// Imported from investidor; return destinations are restricted to this platform.
import React, { useEffect, useState } from 'react';
import { router } from '@inertiajs/react';
import { ArrowLeft } from 'lucide-react';
import { Trans } from './source-text'; // Import Trans component

interface BackButtonProps {
    to?: string;
    label?: React.ReactNode; // Change type to React.ReactNode to accept <Trans> component
    className?: string;
    theme?: 'light' | 'dark';
    onClick?: () => void;
}

const RETURN_URL_KEY = 'news:return-url';

function normalizeInternalUrl(value: string | null): string | null {
    if (!value || typeof window === 'undefined') {
        return null;
    }

    try {
        const url = value.startsWith('http')
            ? new URL(value)
            : new URL(value, window.location.origin);

        if (url.origin !== window.location.origin) {
            return null;
        }

        const normalized = `${url.pathname}${url.search}${url.hash}`;
        const current = `${window.location.pathname}${window.location.search}${window.location.hash}`;

        return normalized !== current ? normalized : null;
    } catch {
        return null;
    }
}

function getStoredReturnUrl(): string | null {
    try {
        return normalizeInternalUrl(sessionStorage.getItem(RETURN_URL_KEY));
    } catch {
        return null;
    }
}

function getReturnUrlFromPage(): string | null {
    if (typeof window === 'undefined') {
        return null;
    }

    const params = new URLSearchParams(window.location.search);
    const fromParam = normalizeInternalUrl(params.get('from'));

    if (fromParam) {
        return fromParam;
    }

    return null;
}

function getInternalReferrerUrl(): string | null {
    if (typeof document === 'undefined') {
        return null;
    }

    return normalizeInternalUrl(document.referrer);
}

export const BackButton: React.FC<BackButtonProps> = ({
    to,
    label = <Trans>Voltar</Trans>, // Use Trans component for default label
    className = '',
    theme = 'light',
    onClick,
}) => {
    const [showFloatingButton, setShowFloatingButton] = useState(false);

    useEffect(() => {
        const handleScroll = () => {
            setShowFloatingButton(window.scrollY > 220);
        };

        handleScroll();
        window.addEventListener('scroll', handleScroll, { passive: true });

        return () => window.removeEventListener('scroll', handleScroll);
    }, []);

    const themeClasses =
        theme === 'dark'
            ? 'border-white/20 bg-white/10 text-white shadow-lg backdrop-blur-md hover:bg-white/20'
            : 'border-red-100 bg-white text-[#ED1C24] shadow-sm hover:border-red-200 hover:bg-red-50';

    const baseClasses =
        'inline-flex items-center gap-2 rounded-full border px-4 py-2 text-sm font-semibold transition-all duration-200 focus:outline-none focus:ring-2 focus:ring-[#ED1C24]/25 active:scale-[0.98]';

    const floatingClasses = [
        'fixed bottom-5 left-4 z-50 max-w-[calc(100vw-2rem)] sm:bottom-6 sm:left-6',
        'border-red-100 bg-white text-[#ED1C24] shadow-xl ring-1 ring-black/5 hover:border-red-200 hover:bg-red-50',
        showFloatingButton
            ? 'pointer-events-auto translate-y-0 opacity-100'
            : 'pointer-events-none translate-y-3 opacity-0',
    ].join(' ');

    const renderContent = () => (
        <>
            <ArrowLeft size={16} aria-hidden="true" />
            <span className="truncate">{label}</span>
        </>
    );

    const handleClick = () => {
        if (onClick) {
            onClick();
            return;
        }

        const explicitReturnUrl = getReturnUrlFromPage();
        const storedReturnUrl = getStoredReturnUrl();

        if (explicitReturnUrl) {
            router.visit(explicitReturnUrl);
        } else if (storedReturnUrl) {
            router.visit(storedReturnUrl);
        } else {
            router.visit(getInternalReferrerUrl() || to || '/');
        }
    };

    return (
        <>
            <button
                type="button"
                onClick={handleClick}
                className={`${baseClasses} ${themeClasses} ${className}`}
                aria-label={typeof label === 'string' ? label : undefined} // aria-label should be a string
            >
                {renderContent()}
            </button>
            <button
                type="button"
                onClick={handleClick}
                className={`${baseClasses} ${floatingClasses}`}
                aria-label={typeof label === 'string' ? label : undefined} // aria-label should be a string
                aria-hidden={!showFloatingButton}
                tabIndex={showFloatingButton ? undefined : -1}
            >
                {renderContent()}
            </button>
        </>
    );
};

export default BackButton;