console.log("paginator.js wurde erfolgreich geladen!");
(function () {
    'use strict';

    const state = {
        items: [],
        sorted: [],
        category: 'all',
        sort: 'alphabet',
        limit: 10,
        page: 1,
    };

    function loadData() {
        const el = document.getElementById('s-res-data');
        if (!el) return [];
        try {
            return JSON.parse(el.textContent);
        } catch (e) {
            console.error('Suchergebnis-Daten konnten nicht gelesen werden', e);
            return [];
        }
    }

    function applyFilterAndSort() {
        let list = state.items.slice();

        if (state.category && state.category !== 'all') {
            list = list.filter(item => (item.category || '') === state.category);
        }

        switch (state.sort) {
            case 'likes':
                list.sort((a, b) => (b.likes || 0) - (a.likes || 0));
                break;
            case 'newest':
                list.sort((a, b) => (b.creationDate || '').localeCompare(a.creationDate || ''));
                break;
            case 'oldest':
                list.sort((a, b) => (a.creationDate || '').localeCompare(b.creationDate || ''));
                break;
            default:
                list.sort((a, b) => (a.title || '').localeCompare(b.title || '', 'de', { sensitivity: 'base' }));
        }

        state.sorted = list;
        const totalPages = Math.max(1, Math.ceil(state.sorted.length / state.limit));
        state.page = Math.min(Math.max(state.page, 1), totalPages);
    }

    function el(tag, className, text) {
        const e = document.createElement(tag);
        if (className) e.className = className;
        if (text !== undefined) e.textContent = text;
        return e;
    }

    function renderList() {
        const container = document.querySelector('.s-res-list');
        if (!container) return;

        const start = (state.page - 1) * state.limit;
        const pageItems = state.sorted.slice(start, start + state.limit);

        container.innerHTML = '';

        if (pageItems.length === 0) {
            container.appendChild(el('p', null, 'Keine Beiträge zu diesem Suchbegriff gefunden.'));
            return;
        }

        pageItems.forEach(item => {
            const item_el = el('div', 's-res-item');
            item_el.dataset.likes = item.likes;
            item_el.dataset.category = item.category;

            const link = el('a', 's-res-link', item.title);
            link.href = 'index.php?pfad=showArticle&id=' + encodeURIComponent(item.id);

            const title = el('h2', 's-res-item-title');
            title.appendChild(link);

            const authorName = el('span', 's-res-author-name', item.author);
            const author = el('p', 's-res-author', 'Von: ');
            author.appendChild(authorName);

            const likes = el('span', 's-res-likes', '❤️ ' + item.likes);

            const metaRow = el('div', 's-res-meta-row');
            metaRow.appendChild(author);
            metaRow.appendChild(likes);

            const content = el('div', 's-res-content');
            content.appendChild(title);
            content.appendChild(metaRow);

            item_el.appendChild(content);
            item_el.appendChild(el('div', 's-res-arrow', '→'));

            container.appendChild(item_el);
        });
    }

    function renderMeta() {
        const metaEl = document.querySelector('.s-res-meta');
        const queryInput = document.getElementById('site-search');
        if (metaEl) {
            const q = queryInput ? queryInput.value : '';
            metaEl.textContent = state.sorted.length + ' Treffer für Ihre Suchanfrage "' + q + '"';
        }
    }

    function renderPagination() {
        const nav = document.querySelector('.s-res-page-navigation');
        if (!nav) return;

        const totalPages = Math.max(1, Math.ceil(state.sorted.length / state.limit));
        nav.innerHTML = '';

        const makeBtn = (label, page, disabled, active) => {
            const btn = el('button', 's-res-page-btn' + (active ? ' is-active' : ''), label);
            btn.type = 'button';
            btn.disabled = !!disabled;
            btn.addEventListener('click', () => goToPage(page));
            return btn;
        };

        nav.appendChild(makeBtn('«', state.page - 1, state.page <= 1));

        const windowSize = 2;
        for (let p = 1; p <= totalPages; p++) {
            const edge = p === 1 || p === totalPages;
            const near = Math.abs(p - state.page) <= windowSize;
            if (!edge && !near) {
                if (p === 2 || p === totalPages - 1) nav.appendChild(el('span', 's-res-page-dots', '…'));
                continue;
            }
            nav.appendChild(makeBtn(String(p), p, false, p === state.page));
        }

        nav.appendChild(makeBtn('»', state.page + 1, state.page >= totalPages));
    }

    function updateUrl() {
        const url = new URL(window.location.href);
        url.searchParams.set('sort', state.sort);
        url.searchParams.set('category', state.category);
        url.searchParams.set('limit', state.limit);
        url.searchParams.set('page', state.page);
        window.history.replaceState(null, '', url);
    }

    function rerender() {
        applyFilterAndSort();
        renderList();
        renderMeta();
        renderPagination();
        updateUrl();
    }

    function goToPage(page) {
        const totalPages = Math.max(1, Math.ceil(state.sorted.length / state.limit));
        state.page = Math.min(Math.max(page, 1), totalPages);
        renderList();
        renderPagination();
        updateUrl();
    }

    function initPaginator() {
        console.log("initPaginator gestartet");
        state.items = loadData();
        console.log("Geladene Items:", state.items);

        const checkedSort = document.querySelector('.sort-radio:checked');
        console.log("checkedSort:", checkedSort);
        state.sort = checkedSort ? checkedSort.value : 'alphabet';

        const categorySelect = document.getElementById('category-filter');
        console.log("categorySelect:", categorySelect);
        state.category = categorySelect ? categorySelect.value.toLowerCase() : 'all';

        const limitSelect = document.getElementById('s-res-per-page');
        console.log("limitSelect:", limitSelect);
        state.limit = limitSelect ? parseInt(limitSelect.value, 10) || 10 : 10;

        const params = new URLSearchParams(window.location.search);
        state.page = parseInt(params.get('page') || '1', 10) || 1;

        document.querySelectorAll('.sort-radio').forEach(radio => {
            radio.addEventListener('change', function () {
                state.sort = this.value;
                state.page = 1;
                rerender();
            });
        });

        if (categorySelect) {
            categorySelect.addEventListener('change', function () {
                state.category = this.value.toLowerCase();
                state.page = 1;
                rerender();
            });
        }

        if (limitSelect) {
            limitSelect.addEventListener('change', function () {
                state.limit = parseInt(this.value, 10) || 10;
                state.page = 1;
                rerender();
            });
        }

        // "Filter anwenden"-Button wird bei aktivem JS nicht gebraucht
        const applyBtn = document.querySelector('.s-res-apply-btn');
        if (applyBtn) applyBtn.style.display = 'none';

        // Server-gerenderte Pagination-Links durch clientseitige Steuerung ersetzen
        document.querySelectorAll('.s-res-page-navigation .s-res-page-btn').forEach(link => {
            link.addEventListener('click', function (evt) {
                evt.preventDefault();
                const target = parseInt(this.getAttribute('data-page'), 10);
                if (!isNaN(target)) goToPage(target);
            });
        });

        rerender();
        console.log("initPaginator abgeschlossen, State:", state);
    }

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', initPaginator);
    } else {
        initPaginator();
    }
})();