1 files changed, 158 insertions, 0 deletions
diff --git a/web_src/js/features/dropzone.ts b/web_src/js/features/dropzone.ts
new file mode 100644
index 0000000000..392bc1db66
--- /dev/null
+++ b/web_src/js/features/dropzone.ts
@@ -0,0 +1,158 @@
+import {svg} from '../svg.ts';
+import {htmlEscape} from 'escape-goat';
+import {clippie} from 'clippie';
+import {showTemporaryTooltip} from '../modules/tippy.ts';
+import {GET, POST} from '../modules/fetch.ts';
+import {showErrorToast} from '../modules/toast.ts';
+import {createElementFromHTML, createElementFromAttrs} from '../utils/dom.ts';
+import {isImageFile, isVideoFile} from '../utils.ts';
+
+const {csrfToken, i18n} = window.config;
+
+// dropzone has its owner event dispatcher (emitter)
+export const DropzoneCustomEventReloadFiles = 'dropzone-custom-reload-files';
+export const DropzoneCustomEventRemovedFile = 'dropzone-custom-removed-file';
+export const DropzoneCustomEventUploadDone = 'dropzone-custom-upload-done';
+
+async function createDropzone(el, opts) {
+  const [{Dropzone}] = await Promise.all([
+    import(/* webpackChunkName: "dropzone" */'dropzone'),
+    import(/* webpackChunkName: "dropzone" */'dropzone/dist/dropzone.css'),
+  ]);
+  return new Dropzone(el, opts);
+}
+
+export function generateMarkdownLinkForAttachment(file, {width, dppx} = {}) {
+  let fileMarkdown = `[${file.name}](/attachments/${file.uuid})`;
+  if (isImageFile(file)) {
+    fileMarkdown = `!${fileMarkdown}`;
+    if (width > 0 && dppx > 1) {
+      // Scale down images from HiDPI monitors. This uses the <img> tag because it's the only
+      // method to change image size in Markdown that is supported by all implementations.
+      // Make the image link relative to the repo path, then the final URL is "/sub-path/owner/repo/attachments/{uuid}"
+      fileMarkdown = `<img width="${Math.round(width / dppx)}" alt="${htmlEscape(file.name)}" src="attachments/${htmlEscape(file.uuid)}">`;
+    } else {
+      // Markdown always renders the image with a relative path, so the final URL is "/sub-path/owner/repo/attachments/{uuid}"
+      // TODO: it should also use relative path for consistency, because absolute is ambiguous for "/sub-path/attachments" or "/attachments"
+      fileMarkdown = `![${file.name}](/attachments/${file.uuid})`;
+    }
+  } else if (isVideoFile(file)) {
+    fileMarkdown = `<video src="attachments/${htmlEscape(file.uuid)}" title="${htmlEscape(file.name)}" controls></video>`;
+  }
+  return fileMarkdown;
+}
+
+function addCopyLink(file) {
+  // Create a "Copy Link" element, to conveniently copy the image or file link as Markdown to the clipboard
+  // The "<a>" element has a hardcoded cursor: pointer because the default is overridden by .dropzone
+  const copyLinkEl = createElementFromHTML(`
+<div class="tw-text-center">
+  <a href="#" class="tw-cursor-pointer">${svg('octicon-copy', 14)} Copy link</a>
+</div>`);
+  copyLinkEl.addEventListener('click', async (e) => {
+    e.preventDefault();
+    const success = await clippie(generateMarkdownLinkForAttachment(file));
+    showTemporaryTooltip(e.target, success ? i18n.copy_success : i18n.copy_error);
+  });
+  file.previewTemplate.append(copyLinkEl);
+}
+
+/**
+ * @param {HTMLElement} dropzoneEl
+ */
+export async function initDropzone(dropzoneEl) {
+  const listAttachmentsUrl = dropzoneEl.closest('[data-attachment-url]')?.getAttribute('data-attachment-url');
+  const removeAttachmentUrl = dropzoneEl.getAttribute('data-remove-url');
+  const attachmentBaseLinkUrl = dropzoneEl.getAttribute('data-link-url');
+
+  let disableRemovedfileEvent = false; // when resetting the dropzone (removeAllFiles), disable the "removedfile" event
+  let fileUuidDict = {}; // to record: if a comment has been saved, then the uploaded files won't be deleted from server when clicking the Remove in the dropzone
+  const opts = {
+    url: dropzoneEl.getAttribute('data-upload-url'),
+    headers: {'X-Csrf-Token': csrfToken},
+    acceptedFiles: ['*/*', ''].includes(dropzoneEl.getAttribute('data-accepts')) ? null : dropzoneEl.getAttribute('data-accepts'),
+    addRemoveLinks: true,
+    dictDefaultMessage: dropzoneEl.getAttribute('data-default-message'),
+    dictInvalidFileType: dropzoneEl.getAttribute('data-invalid-input-type'),
+    dictFileTooBig: dropzoneEl.getAttribute('data-file-too-big'),
+    dictRemoveFile: dropzoneEl.getAttribute('data-remove-file'),
+    timeout: 0,
+    thumbnailMethod: 'contain',
+    thumbnailWidth: 480,
+    thumbnailHeight: 480,
+  };
+  if (dropzoneEl.hasAttribute('data-max-file')) opts.maxFiles = Number(dropzoneEl.getAttribute('data-max-file'));
+  if (dropzoneEl.hasAttribute('data-max-size')) opts.maxFilesize = Number(dropzoneEl.getAttribute('data-max-size'));
+
+  // there is a bug in dropzone: if a non-image file is uploaded, then it tries to request the file from server by something like:
+  // "http://localhost:3000/owner/repo/issues/[object%20Event]"
+  // the reason is that the preview "callback(dataURL)" is assign to "img.onerror" then "thumbnail" uses the error object as the dataURL and generates '<img src="[object Event]">'
+  const dzInst = await createDropzone(dropzoneEl, opts);
+  dzInst.on('success', (file, resp) => {
+    file.uuid = resp.uuid;
+    fileUuidDict[file.uuid] = {submitted: false};
+    const input = createElementFromAttrs('input', {name: 'files', type: 'hidden', id: `dropzone-file-${resp.uuid}`, value: resp.uuid});
+    dropzoneEl.querySelector('.files').append(input);
+    addCopyLink(file);
+    dzInst.emit(DropzoneCustomEventUploadDone, {file});
+  });
+
+  dzInst.on('removedfile', async (file) => {
+    if (disableRemovedfileEvent) return;
+
+    dzInst.emit(DropzoneCustomEventRemovedFile, {fileUuid: file.uuid});
+    document.querySelector(`#dropzone-file-${file.uuid}`)?.remove();
+    // when the uploaded file number reaches the limit, there is no uuid in the dict, and it doesn't need to be removed from server
+    if (removeAttachmentUrl && fileUuidDict[file.uuid] && !fileUuidDict[file.uuid].submitted) {
+      await POST(removeAttachmentUrl, {data: new URLSearchParams({file: file.uuid})});
+    }
+  });
+
+  dzInst.on('submit', () => {
+    for (const fileUuid of Object.keys(fileUuidDict)) {
+      fileUuidDict[fileUuid].submitted = true;
+    }
+  });
+
+  dzInst.on(DropzoneCustomEventReloadFiles, async () => {
+    try {
+      const resp = await GET(listAttachmentsUrl);
+      const respData = await resp.json();
+      // do not trigger the "removedfile" event, otherwise the attachments would be deleted from server
+      disableRemovedfileEvent = true;
+      dzInst.removeAllFiles(true);
+      disableRemovedfileEvent = false;
+
+      dropzoneEl.querySelector('.files').innerHTML = '';
+      for (const el of dropzoneEl.querySelectorAll('.dz-preview')) el.remove();
+      fileUuidDict = {};
+      for (const attachment of respData) {
+        const file = {name: attachment.name, uuid: attachment.uuid, size: attachment.size};
+        const imgSrc = `${attachmentBaseLinkUrl}/${file.uuid}`;
+        dzInst.emit('addedfile', file);
+        dzInst.emit('thumbnail', file, imgSrc);
+        dzInst.emit('complete', file);
+        addCopyLink(file); // it is from server response, so no "type"
+        fileUuidDict[file.uuid] = {submitted: true};
+        const input = createElementFromAttrs('input', {name: 'files', type: 'hidden', id: `dropzone-file-${file.uuid}`, value: file.uuid});
+        dropzoneEl.querySelector('.files').append(input);
+      }
+      if (!dropzoneEl.querySelector('.dz-preview')) {
+        dropzoneEl.classList.remove('dz-started');
+      }
+    } catch (error) {
+      // TODO: if listing the existing attachments failed, it should stop from operating the content or attachments,
+      //  otherwise the attachments might be lost.
+      showErrorToast(`Failed to load attachments: ${error}`);
+      console.error(error);
+    }
+  });
+
+  dzInst.on('error', (file, message) => {
+    showErrorToast(`Dropzone upload error: ${message}`);
+    dzInst.removeFile(file);
+  });
+
+  if (listAttachmentsUrl) dzInst.emit(DropzoneCustomEventReloadFiles);
+  return dzInst;
+}