export function getBottomNavHTML() {
    return `
    <nav id="app-bottom-nav" aria-label="Główna nawigacja">
        <div id="app-bottom-nav-dock" class="bottom-dock">
            <button type="button" id="recipe-nav-toggle" class="recipe-nav-toggle" aria-label="Otwórz menu" aria-expanded="false" aria-controls="app-bottom-nav-dock">
                <i id="recipe-nav-toggle-icon" class="fas fa-book-open" aria-hidden="true"></i>
            </button>
            <div class="nav-slot">
                <button type="button" data-tab="planner" id="nav-planner" class="nav-tab is-active" aria-label="Planer" aria-current="page">
                    <i class="far fa-calendar-alt" aria-hidden="true"></i>
                    <span class="nav-label">Planer</span>
                </button>
            </div>
            <div class="nav-slot">
                <button type="button" data-tab="recipes" id="nav-recipes" class="nav-tab" aria-label="Katalog">
                    <i class="fas fa-book-open" aria-hidden="true"></i>
                    <span class="nav-label">Katalog</span>
                </button>
            </div>
            <div class="nav-slot">
                <button type="button" data-tab="pantry" id="nav-pantry" class="nav-tab" aria-label="Spiżarnia">
                    <i class="fas fa-warehouse" aria-hidden="true"></i>
                    <span class="nav-label">Spiżarnia</span>
                </button>
            </div>
            <div class="nav-slot" style="position:relative;">
                <button type="button" data-tab="shopping" id="nav-shopping" class="nav-tab" aria-label="Zakupy">
                    <i class="fas fa-cart-shopping" aria-hidden="true"></i>
                    <span class="nav-label">Zakupy</span>
                </button>
            </div>
        </div>
    </nav>
    `;
}

export function setupBottomNav({ refreshPantry, refreshShoppingList } = {}) {
    const main = document.getElementById('main-view');
    const planner = document.getElementById('planner-view');
    const pantry = document.getElementById('pantry-view');
    const shopping = document.getElementById('shopping-view');
    const nav = document.getElementById('app-bottom-nav');
    if (!main || !planner || !pantry || !shopping || !nav) return;

    const TABS = ['recipes', 'planner', 'pantry', 'shopping'];
    const COLLAPSED_TABS = new Set();
    const EXTRA_CONTROL_SLOTS = { recipes: 2, pantry: 2, shopping: 1 };
    const DOUBLE_COMPACT_TABS = new Set(['recipes', 'pantry']);
    const COLLAPSED_TAB_ICON = { recipes: 'fa-book-open', pantry: 'fa-warehouse' };
    const COLLAPSED_TAB_LABEL = { recipes: 'Otwórz menu katalogu', pantry: 'Otwórz menu spiżarni' };
    let isRecipeMenuOpen = false;
    let activeTab = 'planner';
    let previousTab = 'planner';
    let collapseTimer = null;

    const syncRecipeNavMetrics = () => {
        const rootFontSize = parseFloat(window.getComputedStyle(document.documentElement).fontSize) || 16;
        const navStyles = window.getComputedStyle(nav);
        const navPadLeft = parseFloat(navStyles.paddingLeft) || 0;
        const navPadRight = parseFloat(navStyles.paddingRight) || 0;
        const navContentWidth = nav.clientWidth - navPadLeft - navPadRight;
        const isCompact = window.matchMedia('(max-width: 380px)').matches;
        const dockInset = (isCompact ? 1.6 : 2.4) * rootFontSize;
        const dockMax = (isCompact ? 22.5 : 24.5) * rootFontSize;
        const dockWidth = Math.min(navContentWidth - dockInset, dockMax);
        if (dockWidth <= 0) return;

        const padLeft = (isCompact ? 0.38 : 0.42) * rootFontSize;
        const padRight = (isCompact ? 0.38 : 0.42) * rootFontSize;
        const columnGap = (isCompact ? 0.05 : 0.06) * rootFontSize;
        const dockLeft = navPadLeft + ((navContentWidth - dockWidth) / 2);
        const controlSize = (isCompact ? 2.95 : 3.05) * rootFontSize;
        const expandedDockHeight = controlSize;
        const controlGap = 0.5 * rootFontSize;
        const controlsLift = Math.max(0, (expandedDockHeight - controlSize) / 2);
        const collapsedDockWidth = controlSize;
        const collapsedSlotWidth = Math.max(32, collapsedDockWidth - padLeft - padRight);
        const controlCluster = controlSize + controlGap;
        const compactExtraWidth = (EXTRA_CONTROL_SLOTS[activeTab] || 0) * controlCluster;
        const filterLeft = dockLeft + dockWidth - controlSize;
        const searchButtonLeft = filterLeft - controlGap - controlSize;
        const searchRight = Math.max(16, nav.clientWidth - filterLeft + controlGap);

        nav.style.setProperty('--recipe-dock-width', `${dockWidth}px`);
        nav.style.setProperty('--recipe-collapsed-dock-width', `${collapsedDockWidth}px`);
        nav.style.setProperty('--recipe-toggle-size', `${collapsedSlotWidth}px`);
        nav.style.setProperty('--nav-compact-extra-width', `${compactExtraWidth}px`);
        nav.style.setProperty('--nav-compact-translate-x', `${compactExtraWidth * -0.5}px`);
        document.documentElement.style.setProperty('--recipe-dock-width', `${dockWidth}px`);
        document.documentElement.style.setProperty('--catalog-menu-left', `${dockLeft}px`);
        document.documentElement.style.setProperty('--catalog-menu-width', `${collapsedDockWidth}px`);
        document.documentElement.style.setProperty('--catalog-filter-left', `${filterLeft}px`);
        document.documentElement.style.setProperty('--catalog-search-btn-left', `${searchButtonLeft}px`);
        document.documentElement.style.setProperty('--catalog-search-right', `${searchRight}px`);
        document.documentElement.style.setProperty('--recipe-control-size', `${controlSize}px`);
        document.documentElement.style.setProperty('--recipe-controls-lift', `${controlsLift}px`);
    };

    const updateToggleForTab = (tab) => {
        const icon = document.getElementById('recipe-nav-toggle-icon');
        const button = document.getElementById('recipe-nav-toggle');
        const nextIcon = COLLAPSED_TAB_ICON[tab];
        if (icon && nextIcon) {
            icon.className = `fas ${nextIcon}`;
        }
        if (button && COLLAPSED_TAB_LABEL[tab]) {
            button.setAttribute('aria-label', COLLAPSED_TAB_LABEL[tab]);
        }
    };

    const setRecipeMenuOpen = (open) => {
        syncRecipeNavMetrics();
        window.clearTimeout(collapseTimer);
        isRecipeMenuOpen = open;
        nav.classList.remove('is-nav-collapsing');
        nav.classList.toggle('is-nav-menu-open', open);
        document.documentElement.classList.toggle('is-nav-menu-open', open);
        document.getElementById('recipe-nav-toggle')?.setAttribute('aria-expanded', open ? 'true' : 'false');
    };

    const apply = (tab) => {
        const wasCollapsedTab = COLLAPSED_TABS.has(previousTab);
        const isCollapsedTab = COLLAPSED_TABS.has(tab);
        const isCompactTab = (EXTRA_CONTROL_SLOTS[tab] || 0) > 0;
        const isDoubleCompact = DOUBLE_COMPACT_TABS.has(tab);
        main.classList.toggle('hidden', tab !== 'recipes');
        planner.classList.toggle('hidden', tab !== 'planner');
        pantry.classList.toggle('hidden', tab !== 'pantry');
        shopping.classList.toggle('hidden', tab !== 'shopping');
        nav.classList.toggle('is-collapsed-tab', isCollapsedTab);
        nav.classList.toggle('is-compact-tab', isCompactTab);
        nav.classList.toggle('is-double-compact', isDoubleCompact);
        activeTab = tab;
        updateToggleForTab(tab);
        syncRecipeNavMetrics();
        setRecipeMenuOpen(false);

        if (isCollapsedTab && (!wasCollapsedTab || tab !== previousTab)) {
            nav.classList.add('is-nav-menu-open', 'is-nav-collapsing');
            document.documentElement.classList.add('is-nav-menu-open');
            document.getElementById('recipe-nav-toggle')?.setAttribute('aria-expanded', 'false');
            requestAnimationFrame(() => {
                requestAnimationFrame(() => {
                    requestAnimationFrame(() => {
                        nav.classList.remove('is-nav-menu-open');
                        document.documentElement.classList.remove('is-nav-menu-open');
                        collapseTimer = window.setTimeout(() => {
                            nav.classList.remove('is-nav-collapsing');
                        }, 500);
                    });
                });
            });
        }

        if (tab === 'pantry' && typeof refreshPantry === 'function') refreshPantry();
        if (tab === 'shopping' && typeof refreshShoppingList === 'function') refreshShoppingList();

        nav.querySelectorAll('.nav-tab[data-tab]').forEach((btn) => {
            const id = btn.getAttribute('data-tab');
            if (btn.hasAttribute('disabled')) return;
            if (TABS.includes(id)) {
                const isActive = id === tab;
                btn.classList.toggle('is-active', isActive);
                if (isActive) btn.setAttribute('aria-current', 'page');
                else btn.removeAttribute('aria-current');
            }
        });

        window.dispatchEvent(new CustomEvent('app-tab-change', { detail: { tab } }));
        previousTab = tab;
    };

    nav.addEventListener('click', (e) => {
        const toggle = e.target.closest('#recipe-nav-toggle');
        if (toggle) {
            e.stopPropagation();
            setRecipeMenuOpen(!isRecipeMenuOpen);
            window.closeRecipeSearch?.();
            window.closePantrySearch?.();
            window.closePantryFilter?.();
            window.closeShoppingCalendar?.();
            window.closeShoppingBoughtPopup?.();
            window.closeFilters?.();
            return;
        }

        const btn = e.target.closest('.nav-tab[data-tab]');
        if (!btn || btn.hasAttribute('disabled')) return;
        const tab = btn.getAttribute('data-tab');
        if (TABS.includes(tab)) apply(tab);
    });

    document.addEventListener('click', (e) => {
        if (!isRecipeMenuOpen || !nav.classList.contains('is-collapsed-tab')) return;
        if (e.composedPath().includes(nav)) return;
        setRecipeMenuOpen(false);
    });

    document.addEventListener('keydown', (e) => {
        if (e.key === 'Escape' && isRecipeMenuOpen) setRecipeMenuOpen(false);
    });

    window.addEventListener('resize', syncRecipeNavMetrics);

    apply('planner');

    window.switchAppTab = (tab) => {
        if (TABS.includes(tab)) apply(tab);
    };

    window.refreshStockViews = () => {
        if (typeof refreshPantry === 'function') refreshPantry();
    };
}