(() => {

/**

* Check and set a global guard variable.

* If this content script is injected into the same page again,

* it will do nothing next time.

*/

if (window.hasRun) {

return;

}

window.hasRun = true;

function createTooltip () {

let tip = document.getElementById("tooltip")

if (!tip) {

tip = document.createElement('div');

tip.id = 'tooltip';

document.body.append(tip);

}

tip.style.display = "none";

return tip;

}

const tip = createTooltip();

function handler (event, { schema }) {

const columns = schema.map(column => `<div><span class="name">${column.column_name}</span> <span class="type">(${column.type})</span></div>`)

const rect = tip.getBoundingClientRect();

const rectWidth = rect.width + 16;

const vWidth = window.innerWidth - rectWidth;

const rectX = event.clientX + rectWidth;

const minX = rectX;

const maxX = window.innerWidth;

const x = rectX < minX ? rectWidth : rectX > maxX ? vWidth : event.clientX;

tip.style.display = "block";

tip.style.left = `${x}px`;

tip.style.top = `${event.clientY}px`;

tip.innerHTML = columns.join("");

}

const links = document.getElementsByClassName('object-link');

for (let item of links) {

const filename = item.textContent.trim();

if (filename.endsWith('.parquet')) {

item.addEventListener('mouseover', (event) => {

const sending = browser.runtime.sendMessage({ filename });

sending.then((d) => handler(event, d));

});

item.addEventListener('mouseout', (event) => {

tip.style.display = "none";

})

}

}

})();