// This is split into comments so it doesn't look as gross with the closure tabs

window.onload = function () {
  document.getElementById('nojs').hidden = true;
  document.getElementById('block').hidden = false;
};

// File submit AJAX request
// After successful upload, actuate the file by calling actuate() on the successfully uploaded file
document.getElementById('upload').onsubmit = function () {
  // Reset error message and success message
  document.getElementById('upload-err').innerText = '';
  document.getElementById('actuate-err').innerText = '';
  document.getElementById('upload-response').innerText = '';
  document.getElementById('download-link').innerText = '';
  // Make AJAX request
  let xhr = new XMLHttpRequest();
  xhr.open('POST', '/api/v1/upload');
  let formData = new FormData(this);
  xhr.send(formData);
  xhr.onreadystatechange = function () {
    if (xhr.readyState === 4) {
      let response = JSON.parse(xhr.responseText);
      if (xhr.status === 201) {
        // Display upload success message to the user
        document.getElementById('upload-response').innerText = response.msg;
        actuate(response);
      } else {
        // Display upload error message to the user
        document.getElementById('upload-err').innerText = response.error;
        // DEBUG: Print full error if unknown error occurs
        if (xhr.status === 500) console.error(response.error_msg);
      }
    }
  };
  document.getElementById('upload').reset();
  return false;
};

// Actuate button AJAX request
// Should always be called after upload
// Implies that upload has been successful since it relies on the upload response
//
function actuate(file) {
  let xhr = new XMLHttpRequest();
  xhr.open('POST', '/api/v1/actuate');
  let data = {
    file: file.file,
  };
  xhr.setRequestHeader('Content-Type', 'application/json; charset=utf-8');
  xhr.setRequestHeader('X-CSRF-TOKEN', file.csrf);
  xhr.send(JSON.stringify(data));
  xhr.onreadystatechange = function () {
    if (xhr.readyState === 4) {
      let response = JSON.parse(xhr.responseText);
      if (xhr.status === 200 || xhr.status === 500) {
        createDownload(response.file);
      }
      if (xhr.status === 500) {
        document.getElementById('actuate-err').innerText = response.error;
        // DEBUG: Print full error if unknown error occurs
        console.error(response.error_msg);
      }
    }
    return;
  };
}

// Creates the download element
function createDownload(response) {
  if (!response) return;
  const tempName = response.filename;
  const downloadName = response.name.split('.')[0];
  const downloadLink = document.createElement('a');
  downloadLink.setAttribute('href', `/api/v1/download/?filename=${tempName}`);
  downloadLink.setAttribute('download', `${downloadName}.csv`);
  downloadLink.innerText = 'Download CSV of results here.';
  document.getElementById('download-link').appendChild(downloadLink);
  return;
}