Untitled

const fileSelector = document.getElementById("fileInput");
fileSelector.addEventListener("change", (event) => {
  const fileList = event.target.files;
  danger.hidden = true;
  danger.innerHTML = "";
  showFiles(fileList);
});

let fileObject = {};
const danger = document.getElementById("danger");

function showFiles(fileList) {
  fileObject = {};
  const output = document.getElementById("output");
  let counter = 0;
  output.innerHTML = `
    <div class="spinner-border" role="status">
      <span class="visually-hidden">Loading...</span>
    </div>`;

  readFiles(fileList);
  console.log(fileObject);
  setTimeout(() => {
    output.innerHTML = `<tr>
    <th>№</th>
    <th>Номенклатура</th>
    <th>Количество</th>
    <th>Ед</th>
   </tr>`;
    for (const key in fileObject) {
      counter++;
      output.innerHTML += `<tr> 
        <td>${counter}</td>
        <td>${key}</td>
        <td>${fileObject[key]}</td>
        <td>шт</td>
      </tr>`;
    }
  }, 1000);
}

function readFiles(files) {
  for (const file of files) {
    languageEncoding(file).then((fileInfo) => {
      if (fileInfo.encoding !== "UTF-8") {
        danger.hidden = false;
        danger.innerHTML += file.name + " - have wrong encoding <br/>";
      }
    });
    const reader = new FileReader();
    reader.readAsText(file);

    reader.onload = function () {
      fileInsertToObject(reader.result);
    };

    reader.onerror = function () {
      console.log(reader.error);
    };
  }
}

function fileInsertToObject(file) {
  let formattedFile = file.split("\n");
  formattedFile.shift();

  for (const line of formattedFile) {
    const splitLine = line.split("\t");
    if (!splitLine[2]) continue;
    const amount = splitLine[2].replace(/,/gi, ".");

    if (fileObject.hasOwnProperty(splitLine[1])) {
      fileObject[splitLine[1]] += +amount;
    } else {
      fileObject[splitLine[1]] = +amount;
    }
  }
}