(function () {
  function wireDropzone(options) {
    var zone = document.getElementById(options.zoneId);
    var input = document.getElementById(options.inputId);
    var info = document.getElementById(options.infoId);
    var label = document.getElementById(options.labelId);
    var clearButton = document.querySelector(options.clearSel);
    var submit = document.getElementById(options.submitId);
    var form = document.getElementById(options.formId);
    var overlay = document.getElementById(options.overlayId);

    if (!zone || !input || !info || !label || !submit) {
      return;
    }

    function showFiles(files) {
      var validFiles = [];
      for (var i = 0; i < files.length; i++) {
        var name = files[i].name.toLowerCase();
        if (name.endsWith('.dcm') || name.endsWith('.zip')) {
          validFiles.push(files[i]);
        }
      }

      if (!validFiles.length) {
        return;
      }

      if (options.multi) {
        var totalSizeMB = 0;
        for (var j = 0; j < validFiles.length; j++) {
          totalSizeMB += validFiles[j].size / (1024 * 1024);
        }
        label.textContent = validFiles.length + ' file' + (validFiles.length > 1 ? 's' : '') + ' (' + totalSizeMB.toFixed(1) + ' MB)';
      } else {
        label.textContent = validFiles[0].name;
      }

      info.style.display = 'flex';
      zone.style.display = 'none';
      submit.disabled = false;
    }

    function reset() {
      input.value = '';
      info.style.display = 'none';
      zone.style.display = 'flex';
      submit.disabled = true;
    }

    zone.addEventListener('click', function () {
      input.click();
    });

    zone.addEventListener('dragover', function (event) {
      event.preventDefault();
      zone.classList.add('dragover');
    });

    zone.addEventListener('dragleave', function () {
      zone.classList.remove('dragover');
    });

    zone.addEventListener('drop', function (event) {
      event.preventDefault();
      zone.classList.remove('dragover');
      if (event.dataTransfer.files.length) {
        input.files = event.dataTransfer.files;
        showFiles(event.dataTransfer.files);
      }
    });

    input.addEventListener('change', function () {
      if (input.files.length) {
        showFiles(input.files);
      }
    });

    if (clearButton) {
      clearButton.addEventListener('click', reset);
    }

    if (form && overlay) {
      form.addEventListener('submit', function () {
        overlay.style.display = 'flex';
        submit.disabled = true;
      });
    }
  }

  function initUploadPage() {
    var tabs = document.querySelectorAll('.upload-tab');
    var panels = document.querySelectorAll('.tab-panel');

    if (!tabs.length || !panels.length) {
      return;
    }

    tabs.forEach(function (tab) {
      tab.addEventListener('click', function () {
        tabs.forEach(function (item) {
          item.classList.remove('active');
        });
        panels.forEach(function (panel) {
          panel.classList.remove('active');
        });

        tab.classList.add('active');
        var target = document.getElementById('tab-' + tab.dataset.tab);
        if (target) {
          target.classList.add('active');
        }
      });
    });

    wireDropzone({
      zoneId: 'dropzoneSingle',
      inputId: 'singleInput',
      infoId: 'singleInfo',
      labelId: 'singleFileName',
      clearSel: '.js-clear-single',
      submitId: 'singleSubmit',
      formId: 'singleForm',
      overlayId: 'singleOverlay',
      multi: false
    });

    wireDropzone({
      zoneId: 'dropzoneMulti',
      inputId: 'multiInput',
      infoId: 'multiInfo',
      labelId: 'multiFileName',
      clearSel: '.js-clear-multi',
      submitId: 'multiSubmit',
      formId: 'multiForm',
      overlayId: 'multiOverlay',
      multi: true
    });

    var dirInput = document.getElementById('dirPath');
    var dirSubmit = document.getElementById('dirSubmit');

    if (dirInput && dirSubmit) {
      function checkDir() {
        dirSubmit.disabled = !dirInput.value.trim();
      }

      dirInput.addEventListener('input', checkDir);
      checkDir();
    }
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', initUploadPage);
  } else {
    initUploadPage();
  }
})();