Show chapter transition warning

- on scanlator change
- on skipped chapters

public/locales/en.json

@@ -323,6 +323,7 @@
       "log_out": "Log out",
       "migrate": "Migrate",
       "ok": "Ok",
+      "open": "Open",
       "open_site": "Open Site",
       "options": "Options",
       "popular": "Popular",
@@ -804,6 +805,21 @@
       "previous_page": "Previous page",
       "retry_load_pages": "Retry errored pages"
     },
+    "chapter_transition": {
+      "warning": {
+        "next": {
+          "chapter_number_one": "There is one missing chapter.\nCurrent: {{currentChapter}}\nNext: {{nextChapter}}",
+          "chapter_number_other": "There are {{count}} missing chapters.\nCurrent: {{currentChapter}}\nNext: {{nextChapter}}",
+          "scanlator": "The next chapter has a different scanlator then the current one.\nCurrent: {{currentScanlator}}\nNext: {{nextScanlator}}"
+        },
+        "previous": {
+          "chapter_number_one": "There is one missing chapter.\nPrevious: {{nextChapter}}\nCurrent: {{currentChapter}}",
+          "chapter_number_other": "There are {{count}} missing chapters.\nPrevious: {{nextChapter}}\nCurrent: {{currentChapter}}",
+          "scanlator": "The previous chapter has a different scanlator then the current one.\nPrevious: {{nextScanlator}}\nCurrent: {{currentScanlator}}"
+        },
+        "title": "Chapter transition warning"
+      }
+    },
     "error": {
       "label": {
         "chapter_not_found": "Chapter does not exist",

src/modules/core/utils/AwaitableDialog.tsx

@@ -25,7 +25,7 @@ export const awaitConfirmation = async (
         if (accepted) {
             confirmationPromise.resolve();
         } else {
-            confirmationPromise.reject();
+            confirmationPromise.reject(new Error('Confirmation declined'));
         }
 
         root.unmount();

src/modules/reader/components/overlay/navigation/desktop/ReaderNavBarDesktopChapterNavigation.tsx

@@ -17,13 +17,12 @@ import FormControl from '@mui/material/FormControl';
 import InputLabel from '@mui/material/InputLabel';
 import { Link } from 'react-router-dom';
 import { Select } from '@/modules/core/components/inputs/Select.tsx';
-import { Chapters } from '@/modules/chapter/services/Chapters.ts';
 import { ReaderStateChaptersContext } from '@/modules/reader/contexts/state/ReaderStateChaptersContext.tsx';
 import { ReaderChapterList } from '@/modules/reader/components/overlay/navigation/ReaderChapterList.tsx';
 import { ReaderNavBarDesktopNextPreviousButton } from '@/modules/reader/components/overlay/navigation/desktop/ReaderNavBarDesktopNextPreviousButton.tsx';
 import { getOptionForDirection } from '@/modules/theme/services/ThemeCreator.ts';
 import { ReaderService } from '@/modules/reader/services/ReaderService.ts';
-import { ReaderResumeMode } from '@/modules/reader/types/Reader.types.ts';
+import { ReaderControls } from '@/modules/reader/services/ReaderControls.ts';
 
 export const ReaderNavBarDesktopChapterNavigation = ({
     currentChapter,
@@ -36,6 +35,7 @@ export const ReaderNavBarDesktopChapterNavigation = ({
 >) => {
     const { t } = useTranslation();
     const readerThemeDirection = ReaderService.useGetThemeDirection();
+    const openChapter = ReaderControls.useOpenChapter();
 
     const popupState = usePopupState({ variant: 'popover', popupId: 'reader-nav-bar-desktop-chapter-list' });
 
@@ -46,7 +46,6 @@ export const ReaderNavBarDesktopChapterNavigation = ({
     return (
         <Stack sx={{ flexDirection: 'row', gap: 1 }} dir="ltr">
             <ReaderNavBarDesktopNextPreviousButton
-                component={Link}
                 type="previous"
                 title={t(
                     getOptionForDirection(
@@ -55,20 +54,10 @@ export const ReaderNavBarDesktopChapterNavigation = ({
                         readerThemeDirection,
                     ),
                 )}
-                disabled={getOptionForDirection(!previousChapter, !nextChapter, readerThemeDirection)}
-                to={getOptionForDirection(
-                    previousChapter && Chapters.getReaderUrl(previousChapter),
-                    nextChapter && Chapters.getReaderUrl(nextChapter),
-                    readerThemeDirection,
-                )}
-                replace
-                state={{
-                    resumeMode: getOptionForDirection(
-                        ReaderResumeMode.END,
-                        ReaderResumeMode.START,
-                        readerThemeDirection,
-                    ),
+                onClick={() => {
+                    openChapter(getOptionForDirection('previous', 'next', readerThemeDirection));
                 }}
+                disabled={getOptionForDirection(!previousChapter, !nextChapter, readerThemeDirection)}
             />
             <FormControl sx={{ flexBasis: '70%', flexGrow: 0, flexShrink: 0 }}>
                 <InputLabel id="reader-nav-bar-desktop-chapter-select">{t('chapter.title_one')}</InputLabel>
@@ -97,20 +86,10 @@ export const ReaderNavBarDesktopChapterNavigation = ({
                         readerThemeDirection,
                     ),
                 )}
-                disabled={getOptionForDirection(!nextChapter, !previousChapter, readerThemeDirection)}
-                to={getOptionForDirection(
-                    nextChapter && Chapters.getReaderUrl(nextChapter),
-                    previousChapter && Chapters.getReaderUrl(previousChapter),
-                    readerThemeDirection,
-                )}
-                replace
-                state={{
-                    resumeMode: getOptionForDirection(
-                        ReaderResumeMode.START,
-                        ReaderResumeMode.END,
-                        readerThemeDirection,
-                    ),
+                onClick={() => {
+                    openChapter(getOptionForDirection('next', 'previous', readerThemeDirection));
                 }}
+                disabled={getOptionForDirection(!nextChapter, !previousChapter, readerThemeDirection)}
             />
             <Popover
                 {...bindPopover(popupState)}

src/modules/reader/services/ReaderControls.ts

@@ -8,6 +8,8 @@
 
 import { ContextType, MutableRefObject, useCallback, useMemo } from 'react';
 import { Direction, useTheme } from '@mui/material/styles';
+import { useTranslation } from 'react-i18next';
+import { TFunction } from 'i18next';
 import { userReaderStatePagesContext } from '@/modules/reader/contexts/state/ReaderStatePagesContext.tsx';
 import { getNextIndexFromPage, getNextPageIndex, getPage } from '@/modules/reader/utils/ReaderProgressBar.utils.tsx';
 import { getOptionForDirection } from '@/modules/theme/services/ThemeCreator.ts';
@@ -33,8 +35,10 @@ import { ReaderTapZoneService } from '@/modules/reader/services/ReaderTapZoneSer
 import { isContinuousReadingMode } from '@/modules/reader/utils/ReaderSettings.utils.tsx';
 import { getReaderChapterFromCache } from '@/modules/reader/utils/Reader.utils.ts';
 import { Chapters } from '@/modules/chapter/services/Chapters.ts';
-import { DirectionOffset } from '@/Base.types.ts';
+import { DirectionOffset, TranslationKey } from '@/Base.types.ts';
 import { useMetadataServerSettings } from '@/modules/settings/services/ServerSettingsMetadata.ts';
+import { TChapterReader } from '@/modules/chapter/Chapter.types.ts';
+import { awaitConfirmation } from '@/modules/core/utils/AwaitableDialog.tsx';
 
 const getScrollDirectionInvert = (
     scrollDirection: ScrollDirection,
@@ -147,8 +151,9 @@ export class ReaderControls {
     }
 
     static useOpenChapter(): (offset: 'previous' | 'next') => void {
+        const { t } = useTranslation();
         const { readingMode } = ReaderService.useSettings();
-        const { previousChapter, nextChapter } = useReaderStateChaptersContext();
+        const { currentChapter, previousChapter, nextChapter } = useReaderStateChaptersContext();
 
         const openPreviousChapter = ReaderService.useNavigateToChapter(previousChapter, ReaderResumeMode.END);
         const openNextChapter = ReaderService.useNavigateToChapter(nextChapter, ReaderResumeMode.START);
@@ -157,19 +162,80 @@ export class ReaderControls {
             (offset) => {
                 switch (offset) {
                     case 'previous':
-                        openPreviousChapter();
+                        ReaderControls.checkNextChapterConsistency(t, offset, currentChapter, previousChapter).then(
+                            openPreviousChapter,
+                        );
                         break;
                     case 'next':
-                        openNextChapter();
+                        ReaderControls.checkNextChapterConsistency(t, offset, currentChapter, nextChapter).then(
+                            openNextChapter,
+                        );
                         break;
                     default:
                         throw new Error(`Unexpected "offset" (${offset})`);
                 }
             },
-            [openPreviousChapter, openNextChapter, readingMode.value],
+            [t, currentChapter?.id, openPreviousChapter, openNextChapter, readingMode.value],
         );
     }
 
+    private static async checkNextChapterConsistency(
+        t: TFunction,
+        offset: 'previous' | 'next',
+        currentChapter?: TChapterReader | null,
+        chapterToOpen?: TChapterReader | null,
+    ): Promise<void> {
+        if (!currentChapter || !chapterToOpen) {
+            return;
+        }
+
+        const missingChapters = Math.abs(currentChapter.chapterNumber - chapterToOpen.chapterNumber);
+        const isSameScanlator = currentChapter.scanlator === chapterToOpen.scanlator;
+        const isContinuousChapter = missingChapters === 1;
+
+        const showWarning = !isSameScanlator || !isContinuousChapter;
+        if (!showWarning) {
+            return;
+        }
+
+        const offsetToTranslationKeys: Record<typeof offset, Record<'scanlator' | 'chapter_number', TranslationKey>> = {
+            previous: {
+                scanlator: 'reader.chapter_transition.warning.previous.scanlator',
+                chapter_number: 'reader.chapter_transition.warning.previous.chapter_number',
+            },
+            next: {
+                scanlator: 'reader.chapter_transition.warning.next.scanlator',
+                chapter_number: 'reader.chapter_transition.warning.next.chapter_number',
+            },
+        };
+
+        const sameScanlator = isSameScanlator
+            ? ''
+            : t(offsetToTranslationKeys[offset].scanlator, {
+                  nextScanlator: chapterToOpen.scanlator,
+                  currentScanlator: currentChapter.scanlator,
+              });
+        const continuousChapter = isContinuousChapter
+            ? ''
+            : t(offsetToTranslationKeys[offset].chapter_number, {
+                  count: missingChapters,
+                  nextChapter: `#${chapterToOpen.chapterNumber} ${chapterToOpen.name}`,
+                  currentChapter: `#${currentChapter.chapterNumber} ${currentChapter.name}`,
+              });
+        const warningLineBreak = !isSameScanlator && !isContinuousChapter ? '\n\n' : '';
+        const warning = `${sameScanlator}${warningLineBreak}${continuousChapter}`;
+
+        await awaitConfirmation({
+            title: t('reader.chapter_transition.warning.title'),
+            message: warning,
+            actions: {
+                confirm: {
+                    title: t('global.button.open'),
+                },
+            },
+        });
+    }
+
     static useOpenPage(): (page: number | 'previous' | 'next', forceDirection?: Direction) => void {
         const { currentPageIndex, setPageToScrollToIndex, pages, transitionPageMode, setTransitionPageMode } =
             userReaderStatePagesContext();