Implement custom feed favicons (#7646)

Closes #3789, #6503

Icon setting when no custom icon is set yet:

![image](https://github.com/user-attachments/assets/28b07dd0-7dac-4c76-b1d7-77035f91a87a)

- `Change...` button opens a file dialog, and after selecting a file shows the chosen icon in the preview on the left. `Submit` must be clicked after selecting the icon.
- `Reset to default` changes the preview icon to the default one, and also requires `Submit` to be clicked to apply the changes.

Full list of changes:
- CSP now includes `blob:` in `img-src` for
   - `indexAction()` and `feedAction()` in `subscriptionController.php`
   - all of the view actions in `indexController.php`
- Introduce new attribute `customFavicon (boolean)` for feeds that indicates if the feed has a custom favicon
   - `hashFavicon()` in `Feed.php` is dependent on this attribute
      - `hashFavicon()` has a new parameter called `skipCache (boolean)` that allows the reset of the favicon hash for the Feed object
      - `resetFaviconHash()` just calls `hashFavicon(skipCache: true)`
- `f.php` URLs now have the format of `/f.php?h=XXXXX&t=cachebuster`, where the `t` parameter is only used for serving custom favicons
   - if `t` parameter is set, `f.php` returns a `Cache-Control: immutable` header
- `stripos` and `strpos` were changed to `str_contains` in various places (refactor)
- JS for handling the custom favicon configuration logic is in `extra.js` inside `init_update_feed()` which is called when feed configuration is opened from the aside or when the subscription management page with the feed is loaded
   - Server-side code for uploading the icon in `subscriptionController.php` under `feedAction()`
   - Errors that may occur during the setting of a custom favicon:
      - Unsupported image file type (handled only server-side with `isImgMime()`)
      - When the file is bigger than 1 MiB (default), handled both client-side and server-side
      - Standard feed error when `updateFeed()` fails
- JS vars `javascript_vars.phtml` are no longer escaped with `htmlspecialchars()`, instead with json encoding,
- CSS for disabled buttons was added
- Max favicon file size is configurable with the `max_favicon_upload_size` option in `config.php` (not exposed via UI)
- Custom favicons are currently deleted only when they are either reset to the default icon, or the feed gets deleted. They do not get deleted when the user deletes their account without removing their feeds first.
- ` faviconPrepare()` and `faviconRebuild()` are not allowed to be called when the `customFavicon` attribute is `true`
- New i18n strings:
   - `'sub.feed.icon' => 'Icon'`
   - `'sub.feed.change_favicon' => 'Change…'`
   - `'sub.feed.reset_favicon' => 'Reset to default'`
   - `'sub.feed.favicon_changed_by_ext' => 'The icon has been set by the <b>%s</b> extension.'`
   - `'feedback.sub.feed.favicon.too_large' => 'Uploaded icon is too large. The maximum file size is <em>%s</em>.'`
   - `'feedback.sub.feed.favicon.unsupported_format' => 'Unsupported image file format!'`
- Extension hook `custom_favicon_hash`
   - `setCustomFavicon()` method
   - `resetCustomFavicon()` method
   - `customFaviconExt` and `customFaviconDisallowDel` attributes
   - example of usage: https://github.com/FreshRSS/Extensions/pull/337
- Extension hook `custom_favicon_btn_url`
   - Allows extensions to implement a button for setting a custom favicon for individual feeds by providing an URL. The URL will be sent a POST request with the `extAction` field set to either `query_icon_info` or `update_icon`, along with an `id` field which describes the feed's ID.

1 files changed, 172 insertions, 15 deletions

diff --git a/app/Models/Feed.php b/app/Models/Feed.php
index 3c5fed507..b91d1af75 100644
--- a/app/Models/Feed.php
+++ b/app/Models/Feed.php
@@ -92,27 +92,171 @@ class FreshRSS_Feed extends Minz_Model {
 	public function hash(): string {
 		if ($this->hash == '') {
 			$salt = FreshRSS_Context::systemConf()->salt;
-			$params = $this->url;
-			$curl_params = $this->attributeArray('curl_params');
-			if (is_array($curl_params)) {
-				// Content provided through a proxy may be completely different
-				$params .= is_string($curl_params[CURLOPT_PROXY] ?? null) ? $curl_params[CURLOPT_PROXY] : '';
-			}
+			$params = $this->url . $this->proxyParam();
 			$this->hash = sha1($salt . $params);
 		}
 		return $this->hash;
 	}
 
-	public function hashFavicon(): string {
-		if ($this->hashFavicon == '') {
+	public function resetFaviconHash(): void {
+		$this->hashFavicon(skipCache: true);
+	}
+
+	public function proxyParam(): string {
+		$curl_params = $this->attributeArray('curl_params');
+		if (is_array($curl_params)) {
+			// Content provided through a proxy may be completely different
+			return is_string($curl_params[CURLOPT_PROXY] ?? null) ? $curl_params[CURLOPT_PROXY] : '';
+		}
+		return '';
+	}
+
+	/**
+	* Resets the custom favicon to the default one. Also deletes the favicon when allowed by extension.
+	*
+	* @param array{'url'?:string,'kind'?:int,'category'?:int,'name'?:string,'website'?:string,'description'?:string,'lastUpdate'?:int,'priority'?:int,
+	* 	'pathEntries'?:string,'httpAuth'?:string,'error'?:int,'ttl'?:int,'attributes'?:string|array<string,mixed>} &$values &$values
+	*
+	* @param bool $updateFeed Whether `updateFeed()` should be called immediately. If false, it must be handled manually.
+	*
+	* @return void
+	*
+	* @throws FreshRSS_Feed_Exception
+	*/
+	public function resetCustomFavicon(?array &$values = null, bool $updateFeed = true) {
+		if (!$this->customFavicon()) {
+			return;
+		}
+		if (!$this->attributeBoolean('customFaviconDisallowDel')) {
+			FreshRSS_Feed::faviconDelete($this->hashFavicon());
+		}
+		$this->_attribute('customFavicon', false);
+		$this->_attribute('customFaviconExt', null);
+		$this->_attribute('customFaviconDisallowDel', false);
+		if ($values !== null) {
+			$values['attributes'] = $this->attributes();
+			$feedDAO = FreshRSS_Factory::createFeedDao();
+			if ($updateFeed && !$feedDAO->updateFeed($this->id(), $values)) {
+				throw new FreshRSS_Feed_Exception();
+			}
+		}
+		$this->resetFaviconHash();
+	}
+
+	/**
+	* Set a custom favicon for the feed.
+	*
+	* @param string $contents Contents of the favicon file. Optional if $tmpPath is set.
+	* @param string $tmpPath Use only when handling file uploads. (value from `tmp_name` goes here)
+	*
+	* @param array{'url'?:string,'kind'?:int,'category'?:int,'name'?:string,'website'?:string,'description'?:string,'lastUpdate'?:int,'priority'?:int,
+	* 	'pathEntries'?:string,'httpAuth'?:string,'error'?:int,'ttl'?:int,'attributes'?:string|array<string,mixed>} &$values &$values
+	*
+	* @param bool $updateFeed Whether `updateFeed()` should be called immediately. If false, it must be handled manually.
+	* @param string $extName The extension name of the calling extension.
+	* @param bool $disallowDelete Whether the icon can be later deleted when it's being reset. Intended for use by extensions.
+	* @param bool $overrideCustomIcon Whether a custom favicon set by a user can be overridden.
+	*
+	* @return string|null Path where the favicon can be found. Useful for checking if the favicon already exists, before downloading it for example.
+	*
+	* @throws FreshRSS_UnsupportedImageFormat_Exception
+	* @throws FreshRSS_Feed_Exception
+	*/
+	public function setCustomFavicon(
+		?string $contents = null,
+		string $tmpPath = '',
+		?array &$values = null,
+		bool $updateFeed = true,
+		?string $extName = null,
+		bool $disallowDelete = false,
+		bool $overrideCustomIcon = false
+	): ?string {
+		if ($contents === null && $tmpPath !== '') {
+			$contents = file_get_contents($tmpPath);
+		}
+
+		$attributesOnly = $contents === null && $tmpPath === '';
+		if (!$attributesOnly && !isImgMime(is_string($contents) ? $contents : '')) {
+			throw new FreshRSS_UnsupportedImageFormat_Exception();
+		}
+
+		$oldHash = '';
+		$oldDisallowDelete = false;
+		if ($this->customFavicon()) {
+			/* If $overrideCustomFavicon is true, custom favicons set by extensions can be overridden,
+			 * but not ones explicitly set by the user */
+			if (!$overrideCustomIcon && $this->customFaviconExt() === null) {
+				return null;
+			}
+			$oldHash = $this->hashFavicon(skipCache: true);
+			$oldDisallowDelete = $this->attributeBoolean('customFaviconDisallowDel');
+		}
+		$this->_attribute('customFavicon', true);
+		$this->_attribute('customFaviconExt', $extName);
+		$this->_attribute('customFaviconDisallowDel', $disallowDelete);
+
+		require_once(LIB_PATH . '/favicons.php');
+		$newPath = FAVICONS_DIR . $this->hashFavicon(skipCache: true) . '.ico';
+		if ($attributesOnly && !file_exists($newPath)) {
+			$updateFeed = false;
+		}
+
+		if ($values !== null) {
+			$values['attributes'] = $this->attributes();
+			$feedDAO = FreshRSS_Factory::createFeedDao();
+			if ($updateFeed && !$feedDAO->updateFeed($this->id(), $values)) {
+				throw new FreshRSS_Feed_Exception();
+			}
+		}
+
+		if ($tmpPath !== '') {
+			move_uploaded_file($tmpPath, $newPath);
+		} elseif ($contents !== null) {
+			file_put_contents($newPath, $contents);
+		}
+
+		if ($oldHash !== '' && !$oldDisallowDelete) {
+			FreshRSS_Feed::faviconDelete($oldHash);
+		}
+
+		return $newPath;
+	}
+
+	/**
+	* Checks if the feed has a custom favicon set by an extension.
+	* Additionally, it also checks if the extension that set the icon is still enabled
+	* And if not, it resets attributes related to custom favicons.
+	*
+	* @return string|null The name of the extension that set the icon.
+	*/
+	public function customFaviconExt(): ?string {
+		$customFaviconExt = $this->attributeString('customFaviconExt');
+		if ($customFaviconExt !== null && !Minz_ExtensionManager::isExtensionEnabled($customFaviconExt)) {
+			$this->_attribute('customFavicon', false);
+			$this->_attribute('customFaviconExt', null);
+			$this->_attribute('customFaviconDisallowDel', false);
+			$customFaviconExt = null;
+		}
+		return $customFaviconExt;
+	}
+
+	public function customFavicon(): bool {
+		$this->customFaviconExt();
+		return $this->attributeBoolean('customFavicon') ?? false;
+	}
+
+	public function hashFavicon(bool $skipCache = false): string {
+		if ($this->hashFavicon == '' || $skipCache) {
 			$salt = FreshRSS_Context::systemConf()->salt;
-			$params = $this->website(fallback: true);
-			$curl_params = $this->attributeArray('curl_params');
-			if (is_array($curl_params)) {
-				// Content provided through a proxy may be completely different
-				$params .= is_string($curl_params[CURLOPT_PROXY] ?? null) ? $curl_params[CURLOPT_PROXY] : '';
+			$params = '';
+			if ($this->customFavicon()) {
+				$current = $this->id . Minz_User::name();
+				$hookParams = Minz_ExtensionManager::callHook('custom_favicon_hash', $this);
+				$params = $hookParams !== null ? $hookParams : $current;
+			} else {
+				$params = $this->website(fallback: true) . $this->proxyParam();
 			}
-			$this->hashFavicon = hash('crc32b', $salt . $params);
+			$this->hashFavicon = hash('crc32b', $salt . (is_string($params) ? $params : ''));
 		}
 		return $this->hashFavicon;
 	}
@@ -257,6 +401,9 @@ class FreshRSS_Feed extends Minz_Model {
 
 	public function faviconPrepare(bool $force = false): void {
 		require_once(LIB_PATH . '/favicons.php');
+		if ($this->customFavicon()) {
+			return;
+		}
 		$url = $this->website(fallback: true);
 		$txt = FAVICONS_DIR . $this->hashFavicon() . '.txt';
 		if (@file_get_contents($txt) !== $url) {
@@ -286,7 +433,14 @@ class FreshRSS_Feed extends Minz_Model {
 		@unlink($path . '.txt');
 	}
 	public function favicon(): string {
-		return Minz_Url::display('/f.php?' . $this->hashFavicon());
+		$hash = $this->hashFavicon();
+		$url = '/f.php?h=' . $hash;
+		if ($this->customFavicon()
+			// when the below attribute is set, icon won't be changing frequently so cache buster is not needed
+			&& !$this->attributeBoolean('customFaviconDisallowDel')) {
+			$url .= '&t=' . @filemtime(DATA_PATH . '/favicons/' . $hash . '.ico');
+		}
+		return Minz_Url::display($url);
 	}
 
 	public function _id(int $value): void {
@@ -1069,6 +1223,9 @@ class FreshRSS_Feed extends Minz_Model {
 	}
 
 	private function faviconRebuild(): void {
+		if ($this->customFavicon()) {
+			return;
+		}
 		FreshRSS_Feed::faviconDelete($this->hashFavicon());
 		$this->faviconPrepare(true);
 	}