import { callback as paymentCallback } from '@/routes/wallet/payment';
import type { PaystackInit } from '@/types/wallet';

type PaystackCallbackResponse = {
    reference: string;
};

type PaystackHandler = {
    openIframe: () => void;
};

declare global {
    interface Window {
        PaystackPop?: {
            setup: (config: {
                key: string;
                email: string;
                amount: number;
                ref: string;
                onClose: () => void;
                callback: (response: PaystackCallbackResponse) => void;
            }) => PaystackHandler;
        };
    }
}

let scriptPromise: Promise<void> | null = null;

function loadPaystackScript(): Promise<void> {
    if (typeof window === 'undefined') {
        return Promise.resolve();
    }

    if (window.PaystackPop) {
        return Promise.resolve();
    }

    if (scriptPromise) {
        return scriptPromise;
    }

    scriptPromise = new Promise((resolve, reject) => {
        const script = document.createElement('script');
        script.src = 'https://js.paystack.co/v1/inline.js';
        script.async = true;
        script.onload = () => resolve();
        script.onerror = () => reject(new Error('Failed to load Paystack.'));
        document.body.appendChild(script);
    });

    return scriptPromise;
}

export function usePaystackInline(): {
    openPayment: (init: PaystackInit) => Promise<void>;
} {
    async function openPayment(init: PaystackInit): Promise<void> {
        await loadPaystackScript();

        if (!window.PaystackPop) {
            throw new Error('Paystack is unavailable.');
        }

        const callbackUrl = paymentCallback.url();

        const handler = window.PaystackPop.setup({
            key: init.public_key,
            email: init.email,
            amount: init.amount_kobo,
            ref: init.reference,
            onClose: () => {},
            callback: (response) => {
                const url = new URL(callbackUrl, window.location.origin);
                url.searchParams.set('reference', response.reference);
                window.location.href = url.toString();
            },
        });

        handler.openIframe();
    }

    return { openPayment };
}