import NotificationBell from './NotificationBell';
import ThemeToggle from './ui/ThemeToggle';
import AuthWidget from './AuthWidget';
import UserDisplay from './ui/UserDisplay';
import { useEffect, useRef, useState } from 'preact/hooks';
import { useSpring, animated } from '@react-spring/web';
import { hydrateAuthFromStorage } from '../stores/authStore';

const ITEMS = [
    { id: 'dashboard',       label: 'Dashboard',        href: '/' },
    { id: 'work-orders',     label: 'Putni nalozi',     href: '/putni-nalozi' },
    { id: 'service-records', label: 'Servisni zapisi',  href: '/servisni-zapisi' },
    { id: 'vehicles',        label: 'Vozila',           href: '/vehicles' },
    { id: 'clients',         label: 'Klijenti',         href: '/clients' },
];

function normalizePath(p) {
    const value = String(p || '/');
    if (value.length > 1 && value.endsWith('/')) return value.slice(0, -1);
    return value;
}

function getActiveIndex(path) {
    const idx = ITEMS.findIndex((item) => item.href === path);
    return idx >= 0 ? idx : 0;
}

export default function Navbar({ minimal = false }) {
    // Navbar ostaje montiran (transition:persist) — pratimo promjene pathname preko astro:page-load
    const [pathname, setPathname] = useState(() =>
        typeof window !== 'undefined' ? normalizePath(window.location.pathname) : '/'
    );

    const itemRefs = useRef([]);
    const [indicatorStyle, setIndicatorStyle] = useState({ left: 0, width: 0 });
    // Na prvom renderu preskočimo animaciju (pill se pojavljuje na ispravnoj poziciji bez slide-a od 0)
    const [skipAnimation, setSkipAnimation] = useState(true);

    const activeIndex = getActiveIndex(pathname);

    const measureIndicator = (currentIndex) => {
        const idx = currentIndex ?? activeIndex;
        const el = itemRefs.current[idx];
        if (!el) return;
        const parent = el.closest('ul');
        if (!parent) return;
        const parentRect = parent.getBoundingClientRect();
        const elRect = el.getBoundingClientRect();
        setIndicatorStyle({
            left: elRect.left - parentRect.left,
            width: elRect.width,
        });
    };

    // Mount: izmjeri početnu poziciju bez animacije, pa uključi animaciju za buduće navigacije
    useEffect(() => {
        hydrateAuthFromStorage();

        const timer = setTimeout(() => {
            measureIndicator();
            setSkipAnimation(false);
        }, 30);

        // Sluša Astro view-transition navigaciju (Navbar ostaje montiran zahvaljujući transition:persist)
        const handlePageLoad = () => {
            setPathname(normalizePath(window.location.pathname));
        };
        document.addEventListener('astro:page-load', handlePageLoad);

        return () => {
            clearTimeout(timer);
            document.removeEventListener('astro:page-load', handlePageLoad);
        };
    }, []);

    // Kad se promijeni activeIndex (nova stranica), animiraj pill na novu poziciju
    useEffect(() => {
        if (!skipAnimation) {
            measureIndicator();
        }
    }, [activeIndex]);

    // react-spring: animirani klizač
    // immediate=true na prvom renderu → pill se ne animira od lijevog ruba, već skače na pravo mjesto
    const springStyle = useSpring({
        left: indicatorStyle.left,
        width: indicatorStyle.width,
        immediate: skipAnimation,
        config: { tension: 340, friction: 28 },
    });

    const currentItem = ITEMS[activeIndex];

    return (
        <nav className="sticky top-0 z-30 mb-4 rounded-lg border border-border-hairline bg-canvas-elevated/95 px-4 py-3 backdrop-blur overflow-visible">
            <div className="flex flex-wrap items-center justify-between gap-2">
                {/* Logo + korisnik */}
                <a href="/" className="flex flex-col hover:opacity-80">
                    <span className="text-base font-bold tracking-tight text-text-main">ERP</span>
                    {!minimal && <UserDisplay field="ime_prezime" className="text-xs text-text-muted" />}
                </a>

                {/* Navigacijski linkovi s react-spring klizačem */}
                <ul className="relative hidden items-center gap-1 text-sm sm:flex">
                    {/* Animirani pozadinski klizač */}
                    <animated.li
                        aria-hidden="true"
                        style={{
                            position: 'absolute',
                            top: 0,
                            bottom: 0,
                            borderRadius: '0.5rem',
                            backgroundColor: 'rgb(238 242 255)',
                            pointerEvents: 'none',
                            ...springStyle,
                        }}
                    />
                    {ITEMS.map((item, idx) => (
                        <li key={item.id} ref={(el) => (itemRefs.current[idx] = el)}>
                            <a
                                href={item.href}
                                className={
                                    pathname === item.href
                                        ? 'relative z-10 block rounded-lg px-3 py-2 font-medium text-indigo-700'
                                        : 'relative z-10 block rounded-lg px-3 py-2 text-text-main hover:text-indigo-600'
                                }
                            >
                                {item.label}
                            </a>
                        </li>
                    ))}
                </ul>

                {/* Desna strana */}
                <div className="flex items-center gap-2">
                    {/* Mobilni dropdown */}
                    <details className="relative sm:hidden">
                        <summary className="list-none cursor-pointer rounded-lg border border-border-hairline bg-canvas-base px-3 py-1.5 text-xs font-medium text-text-main hover:bg-canvas-deep select-none">
                            ☰ {currentItem?.label || 'Izbornik'}
                        </summary>
                        {/* Dropdown je positioniran fixed-like kroz visoki z-index kako ne bi bio odsječen */}
                        <div className="absolute left-0 top-full mt-1 z-50 min-w-52 rounded-lg border border-border-hairline bg-canvas-elevated shadow-xl">
                            <div className="border-b border-border-hairline px-3 py-2 text-[11px] uppercase tracking-wide text-text-muted">
                                Navigacija
                            </div>
                            <ul className="py-1">
                                {ITEMS.map((item) => (
                                    <li key={`mobile-${item.id}`}>
                                        <a
                                            href={item.href}
                                            className={
                                                pathname === item.href
                                                    ? 'flex items-center gap-2 bg-indigo-50 px-3 py-2.5 text-sm font-medium text-indigo-700'
                                                    : 'flex items-center gap-2 px-3 py-2.5 text-sm text-text-main hover:bg-canvas-deep'
                                            }
                                        >
                                            {pathname === item.href && <span className="h-1.5 w-1.5 rounded-full bg-indigo-500" />}
                                            {item.label}
                                        </a>
                                    </li>
                                ))}
                            </ul>
                        </div>
                    </details>
                    <ThemeToggle />
                    <NotificationBell />
                    <AuthWidget />
                </div>
            </div>
        </nav>
    );
}