// Anhänge: Dateiauswahl, Einfügen aus Zwischenablage (Strg+V) und Drag & Drop.
(function () {
  function initAttach(form) {
    var input = form.querySelector(".attach-input");
    var list = form.querySelector(".attach-list");
    if (!input) return;
    var dt = new DataTransfer();
    var pasteCount = 0;

    function refresh() {
      input.files = dt.files;
      list.innerHTML = "";
      Array.prototype.forEach.call(dt.files, function (f, i) {
        var chip = document.createElement("span");
        chip.className = "attach-chip";
        chip.textContent = (f.name || "Datei") + " ";
        var x = document.createElement("button");
        x.type = "button";
        x.textContent = "×";
        x.title = "Entfernen";
        x.addEventListener("click", function () {
          var keep = new DataTransfer();
          Array.prototype.forEach.call(dt.files, function (ff, j) {
            if (j !== i) keep.items.add(ff);
          });
          dt = keep;
          refresh();
        });
        chip.appendChild(x);
        list.appendChild(chip);
      });
    }

    function addFiles(files) {
      var added = false;
      Array.prototype.forEach.call(files, function (f) {
        if (f) { dt.items.add(f); added = true; }
      });
      if (added) refresh();
    }

    input.addEventListener("change", function () {
      addFiles(input.files);
    });

    form.addEventListener("paste", function (e) {
      var items = e.clipboardData && e.clipboardData.items;
      if (!items) return;
      var imgs = [];
      for (var i = 0; i < items.length; i++) {
        if (items[i].kind === "file") {
          var f = items[i].getAsFile();
          if (f) {
            if (!f.name || f.name === "image.png") {
              pasteCount++;
              var ext = (f.type && f.type.split("/")[1]) || "png";
              f = new File([f], "einfuegung-" + pasteCount + "." + ext, { type: f.type });
            }
            imgs.push(f);
          }
        }
      }
      if (imgs.length) { e.preventDefault(); addFiles(imgs); }
    });

    ["dragover", "dragenter"].forEach(function (ev) {
      form.addEventListener(ev, function (e) { e.preventDefault(); form.classList.add("dragging"); });
    });
    ["dragleave", "drop"].forEach(function (ev) {
      form.addEventListener(ev, function (e) { e.preventDefault(); form.classList.remove("dragging"); });
    });
    form.addEventListener("drop", function (e) {
      if (e.dataTransfer && e.dataTransfer.files) addFiles(e.dataTransfer.files);
    });
  }

  document.querySelectorAll("form.attach-form").forEach(initAttach);
})();