(function () {
  function qs(id) { return document.getElementById(id); }

  function humanSize(bytes) {
    if (!bytes && bytes !== 0) return '';
    var units = ['B', 'KB', 'MB', 'GB'];
    var i = 0;
    var n = bytes;
    while (n >= 1024 && i < units.length - 1) { n /= 1024; i++; }
    return (Math.round(n * 10) / 10) + ' ' + units[i];
  }

  function buildThumbLi(filename) {
    var imgUrl = 'img/' + encodeURIComponent(filename);
    var title = filename;
    return (
      "<li>" +
      "  <a class='thumb' name='leaf' href='" + imgUrl + "' title='" + title + "'>" +
      "    <img src='" + imgUrl + "' alt='" + title + "' width='75' height='75'/>" +
      "  </a>" +
      "  <div class='caption'></div>" +
      "</li>"
    );
  }

  function setStatus(text) {
    var el = qs('upload-status');
    if (el) el.textContent = text || '';
  }

  function init() {
    var dropzone = qs('dropzone');
    var fileInput = qs('file-input');
    var previewWrap = qs('upload-preview');
    var previewImg = qs('preview-img');
    var previewMeta = qs('preview-meta');
    var uploadBtn = qs('upload-btn');

    if (!dropzone || !fileInput || !uploadBtn) return;

    var selectedFile = null;

    function showPreview(file) {
      selectedFile = file;
      uploadBtn.disabled = !file;
      setStatus('');

      if (!file) {
        if (previewWrap) previewWrap.style.display = 'none';
        return;
      }

      if (previewWrap) previewWrap.style.display = 'block';
      if (previewMeta) previewMeta.textContent = file.name + ' · ' + humanSize(file.size);

      var reader = new FileReader();
      reader.onload = function (e) {
        if (previewImg) previewImg.src = e.target.result;
      };
      reader.readAsDataURL(file);
    }

    function isImageFile(file) {
      return file && file.type && file.type.indexOf('image/') === 0;
    }

    function onFiles(files) {
      if (!files || !files.length) return;
      var f = files[0];
      if (!isImageFile(f)) {
        setStatus('이미지 파일만 업로드 가능합니다.');
        return;
      }
      showPreview(f);
    }

    dropzone.addEventListener('dragover', function (e) {
      e.preventDefault();
      dropzone.classList.add('dragover');
    });
    dropzone.addEventListener('dragleave', function () {
      dropzone.classList.remove('dragover');
    });
    dropzone.addEventListener('drop', function (e) {
      e.preventDefault();
      dropzone.classList.remove('dragover');
      onFiles(e.dataTransfer.files);
    });

    fileInput.addEventListener('change', function () {
      onFiles(fileInput.files);
    });

    uploadBtn.addEventListener('click', function () {
      if (!selectedFile) return;
      uploadBtn.disabled = true;
      setStatus('업로드 중...');

      var fd = new FormData();
      fd.append('image', selectedFile);

      fetch('api/upload_image.php', {
        method: 'POST',
        body: fd,
        credentials: 'same-origin'
      })
        .then(function (r) { return r.json(); })
        .then(function (data) {
          if (!data || !data.ok) {
            throw new Error((data && data.error) ? data.error : '업로드 실패');
          }

          // Add immediately to current gallery
          var filename = data.filename;
          if (window.dreamgirlGallery && typeof window.dreamgirlGallery.appendImage === 'function') {
            window.dreamgirlGallery.appendImage(buildThumbLi(filename));
          } else {
            // fallback: append to DOM
            var ul = document.querySelector('#thumbs ul.thumbs');
            if (ul) ul.insertAdjacentHTML('beforeend', buildThumbLi(filename));
          }

          // keep in-memory list (doesn't persist; list_images.php handles persistence)
          if (window.DREAMGIRL_IMAGES && window.DREAMGIRL_IMAGES.push) {
            window.DREAMGIRL_IMAGES.push(filename);
          }

          setStatus('업로드 완료: ' + filename);
          // reset
          selectedFile = null;
          if (fileInput) fileInput.value = '';
          if (previewWrap) previewWrap.style.display = 'none';
        })
        .catch(function (err) {
          setStatus('에러: ' + (err && err.message ? err.message : '업로드 실패'));
        })
        .finally(function () {
          uploadBtn.disabled = false;
        });
    });
  }

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