Fix back button when previous page should be ignored

In case the previous page in the history should be ignored, the back button just went back to the root page (library).
Instead, it should try to go back to the next page in the history until there is no page to go back to anymore.

src/base/hooks/useBackButton.ts

@@ -11,7 +11,8 @@ import { useCallback } from 'react';
 import { AppRoutes } from '@/base/AppRoute.constants.ts';
 import { useAppPageHistoryContext } from '@/base/contexts/AppPageHistoryContext.tsx';
 
-const PAGES_TO_IGNORE: readonly RegExp[] = [/\/manga\/[0-9]+\/chapter\/[0-9]+/g];
+const READER_REGEX = /\/manga\/[0-9]+\/chapter\/[0-9]+/g;
+const PAGES_TO_IGNORE: readonly RegExp[] = [READER_REGEX];
 
 export const useBackButton = () => {
     const navigate = useNavigate();
@@ -19,16 +20,39 @@ export const useBackButton = () => {
     const history = useAppPageHistoryContext();
 
     return useCallback(() => {
-        const isHistoryEmpty = !history.length;
-        const isLastPageInHistoryCurrentPage = history.length === 1 && history[0] === location.pathname;
-        const ignorePreviousPage = history.length && PAGES_TO_IGNORE.some((page) => !!history.slice(-2)[0].match(page));
+        const getDelta = (historyToCheck: string[] = history, delta: number = 0) => {
+            const isHistoryEmpty = !historyToCheck.length;
+            if (isHistoryEmpty) {
+                return 0;
+            }
 
-        const canNavigateBack = !ignorePreviousPage && !isHistoryEmpty && !isLastPageInHistoryCurrentPage;
-        if (canNavigateBack) {
-            navigate(-1);
+            const isLastPageInHistoryCurrentPage =
+                historyToCheck.length === 1 && historyToCheck[0] === location.pathname;
+            if (isLastPageInHistoryCurrentPage) {
+                return 0;
+            }
+
+            const previousPage = historyToCheck.slice(-2)[0];
+
+            const isPreviousPageCurrentPage = previousPage === location.pathname;
+            const ignorePreviousPage = PAGES_TO_IGNORE.some((page) => !!previousPage.match(page));
+
+            const skipPreviousPage = isPreviousPageCurrentPage || ignorePreviousPage;
+            if (!skipPreviousPage) {
+                return delta - 1;
+            }
+
+            return getDelta(historyToCheck.slice(0, -1), delta - 1);
+        };
+
+        const backDelta = getDelta();
+
+        const canNavigateBack = backDelta < 0;
+        if (!canNavigateBack) {
+            navigate(AppRoutes.library.path());
             return;
         }
 
-        navigate(AppRoutes.library.path());
+        navigate(backDelta);
     }, [history, location.pathname]);
 };