"use client";

import { zodResolver } from "@hookform/resolvers/zod";
import { useForm, Controller } from "react-hook-form";
import { Button } from "@/components/ui/button";
import {
  Form,
  FormControl,
  FormDescription,
  FormField,
  FormItem,
  FormLabel,
  FormMessage,
} from "@/components/ui/form";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import { RadioGroup, RadioGroupItem } from "@/components/ui/radio-group";
import { Card, CardContent, CardHeader, CardTitle, CardDescription } from "@/components/ui/card";
import { CoinPurchaseSchema, type CoinPurchaseInput, CoinPurchasePackageEnum, PaymentGatewayEnum, SupportedCurrencyEnum } from "@/lib/schemas";
import type { CoinPackageDetails, CurrencyInfo } from "@/lib/types";
import { useToast } from "@/hooks/use-toast";
import { useRouter } from "next/navigation"; 
import { useState, useEffect } from "react";
import { Loader2, Coins, CreditCard, ShoppingCart, Lock } from "lucide-react";
import { usePaystackPayment, PaystackButton, PaystackConsumer } from 'react-paystack';
import { useFlutterwave, closePaymentModal } from 'flutterwave-react-v3';
import { initiateCoinPurchase, verifyPaymentAndAwardCoins } from "@/lib/actions/billing"; 
import { getLoggedInUser, type LoggedInUser } from "@/lib/actions/auth";

const paystackPublicKey = process.env.NEXT_PUBLIC_PAYSTACK_PUBLIC_KEY || '';
const flutterwavePublicKey = process.env.NEXT_PUBLIC_FLUTTERWAVE_PUBLIC_KEY || '';

const COIN_BASE_PRICE_NGN = 10; // 1 Coin = 10 NGN

const coinPackages: CoinPackageDetails[] = [
  { id: 'small_50', name: "Small Pack", coins: 50, priceNGN: 50 * COIN_BASE_PRICE_NGN, description: "Get started with 50 coins." },
  { id: 'medium_150', name: "Medium Pack", coins: 150, priceNGN: 150 * COIN_BASE_PRICE_NGN, description: "Most popular: 150 coins." },
  { id: 'large_300', name: "Large Pack", coins: 300, priceNGN: 300 * COIN_BASE_PRICE_NGN, description: "Best value: 300 coins." },
];

const currencyRatesList: CurrencyInfo[] = [
    { code: 'NGN', symbol: '₦', rate: 1, name: 'Nigerian Naira' },
    { code: 'USD', symbol: '$', rate: 0.00063, name: 'US Dollar' }, 
    { code: 'GBP', symbol: '£', rate: 0.00050, name: 'British Pound' }, 
    { code: 'EUR', symbol: '€', rate: 0.00058, name: 'Euro' }, 
    { code: 'GHS', symbol: 'GH₵', rate: 0.0094, name: 'Ghanaian Cedi' }, 
    { code: 'KES', symbol: 'KSh', rate: 0.093, name: 'Kenyan Shilling' }, 
    { code: 'ZAR', symbol: 'R', rate: 0.012, name: 'South African Rand' }, 
    { code: 'UGX', symbol: 'USh', rate: 2.5, name: 'Ugandan Shilling' },
    { code: 'TZS', symbol: 'TSh', rate: 1.6, name: 'Tanzanian Shilling' },
    { code: 'RWF', symbol: 'RF', rate: 0.82, name: 'Rwandan Franc' },
    { code: 'XOF', symbol: 'CFA', rate: 0.38, name: 'West African CFA franc' }, 
    { code: 'XAF', symbol: 'FCFA', rate: 0.38, name: 'Central African CFA franc' }, 
    { code: 'CAD', symbol: 'CA$', rate: 0.00086, name: 'Canadian Dollar' }, 
    { code: 'EGP', symbol: 'E£', rate: 0.030, name: 'Egyptian Pound' }, 
    { code: 'GNF', symbol: 'FG', rate: 5.4, name: 'Guinean Franc' },
    { code: 'MAD', symbol: 'MAD', rate: 0.0063, name: 'Moroccan Dirham' }, 
    { code: 'MWK', symbol: 'MK', rate: 1.1, name: 'Malawian Kwacha' },
    { code: 'SLL', symbol: 'Le', rate: 14.0, name: 'Sierra Leonean Leone (New)'}, 
    { code: 'STD', symbol: 'Db', rate: 14.0, name: 'São Tomé & Príncipe Dobra (New)' }, 
    { code: 'ZMW', symbol: 'ZK', rate: 0.017, name: 'Zambian Kwacha' }, 
    { code: 'CLP', symbol: 'CLP$', rate: 0.58, name: 'Chilean Peso' },
    { code: 'COP', symbol: 'COL$', rate: 2.5, name: 'Colombian Peso' },
];


export function CoinPurchaseForm() {
  const { toast } = useToast();
  const router = useRouter();
  const [isLoading, setIsLoading] = useState(false);
  const [currentUser, setCurrentUser] = useState<LoggedInUser | null>(null);

  useEffect(() => {
    getLoggedInUser().then(setCurrentUser);
  }, []);

  const form = useForm<CoinPurchaseInput>({
    resolver: zodResolver(CoinPurchaseSchema),
    defaultValues: {
      package: "medium_150",
      currency: "NGN",
      paymentGateway: "paystack",
      email: currentUser?.email || "",
      name: currentUser?.name || "",
    },
  });

  const selectedPackageId = form.watch("package");
  const selectedCurrencyCode = form.watch("currency");

  const selectedPkg = coinPackages.find(p => p.id === selectedPackageId) || coinPackages[0];
  const selectedCurrInfo = currencyRatesList.find(c => c.code === selectedCurrencyCode) || currencyRatesList[0];
  
  const priceInSelectedCurrency = parseFloat((selectedPkg.priceNGN * selectedCurrInfo.rate).toFixed(2));

  useEffect(() => {
    form.setValue("amountInSelectedCurrency", priceInSelectedCurrency);
    form.setValue("amountInNGN", selectedPkg.priceNGN);
    form.setValue("coinsToCredit", selectedPkg.coins);
    if (currentUser) {
      form.setValue("email", currentUser.email);
      form.setValue("name", currentUser.name);
    }
  }, [selectedPkg, priceInSelectedCurrency, form, currentUser]);


  const handlePaymentSuccess = async (response: any, gateway: 'paystack' | 'flutterwave') => {
    console.log(`${gateway} success response:`, response);
    toast({ title: `${gateway} Payment Submitted (Simulation)`, description: `Ref: ${response.reference || response.transaction_id}. Verifying...` });
    setIsLoading(true);
    // SIMULATE webhook verification for now
    const verificationResult = await verifyPaymentAndAwardCoins(gateway, response.reference || response.transaction_id, response);
    toast({
      title: verificationResult.success ? "Purchase Complete!" : "Verification Issue",
      description: verificationResult.message,
      variant: verificationResult.success ? "default" : "destructive",
    });
    if (verificationResult.success) {
      router.refresh(); 
    }
    setIsLoading(false);
  };

  const handlePaymentClose = (gateway: 'paystack' | 'flutterwave') => {
    console.log(`${gateway} payment modal closed.`);
    toast({ title: "Payment Cancelled", description: "The payment process was cancelled.", variant: "default" });
    setIsLoading(false);
  };
  
  // Paystack Config
  const paystackConfig = {
    reference: new Date().getTime().toString(), 
    email: form.getValues("email"),
    amount: priceInSelectedCurrency * 100, // Amount in kobo
    currency: selectedCurrencyCode,
    publicKey: paystackPublicKey,
    metadata: {
        userId: currentUser?._id,
        packageName: selectedPkg.name,
        coins: selectedPkg.coins,
        custom_fields: [
            {
            display_name: "Package",
            variable_name: "package",
            value: selectedPkg.name
            },
             {
            display_name: "Coins",
            variable_name: "coins",
            value: selectedPkg.coins
            }
        ]
    }
  };

  // Flutterwave Config
  const flutterwaveConfig = {
    public_key: flutterwavePublicKey,
    tx_ref: new Date().getTime().toString(), 
    amount: priceInSelectedCurrency,
    currency: selectedCurrencyCode,
    payment_options: "card,mobilemoney,ussd",
    customer: {
      email: form.getValues("email"),
      name: form.getValues("name") || "Anita Deploy User",
    },
    customizations: {
      title: "Anita Deploy - Coin Purchase",
      description: `Payment for ${selectedPkg.coins} coins`,
      logo: "https://placehold.co/100x100.png?text=AD", 
    },
  };

  const initializePaystackPayment = usePaystackPayment(paystackConfig);
  const handleFlutterwavePayment = useFlutterwave(flutterwaveConfig);


  async function onSubmit(values: CoinPurchaseInput) {
    setIsLoading(true);

    if (!paystackPublicKey || !flutterwavePublicKey) {
        toast({title: "Configuration Error", description: "Payment gateway keys are not set. Please contact support.", variant: "destructive"});
        setIsLoading(false);
        return;
    }

    if (!currentUser) {
      toast({title: "Error", description: "User not loaded. Please refresh.", variant: "destructive"});
      setIsLoading(false);
      return;
    }
    
    const currentPaystackConfig = {
        ...paystackConfig,
        reference: `anitad_${currentUser._id}_${new Date().getTime()}`,
        email: values.email,
        amount: values.amountInSelectedCurrency * 100,
        currency: values.currency,
         metadata: {
            userId: currentUser._id,
            packageName: selectedPkg.name,
            coins: selectedPkg.coins,
            transactionType: "coin_purchase",
            custom_fields: [
                { display_name: "Package", variable_name: "package", value: selectedPkg.name },
                { display_name: "Coins", variable_name: "coins", value: selectedPkg.coins }
            ]
        }
    };

    const currentFlutterwaveConfig = {
        ...flutterwaveConfig,
        tx_ref: `anitad_${currentUser._id}_${new Date().getTime()}`,
        amount: values.amountInSelectedCurrency,
        currency: values.currency,
        customer: {
            email: values.email,
            name: values.name || "Anita Deploy User",
        },
        meta: {
            userId: currentUser._id,
            packageName: selectedPkg.name,
            coins: selectedPkg.coins,
            transactionType: "coin_purchase"
        }
    };
    
    const initResult = await initiateCoinPurchase({
        ...values,
    });

    if (!initResult.success || !initResult.transactionReference) {
        toast({ title: "Initiation Failed", description: initResult.message, variant: "destructive" });
        setIsLoading(false);
        return;
    }

    currentPaystackConfig.reference = initResult.transactionReference;
    currentFlutterwaveConfig.tx_ref = initResult.transactionReference;

    if (values.paymentGateway === "paystack") {
      initializePaystackPayment({
        onSuccess: (response) => handlePaymentSuccess(response, 'paystack'),
        onClose: () => handlePaymentClose('paystack'),
        config: currentPaystackConfig,
      });
    } else if (values.paymentGateway === "flutterwave") {
      handleFlutterwavePayment({
        callback: (response) => {
          handlePaymentSuccess(response, 'flutterwave');
          closePaymentModal(); 
        },
        onClose: () => handlePaymentClose('flutterwave'),
      });
    }
  }


  return (
    <Form {...form}>
      <form onSubmit={form.handleSubmit(onSubmit)} className="space-y-8">
        
        <FormField
          control={form.control}
          name="package"
          render={({ field }) => (
            <FormItem className="space-y-3">
              <FormLabel className="text-lg font-semibold">1. Select Coin Package</FormLabel>
              <FormControl>
                <RadioGroup
                  onValueChange={field.onChange}
                  defaultValue={field.value}
                  className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4"
                >
                  {coinPackages.map((pkg) => (
                    <FormItem key={pkg.id} className="flex-1">
                      <FormControl>
                        <RadioGroupItem value={pkg.id} id={pkg.id} className="sr-only" />
                      </FormControl>
                      <Label
                        htmlFor={pkg.id}
                        className={`flex flex-col items-center justify-between rounded-lg border-2 bg-card p-4 hover:bg-accent hover:text-accent-foreground cursor-pointer transition-all
                          ${field.value === pkg.id ? "border-primary ring-2 ring-primary shadow-lg" : "border-muted"}`}
                      >
                        <div className="flex items-center text-xl font-semibold mb-2">
                          <Coins className="mr-2 h-6 w-6 text-yellow-500" /> {pkg.coins} Coins
                        </div>
                        <p className="text-sm font-bold text-primary">{pkg.name}</p>
                        <p className="text-xs text-muted-foreground mt-1">{pkg.description}</p>
                        <p className="text-lg font-semibold mt-3 text-foreground">
                            {currencyRatesList.find(c => c.code === 'NGN')?.symbol}
                            {pkg.priceNGN.toLocaleString()}
                        </p>
                      </Label>
                    </FormItem>
                  ))}
                </RadioGroup>
              </FormControl>
              <FormMessage />
            </FormItem>
          )}
        />

        <FormField
          control={form.control}
          name="currency"
          render={({ field }) => (
            <FormItem>
              <FormLabel className="text-lg font-semibold">2. Select Currency</FormLabel>
              <Select onValueChange={field.onChange} defaultValue={field.value}>
                <FormControl>
                  <SelectTrigger className="w-full md:w-[280px]">
                    <SelectValue placeholder="Select currency" />
                  </SelectTrigger>
                </FormControl>
                <SelectContent>
                  {currencyRatesList.map((currency) => (
                    <SelectItem key={currency.code} value={currency.code}>
                      {currency.name} ({currency.symbol})
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
              <FormDescription>
                The price will be converted to your selected currency.
              </FormDescription>
              <FormMessage />
            </FormItem>
          )}
        />
        
        <Card className="bg-secondary/50 shadow-md">
            <CardHeader>
                <CardTitle className="text-xl">Order Summary</CardTitle>
            </CardHeader>
            <CardContent className="space-y-2">
                <p className="text-lg">
                    <span className="font-medium text-muted-foreground">Package:</span> {selectedPkg.name} ({selectedPkg.coins} Coins)
                </p>
                <p className="text-2xl font-bold text-primary">
                    <span className="font-medium text-muted-foreground">Total:</span> {selectedCurrInfo.symbol}
                    {priceInSelectedCurrency.toLocaleString(undefined, { minimumFractionDigits: 2, maximumFractionDigits: 2 })}
                     <span className="text-sm font-normal text-muted-foreground ml-1"> ({selectedCurrencyCode})</span>
                </p>
                {selectedCurrencyCode !== 'NGN' && (
                    <p className="text-sm text-muted-foreground">
                        (Approx. {currencyRatesList.find(c => c.code === 'NGN')?.symbol}
                        {selectedPkg.priceNGN.toLocaleString()} NGN)
                    </p>
                )}
            </CardContent>
        </Card>


        <FormField
          control={form.control}
          name="paymentGateway"
          render={({ field }) => (
            <FormItem className="space-y-3">
              <FormLabel className="text-lg font-semibold">3. Select Payment Gateway</FormLabel>
              <FormControl>
                <RadioGroup
                  onValueChange={field.onChange}
                  defaultValue={field.value}
                  className="flex flex-col sm:flex-row gap-4"
                >
                  <FormItem className="flex-1">
                    <FormControl>
                      <RadioGroupItem value="paystack" id="paystack" className="sr-only" />
                    </FormControl>
                    <Label htmlFor="paystack" className={`flex items-center justify-center rounded-lg border-2 p-4 hover:bg-accent hover:text-accent-foreground cursor-pointer ${field.value === "paystack" ? "border-primary ring-2 ring-primary" : "border-muted"}`}>
                      <img src="https://assets.paystack.com/assets/img/logos/paystack-logo-vector-deep-blue.svg" alt="Paystack" className="h-7" data-ai-hint="paystack logo"/>
                    </Label>
                  </FormItem>
                  <FormItem className="flex-1">
                    <FormControl>
                      <RadioGroupItem value="flutterwave" id="flutterwave" className="sr-only" />
                    </FormControl>
                    <Label htmlFor="flutterwave" className={`flex items-center justify-center rounded-lg border-2 p-4 hover:bg-accent hover:text-accent-foreground cursor-pointer ${field.value === "flutterwave" ? "border-primary ring-2 ring-primary" : "border-muted"}`}>
                       <img src="https://flutterwave.com/images/logo-colored.svg" alt="Flutterwave" className="h-7" data-ai-hint="flutterwave logo"/>
                    </Label>
                  </FormItem>
                </RadioGroup>
              </FormControl>
              <FormMessage />
            </FormItem>
          )}
        />


        <Button type="submit" size="lg" className="w-full text-base py-6" disabled={isLoading}>
          {isLoading ? (
            <Loader2 className="mr-2 h-5 w-5 animate-spin" />
          ) : (
            <ShoppingCart className="mr-2 h-5 w-5" />
          )}
          Proceed to Payment
        </Button>
        <p className="text-xs text-muted-foreground text-center flex items-center justify-center">
            <Lock className="h-3 w-3 mr-1.5"/> Secure payment processing by Paystack & Flutterwave.
        </p>
      </form>
    </Form>
  );
}