function normalized(text) {
    return String(text || "").trim().toLowerCase();
}

function origin(text) {
    const match = String(text || "").match(/^https?:\/\/[^/]+/i);
    return match ? match[0].toLowerCase() : "";
}

function filterItems(items, query, browserOrigin) {
    const needle = normalized(query);
    const observed = origin(browserOrigin);
    return (items || []).filter(item => {
        return needle.length === 0 || String(item.searchText || "").includes(needle);
    }).map((item, index) => {
        const exactOrigin = observed.length > 0 && (item.origins || []).some(candidate => {
            return origin(candidate) === observed;
        });
        return {
            "item": item,
            "index": index,
            "originRank": needle.length === 0 && exactOrigin ? 0 : 1,
            "favoriteRank": item.favorite ? 0 : 1
        };
    }).sort((a, b) => {
        return (a.originRank - b.originRank) || (a.favoriteRank - b.favoriteRank) || a.item.title.localeCompare(b.item.title) || (a.index - b.index);
    }).map(entry => {
        return entry.item;
    });
}

function groups(items) {
    const favorites = [];
    const all = [];
    for (let i = 0; i < (items || []).length; i++) {
        if (items[i].favorite)
            favorites.push(items[i]);
        else
            all.push(items[i]);
    }
    return [{
        "label": "favorites",
        "items": favorites
    }, {
        "label": "all items",
        "items": all
    }].filter(group => {
        return group.items.length > 0;
    });
}

function nextSelection(items, selectedId, delta) {
    if (!items || items.length === 0)
        return "";
    let index = items.findIndex(item => {
        return item.id === selectedId;
    });
    if (index < 0)
        index = delta > 0 ? -1 : 0;
    return items[(index + delta + items.length) % items.length].id;
}

if (typeof module !== "undefined")
    module.exports = { normalized, origin, filterItems, groups, nextSelection };