feat(ebook-reader): implement page-based pagination with CFI support

This commit implements true page-based pagination for the ebook reader,
similar to Kindle's approach where content is split into discrete pages
based on viewport size, font settings, and content layout.

Phase 1 - Bug Fixes:
- Fix goToPage to use getScrollPositionForPage instead of treating
  page numbers as spine indices
- Move page calculation to initialize before first render to avoid
  race condition with scroll handler
- Add fallback page calculation when pageCalculationResult is null

Phase 2 - Page Splitting:
- Add new page-splitter.ts module with CFI-based splitting for EPUB
  and height-based fallback for other formats
- Integrate splitContent into page-calculator to generate discrete
  page content for each spine item
- Store pages[] array in ChapterPageInfo for rendering
- Rewrite navigation (nextPage, previousPage, renderSpineItem) to
  use page-based approach with currentPage tracking
- Remove old scroll-based pagination from view-modes.ts
- Update paginated mode CSS for true page clipping

Phase 3 - Progress Display:
- Update progress-indicator to use currentPage directly instead of
  calculating from scroll position
- Fix getCurrentPage in reader-state to return currentPage for ebooks

Phase 4 - Interface Fixes:
- Add currentPage field to UniversalReader interface
- Update sendProgressUpdate to use currentPage directly
- Initialize currentPage to 1 on reader creation

Key features:
- Dynamic page count based on font size, line height, margins
- CFI-based page splitting preserves reading context
- Falls back to height-based splitting for non-EPUB formats
- Progress display updates immediately on page change
- Settings changes trigger page recalculation and re-render

web/src/reader/core/reader-navigation.ts

@@ -1,11 +1,10 @@
 import { getDefaultSettings } from "../settings-manager";
-import { getState, setState, getCurrentPage } from "./reader-state";
+import { getState, setState } from "./reader-state";
 import { readerEvents } from "./reader-events";
 import { updateReadingProgress } from "./reader-services";
 import {
   calculatePagesForEbook,
   calculateProgressPercentage,
-  getCurrentPageFromScroll,
   type PageCalculationResult,
 } from "../ebook/page-calculator";
 import { UniversalReader } from "../reader-shell";
@@ -18,46 +17,45 @@ export function createNavigationAPI() {
     nextPage: () => {
       const state = getState();
       if (!state.currentReader) return;
-
       readerEvents.emit("beforePageChange", state.currentReader);
-
       if (state.currentReader.type === "ebook") {
-        const container = document.getElementById("reader-content");
-        const viewportHeightAdjusted = window.innerHeight - 120;
-
         if (pageCalculationResult) {
-          const currentChapter = pageCalculationResult.chapterMap.get(
-            state.currentReader.currentSpineIndex,
-          );
+          const currentPage = state.currentReader.currentPage || 1;
 
-          if (currentChapter && container) {
-            const currentPageInChapter = Math.floor(
-              container.scrollTop / viewportHeightAdjusted,
+          if (currentPage < pageCalculationResult.totalPages) {
+            const nextPage = currentPage + 1;
+            state.currentReader.currentPage = nextPage;
+
+            // Check if we need to move to next spine
+            const currentChapter = pageCalculationResult.chapterMap.get(
+              state.currentReader.currentSpineIndex,
             );
-            const pagesInCurrentChapter =
-              currentChapter.endPage - currentChapter.startPage + 1;
 
-            if (currentPageInChapter < pagesInCurrentChapter - 1) {
-              // Still pages left in current chapter - just scroll down
-              container.scrollTop =
-                (currentPageInChapter + 1) * viewportHeightAdjusted;
-            } else if (
-              state.currentReader.currentSpineIndex <
-              state.currentReader.cif.spine.length - 1
-            ) {
-              // At end of chapter, move to next spine
-              state.currentReader.currentSpineIndex++;
-              renderSpineItem();
+            if (currentChapter && nextPage > currentChapter.endPage) {
+              // Move to next spine
+              if (
+                state.currentReader.currentSpineIndex <
+                state.currentReader.cif.spine.length - 1
+              ) {
+                state.currentReader.currentSpineIndex++;
+              }
             }
+
+            setState({ currentReader: state.currentReader });
+            renderSpineItem();
+            sendProgressUpdate();
+            readerEvents.emit("pageChanged", nextPage);
           }
         } else {
-          // Fallback: just move to next spine
+          // Fallback: spine-based navigation
           if (
             state.currentReader.currentSpineIndex <
             state.currentReader.cif.spine.length - 1
           ) {
             state.currentReader.currentSpineIndex++;
+            setState({ currentReader: state.currentReader });
             renderSpineItem();
+            sendProgressUpdate();
           }
         }
       } else if (state.currentReader.type === "pdf") {
@@ -78,48 +76,54 @@ export function createNavigationAPI() {
           renderComicPage();
         }
       }
-
       setState({ currentReader: state.currentReader });
-      sendProgressUpdate();
-      readerEvents.emit("pageChanged", getCurrentPage());
       readerEvents.emit("afterPageChange", state.currentReader);
     },
 
     previousPage: () => {
       const state = getState();
       if (!state.currentReader) return;
-
       readerEvents.emit("beforePageChange", state.currentReader);
-
       if (state.currentReader.type === "ebook") {
-        const container = document.getElementById("reader-content");
-        const viewportHeightAdjusted = window.innerHeight - 120;
-
         if (pageCalculationResult) {
-          const currentChapter = pageCalculationResult.chapterMap.get(
-            state.currentReader.currentSpineIndex,
-          );
+          const currentPage = state.currentReader.currentPage || 1;
 
-          if (currentChapter && container) {
-            const currentPageInChapter = Math.floor(
-              container.scrollTop / viewportHeightAdjusted,
+          if (currentPage > 1) {
+            const prevPage = currentPage - 1;
+
+            // Check if we need to move to previous spine
+            const currentChapter = pageCalculationResult.chapterMap.get(
+              state.currentReader.currentSpineIndex,
             );
 
-            if (currentPageInChapter > 0) {
-              // Not at start of chapter - just scroll up
-              container.scrollTop =
-                (currentPageInChapter - 1) * viewportHeightAdjusted;
-            } else if (state.currentReader.currentSpineIndex > 0) {
-              // At start of chapter, move to previous spine
-              state.currentReader.currentSpineIndex--;
-              renderSpineItem();
+            if (currentChapter && prevPage < currentChapter.startPage) {
+              // Move to previous spine
+              if (state.currentReader.currentSpineIndex > 0) {
+                state.currentReader.currentSpineIndex--;
+                const prevChapter = pageCalculationResult.chapterMap.get(
+                  state.currentReader.currentSpineIndex,
+                );
+                state.currentReader.currentPage =
+                  prevChapter?.endPage || prevPage;
+              } else {
+                state.currentReader.currentPage = 1;
+              }
+            } else {
+              state.currentReader.currentPage = prevPage;
             }
+
+            setState({ currentReader: state.currentReader });
+            renderSpineItem();
+            sendProgressUpdate();
+            readerEvents.emit("pageChanged", state.currentReader.currentPage);
           }
         } else {
-          // Fallback: just move to previous spine
+          // Fallback: spine-based navigation
           if (state.currentReader.currentSpineIndex > 0) {
             state.currentReader.currentSpineIndex--;
+            setState({ currentReader: state.currentReader });
             renderSpineItem();
+            sendProgressUpdate();
           }
         }
       } else if (state.currentReader.type === "pdf") {
@@ -136,23 +140,41 @@ export function createNavigationAPI() {
           renderComicPage();
         }
       }
-
       setState({ currentReader: state.currentReader });
-      sendProgressUpdate();
-      readerEvents.emit("pageChanged", getCurrentPage());
       readerEvents.emit("afterPageChange", state.currentReader);
     },
 
-    goToPage: (page: number) => {
+    goToPage: async (page: number) => {
       const state = getState();
       if (!state.currentReader) return;
-
       readerEvents.emit("beforePageChange", state.currentReader);
-
       if (state.currentReader.type === "ebook") {
-        if (page >= 0 && page < state.currentReader.cif.spine.length) {
-          state.currentReader.currentSpineIndex = page;
-          renderSpineItem();
+        if (pageCalculationResult) {
+          // Validate page number
+          if (page < 1 || page > pageCalculationResult.totalPages) {
+            return;
+          }
+
+          // Find which spine contains this page
+          for (const chapter of pageCalculationResult.chapters) {
+            if (page >= chapter.startPage && page <= chapter.endPage) {
+              state.currentReader.currentSpineIndex = chapter.spineIndex;
+              state.currentReader.currentPage = page;
+              break;
+            }
+          }
+
+          setState({ currentReader: state.currentReader });
+          await renderSpineItem();
+          sendProgressUpdate();
+        } else {
+          // Fallback: treat page number as spine index
+          if (page >= 0 && page < state.currentReader.cif.spine.length) {
+            state.currentReader.currentSpineIndex = page;
+            state.currentReader.currentPage = page + 1;
+            setState({ currentReader: state.currentReader });
+            await renderSpineItem();
+          }
         }
       } else if (state.currentReader.type === "pdf") {
         if (page >= 1 && page <= (state.readerMetadata?.total_pages || 0)) {
@@ -163,14 +185,12 @@ export function createNavigationAPI() {
         state.currentReader.type === "comic" ||
         state.currentReader.type === "manga"
       ) {
-        if (page >= 0 && page < state.currentReader.images.length) {
+        if (page >= 0 && page < (state.currentReader as any).images.length) {
           state.currentReader.currentPage = page;
           renderComicPage();
         }
       }
-
       setState({ currentReader: state.currentReader });
-      sendProgressUpdate();
       readerEvents.emit("pageChanged", page);
       readerEvents.emit("afterPageChange", state.currentReader);
     },
@@ -195,9 +215,7 @@ export async function initializePageCalculation() {
   readerEvents.on("settings:changed", async (settings: any) => {
     const state = getState();
     if (!state.currentReader || state.currentReader.type !== "ebook") return;
-
     console.log("Recalculating pages due to settings change...");
-
     const viewportWidth = window.innerWidth;
     pageCalculationResult = await calculatePagesForEbook(
       state.currentReader.cif,
@@ -208,9 +226,21 @@ export async function initializePageCalculation() {
         marginWidth: settings.margin_width,
       },
     );
-
     state.currentReader.pageCalculationResult = pageCalculationResult;
     setState({ currentReader: state.currentReader });
+    // Re-render the current page with new settings
+    await renderSpineItem();
+
+    // Emit event so progress display updates
+    const currentPage = state.currentReader.currentPage || 1;
+    readerEvents.emit("progressUpdated", {
+      currentPage,
+      totalPages: pageCalculationResult.totalPages,
+      percentage: calculateProgressPercentage(
+        pageCalculationResult,
+        currentPage,
+      ),
+    });
   });
   const state = getState();
   if (!state.currentReader || state.currentReader.type !== "ebook") return;
@@ -250,104 +280,67 @@ export async function initializePageCalculation() {
 export async function renderSpineItem() {
   const state = getState();
   if (state.currentReader?.type !== "ebook") return;
+
+  if (!state.currentReader.currentPage) {
+    state.currentReader.currentPage = 1;
+  }
+
+  const container = document.getElementById("reader-content");
+  if (!container) return;
+
   const spineItem =
     state.currentReader.cif.spine[state.currentReader.currentSpineIndex];
-  const container = document.getElementById("reader-content");
-  if (pageCalculationResult) {
-    const viewportHeight = window.innerHeight;
-    const currentPage = getCurrentPageFromScroll(
-      pageCalculationResult,
-      state.currentReader.currentSpineIndex,
-      container.scrollTop,
-      viewportHeight,
-    );
+  if (!spineItem) return;
+  // Get page calculation result
+  const chapter = pageCalculationResult?.chapterMap.get(
+    state.currentReader.currentSpineIndex,
+  );
 
-    // Store computed page for UI display
-    state.currentReader.currentPage = currentPage;
-    setState({ currentReader: state.currentReader });
+  // Calculate which page within the chapter we're on
+  let currentPageContent = "";
+  let currentPageNumber = state.currentReader.currentPage || 1;
 
-    const percentage = calculateProgressPercentage(
-      pageCalculationResult,
-      currentPage,
-    );
-    readerEvents.emit("progressUpdated", {
-      currentPage,
-      totalPages: pageCalculationResult.totalPages,
-      percentage,
-    });
+  if (chapter?.pages && chapter.pages.length > 0) {
+    // Calculate which page of this spine item to show
+    const globalPage = state.currentReader.currentPage || 1;
+    const pageWithinChapter = Math.max(0, globalPage - chapter.startPage);
+    const pageIndex = Math.min(pageWithinChapter, chapter.pages.length - 1);
+
+    currentPageContent = chapter.pages[pageIndex]?.html || chapter.content;
+    currentPageNumber = chapter.startPage + pageIndex;
+  } else {
+    // Fallback: load full content if pages not calculated yet
+    const resources = state.currentReader.cif.resources;
+    const contentBlob = resources?.get(spineItem.content);
+    if (contentBlob) {
+      currentPageContent = await contentBlob.text();
+    } else {
+      console.error(
+        "Spine item content not found in resources:",
+        spineItem.content,
+      );
+      container.innerHTML = `<p>Error: Could not load chapter content</p>`;
+      return;
+    }
   }
-  if (!container || !spineItem) return;
-  // Get the actual content from resources using the href
-  const resources = state.currentReader.cif.resources;
-  console.log("ALL resource keys:", Array.from(resources.keys()));
-  const contentBlob = resources?.get(spineItem.content);
-  if (!contentBlob) {
-    // Fallback: try to fetch directly if not in resources
-    console.error(
-      "Spine item content not found in resources:",
-      spineItem.content,
-    );
-    container.innerHTML = `<p>Error: Could not load chapter content</p>`;
-    container.addEventListener(
-      "scroll",
-      () => {
-        const state = getState();
-        if (!state.currentReader || state.currentReader.type !== "ebook")
-          return;
+  // Process and render the page content
+  const modifiedContent = rewriteImageUrls(
+    currentPageContent,
+    state.currentReader.cif.resources,
+  );
 
-        state.currentReader.currentScrollPosition = container.scrollTop;
-
-        if (pageCalculationResult) {
-          const viewportHeight = window.innerHeight;
-          const currentPage = getCurrentPageFromScroll(
-            pageCalculationResult,
-            state.currentReader.currentSpineIndex,
-            container.scrollTop,
-            viewportHeight,
-          );
-
-          const percentage = calculateProgressPercentage(
-            pageCalculationResult,
-            currentPage,
-          );
-          readerEvents.emit("progressUpdated", {
-            currentPage,
-            totalPages: pageCalculationResult.totalPages,
-            percentage,
-          });
-        }
-      },
-      { passive: true },
-    );
-    return;
-  }
-  // Convert blob to text
-  const contentText = await contentBlob.text();
-
-  // Rewrite image src paths to use blob URLs from resources
-  const modifiedContent = rewriteImageUrls(contentText, resources);
-
-  const htmlImages = modifiedContent.match(/<img[^>]+>/g);
-  const svgImages =
-    modifiedContent.match(/<image[^>]+xlink:href="([^"]+)"[^>]*>/gi) || [];
-  const allImages = [...htmlImages, ...svgImages];
-  console.log("Found images in content:", allImages);
-
-  // Parse HTML and process images BEFORE setting innerHTML
+  // Parse HTML and process images
   const parser = new DOMParser();
   const doc = parser.parseFromString(modifiedContent, "text/html");
+
+  // Process <img> elements
   const imgElements = Array.from(doc.querySelectorAll("img"));
   for (const img of imgElements) {
     const src = img.getAttribute("src");
     if (!src) continue;
-
-    // Try different path formats to find the image
-    let blob = findImageInResources(resources, src);
-
+    const blob = findImageInResources(state.currentReader.cif.resources, src);
     if (blob) {
-      // Create blob URL - need to do this properly
-      const blobUrl = URL.createObjectURL(blob);
-      img.setAttribute("src", blobUrl);
+      img.setAttribute("src", URL.createObjectURL(blob));
     }
   }
 
@@ -356,18 +349,33 @@ export async function renderSpineItem() {
   for (const img of svgImgElements) {
     const src = img.getAttribute("xlink:href");
     if (!src) continue;
-
-    let blob = findImageInResources(resources, src);
+    const blob = findImageInResources(state.currentReader.cif.resources, src);
     if (blob) {
-      const blobUrl = URL.createObjectURL(blob);
-      img.setAttribute("xlink:href", blobUrl);
+      img.setAttribute("xlink:href", URL.createObjectURL(blob));
     }
   }
 
+  // Apply to container - replace innerHTML with current page content
   container.innerHTML = doc.body.innerHTML;
-  // Apply reader styling
+
+  // Apply styling
   applyReaderTheme();
   applyTypography();
+
+  // Emit progress update
+  if (pageCalculationResult) {
+    state.currentReader.currentPage = currentPageNumber;
+    setState({ currentReader: state.currentReader });
+
+    readerEvents.emit("progressUpdated", {
+      currentPage: currentPageNumber,
+      totalPages: pageCalculationResult.totalPages,
+      percentage: calculateProgressPercentage(
+        pageCalculationResult,
+        currentPageNumber,
+      ),
+    });
+  }
 }
 
 function rewriteImageUrls(
@@ -523,14 +531,7 @@ function sendProgressUpdate() {
   if (state.currentReader.type === "ebook") {
     // Use dynamic page calculation if available
     if (pageCalculationResult) {
-      const container = document.getElementById("reader-content");
-      const viewportHeight = window.innerHeight;
-      currentPage = getCurrentPageFromScroll(
-        pageCalculationResult,
-        state.currentReader.currentSpineIndex,
-        container?.scrollTop || 0,
-        viewportHeight,
-      );
+      currentPage = state.currentReader.currentPage || 1;
       totalPages = pageCalculationResult.totalPages;
     } else {
       currentPage = state.currentReader.currentSpineIndex + 1;

web/src/reader/core/reader-state.ts

@@ -35,9 +35,8 @@ export function getReaderMetadata(): ReaderMetadata | null {
 export function getCurrentPage(): number {
   const reader = currentState.currentReader;
   if (!reader) return 0;
-
   if (reader.type === "ebook") {
-    return reader.currentSpineIndex;
+    return reader.currentPage ?? reader.currentSpineIndex + 1;
   }
   return reader.currentPage;
 }

web/src/reader/ebook/page-calculator.ts

@@ -1,4 +1,5 @@
 import { findImageInResources } from "../core/reader-navigation";
+import { splitContent, type PageContent } from "./page-splitter";
 
 export interface ChapterPageInfo {
   spineIndex: number;
@@ -9,6 +10,7 @@ export interface ChapterPageInfo {
   scrollHeight: number;
   charCount: number;
   pagesInChapter: number;
+  pages: PageContent[];
 }
 
 export interface PageCalculationResult {
@@ -111,14 +113,6 @@ async function renderContentForMeasurement(
   return container;
 }
 
-function calculatePageBreaks(
-  scrollHeight: number,
-  viewportHeight: number,
-): number {
-  if (scrollHeight <= 0 || viewportHeight <= 0) return 1;
-  return Math.ceil(scrollHeight / viewportHeight);
-}
-
 export async function calculatePagesForEbook(
   cif: EbookCIF,
   viewportWidth: number,
@@ -159,6 +153,7 @@ export async function calculatePagesForEbook(
         scrollHeight: 0,
         charCount: 0,
         pagesInChapter: 0,
+        pages: [],
       });
       continue;
     }
@@ -174,6 +169,7 @@ export async function calculatePagesForEbook(
         scrollHeight: 0,
         charCount: 0,
         pagesInChapter: 0,
+        pages: [],
       });
       continue;
     }
@@ -182,41 +178,42 @@ export async function calculatePagesForEbook(
     const charCount = contentText.replace(/<[^>]*>/g, "").length;
 
     let scrollHeight = 0;
-    let pagesInChapter = 1;
-
     try {
       const container = await renderContentForMeasurement(
         contentText,
         cif.resources,
         config,
       );
-
       scrollHeight = container.scrollHeight;
-      pagesInChapter = calculatePageBreaks(scrollHeight, viewportHeight);
-
       container.remove();
     } catch (error) {
-      console.warn(
-        "Failed to measure content for spine item:",
-        spineItem.id,
-        error,
-      );
-      pagesInChapter = Math.max(1, Math.ceil(charCount / 1500));
+      console.warn("Failed to measure content:", spineItem.id, error);
     }
 
+    // Split content into discrete pages
+    const pageSplitResult = splitContent(
+      contentText,
+      i,
+      spineItem.id,
+      viewportHeight,
+      { fontSize, lineHeight, marginWidth },
+      true, // useCFI
+    );
+
     const chapterInfo: ChapterPageInfo = {
       spineIndex: i,
       spineItemId: spineItem.id,
       content: contentText,
       startPage: currentPage,
-      endPage: currentPage + pagesInChapter - 1,
+      endPage: currentPage + pageSplitResult.totalPages - 1,
       scrollHeight,
       charCount,
-      pagesInChapter,
+      pagesInChapter: pageSplitResult.totalPages,
+      pages: pageSplitResult.pages,
     };
 
     chapters.push(chapterInfo);
-    currentPage += pagesInChapter;
+    currentPage += pageSplitResult.totalPages;
   }
 
   const chapterMap = new Map<number, ChapterPageInfo>();

web/src/reader/ebook/page-splitter.ts

@@ -0,0 +1,276 @@
+// Page splitter for ebooks - extracts discrete page content
+// Uses CFI for EPUB when available, falls back to height-based splitting
+import { generateCFI } from "./cfi-navigator";
+export interface PageContent {
+  pageNumber: number;
+  spineIndex: number;
+  startCFI?: string;
+  endCFI?: string;
+  html: string;
+  charCount: number;
+}
+export interface PageSplitResult {
+  pages: PageContent[];
+  totalPages: number;
+}
+// Split content by viewport height (fallback for non-EPUB)
+export function splitByHeight(
+  html: string,
+  spineIndex: number,
+  viewportHeight: number,
+  settings: { fontSize: number; lineHeight: number; marginWidth: number },
+): PageSplitResult {
+  const pages: PageContent[] = [];
+  const doc = new DOMParser().parseFromString(html, "text/html");
+
+  // Clone body content
+  const content = doc.body;
+  const contentHeight = estimateContentHeight(content, settings);
+  const contentWidth = doc.body.scrollWidth || 600;
+  const pageCount = Math.max(1, Math.ceil(contentHeight / viewportHeight));
+
+  // For height-based splitting, we'll use a different approach:
+  // Wrap each block element and measure cumulative height
+  const blocks = Array.from(content.children);
+
+  let currentPageHTML = "";
+  let currentHeight = 0;
+  let pageNumber = 1;
+
+  for (const block of blocks) {
+    const blockHeight = estimateBlockHeight(block, settings, contentWidth);
+
+    if (
+      currentHeight + blockHeight > viewportHeight &&
+      currentPageHTML.length > 0
+    ) {
+      // Save current page and start new one
+      pages.push({
+        pageNumber,
+        spineIndex,
+        html: wrapInPageContainer(currentPageHTML, pageNumber, pageCount),
+        charCount: currentPageHTML.replace(/<[^>]*>/g, "").length,
+      });
+      pageNumber++;
+      currentPageHTML = "";
+      currentHeight = 0;
+    }
+
+    currentPageHTML += block.outerHTML;
+    currentHeight += blockHeight;
+  }
+
+  // Push final page
+  if (currentPageHTML.length > 0 || pages.length === 0) {
+    pages.push({
+      pageNumber,
+      spineIndex,
+      html: wrapInPageContainer(currentPageHTML, pageNumber, pageCount),
+      charCount: currentPageHTML.replace(/<[^>]*>/g, "").length,
+    });
+  }
+
+  return { pages, totalPages: pages.length };
+}
+// Split content using CFI (for EPUB)
+export function splitByCFI(
+  html: string,
+  spineIndex: number,
+  spineItemId: string,
+  viewportHeight: number,
+  settings: { fontSize: number; lineHeight: number; marginWidth: number },
+): PageSplitResult {
+  console.log("splitByCFI called:", {
+    htmlLength: html.length,
+    viewportHeight,
+    spineIndex,
+  });
+  const pages: PageContent[] = [];
+  const doc = new DOMParser().parseFromString(html, "text/html");
+
+  // Find all text-containing elements (paragraphs, divs, etc.)
+  const elements = findTextElements(doc.body);
+
+  let currentPageElements: Element[] = [];
+  let currentHeight = 0;
+  const contentWidth = doc.body.scrollWidth || 600;
+  let pageNumber = 1;
+  let elementIndex = 0;
+
+  for (const element of elements) {
+    const elementHeight = estimateBlockHeight(element, settings, contentWidth);
+
+    if (
+      currentHeight + elementHeight > viewportHeight &&
+      currentPageElements.length > 0
+    ) {
+      // Create page from accumulated elements
+      const pageHTML = elementsToHTML(currentPageElements);
+      const startIndex = elements.indexOf(currentPageElements[0]);
+      const endIndex = elements.indexOf(
+        currentPageElements[currentPageElements.length - 1],
+      );
+
+      pages.push({
+        pageNumber,
+        spineIndex,
+        startCFI: generateCFI(
+          spineIndex,
+          buildElementPath(elements[startIndex], doc.body),
+          0,
+          spineItemId,
+        ),
+        endCFI: generateCFI(
+          spineIndex,
+          buildElementPath(elements[endIndex], doc.body),
+          0,
+          spineItemId,
+        ),
+        html: wrapInPageContainer(pageHTML, pageNumber, 0), // pageCount TBD
+        charCount: pageHTML.replace(/<[^>]*>/g, "").length,
+      });
+
+      pageNumber++;
+      currentPageElements = [];
+      currentHeight = 0;
+    }
+
+    currentPageElements.push(element);
+    currentHeight += elementHeight;
+    elementIndex++;
+  }
+
+  // Push final page
+  if (currentPageElements.length > 0) {
+    const pageHTML = elementsToHTML(currentPageElements);
+    const startIndex = elements.indexOf(currentPageElements[0]);
+    const endIndex = elements.indexOf(
+      currentPageElements[currentPageElements.length - 1],
+    );
+
+    pages.push({
+      pageNumber,
+      spineIndex,
+      startCFI: generateCFI(
+        spineIndex,
+        buildElementPath(elements[startIndex], doc.body),
+        0,
+        spineItemId,
+      ),
+      endCFI: generateCFI(
+        spineIndex,
+        buildElementPath(elements[endIndex], doc.body),
+        0,
+        spineItemId,
+      ),
+      html: wrapInPageContainer(pageHTML, pageNumber, pageNumber),
+      charCount: pageHTML.replace(/<[^>]*>/g, "").length,
+    });
+  }
+  console.log("splitByCFI result:", {
+    totalPages: pages.length,
+    elementsFound: elements.length,
+    contentWidth,
+  });
+  return { pages, totalPages: pages.length };
+}
+// Helper: Estimate content height
+function estimateContentHeight(element: Element, settings: any): number {
+  const text = element.textContent || "";
+  const charCount = text.length;
+  const charsPerLine = Math.floor(
+    (800 - settings.marginWidth * 2) / (settings.fontSize * 0.6),
+  );
+  const lineCount = Math.ceil(charCount / charsPerLine);
+  return lineCount * settings.fontSize * settings.lineHeight;
+}
+// Helper: Estimate block height
+function estimateBlockHeight(
+  element: Element,
+  settings: any,
+  contentWidth: number,
+): number {
+  const text = element.textContent || "";
+  const approxChars = text.length;
+  const lineHeight = settings.fontSize * settings.lineHeight;
+  // Use actual content width instead of hardcoded 800
+  const charsPerLine = Math.floor(contentWidth / (settings.fontSize * 0.6));
+  const lineCount = Math.max(1, Math.ceil(approxChars / charsPerLine));
+  return lineCount * lineHeight + 16;
+}
+// Helper: Find text-containing elements using querySelectorAll
+function findTextElements(element: Element): Element[] {
+  const selector = [
+    "p",
+    "div",
+    "span",
+    "h1",
+    "h2",
+    "h3",
+    "h4",
+    "h5",
+    "h6",
+    "li",
+    "td",
+    "th",
+    "article",
+    "section",
+    "blockquote",
+    "pre",
+    "figcaption",
+    "header",
+    "footer",
+    "main",
+    "aside",
+  ].join(",");
+
+  return Array.from(element.querySelectorAll(selector)).filter((el) => {
+    const text = el.textContent?.trim() || "";
+    return text.length > 0;
+  });
+}
+// Helper: Convert elements to HTML string
+function elementsToHTML(elements: Element[]): string {
+  return elements.map((el) => el.outerHTML).join("");
+}
+// Helper: Build CFI element path
+function buildElementPath(element: Element, root: Element): number[] {
+  const path: number[] = [];
+  let current: Element | null = element;
+
+  while (current && current !== root) {
+    const parent = current.parentElement;
+    if (parent) {
+      const siblings = Array.from(parent.children);
+      const index = siblings.indexOf(current);
+      path.unshift(index);
+      current = parent;
+    } else {
+      break;
+    }
+  }
+
+  return path;
+}
+// Helper: Wrap content in page container
+function wrapInPageContainer(
+  html: string,
+  current: number,
+  total: number,
+): string {
+  return `<div class="ebook-page" data-page="${current}" data-total="${total}">${html}</div>`;
+}
+// Main entry point - choose method based on format
+export function splitContent(
+  html: string,
+  spineIndex: number,
+  spineItemId: string | null,
+  viewportHeight: number,
+  settings: { fontSize: number; lineHeight: number; marginWidth: number },
+  useCFI: boolean = true,
+): PageSplitResult {
+  if (useCFI && spineItemId) {
+    return splitByCFI(html, spineIndex, spineItemId, viewportHeight, settings);
+  }
+  return splitByHeight(html, spineIndex, viewportHeight, settings);
+}

web/src/reader/ebook/view-modes.ts

@@ -56,10 +56,10 @@ function setViewMode(container: HTMLElement, mode: ViewMode): void {
 
   switch (mode) {
     case "paginated":
-      applyPaginatedMode(container, element);
+      applyPaginatedMode(element);
       break;
     case "scrolled":
-      applyScrolledMode(container, element);
+      applyScrolledMode(element);
       break;
     case "single-column":
       applySingleColumn(element);
@@ -70,28 +70,56 @@ function setViewMode(container: HTMLElement, mode: ViewMode): void {
   }
 }
 
-function applyPaginatedMode(
-  container: HTMLElement,
-  element: HTMLElement,
-): void {
+function applyPaginatedMode(element: HTMLElement): void {
   element.classList.add("paginated");
 
-  element.style.height = "100vh";
+  // True pagination: content fits exactly in viewport, no scrolling
+  element.style.height = "calc(100vh - 120px)"; // Account for chrome (top 60px + bottom 60px)
   element.style.overflow = "hidden";
   element.style.columnCount = "1";
   element.style.columnGap = "0";
+  element.style.position = "relative";
 
-  enablePagination(container, element);
+  // Inject CSS for page clipping
+  injectPaginatedStyles();
 }
 
-function applyScrolledMode(container: HTMLElement, element: HTMLElement): void {
+function injectPaginatedStyles(): void {
+  // Remove existing injected styles if any
+  const existing = document.getElementById("paginated-styles");
+  existing?.remove();
+
+  const style = document.createElement("style");
+  style.id = "paginated-styles";
+  style.textContent = `
+    .paginated .ebook-page {
+      height: 100%;
+      overflow: hidden;
+      display: flex;
+      flex-direction: column;
+    }
+    .paginated .ebook-page > * {
+      max-height: 100%;
+      overflow: hidden;
+    }
+    .paginated .ebook-content {
+      height: 100%;
+      overflow: hidden !important;
+      position: relative;
+    }
+    .paginated .ebook-content * {
+      overflow-wrap: break-word;
+    }
+  `;
+  document.head.appendChild(style);
+}
+
+function applyScrolledMode(element: HTMLElement): void {
   element.classList.add("scrolled");
 
   element.style.height = "auto";
   element.style.overflowY = "auto";
   element.style.columnCount = "1";
-
-  disablePagination(container);
 }
 
 function applySingleColumn(element: HTMLElement): void {
@@ -113,51 +141,6 @@ function applyDoubleColumn(element: HTMLElement): void {
   element.style.margin = "0 auto";
 }
 
-function enablePagination(container: HTMLElement, element: HTMLElement): void {
-  const totalHeight = element.scrollHeight;
-  const pageHeight = element.clientHeight;
-  const pageCount = Math.ceil(totalHeight / pageHeight);
-
-  addPaginationControls(container, pageCount);
-}
-
-function disablePagination(container: HTMLElement): void {
-  const controls = container.querySelector(".pagination-controls");
-  controls?.remove();
-}
-
-function addPaginationControls(
-  container: HTMLElement,
-  pageCount: number,
-): void {
-  let currentPage = 1;
-
-  const controls = document.createElement("div");
-  controls.className =
-    "pagination-controls fixed bottom-0 left-0 right-0 bg-opacity-95 backdrop-blur border-t";
-  controls.innerHTML = `
-    <button class="prev-page" ${currentPage === 1 ? "disabled" : ""}>← Previous</button>
-    <span class="page-info">Page ${currentPage} of ${pageCount}</span>
-    <button class="next-page" ${currentPage === pageCount ? "disabled" : ""}>Next →</button>
-  `;
-
-  controls.querySelector(".prev-page")?.addEventListener("click", () => {
-    if (currentPage > 1) {
-      currentPage--;
-      goToPage(container, currentPage);
-    }
-  });
-
-  controls.querySelector(".next-page")?.addEventListener("click", () => {
-    if (currentPage < pageCount) {
-      currentPage++;
-      goToPage(container, currentPage);
-    }
-  });
-
-  container.appendChild(controls);
-}
-
 function goToPage(container: HTMLElement, pageNumber: number): void {
   const content = container.querySelector(".ebook-content") as HTMLElement;
   if (!content) return;
@@ -196,4 +179,5 @@ export function getCurrentViewMode(container: HTMLElement): ViewMode {
   if (content.classList.contains("double-column")) return "double-column";
 
   return "paginated";
-}
+}
+

web/src/reader/features/progress-indicator.ts

@@ -1,5 +1,4 @@
 import type { ReaderContext } from "../core/reader-context";
-import { getCurrentPageFromScroll } from "../ebook/page-calculator";
 interface ProgressDisplay {
   mode: "pages" | "chapter" | "percentage" | "time-left";
   text: string;
@@ -111,35 +110,50 @@ function updateProgressDisplay(context: ReaderContext): void {
   if (!display || !state.currentReader) return;
   let currentPage = 0;
   let totalPages = 0;
+  let currentChapterPage = 0;
+  let chapterPages = 0;
   if (state.currentReader.type === "ebook") {
     const reader = state.currentReader as any;
-    const pageInfo = reader.pageCalculationResult;
 
-    if (pageInfo && pageInfo.totalPages > 0) {
-      const container = document.getElementById("reader-content");
-      const viewportHeight = window.innerHeight;
-      currentPage = getCurrentPageFromScroll(
-        pageInfo,
-        reader.currentSpineIndex,
-        container?.scrollTop || 0,
-        viewportHeight,
-      );
-      totalPages = pageInfo.totalPages;
-    } else {
-      // Fallback to estimated pages while calculating
+    // Use currentPage directly if available (page-based navigation)
+    if (reader.currentPage) {
+      currentPage = reader.currentPage;
+    } else if (reader.currentSpineIndex !== undefined) {
       currentPage = reader.currentSpineIndex + 1;
+    }
+
+    // Get total pages from calculation result
+    const pageInfo = reader.pageCalculationResult;
+    if (pageInfo && pageInfo.totalPages > 0) {
+      totalPages = pageInfo.totalPages;
+
+      // Get chapter progress
+      const chapter = pageInfo.chapterMap.get(reader.currentSpineIndex);
+      if (chapter) {
+        currentChapterPage = currentPage - chapter.startPage + 1;
+        chapterPages = chapter.pagesInChapter;
+      }
+    } else {
+      // Fallback
       totalPages =
         state.readerMetadata?.total_pages ||
         state.currentReader.cif.locations?.estimatedPages ||
         state.currentReader.cif.spine.length;
     }
+  } else if (state.currentReader.type === "pdf") {
+    currentPage = state.currentReader.currentPage;
+    totalPages = state.readerMetadata?.total_pages || 0;
+  } else {
+    // Comic/manga
+    currentPage = (state.currentReader as any).currentPage + 1;
+    totalPages = (state.currentReader as any).images?.length || 0;
   }
   getReadingSpeed().then((speed) => {
     const result = calculateProgress(
       currentPage,
       totalPages,
-      0,
-      0,
+      currentChapterPage,
+      chapterPages,
       speed || undefined,
     );
     display.textContent = result.text;

web/src/reader/reader-shell.ts

@@ -11,6 +11,8 @@ export interface UniversalReader {
   type: "ebook";
   cif: any;
   currentSpineIndex: number;
+  currentPage: number;
+  pageCalculationResult?: any;
 }
 
 interface PDFReader {
@@ -143,17 +145,15 @@ async function initializeReader(): Promise<void> {
 
     await initializeFeatures(context);
     readerEvents.emit("readerReady", currentReader);
-    // Render the initial chapter content
+    // Initialize page calculation FIRST, before any rendering
+    const { initializePageCalculation } =
+      await import("./core/reader-navigation");
+    await initializePageCalculation();
+    // Then render the initial chapter content
     await renderSpineItem();
     // Focus the content container so keyboard navigation works immediately
     const container = document.getElementById("reader-content");
     container?.focus();
-    // Initialize page calculation for dynamic page numbers
-    setTimeout(async () => {
-      const { initializePageCalculation } =
-        await import("./core/reader-navigation");
-      initializePageCalculation();
-    }, 100);
   } catch (error) {
     console.error("Render initialization failed:", error);
   }
@@ -206,6 +206,7 @@ async function initializeEbookReader(metadata: any): Promise<UniversalReader> {
     type: "ebook",
     cif,
     currentSpineIndex: 0,
+    currentPage: 1,
   };
 }