function normalizeSearch(value) {
    return String(value || '')
        .normalize('NFKD').replace(/[\u0300-\u036f]/g, '')
        .toLowerCase()
        .replace(/([a-z])([0-9])/g, '$1 $2')
        .replace(/([0-9])([a-z])/g, '$1 $2')
        .replace(/[^a-z0-9]+/g, ' ').trim()
        .split(/\s+/).filter(Boolean)
        .map(token => token.length > 3 && token.endsWith('s') ? token.slice(0, -1) : token);
}

function matchesSearch(channel, query) {
    const wanted = normalizeSearch(query);
    if (!wanted.length) return true;
    const corpus = normalizeSearch([
        channel.displayName, channel.standardName, channel.fingerprint,
        ...(channel.variants || []).flatMap(variant => [variant.name, variant.tvgId, variant.categoryName])
    ].filter(Boolean).join(' '));
    return wanted.every(token => corpus.some(candidate => {
        if (/^\d+$/.test(token)) return /^\d+$/.test(candidate) && Number(candidate) === Number(token);
        return candidate.includes(token);
    }));
}

module.exports = { matchesSearch, normalizeSearch };