yellow-400';
      case 'canceled':
        return 'bg-red-100 text-red-800 dark:bg-red-900/30 dark:text-red-400';
      default:
        return 'bg-gray-100 text-gray-800 dark:bg-gray-900/30 dark:text-gray-400';
    }
  };

  if (isLoadingSubscription) {
    return (
      <MobileContainer>
        <div className="flex items-center justify-center h-full">
          <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-rose-500"></div>
        </div>
      </MobileContainer>
    );
  }

  return (
    <MobileContainer>
      <div className="flex-1 overflow-y-auto p-4 space-y-4">
        <h1 className="text-3xl font-bold text-slate-900 dark:text-white mb-4">
          Subscription
        </h1>

        {subscription && (
          <GlassCard>
            <div className="flex gap-2 mb-3">
              <span className="inline-block bg-rose-500 text-white text-xs font-semibold px-3 py-1 rounded-full">
                {subscription.tier.toUpperCase()}
              </span>
              <span className={`inline-block text-xs font-semibold px-3 py-1 rounded-full ${getStatusColor(subscription.status)}`}>
                {subscription.status}
              </span>
            </div>

            <h2 className="text-xl font-bold text-slate-800 dark:text-avus mb-2">
              Current Plan: {PLANS.find((p) => p.tier === subscription.tier)?.name || subscription.tier}
            </h2>

            {subscription.currentPeriodEnd && (
              <p className="text-sm text-slate-600 dark:text-titanio mb-3">
                Next billing date: {format(new Date(subscription.currentPeriodEnd), 'MMM dd, yyyy')}
              </p>
            )}

            {subscription.cancelAtPeriodEnd && (
              <div className="bg-yellow-50 dark:bg-yellow-900/20 border border-yellow-200 dark:border-yellow-700 rounded-xl p-3 mb-3">
                <p className="text-sm text-yellow-800 dark:text-yellow-300">
                  Your subscription will be canceled at the end of the current billing period.
                </p>
              </div>
            )}

            <div className="mt-4">
              {subscription.cancelAtPeriodEnd ? (
                <button
                  onClick={handleReactivate}
                  disabled={reactivateMutation.isPending}
                  className="w-full py-3 px-4 border-2 border-rose-500 text-rose-500 rounded-xl font-semibold min-h-[44px] hover:bg-rose-50 dark:hover:bg-rose-900/20 disabled:opacity-50"
                >
                  Reactivate
                </button>
              ) : subscription.tier !== 'free' ? (
                <button
                  onClick={handleCancel}
                  disabled={cancelMutation.isPending}
                  className="w-full py-3 px-4 border-2 border-red-500 text-red-500 rounded-xl font-semibold min-h-[44px] hover:bg-red-50 dark:hover:bg-red-900/20 disabled:opacity-50"
                >
                  Cancel Subscription
                </button>
              ) : null}
            </div>
          </GlassCard>
        )}

        <GlassCard>
          <div className="flex justify-between items-center mb-4">
            <h2 className="text-xl font-bold text-slate-800 dark:text-avus">
              Available Plans
            </h2>

            <div className="flex bg-slate-100 dark:bg-scuro rounded-lg p-1">
              <button
                onClick={() => setBillingCycle('monthly')}
                className={`px-3 py-1 text-sm font-medium rounded min-h-[36px] ${
                  billingCycle === 'monthly'
                    ? 'bg-white dark:bg-nero text-rose-500 shadow-sm'
                    : 'text-slate-600 dark:text-titanio'
                }`}
              >
                Monthly
              </button>
              <button
                onClick={() => setBillingCycle('yearly')}
                className={`px-3 py-1 text-sm font-medium rounded min-h-[36px] ${
                  billingCycle === 'yearly'
                    ? 'bg-white dark:bg-nero text-rose-500 shadow-sm'
                    : 'text-slate-600 dark:text-titanio'
                }`}
              >
                Yearly
              </button>
            </div>
          </div>

          <div className="space-y-4">
            {PLANS.map((plan) => (
              <MobileTierCard
                key={plan.tier}
                plan={plan}
                billingCycle={billingCycle}
                currentTier={subscription?.tier}
                isLoading={checkoutMutation.isPending}
                onUpgrade={() => handleUpgradeClick(plan.tier)}
              />
            ))}
          </div>
        </GlassCard>

        <GlassCard>
          <h2 className="text-xl font-bold text-slate-800 dark:text-avus mb-4">
            Billing History
          </h2>

          {isLoadingInvoices ? (
            <div className="flex justify-center p-6">
              <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-rose-500"></div>
            </div>
          ) : invoices.length === 0 ? (
            <p className="text-center text-sm text-slate-600 dark:text-titanio p-6">
              No billing history available
            </p>
          ) : (
            <div className="space-y-2">
              {invoices.map((invoice: { id: string; date: string; amount: number; status: string; pdfUrl?: string }) => (
                <div
                  key={invoice.id}
                  className="flex justify-between items-center p-3 bg-slate-50 dark:bg-scuro rounded-xl"
                >
                  <div>
                    <div className="text-sm font-medium text-slate-800 dark:text-avus">
                      {format(new Date(invoice.date), 'MMM dd, yyyy')}
                    </div>
                    <div className="text-xs text-slate-600 dark:text-titanio">
                      ${(invoice.amount / 100).toFixed(2)}
                    </div>
                  </div>
                  <div className="flex items-center gap-2">
                    <span className={`text-xs px-2 py-1 rounded-full ${
                      invoice.status === 'paid'
                        ? 'bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-400'
                        : invoice.status === 'pending'
                        ? 'bg-yellow-100 text-yellow-800 dark:bg-yellow-900/30 dark:text-yellow-400'
                        : 'bg-red-100 text-red-800 dark:bg-red-900/30 dark:text-red-400'
                    }`}>
                      {invoice.status}
                    </span>
                    {invoice.pdfUrl && (
                      <a
                        href={invoice.pdfUrl}
                        target="_blank"
                        rel="noopener noreferrer"
                        className="text-rose-500 text-sm min-h-[44px] min-w-[44px] flex items-center justify-center"
                      >
                        ↓
                      </a>
                    )}
                  </div>
                </div>
              ))}
            </div>
          )}
        </GlassCard>

        <Elements stripe={stripePromise}>
          <DonationSectionMobile currentTier={subscription?.tier} />
        </Elements>
      </div>

      <MobileModal
        isOpen={showPaymentDialog}
        onClose={() => !checkoutMutation.isPending && setShowPaymentDialog(false)}
        title={`Upgrade to ${selectedTier && PLANS.find((p) => p.tier === selectedTier)?.name}`}
      >
        <Elements stripe={stripePromise} options={paymentElementsOptions}>
          <PaymentMethodForm
            onSubmit={handlePaymentSubmit}
            isLoading={checkoutMutation.isPending}
          />
        </Elements>
      </MobileModal>
    </MobileContainer>
  );
};