1 files changed, 114 insertions, 0 deletions
diff --git a/apps/files/src/actions/downloadAction.ts b/apps/files/src/actions/downloadAction.ts
new file mode 100644
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+++ b/apps/files/src/actions/downloadAction.ts
@@ -0,0 +1,114 @@
+/**
+ * SPDX-FileCopyrightText: 2023 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+import type { Node, View } from '@nextcloud/files'
+import { FileAction, FileType, DefaultType } from '@nextcloud/files'
+import { t } from '@nextcloud/l10n'
+import { isDownloadable } from '../utils/permissions'
+
+import ArrowDownSvg from '@mdi/svg/svg/arrow-down.svg?raw'
+
+/**
+ * Trigger downloading a file.
+ *
+ * @param url The url of the asset to download
+ * @param name Optionally the recommended name of the download (browsers might ignore it)
+ */
+function triggerDownload(url: string, name?: string) {
+	const hiddenElement = document.createElement('a')
+	hiddenElement.download = name ?? ''
+	hiddenElement.href = url
+	hiddenElement.click()
+}
+
+/**
+ * Find the longest common path prefix of both input paths
+ * @param first The first path
+ * @param second The second path
+ */
+function longestCommonPath(first: string, second: string): string {
+	const firstSegments = first.split('/').filter(Boolean)
+	const secondSegments = second.split('/').filter(Boolean)
+	let base = ''
+	for (const [index, segment] of firstSegments.entries()) {
+		if (index >= second.length) {
+			break
+		}
+		if (segment !== secondSegments[index]) {
+			break
+		}
+		const sep = base === '' ? '' : '/'
+		base = `${base}${sep}${segment}`
+	}
+	return base
+}
+
+const downloadNodes = function(nodes: Node[]) {
+	let url: URL
+
+	if (nodes.length === 1) {
+		if (nodes[0].type === FileType.File) {
+			return triggerDownload(nodes[0].encodedSource, nodes[0].displayname)
+		} else {
+			url = new URL(nodes[0].encodedSource)
+			url.searchParams.append('accept', 'zip')
+		}
+	} else {
+		url = new URL(nodes[0].encodedSource)
+		let base = url.pathname
+		for (const node of nodes.slice(1)) {
+			base = longestCommonPath(base, (new URL(node.encodedSource).pathname))
+		}
+		url.pathname = base
+
+		// The URL contains the path encoded so we need to decode as the query.append will re-encode it
+		const filenames = nodes.map((node) => decodeURIComponent(node.encodedSource.slice(url.href.length + 1)))
+		url.searchParams.append('accept', 'zip')
+		url.searchParams.append('files', JSON.stringify(filenames))
+	}
+
+	if (url.pathname.at(-1) !== '/') {
+		url.pathname = `${url.pathname}/`
+	}
+
+	return triggerDownload(url.href)
+}
+
+export const action = new FileAction({
+	id: 'download',
+	default: DefaultType.DEFAULT,
+
+	displayName: () => t('files', 'Download'),
+	iconSvgInline: () => ArrowDownSvg,
+
+	enabled(nodes: Node[], view: View) {
+		if (nodes.length === 0) {
+			return false
+		}
+
+		// We can only download dav files and folders.
+		if (nodes.some(node => !node.isDavResource)) {
+			return false
+		}
+
+		// Trashbin does not allow batch download
+		if (nodes.length > 1 && view.id === 'trashbin') {
+			return false
+		}
+
+		return nodes.every(isDownloadable)
+	},
+
+	async exec(node: Node) {
+		downloadNodes([node])
+		return null
+	},
+
+	async execBatch(nodes: Node[]) {
+		downloadNodes(nodes)
+		return new Array(nodes.length).fill(null)
+	},
+
+	order: 30,
+})