'use client';

import React, { useState, useEffect } from 'react';
import { Card, CardHeader, CardTitle, CardContent } from '@/components/ui/Card';
import { Button } from '@/components/ui/Button';
import { Badge } from '@/components/ui/Badge';
import { showToast } from '@/components/ui/Toast';
import { useRouter } from 'next/navigation';
import { BillingToggle } from '@/components/ui/BillingToggle';
import { ObfuscatedMailto } from '@/components/ui/ObfuscatedMailto';

export default function PricingPage() {
  const router = useRouter();
  const [loading, setLoading] = useState<string | null>(null);
  const [currentPlan, setCurrentPlan] = useState<string>('FREE');
  const [currentInterval, setCurrentInterval] = useState<'month' | 'year' | null>(null);
  const [billingPeriod, setBillingPeriod] = useState<'month' | 'year'>('month');

  useEffect(() => {
    // Fetch current user plan
    const fetchUserPlan = async () => {
      try {
        const response = await fetch('/api/user/plan');
        if (response.ok) {
          const data = await response.json();
          setCurrentPlan(data.plan || 'FREE');
          setCurrentInterval(data.interval || null);
        }
      } catch (error) {
        console.error('Error fetching user plan:', error);
      }
    };

    fetchUserPlan();
  }, []);

  const handleUpgrade = async (plan: 'PRO' | 'BUSINESS') => {
    setLoading(plan);

    try {
      const response = await fetch('/api/stripe/create-checkout-session', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({
          plan,
          billingInterval: billingPeriod === 'month' ? 'month' : 'year',
        }),
      });

      if (!response.ok) {
        throw new Error('Failed to create checkout session');
      }

      const { url } = await response.json();
      window.location.href = url;
    } catch (error) {
      console.error('Error creating checkout session:', error);
      showToast('Failed to start checkout. Please try again.', 'error');
      setLoading(null);
    }
  };

  const handleDowngrade = async () => {
    // Show confirmation dialog
    const confirmed = window.confirm(
      'Are you sure you want to downgrade to the Free plan? Your subscription will be canceled immediately and you will lose access to premium features.'
    );

    if (!confirmed) {
      return;
    }

    setLoading('FREE');

    try {
      const response = await fetch('/api/stripe/cancel-subscription', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
      });

      if (!response.ok) {
        const error = await response.json();
        throw new Error(error.error || 'Failed to cancel subscription');
      }

      showToast('Successfully downgraded to Free plan', 'success');

      // Refresh to update the plan
      setTimeout(() => {
        window.location.reload();
      }, 1500);
    } catch (error: any) {
      console.error('Error canceling subscription:', error);
      showToast(error.message || 'Failed to downgrade. Please try again.', 'error');
      setLoading(null);
    }
  };

  // Helper function to check if this is the user's exact current plan (plan + interval)
  const isCurrentPlanWithInterval = (planType: string, interval: 'month' | 'year') => {
    return currentPlan === planType && currentInterval === interval;
  };

  // Helper function to check if user has this plan but different interval
  const hasPlanDifferentInterval = (planType: string) => {
    return currentPlan === planType && currentInterval && currentInterval !== billingPeriod;
  };

  const selectedInterval = billingPeriod === 'month' ? 'month' : 'year';

  const plans = [
    {
      key: 'free',
      name: 'Free',
      price: '€0',
      period: 'forever',
      showDiscount: false,
      features: [
        '3 active dynamic QR codes (8 types available)',
        'Unlimited static QR codes',
        'Basic scan tracking',
        'Standard QR design templates',
        'Download as SVG/PNG',
      ],
      buttonText: currentPlan === 'FREE' ? 'Current Plan' : 'Downgrade to Free',
      buttonVariant: 'outline' as const,
      disabled: currentPlan === 'FREE',
      popular: false,
      onDowngrade: handleDowngrade,
    },
    {
      key: 'pro',
      name: 'Pro',
      price: billingPeriod === 'month' ? '€9' : '€90',
      period: billingPeriod === 'month' ? 'per month' : 'per year',
      showDiscount: billingPeriod === 'year',
      features: [
        '50 dynamic QR codes',
        'Unlimited static QR codes',
        'Advanced analytics (scans, devices, locations)',
        'Custom branding (colors & logos)',
      ],
      buttonText: isCurrentPlanWithInterval('PRO', selectedInterval)
        ? 'Current Plan'
        : hasPlanDifferentInterval('PRO')
          ? `Switch to ${billingPeriod === 'month' ? 'Monthly' : 'Yearly'}`
          : 'Upgrade to Pro',
      buttonVariant: 'primary' as const,
      disabled: isCurrentPlanWithInterval('PRO', selectedInterval),
      popular: true,
      onUpgrade: () => handleUpgrade('PRO'),
    },
    {
      key: 'business',
      name: 'Business',
      price: billingPeriod === 'month' ? '€29' : '€290',
      period: billingPeriod === 'month' ? 'per month' : 'per year',
      showDiscount: billingPeriod === 'year',
      features: [
        '500 dynamic QR codes',
        'Unlimited static QR codes',
        'Everything from Pro',
        'Bulk QR Creation (up to 1,000)',
        'Priority email support',
        'Advanced tracking & insights',
      ],
      buttonText: isCurrentPlanWithInterval('BUSINESS', selectedInterval)
        ? 'Current Plan'
        : hasPlanDifferentInterval('BUSINESS')
          ? `Switch to ${billingPeriod === 'month' ? 'Monthly' : 'Yearly'}`
          : 'Upgrade to Business',
      buttonVariant: 'primary' as const,
      disabled: isCurrentPlanWithInterval('BUSINESS', selectedInterval),
      popular: false,
      onUpgrade: () => handleUpgrade('BUSINESS'),
    },
  ];

  return (
    <div className="container mx-auto px-4 py-12">
      <div className="text-center mb-12">
        <h1 className="text-4xl font-bold text-gray-900 mb-4">
          Choose Your Plan
        </h1>
        <p className="text-xl text-gray-600">
          Select the perfect plan for your QR code needs
        </p>
      </div>

      <div className="flex justify-center mb-8">
        <BillingToggle value={billingPeriod} onChange={setBillingPeriod} />
      </div>

      <div className="grid md:grid-cols-3 gap-8 max-w-6xl mx-auto">
        {plans.map((plan) => (
          <Card
            key={plan.key}
            className={plan.popular ? 'border-primary-500 shadow-xl relative' : ''}
          >
            {plan.popular && (
              <div className="absolute -top-4 left-1/2 transform -translate-x-1/2">
                <Badge variant="info" className="px-3 py-1">
                  Most Popular
                </Badge>
              </div>
            )}

            <CardHeader className="text-center pb-8">
              <CardTitle className="text-2xl mb-4">
                {plan.name}
              </CardTitle>
              <div className="flex flex-col items-center">
                <div className="flex items-baseline justify-center">
                  <span className="text-4xl font-bold">
                    {plan.price}
                  </span>
                  <span className="text-gray-600 ml-2">
                    {plan.period}
                  </span>
                </div>
                {plan.showDiscount && (
                  <Badge variant="success" className="mt-2">
                    Save 16%
                  </Badge>
                )}
              </div>
            </CardHeader>

            <CardContent className="space-y-6">
              <ul className="space-y-3">
                {plan.features.map((feature: string, index: number) => (
                  <li key={index} className="flex items-start space-x-3">
                    <svg className="w-5 h-5 text-success-500 flex-shrink-0 mt-0.5" fill="currentColor" viewBox="0 0 20 20">
                      <path fillRule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clipRule="evenodd" />
                    </svg>
                    <span className="text-gray-700">{feature}</span>
                  </li>
                ))}
              </ul>

              <Button
                variant={plan.buttonVariant}
                className="w-full"
                size="lg"
                disabled={plan.disabled || loading === plan.key.toUpperCase()}
                onClick={plan.key === 'free' ? (plan as any).onDowngrade : (plan as any).onUpgrade}
              >
                {loading === plan.key.toUpperCase() ? 'Processing...' : plan.buttonText}
              </Button>
            </CardContent>
          </Card>
        ))}
      </div>

      <div className="text-center mt-12">
        <p className="text-gray-600">
          All plans include unlimited static QR codes and basic customization.
        </p>
        <p className="text-gray-600 mt-2">
          Need help choosing? <ObfuscatedMailto email="support@qrmaster.net" className="text-primary-600 hover:text-primary-700 underline">Contact our team</ObfuscatedMailto>
        </p>
      </div>
    </div>
  );
}
