let text = "";
let keyword = "";

const button = document.getElementById('analyse');

function wordFrequency(texte, keyword) {

    const occurrencies = [];

    const words = text.trim().split(/[^a-zA-Z]/);

    words.forEach(word => {
        if (word === keyword) {
            occurrencies.push(word);
        }
    });

    return occurrencies.length;
}

function infosHTML(htmlText) {

    const infos = {};

    const parser = new DOMParser();

    const newDoc = parser.parseFromString(htmlText, "text/html");

    infos.title = newDoc.getElementsByTagName("title")[0].textContent;
    infos.description = newDoc.querySelector("meta[name='description']").content;

    return infos;
}

button.addEventListener('click', (e) => {
    e.preventDefault();
    text = document.getElementById('zone-html').value;
    keyword = document.getElementById('keyword').value;

    const pageTitle = document.getElementById('page-title');
    const pageDescription = document.getElementById('page-meta-description');

    pageTitle.style.fontWeight = "normal";
    pageTitle.innerText = infosHTML(text).title;

    pageDescription.style.fontWeight = "normal";
    pageDescription.innerText = infosHTML(text).description;

    const keywordNumber = document.getElementById('keyword-number');
    keywordNumber.innerText = `Nombre d'occurrences de "${keyword}" : ${wordFrequency(text, keyword)}`;
});