Fix public handling of limited shares

css/public.css

@@ -0,0 +1,4 @@
+/* Prevent user interaction on content */
+#imgframe {
+	pointer-events: none;
+}

lib/Controller/ApiController.php

@@ -91,8 +91,11 @@ public function setDownloadLimit(string $token, int $limit): Response {
 			$insert = true;
 		}
 
-		// Update DB
+		// Set new limit
 		$shareLimit->setLimit($limit);
+		// Reset existing counter
+		$shareLimit->setDownloads(0);
+		// Update DB
 		if ($insert) {
 			$this->mapper->insert($shareLimit);
 		} else {

src/models/DownloadLimitAction.js

@@ -45,18 +45,21 @@ export default class DownloadLimitAction {
 
 	data() {
 		return {
-			icon: 'icon-download',
+			icon: this._store.loading ? 'icon-loading-small' : 'icon-download',
 			is: this._store.enabled ? ActionInput : null,
 			text: t('files_downloadlimit', 'Download limit'),
 			title: t('files_downloadlimit', 'Download count: {count}', this._store),
 			value: this._store.limit,
+			disabled: this._store.loading,
 		}
 	}
 
 	get handlers() {
 		return {
-			'update:value': debounce((limit) => {
-				setDownloadLimit(this._store.token, limit)
+			'update:value': debounce(async (limit) => {
+				this._store.loading = true
+				await setDownloadLimit(this._store.token, limit)
+				this._store.loading = false
 			}, 300),
 		}
 	}

src/models/LimitEnableAction.js

@@ -57,6 +57,7 @@ export default class LimitEnableAction {
 			is: ActionCheckbox,
 			text: t('files_downloadlimit', 'Limit downloads'),
 			checked: this._store.enabled,
+			disabled: this._store.loading,
 		}
 	}
 

src/models/Store.js

@@ -28,6 +28,7 @@ export default class Store {
 		limit: null,
 		count: null,
 		token: null,
+		loading: false,
 	}
 
 	get enabled() {
@@ -62,4 +63,12 @@ export default class Store {
 		this._data.token = token
 	}
 
+	get loading() {
+		return this._data.loading
+	}
+
+	set loading(loading) {
+		this._data.loading = loading
+	}
+
 }

src/public.js

@@ -20,20 +20,64 @@
  *
  */
 import { loadState } from '@nextcloud/initial-state'
-import { translatePlural as n } from '@nextcloud/l10n'
+import { translate as t, translatePlural as n } from '@nextcloud/l10n'
+
+import '../css/public.css'
 
 const { limit, downloads } = loadState(appName, 'download_limit', { limit: -1, downloads: 0 })
 console.debug('[DEBUG]', appName, { limit, downloads })
 
+let count = limit - downloads
+let clicks = 0
+
+const updateCounter = function(span) {
+	if (count === 0) {
+		span.innerText = t(appName, 'You have reached the maximum amount of downloads allowed')
+	} else {
+		span.innerText = n(appName, '1 remaining download allowed', '{count} remaining downloads allowed', count, { count })
+	}
+}
+
 window.addEventListener('DOMContentLoaded', function() {
 	if (limit > 0) {
-		const count = limit - downloads
 		const container = document.getElementById('header-primary-action')
 		const span = document.createElement('span')
 
 		span.style = 'color: var(--color-primary-text); padding: 0 10px;'
-		span.innerText = n('files_downloadlimit', '1 remaining download allowed', '{count} remaining downloads allowed', count, { count })
+		updateCounter(span, count)
 
 		container.prepend(span)
+
+		// Preventing mouse interaction
+		document.querySelector('#files-public-content').oncontextmenu = function(event) {
+			event.preventDefault()
+			event.stopPropagation()
+			return false
+		}
+
+		// Adding double-download warning
+		const downloadButtons = document.querySelectorAll('a[href*="/download/"]') || []
+		new Set(downloadButtons).forEach(button => {
+			button.addEventListener('click', (event) => {
+				// Warn about download limits
+				if (clicks > 0) {
+					if (!confirm(t(appName, 'This share has a limited number of downloads. Are you sure you want to trigger a new download?'))) {
+						event.preventDefault()
+						event.stopPropagation()
+						return
+					}
+				}
+
+				// Handle counts changes
+				count--
+				clicks++
+				updateCounter(span, count)
+
+				// Remove the buttons if share is now expired
+				if (count === 0) {
+					[...downloadButtons].forEach(button => button.remove())
+				}
+			})
+		})
 	}
 })