(function () {
    'use strict';

    var feed = document.getElementById('feed');
    if (!feed) {
        return;
    }

    var loadMoreBtn = document.getElementById('load-more');
    var emptyState = document.getElementById('feed-empty');
    var spinner = loadMoreBtn ? loadMoreBtn.querySelector('.spinner-border') : null;

    var apiUrl = feed.dataset.api;
    var source = feed.dataset.source || '';
    var range = feed.dataset.range || '';

    var currentPage = parseInt(feed.dataset.page, 10) || 1;
    var hasMore = feed.dataset.hasMore === '1';
    var loading = false;

    function timeAgo(iso) {
        var ts = Date.parse(iso);
        if (isNaN(ts)) {
            return '';
        }
        var diff = Math.floor((Date.now() - ts) / 1000);
        if (diff < 60) {
            return 'just now';
        }
        var units = [
            [31536000, 'y'], [2592000, 'mo'], [604800, 'w'],
            [86400, 'd'], [3600, 'h'], [60, 'm']
        ];
        for (var i = 0; i < units.length; i++) {
            if (diff >= units[i][0]) {
                return Math.floor(diff / units[i][0]) + units[i][1] + ' ago';
            }
        }
        return 'just now';
    }

    function refreshTimes() {
        document.querySelectorAll('time[data-timestamp]').forEach(function (el) {
            var text = timeAgo(el.dataset.timestamp);
            if (text) {
                el.textContent = text;
            }
        });
    }

    function setLoading(isLoading) {
        if (!loadMoreBtn) {
            return;
        }
        loadMoreBtn.disabled = isLoading;
        if (spinner) {
            spinner.classList.toggle('d-none', !isLoading);
        }
    }

    function updateButton() {
        if (!loadMoreBtn) {
            return;
        }
        loadMoreBtn.classList.toggle('d-none', !hasMore);
    }

    function loadMore() {
        if (loading || !hasMore) {
            return;
        }
        loading = true;
        setLoading(true);

        var params = new URLSearchParams({ page: String(currentPage + 1) });
        if (source) {
            params.set('source', source);
        }
        if (range) {
            params.set('range', range);
        }

        fetch(apiUrl + '?' + params.toString(), {
            headers: { 'Accept': 'application/json' }
        })
            .then(function (response) {
                if (!response.ok) {
                    throw new Error('HTTP ' + response.status);
                }
                return response.json();
            })
            .then(function (data) {
                if (data.html) {
                    feed.insertAdjacentHTML('beforeend', data.html);
                }

                currentPage = data.page;
                hasMore = Boolean(data.has_more);
                feed.dataset.page = String(currentPage);
                feed.dataset.hasMore = hasMore ? '1' : '0';

                if (emptyState) {
                    emptyState.classList.toggle('d-none', data.total > 0);
                }

                refreshTimes();
                updateButton();
            })
            .catch(function (error) {
                console.error('Failed to load more items:', error);
            })
            .finally(function () {
                loading = false;
                setLoading(false);
            });
    }

    if (loadMoreBtn) {
        loadMoreBtn.addEventListener('click', loadMore);
    }

    refreshTimes();
    window.setInterval(refreshTimes, 60000);
})();