refactor: unify book cache clearing for epub, txt, and xtc files (#1875)

src/activities/browser/OpdsBookBrowserActivity.cpp

@@ -1,6 +1,5 @@
 #include "OpdsBookBrowserActivity.h"
 
-#include <Epub.h>
 #include <GfxRenderer.h>
 #include <I18n.h>
 #include <Logging.h>
@@ -14,6 +13,7 @@
 #include "components/UITheme.h"
 #include "fontIds.h"
 #include "network/HttpDownloader.h"
+#include "util/BookCacheUtils.h"
 #include "util/StringUtils.h"
 #include "util/UrlUtils.h"
 
@@ -283,7 +283,7 @@ void OpdsBookBrowserActivity::downloadBook(const OpdsEntry& book) {
       nullptr, server.username, server.password);
 
   if (result == HttpDownloader::OK) {
-    Epub(filename, "/.crosspoint").clearCache();
+    clearBookCache(filename);
     state = BrowserState::BROWSING;
   } else {
     state = BrowserState::ERROR;

src/activities/settings/ClearCacheActivity.cpp

@@ -8,6 +8,7 @@
 #include "MappedInputManager.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
+#include "util/BookCacheUtils.h"
 
 void ClearCacheActivity::onEnter() {
   Activity::onEnter();
@@ -94,8 +95,8 @@ void ClearCacheActivity::clearCache() {
     file.getName(name, sizeof(name));
     String itemName(name);
 
-    // Only delete directories starting with epub_ or xtc_
-    if (file.isDirectory() && (itemName.startsWith("epub_") || itemName.startsWith("xtc_"))) {
+    // Only delete directories matching known book cache names.
+    if (file.isDirectory() && isBookCacheDirectoryName(itemName.c_str())) {
       String fullPath = "/.crosspoint/" + itemName;
       LOG_DBG("CLEAR_CACHE", "Removing cache: %s", fullPath.c_str());