From ac6d9e84c673633fdfb2dddab1b4e0542df964a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=9A=D1=83=D1=80=D0=BD=D0=B0=D1=82=20=D0=90=D0=BD=D0=B4?=
 =?UTF-8?q?=D1=80=D0=B5=D0=B9?= <sevenhill@live.ru>
Date: Sat, 14 Feb 2026 23:37:08 +0300
Subject: [PATCH] edit

---
 BookReader/Resources/Raw/wwwroot/index.html | 1044 +++++++++----------
 BookReader/ViewModels/ReaderViewModel.cs    |    4 +
 BookReader/Views/ReaderPage.xaml            |    1 +
 BookReader/Views/ReaderPage.xaml.cs         |   12 +-
 4 files changed, 509 insertions(+), 552 deletions(-)

diff --git a/BookReader/Resources/Raw/wwwroot/index.html b/BookReader/Resources/Raw/wwwroot/index.html
index f99416f..4f76275 100644
--- a/BookReader/Resources/Raw/wwwroot/index.html
+++ b/BookReader/Resources/Raw/wwwroot/index.html
@@ -29,7 +29,7 @@
             overflow: hidden;
         }
 
-        #book-content {
+        #book-content, #fb2-content {
             width: 100%;
             height: 100%;
             position: absolute;
@@ -38,8 +38,6 @@
         }
 
         #fb2-content {
-            width: 100%;
-            height: 100%;
             overflow: hidden;
             padding: 20px;
             font-size: 18px;
@@ -58,14 +56,14 @@
             gap: 15px;
         }
 
-            #loading .spinner {
-                width: 40px;
-                height: 40px;
-                border: 4px solid #ddd;
-                border-top: 4px solid #5D4037;
-                border-radius: 50%;
-                animation: spin 1s linear infinite;
-            }
+        .spinner {
+            width: 40px;
+            height: 40px;
+            border: 4px solid #ddd;
+            border-top-color: #5D4037;
+            border-radius: 50%;
+            animation: spin 1s linear infinite;
+        }
 
         @keyframes spin {
             to {
@@ -86,23 +84,8 @@
             gap: 10px;
         }
 
-        #debug-log {
-            position: fixed;
-            bottom: 0;
-            left: 0;
-            right: 0;
-            max-height: 200px;
-            overflow-y: auto;
-            background: rgba(0,0,0,0.9);
-            color: #0f0;
-            font-size: 11px;
-            font-family: monospace;
-            padding: 5px;
-            z-index: 9999;
-            display: none;
-        }
-        /* Прозрачные зоны для тачей поверх всего */
-        #touch-left, #touch-right, #touch-center {
+        /* Прозрачные зоны для тачей */
+        .touch-zone {
             position: fixed;
             top: 0;
             height: 100%;
@@ -138,166 +121,154 @@
             <span id="error-text"></span>
         </div>
     </div>
-    <!-- Невидимые зоны тачей поверх iframe epub.js -->
-    <div id="touch-left"></div>
-    <div id="touch-center"></div>
-    <div id="touch-right"></div>
+    <div id="touch-left" class="touch-zone"></div>
+    <div id="touch-center" class="touch-zone"></div>
+    <div id="touch-right" class="touch-zone"></div>
+
     <script src="_framework/hybridwebview.js"></script>
+    <script src="js/jszip.min.js"></script>
+    <script src="js/epub.min.js"></script>
     <script>
-        // ========== DEBUG LOGGING ==========
-        function debugLog(msg) {
-            console.log('[Reader] ' + msg);
-        }
+        (function () {
+            'use strict';
 
-        function showError(msg) {
-            document.getElementById('loading').style.display = 'none';
-            document.getElementById('error-display').style.display = 'flex';
-            document.getElementById('error-text').textContent = msg;
-            debugLog('ERROR: ' + msg);
-        }
+            // ========== КЭШИРОВАННЫЕ DOM-ЭЛЕМЕНТЫ ==========
+            const $ = id => document.getElementById(id);
+            const els = {
+                loading: $('loading'),
+                loadingText: $('loading-text'),
+                errorDisplay: $('error-display'),
+                errorText: $('error-text'),
+                bookContent: $('book-content'),
+                fb2Content: $('fb2-content'),
+            };
 
-        function setLoadingText(msg) {
-            var el = document.getElementById('loading-text');
-            if (el) el.textContent = msg;
-            debugLog(msg);
-        }
+            // ========== СОСТОЯНИЕ ==========
+            const state = {
+                book: null,
+                rendition: null,
+                currentCfi: null,
+                totalPages: 0,
+                currentPage: 0,
+                bookFormat: '',
+                isBookLoaded: false,
+                fb2CurrentPage: 0,
+                fb2TotalPages: 1,
+            };
 
-        // ========== MESSAGE BRIDGE ==========
-        function sendMessage(action, data) {
-            var message = JSON.stringify({ action: action, data: data || {} });
+            // ========== УТИЛИТЫ ==========
+            function debugLog(msg) {
+                console.log('[Reader] ' + msg);
+            }
 
-            try {
-                // .NET MAUI HybridWebView uses hybridWebViewHost
-                if (window.HybridWebView && typeof window.HybridWebView.SendRawMessage === 'function') {
-                    window.HybridWebView.SendRawMessage(message);
-                    return;
+            function showError(msg) {
+                els.loading.style.display = 'none';
+                els.errorDisplay.style.display = 'flex';
+                els.errorText.textContent = msg;
+                debugLog('ERROR: ' + msg);
+            }
+
+            function setLoadingText(msg) {
+                if (els.loadingText) els.loadingText.textContent = msg;
+                debugLog(msg);
+            }
+
+            // Один div для escapeHtml — переиспользуем
+            const _escDiv = document.createElement('div');
+            function escapeHtml(text) {
+                _escDiv.textContent = text;
+                return _escDiv.innerHTML;
+            }
+
+            function base64ToArrayBuffer(base64) {
+                const bin = atob(base64);
+                const len = bin.length;
+                const buf = new ArrayBuffer(len);
+                const view = new Uint8Array(buf);
+                // Обработка блоками для больших файлов — снижает давление на GC
+                for (let i = 0; i < len; i++) {
+                    view[i] = bin.charCodeAt(i);
                 }
-
-                debugLog('No bridge method found on hybridWebViewHost');
-            } catch (e) {
-                debugLog('Bridge error: ' + e.message);
+                return buf;
             }
-        }
 
-        // ========== TOUCH ZONES ==========
-        document.getElementById('touch-left').addEventListener('click', function (e) {
-            e.preventDefault();
-            e.stopPropagation();
-            prevPage();
-        });
-
-        document.getElementById('touch-right').addEventListener('click', function (e) {
-            e.preventDefault();
-            e.stopPropagation();
-            nextPage();
-        });
-
-        document.getElementById('touch-center').addEventListener('click', function (e) {
-            e.preventDefault();
-            e.stopPropagation();
-            sendMessage('toggleMenu', {});
-        });
-
-        // Свайпы на зонах
-        var swipeStartX = 0, swipeStartY = 0, swipeStartTime = 0;
-
-        function onSwipeStart(e) {
-            var touch = e.touches ? e.touches[0] : e;
-            swipeStartX = touch.clientX;
-            swipeStartY = touch.clientY;
-            swipeStartTime = Date.now();
-        }
-
-        function onSwipeEnd(e) {
-            var touch = e.changedTouches ? e.changedTouches[0] : e;
-            var dx = touch.clientX - swipeStartX;
-            var dy = touch.clientY - swipeStartY;
-            var dt = Date.now() - swipeStartTime;
-
-            if (dt > 500) return;
-            if (Math.abs(dx) > Math.abs(dy) && Math.abs(dx) > 50) {
-                if (dx < 0) nextPage();
-                else prevPage();
-            }
-        }
-
-        ['touch-left', 'touch-center', 'touch-right'].forEach(function (id) {
-            var el = document.getElementById(id);
-            el.addEventListener('touchstart', onSwipeStart, { passive: true });
-            el.addEventListener('touchend', onSwipeEnd, { passive: true });
-        });
-        // ========== EPUB READER ==========
-        var book = null;
-        var rendition = null;
-        var currentCfi = null;
-        var totalPages = 0;
-        var currentPage = 0;
-        var bookFormat = '';
-        var isBookLoaded = false;
-
-        window.loadBookFromBase64 = function (base64Data, format, lastPosition) {
-            debugLog('loadBookFromBase64: format=' + format + ', len=' + (base64Data ? base64Data.length : 0));
-            bookFormat = format;
-
-            if (format === 'epub') {
-                loadEpubFromBase64(base64Data, lastPosition);
-            } else if (format === 'fb2') {
-                loadFb2FromBase64(base64Data, lastPosition);
-            } else {
-                showError('Unsupported format: ' + format);
-            }
-        };
-
-        function base64ToArrayBuffer(base64) {
-            var binaryString = atob(base64);
-            var len = binaryString.length;
-            var bytes = new Uint8Array(len);
-            for (var i = 0; i < len; i++) {
-                bytes[i] = binaryString.charCodeAt(i);
-            }
-            return bytes.buffer;
-        }
-
-        function loadEpubFromBase64(base64Data, lastCfi) {
-            setLoadingText('Decoding EPUB...');
-
-            try {
-                var arrayBuffer = base64ToArrayBuffer(base64Data);
-                debugLog('EPUB size: ' + arrayBuffer.byteLength + ' bytes');
-
-                // Check JSZip
-                if (typeof JSZip === 'undefined') {
-                    showError('JSZip not loaded! Cannot open EPUB.');
-                    return;
+            // ========== MESSAGE BRIDGE ==========
+            function sendMessage(action, data) {
+                const message = JSON.stringify({ action, data: data || {} });
+                try {
+                    if (window.HybridWebView && typeof window.HybridWebView.SendRawMessage === 'function') {
+                        window.HybridWebView.SendRawMessage(message);
+                    }
+                } catch (e) {
+                    debugLog('Bridge error: ' + e.message);
                 }
-                debugLog('JSZip version: ' + (JSZip.version || 'unknown'));
+            }
 
-                // Check epub.js
-                if (typeof ePub === 'undefined') {
-                    showError('epub.js not loaded!');
-                    return;
-                }
-                debugLog('ePub function available');
+            // ========== TOUCH / SWIPE ==========
+            let swipeStartX = 0, swipeStartY = 0, swipeStartTime = 0;
 
-                setLoadingText('Opening EPUB...');
+            const touchActions = {
+                'touch-left': () => window.prevPage(),
+                'touch-right': () => window.nextPage(),
+                'touch-center': () => sendMessage('toggleMenu', {}),
+            };
 
-                // First unzip manually to verify the file is valid
-                JSZip.loadAsync(arrayBuffer).then(function (zip) {
-                    debugLog('ZIP opened, files: ' + Object.keys(zip.files).length);
+            function initTouchZones() {
+                Object.keys(touchActions).forEach(id => {
+                    const el = $(id);
+                    if (!el) return;
 
-                    // Now use epub.js
-                    book = ePub(arrayBuffer);
+                    el.addEventListener('click', e => {
+                        e.preventDefault();
+                        e.stopPropagation();
+                        touchActions[id]();
+                    });
 
-                    document.getElementById('fb2-content').style.display = 'none';
-                    document.getElementById('book-content').style.display = 'block';
+                    el.addEventListener('touchstart', e => {
+                        const t = e.touches[0];
+                        swipeStartX = t.clientX;
+                        swipeStartY = t.clientY;
+                        swipeStartTime = Date.now();
+                    }, { passive: true });
 
-                    rendition = book.renderTo('book-content', {
+                    el.addEventListener('touchend', e => {
+                        const t = e.changedTouches[0];
+                        const dx = t.clientX - swipeStartX;
+                        const dt = Date.now() - swipeStartTime;
+                        if (dt < 500 && Math.abs(dx) > Math.abs(t.clientY - swipeStartY) && Math.abs(dx) > 50) {
+                            dx < 0 ? window.nextPage() : window.prevPage();
+                        }
+                    }, { passive: true });
+                });
+            }
+
+            // ========== EPUB ==========
+            function loadEpubFromBase64(base64Data, lastCfi) {
+                setLoadingText('Decoding EPUB...');
+
+                try {
+                    const arrayBuffer = base64ToArrayBuffer(base64Data);
+                    debugLog('EPUB size: ' + arrayBuffer.byteLength + ' bytes');
+
+                    if (typeof JSZip === 'undefined') { showError('JSZip not loaded!'); return; }
+                    if (typeof ePub === 'undefined') { showError('epub.js not loaded!'); return; }
+
+                    setLoadingText('Opening EPUB...');
+
+                    // epub.js сам умеет работать с ArrayBuffer — двойная распаковка не нужна
+                    state.book = ePub(arrayBuffer);
+
+                    els.fb2Content.style.display = 'none';
+                    els.bookContent.style.display = 'block';
+
+                    state.rendition = state.book.renderTo('book-content', {
                         width: '100%',
                         height: '100%',
                         spread: 'none',
                         flow: 'paginated'
                     });
-                    rendition.themes.default({
+
+                    state.rendition.themes.default({
                         'body': {
                             'font-family': 'serif !important',
                             'font-size': '18px !important',
@@ -306,429 +277,400 @@
                             'background-color': '#faf8ef !important',
                             'color': '#333 !important'
                         },
-                        'p': {
-                            'text-indent': '1.5em',
-                            'margin-bottom': '0.5em'
-                        }
+                        'p': { 'text-indent': '1.5em', 'margin-bottom': '0.5em' }
                     });
 
-                    book.ready.then(function () {
-                        debugLog('EPUB ready');
-                        document.getElementById('loading').style.display = 'none';
+                    state.book.ready
+                        .then(() => {
+                            debugLog('EPUB ready');
+                            els.loading.style.display = 'none';
 
-                        try {
-                            var toc = book.navigation.toc || [];
-                            var chapters = toc.map(function (ch) {
-                                return { label: (ch.label || '').trim(), href: ch.href || '' };
-                            });
-                            sendMessage('chaptersLoaded', { chapters: chapters });
-                            debugLog('TOC chapters: ' + chapters.length);
-                        } catch (e) {
-                            debugLog('TOC error: ' + e.message);
-                        }
+                            try {
+                                const toc = state.book.navigation.toc || [];
+                                const chapters = toc.map(ch => ({
+                                    label: (ch.label || '').trim(),
+                                    href: ch.href || ''
+                                }));
+                                sendMessage('chaptersLoaded', { chapters });
+                            } catch (e) {
+                                debugLog('TOC error: ' + e.message);
+                            }
 
-                        return book.locations.generate(1600);
-                    }).then(function () {
-                        totalPages = book.locations.length();
-                        debugLog('Pages: ' + totalPages);
-                        sendMessage('bookReady', { totalPages: totalPages });
-                        isBookLoaded = true;
-                    }).catch(function (e) {
-                        debugLog('Book ready error: ' + e.message);
-                    });
+                            return state.book.locations.generate(1600);
+                        })
+                        .then(() => {
+                            state.totalPages = state.book.locations.length();
+                            debugLog('Pages: ' + state.totalPages);
+                            sendMessage('bookReady', { totalPages: state.totalPages });
+                            state.isBookLoaded = true;
+                        })
+                        .catch(e => debugLog('Book ready error: ' + e.message));
 
-                    rendition.on('relocated', function (location) {
+                    state.rendition.on('relocated', location => {
                         if (!location || !location.start) return;
-                        currentCfi = location.start.cfi;
+                        state.currentCfi = location.start.cfi;
                         try {
-                            var progress = book.locations.percentageFromCfi(currentCfi) || 0;
-                            currentPage = location.start.location || 0;
                             sendMessage('progressUpdate', {
-                                progress: progress,
-                                cfi: currentCfi,
-                                currentPage: currentPage,
-                                totalPages: totalPages,
+                                progress: state.book.locations.percentageFromCfi(state.currentCfi) || 0,
+                                cfi: state.currentCfi,
+                                currentPage: location.start.location || 0,
+                                totalPages: state.totalPages,
                                 chapter: location.start.href || ''
                             });
-                        } catch (e) { }
+                        } catch (e) {
+                            debugLog('Relocated error: ' + e.message);
+                        }
                     });
 
                     setLoadingText('Rendering...');
+                    const displayTarget = (lastCfi && lastCfi !== 'null' && lastCfi !== 'undefined')
+                        ? lastCfi : undefined;
+                    state.rendition.display(displayTarget);
 
-                    if (lastCfi && lastCfi.length > 0 && lastCfi !== 'null' && lastCfi !== 'undefined') {
-                        rendition.display(lastCfi);
-                    } else {
-                        rendition.display();
+                } catch (e) {
+                    showError('EPUB load error: ' + e.message);
+                }
+            }
+
+            // ========== FB2 ==========
+            function loadFb2FromBase64(base64Data, lastPosition) {
+                setLoadingText('Parsing FB2...');
+
+                try {
+                    const arrayBuffer = base64ToArrayBuffer(base64Data);
+                    const bytes = new Uint8Array(arrayBuffer);
+
+                    let xmlText = new TextDecoder('utf-8').decode(bytes);
+
+                    // Перекодируем если нужно
+                    const encMatch = xmlText.match(/encoding=["\']([^"\']+)["\']/i);
+                    if (encMatch) {
+                        const enc = encMatch[1].toLowerCase();
+                        debugLog('FB2 encoding: ' + enc);
+                        if (enc !== 'utf-8') {
+                            try { xmlText = new TextDecoder(enc).decode(bytes); }
+                            catch (e) { debugLog('Re-decode error: ' + e.message); }
+                        }
                     }
 
-                }).catch(function (e) {
-                    showError('ZIP error: ' + e.message);
+                    els.bookContent.style.display = 'none';
+                    els.fb2Content.style.display = 'block';
+
+                    const doc = new DOMParser().parseFromString(xmlText, 'text/xml');
+                    if (doc.querySelector('parsererror')) {
+                        showError('FB2 XML parse error');
+                        return;
+                    }
+
+                    const fb2Html = parseFb2Document(doc);
+                    els.fb2Content.innerHTML = fb2Html.html;
+                    els.loading.style.display = 'none';
+
+                    // Используем requestAnimationFrame вместо setTimeout для точного тайминга
+                    requestAnimationFrame(() => {
+                        requestAnimationFrame(() => {
+                            setupFb2Pagination();
+                            sendMessage('chaptersLoaded', { chapters: fb2Html.chapters });
+                            sendMessage('bookReady', { totalPages: state.totalPages });
+                            state.isBookLoaded = true;
+                            state.bookFormat = 'fb2';
+
+                            if (lastPosition && parseFloat(lastPosition) > 0) {
+                                goToFb2Position(parseFloat(lastPosition));
+                            }
+                            updateFb2Progress();
+                        });
+                    });
+
+                } catch (e) {
+                    showError('FB2 error: ' + e.message);
+                }
+            }
+
+            // ========== FB2 PARSER ==========
+            // Вспомогательная: получить локальное имя тега без namespace
+            function localTag(el) {
+                return el.tagName ? el.tagName.toLowerCase().replace(/.*:/, '') : '';
+            }
+
+            function parseFb2Document(doc) {
+                const chapters = [];
+                const parts = ['<div id="fb2-inner" style="font-size:18px;font-family:serif;line-height:1.6;">'];
+
+                let bodies = doc.querySelectorAll('body');
+                if (!bodies.length) {
+                    bodies = doc.getElementsByTagNameNS('http://www.gribuser.ru/xml/fictionbook/2.0', 'body');
+                }
+
+                let chapterIndex = 0;
+                for (const body of bodies) {
+                    for (const child of body.children) {
+                        if (localTag(child) === 'section') {
+                            const result = parseFb2Section(child, chapterIndex);
+                            parts.push(result.html);
+                            chapters.push(...result.chapters);
+                            chapterIndex += Math.max(result.chapters.length, 1);
+                        }
+                    }
+                }
+
+                parts.push('</div>');
+                if (!chapters.length) chapters.push({ label: 'Start', href: '0' });
+                return { html: parts.join(''), chapters };
+            }
+
+            // Маппинг тегов FB2 → генераторы HTML
+            const sectionTagHandlers = {
+                title(child, idx, chapters) {
+                    const text = (child.textContent || '').trim();
+                    chapters.push({ label: text, href: idx.toString() });
+                    return `<h2 class="fb2-title" data-chapter="${idx}" style="text-align:center;margin:1em 0 .5em">${escapeHtml(text)}</h2>`;
+                },
+                p(child) {
+                    return `<p style="text-indent:1.5em;margin-bottom:.3em">${getInlineHtml(child)}</p>`;
+                },
+                'empty-line'() { return '<br/>'; },
+                subtitle(child) {
+                    return `<h3 style="text-align:center;margin:.8em 0">${escapeHtml(child.textContent || '')}</h3>`;
+                },
+                epigraph(child) {
+                    return `<blockquote style="font-style:italic;margin:1em 2em">${parseInnerParagraphs(child)}</blockquote>`;
+                },
+                poem(child) {
+                    return `<div style="margin:1em 2em">${parsePoem(child)}</div>`;
+                },
+                cite(child) {
+                    return `<blockquote style="margin:1em 2em;padding-left:1em;border-left:3px solid #ccc">${parseInnerParagraphs(child)}</blockquote>`;
+                },
+            };
+
+            function parseFb2Section(section, startIndex) {
+                const chapters = [];
+                const parts = [`<div class="fb2-section" data-section="${startIndex}">`];
+
+                for (const child of section.children) {
+                    const tag = localTag(child);
+
+                    if (tag === 'section') {
+                        const sub = parseFb2Section(child, startIndex + chapters.length);
+                        parts.push(sub.html);
+                        chapters.push(...sub.chapters);
+                    } else if (sectionTagHandlers[tag]) {
+                        parts.push(sectionTagHandlers[tag](child, startIndex + chapters.length, chapters));
+                    }
+                }
+
+                parts.push('</div>');
+                return { html: parts.join(''), chapters };
+            }
+
+            function getInlineHtml(el) {
+                const parts = [];
+                for (const node of el.childNodes) {
+                    if (node.nodeType === 3) {
+                        parts.push(escapeHtml(node.textContent));
+                    } else if (node.nodeType === 1) {
+                        const tag = localTag(node);
+                        const inner = getInlineHtml(node);
+                        if (tag === 'strong' || tag === 'bold') parts.push(`<strong>${inner}</strong>`);
+                        else if (tag === 'emphasis' || tag === 'em') parts.push(`<em>${inner}</em>`);
+                        else if (tag === 'strikethrough') parts.push(`<s>${inner}</s>`);
+                        else parts.push(inner);
+                    }
+                }
+                return parts.join('');
+            }
+
+            function parseInnerParagraphs(el) {
+                const parts = [];
+                for (const child of el.children) {
+                    const tag = localTag(child);
+                    if (tag === 'p') parts.push(`<p>${getInlineHtml(child)}</p>`);
+                    else if (tag === 'text-author') parts.push(`<p style="text-align:right;font-style:italic">— ${escapeHtml(child.textContent || '')}</p>`);
+                }
+                return parts.join('');
+            }
+
+            function parsePoem(el) {
+                const parts = [];
+                for (const child of el.children) {
+                    const tag = localTag(child);
+                    if (tag === 'stanza') {
+                        parts.push('<div style="margin-bottom:1em">');
+                        for (const v of child.children) {
+                            if (localTag(v) === 'v') parts.push(`<p style="text-indent:0">${escapeHtml(v.textContent || '')}</p>`);
+                        }
+                        parts.push('</div>');
+                    } else if (tag === 'title') {
+                        parts.push(`<h4>${escapeHtml(child.textContent || '')}</h4>`);
+                    }
+                }
+                return parts.join('');
+            }
+
+            // ========== FB2 PAGINATION ==========
+            function setupFb2Pagination() {
+                const container = els.fb2Content;
+                const inner = $('fb2-inner');
+                if (!container || !inner) return;
+
+                const w = container.clientWidth;
+                const h = container.clientHeight;
+
+                Object.assign(inner.style, {
+                    columnWidth: w + 'px',
+                    columnGap: '40px',
+                    columnFill: 'auto',
+                    height: h + 'px',
+                    overflow: 'hidden',
                 });
 
-            } catch (e) {
-                showError('EPUB load error: ' + e.message);
+                // Даём браузеру отрисовать колонки
+                requestAnimationFrame(() => {
+                    state.fb2TotalPages = Math.max(1, Math.ceil(inner.scrollWidth / w));
+                    state.totalPages = state.fb2TotalPages;
+                    state.fb2CurrentPage = 0;
+                    showFb2Page(0);
+                    debugLog('FB2 pages: ' + state.fb2TotalPages);
+                });
             }
-        }
 
-        function loadFb2FromBase64(base64Data, lastPosition) {
-            setLoadingText('Parsing FB2...');
-
-            try {
-                var arrayBuffer = base64ToArrayBuffer(base64Data);
-                var bytes = new Uint8Array(arrayBuffer);
-
-                var xmlText;
-                try {
-                    xmlText = new TextDecoder('utf-8').decode(bytes);
-                } catch (e) {
-                    xmlText = new TextDecoder('windows-1251').decode(bytes);
+            function showFb2Page(idx) {
+                idx = Math.max(0, Math.min(idx, state.fb2TotalPages - 1));
+                state.fb2CurrentPage = idx;
+                const inner = $('fb2-inner');
+                if (inner) {
+                    inner.style.transform = `translateX(-${idx * els.fb2Content.clientWidth}px)`;
                 }
+            }
 
-                // Check encoding declaration and re-decode if needed
-                var encodingMatch = xmlText.match(/encoding=["\']([^"\']+)["\']/i);
-                if (encodingMatch) {
-                    var declaredEncoding = encodingMatch[1].toLowerCase();
-                    debugLog('FB2 encoding: ' + declaredEncoding);
-                    if (declaredEncoding !== 'utf-8') {
-                        try {
-                            xmlText = new TextDecoder(declaredEncoding).decode(bytes);
-                        } catch (e) {
-                            debugLog('Re-decode error: ' + e.message);
-                        }
-                    }
+            function updateFb2Progress() {
+                const total = state.fb2TotalPages;
+                const progress = total > 1 ? state.fb2CurrentPage / (total - 1) : 0;
+                sendMessage('progressUpdate', {
+                    progress,
+                    cfi: progress.toString(),
+                    currentPage: state.fb2CurrentPage + 1,
+                    totalPages: total,
+                    chapter: getCurrentFb2Chapter()
+                });
+            }
+
+            function getCurrentFb2Chapter() {
+                const inner = $('fb2-inner');
+                const container = els.fb2Content;
+                if (!inner || !container) return '';
+
+                const maxOffset = state.fb2CurrentPage * container.clientWidth + container.clientWidth;
+                let chapter = '';
+                const titles = inner.querySelectorAll('.fb2-title');
+                for (let i = 0; i < titles.length; i++) {
+                    if (titles[i].offsetLeft <= maxOffset) chapter = titles[i].textContent;
+                    else break; // Заголовки идут по порядку — можно прервать
                 }
+                return chapter;
+            }
 
-                document.getElementById('book-content').style.display = 'none';
-                document.getElementById('fb2-content').style.display = 'block';
+            function goToFb2Position(progress) {
+                showFb2Page(Math.round(progress * (state.fb2TotalPages - 1)));
+            }
 
-                var parser = new DOMParser();
-                var doc = parser.parseFromString(xmlText, 'text/xml');
+            // ========== PUBLIC API ==========
+            window.loadBookFromBase64 = function (base64Data, format, lastPosition) {
+                debugLog(`loadBookFromBase64: format=${format}, len=${base64Data ? base64Data.length : 0}`);
+                state.bookFormat = format;
 
-                var parseError = doc.querySelector('parsererror');
-                if (parseError) {
-                    showError('FB2 XML parse error');
-                    debugLog(parseError.textContent.substring(0, 200));
-                    return;
-                }
+                if (format === 'epub') loadEpubFromBase64(base64Data, lastPosition);
+                else if (format === 'fb2') loadFb2FromBase64(base64Data, lastPosition);
+                else showError('Unsupported format: ' + format);
+            };
 
-                var fb2Html = parseFb2Document(doc);
-                var fb2Container = document.getElementById('fb2-content');
-                fb2Container.innerHTML = fb2Html.html;
-
-                document.getElementById('loading').style.display = 'none';
-
-                setTimeout(function () {
-                    setupFb2Pagination();
-                    sendMessage('chaptersLoaded', { chapters: fb2Html.chapters });
-                    sendMessage('bookReady', { totalPages: totalPages });
-                    isBookLoaded = true;
-                    bookFormat = 'fb2';
-
-                    if (lastPosition && parseFloat(lastPosition) > 0) {
-                        goToFb2Position(parseFloat(lastPosition));
-                    }
+            window.nextPage = function () {
+                if (state.bookFormat === 'epub' && state.rendition) {
+                    state.rendition.next();
+                } else if (state.bookFormat === 'fb2' && state.fb2CurrentPage < state.fb2TotalPages - 1) {
+                    showFb2Page(state.fb2CurrentPage + 1);
                     updateFb2Progress();
-                }, 500);
+                }
+            };
 
-            } catch (e) {
-                showError('FB2 error: ' + e.message);
-            }
-        }
+            window.prevPage = function () {
+                if (state.bookFormat === 'epub' && state.rendition) {
+                    state.rendition.prev();
+                } else if (state.bookFormat === 'fb2' && state.fb2CurrentPage > 0) {
+                    showFb2Page(state.fb2CurrentPage - 1);
+                    updateFb2Progress();
+                }
+            };
 
-        // ========== FB2 PARSER ==========
-        function parseFb2Document(doc) {
-            var chapters = [];
-            var html = '<div id="fb2-inner" style="font-size:18px; font-family:serif; line-height:1.6;">';
+            window.setFontSize = function (size) {
+                if (state.bookFormat === 'epub' && state.rendition) {
+                    state.rendition.themes.fontSize(size + 'px');
+                } else if (state.bookFormat === 'fb2') {
+                    const inner = $('fb2-inner');
+                    if (inner) {
+                        inner.style.fontSize = size + 'px';
+                        requestAnimationFrame(setupFb2Pagination);
+                    }
+                }
+            };
 
-            var bodies = doc.querySelectorAll('body');
-            if (bodies.length === 0) {
-                bodies = doc.getElementsByTagNameNS('http://www.gribuser.ru/xml/fictionbook/2.0', 'body');
-            }
+            window.setFontFamily = function (family) {
+                if (state.bookFormat === 'epub' && state.rendition) {
+                    state.rendition.themes.font(family);
+                } else if (state.bookFormat === 'fb2') {
+                    const inner = $('fb2-inner');
+                    if (inner) {
+                        inner.style.fontFamily = family;
+                        requestAnimationFrame(setupFb2Pagination);
+                    }
+                }
+            };
 
-            var chapterIndex = 0;
-
-            for (var b = 0; b < bodies.length; b++) {
-                var children = bodies[b].children;
-                for (var s = 0; s < children.length; s++) {
-                    var child = children[s];
-                    var tagName = child.tagName ? child.tagName.toLowerCase().replace(/.*:/, '') : '';
-                    if (tagName === 'section') {
-                        var result = parseFb2Section(child, chapterIndex);
-                        html += result.html;
-                        for (var c = 0; c < result.chapters.length; c++) {
-                            chapters.push(result.chapters[c]);
+            window.goToChapter = function (href) {
+                if (state.bookFormat === 'epub' && state.rendition) {
+                    state.rendition.display(href);
+                } else if (state.bookFormat === 'fb2') {
+                    const inner = $('fb2-inner');
+                    const container = els.fb2Content;
+                    if (inner && container) {
+                        const el = inner.querySelector(`[data-chapter="${href}"]`);
+                        if (el) {
+                            showFb2Page(Math.floor(el.offsetLeft / container.clientWidth));
+                            updateFb2Progress();
                         }
-                        chapterIndex += Math.max(result.chapters.length, 1);
                     }
                 }
-            }
+            };
 
-            html += '</div>';
-            if (chapters.length === 0) chapters.push({ label: 'Start', href: '0' });
-            return { html: html, chapters: chapters };
-        }
-
-        function parseFb2Section(section, startIndex) {
-            var chapters = [];
-            var html = '<div class="fb2-section" data-section="' + startIndex + '">';
-
-            var children = section.children;
-            for (var i = 0; i < children.length; i++) {
-                var child = children[i];
-                var tag = child.tagName ? child.tagName.toLowerCase().replace(/.*:/, '') : '';
-
-                switch (tag) {
-                    case 'title':
-                        var titleText = (child.textContent || '').trim();
-                        html += '<h2 class="fb2-title" data-chapter="' + startIndex + '" style="text-align:center; margin:1em 0 0.5em;">' + escapeHtml(titleText) + '</h2>';
-                        chapters.push({ label: titleText, href: startIndex.toString() });
-                        break;
-                    case 'p':
-                        html += '<p style="text-indent:1.5em; margin-bottom:0.3em;">' + getInlineHtml(child) + '</p>';
-                        break;
-                    case 'empty-line':
-                        html += '<br/>';
-                        break;
-                    case 'subtitle':
-                        html += '<h3 style="text-align:center; margin:0.8em 0;">' + escapeHtml(child.textContent || '') + '</h3>';
-                        break;
-                    case 'epigraph':
-                        html += '<blockquote style="font-style:italic; margin:1em 2em;">' + parseInnerParagraphs(child) + '</blockquote>';
-                        break;
-                    case 'poem':
-                        html += '<div style="margin:1em 2em;">' + parsePoem(child) + '</div>';
-                        break;
-                    case 'cite':
-                        html += '<blockquote style="margin:1em 2em; padding-left:1em; border-left:3px solid #ccc;">' + parseInnerParagraphs(child) + '</blockquote>';
-                        break;
-                    case 'section':
-                        var sub = parseFb2Section(child, startIndex + chapters.length);
-                        html += sub.html;
-                        for (var j = 0; j < sub.chapters.length; j++) chapters.push(sub.chapters[j]);
-                        break;
+            window.getProgress = function () {
+                if (state.bookFormat === 'epub' && state.book && state.currentCfi) {
+                    try {
+                        return JSON.stringify({
+                            progress: state.book.locations.percentageFromCfi(state.currentCfi) || 0,
+                            cfi: state.currentCfi,
+                            currentPage: state.currentPage,
+                            totalPages: state.totalPages
+                        });
+                    } catch (e) { return '{}'; }
+                } else if (state.bookFormat === 'fb2') {
+                    const p = state.fb2TotalPages > 1 ? state.fb2CurrentPage / (state.fb2TotalPages - 1) : 0;
+                    return JSON.stringify({
+                        progress: p,
+                        cfi: p.toString(),
+                        currentPage: state.fb2CurrentPage + 1,
+                        totalPages: state.fb2TotalPages
+                    });
                 }
-            }
+                return '{}';
+            };
 
-            html += '</div>';
-            return { html: html, chapters: chapters };
-        }
+            // ========== INIT ==========
+            initTouchZones();
+            setLoadingText('Waiting for book...');
+            sendMessage('readerReady', {});
 
-        function getInlineHtml(el) {
-            var result = '';
-            for (var i = 0; i < el.childNodes.length; i++) {
-                var node = el.childNodes[i];
-                if (node.nodeType === 3) {
-                    result += escapeHtml(node.textContent);
-                } else if (node.nodeType === 1) {
-                    var tag = node.tagName.toLowerCase().replace(/.*:/, '');
-                    if (tag === 'strong' || tag === 'bold') result += '<strong>' + getInlineHtml(node) + '</strong>';
-                    else if (tag === 'emphasis' || tag === 'em') result += '<em>' + getInlineHtml(node) + '</em>';
-                    else if (tag === 'strikethrough') result += '<s>' + getInlineHtml(node) + '</s>';
-                    else result += getInlineHtml(node);
-                }
-            }
-            return result;
-        }
-
-        function parseInnerParagraphs(el) {
-            var html = '';
-            for (var i = 0; i < el.children.length; i++) {
-                var child = el.children[i];
-                var tag = child.tagName ? child.tagName.toLowerCase().replace(/.*:/, '') : '';
-                if (tag === 'p') html += '<p>' + getInlineHtml(child) + '</p>';
-                else if (tag === 'text-author') html += '<p style="text-align:right; font-style:italic;">— ' + escapeHtml(child.textContent || '') + '</p>';
-            }
-            return html;
-        }
-
-        function parsePoem(el) {
-            var html = '';
-            for (var i = 0; i < el.children.length; i++) {
-                var child = el.children[i];
-                var tag = child.tagName ? child.tagName.toLowerCase().replace(/.*:/, '') : '';
-                if (tag === 'stanza') {
-                    html += '<div style="margin-bottom:1em;">';
-                    for (var j = 0; j < child.children.length; j++) {
-                        var v = child.children[j];
-                        if (v.tagName && v.tagName.toLowerCase().replace(/.*:/, '') === 'v')
-                            html += '<p style="text-indent:0;">' + escapeHtml(v.textContent || '') + '</p>';
-                    }
-                    html += '</div>';
-                } else if (tag === 'title') {
-                    html += '<h4>' + escapeHtml(child.textContent || '') + '</h4>';
-                }
-            }
-            return html;
-        }
-
-        function escapeHtml(text) {
-            var div = document.createElement('div');
-            div.textContent = text;
-            return div.innerHTML;
-        }
-
-        // ========== FB2 PAGINATION ==========
-        var fb2CurrentPage = 0;
-        var fb2TotalPages = 1;
-
-        function setupFb2Pagination() {
-            var container = document.getElementById('fb2-content');
-            var inner = document.getElementById('fb2-inner');
-            if (!container || !inner) return;
-
-            var w = container.clientWidth;
-            var h = container.clientHeight;
-
-            inner.style.columnWidth = w + 'px';
-            inner.style.columnGap = '40px';
-            inner.style.columnFill = 'auto';
-            inner.style.height = h + 'px';
-            inner.style.overflow = 'hidden';
-
-            setTimeout(function () {
-                fb2TotalPages = Math.max(1, Math.ceil(inner.scrollWidth / w));
-                totalPages = fb2TotalPages;
-                fb2CurrentPage = 0;
-                showFb2Page(0);
-                debugLog('FB2 pages: ' + fb2TotalPages);
-            }, 300);
-        }
-
-        function showFb2Page(idx) {
-            if (idx < 0) idx = 0;
-            if (idx >= fb2TotalPages) idx = fb2TotalPages - 1;
-            fb2CurrentPage = idx;
-            var inner = document.getElementById('fb2-inner');
-            var container = document.getElementById('fb2-content');
-            if (inner && container) {
-                inner.style.transform = 'translateX(-' + (idx * container.clientWidth) + 'px)';
-            }
-        }
-
-        function updateFb2Progress() {
-            var progress = fb2TotalPages > 1 ? fb2CurrentPage / (fb2TotalPages - 1) : 0;
-            sendMessage('progressUpdate', {
-                progress: progress,
-                cfi: progress.toString(),
-                currentPage: fb2CurrentPage + 1,
-                totalPages: fb2TotalPages,
-                chapter: getCurrentFb2Chapter()
-            });
-        }
-
-        function getCurrentFb2Chapter() {
-            var inner = document.getElementById('fb2-inner');
-            var container = document.getElementById('fb2-content');
-            if (!inner || !container) return '';
-            var offset = fb2CurrentPage * container.clientWidth;
-            var ch = '';
-            var titles = inner.querySelectorAll('.fb2-title');
-            for (var i = 0; i < titles.length; i++) {
-                if (titles[i].offsetLeft <= offset + container.clientWidth) ch = titles[i].textContent;
-            }
-            return ch;
-        }
-
-        function goToFb2Position(progress) {
-            showFb2Page(Math.floor(progress * (fb2TotalPages - 1)));
-        }
-
-        // ========== PUBLIC API ==========
-        window.nextPage = function () {
-            if (bookFormat === 'epub' && rendition) rendition.next();
-            else if (bookFormat === 'fb2' && fb2CurrentPage < fb2TotalPages - 1) {
-                showFb2Page(fb2CurrentPage + 1);
-                updateFb2Progress();
-            }
-        };
-
-        window.prevPage = function () {
-            if (bookFormat === 'epub' && rendition) rendition.prev();
-            else if (bookFormat === 'fb2' && fb2CurrentPage > 0) {
-                showFb2Page(fb2CurrentPage - 1);
-                updateFb2Progress();
-            }
-        };
-
-        window.setFontSize = function (size) {
-            if (bookFormat === 'epub' && rendition) rendition.themes.fontSize(size + 'px');
-            else if (bookFormat === 'fb2') {
-                var inner = document.getElementById('fb2-inner');
-                if (inner) { inner.style.fontSize = size + 'px'; setTimeout(setupFb2Pagination, 100); }
-            }
-        };
-
-        window.setFontFamily = function (family) {
-            if (bookFormat === 'epub' && rendition) rendition.themes.font(family);
-            else if (bookFormat === 'fb2') {
-                var inner = document.getElementById('fb2-inner');
-                if (inner) { inner.style.fontFamily = family; setTimeout(setupFb2Pagination, 100); }
-            }
-        };
-
-        window.goToChapter = function (href) {
-            if (bookFormat === 'epub' && rendition) rendition.display(href);
-            else if (bookFormat === 'fb2') {
-                var inner = document.getElementById('fb2-inner');
-                var container = document.getElementById('fb2-content');
-                if (inner && container) {
-                    var el = inner.querySelector('[data-chapter="' + href + '"]');
-                    if (el) { showFb2Page(Math.floor(el.offsetLeft / container.clientWidth)); updateFb2Progress(); }
-                }
-            }
-        };
-
-        window.getProgress = function () {
-            if (bookFormat === 'epub' && book && currentCfi) {
-                try {
-                    return JSON.stringify({ progress: book.locations.percentageFromCfi(currentCfi) || 0, cfi: currentCfi, currentPage: currentPage, totalPages: totalPages });
-                } catch (e) { return '{}'; }
-            } else if (bookFormat === 'fb2') {
-                var p = fb2TotalPages > 1 ? fb2CurrentPage / (fb2TotalPages - 1) : 0;
-                return JSON.stringify({ progress: p, cfi: p.toString(), currentPage: fb2CurrentPage + 1, totalPages: fb2TotalPages });
-            }
-            return '{}';
-        };
-
-        // ========== INIT ==========
-        debugLog('Page loaded');
-
-        // Log hybridWebViewHost details
-        if (window.HybridWebView) {
-            debugLog('hybridWebView found!');
-            var methods = [];
-            for (var k in window.HybridWebView) {
-                methods.push(k + ':' + typeof window.HybridWebView[k]);
-            }
-            debugLog('Methods: ' + methods.join(', '));
-        }
-
-        setLoadingText('Waiting for book...');
-        sendMessage('readerReady', {});
-    </script>
-
-    <!-- IMPORTANT: Load JSZip BEFORE epub.js -->
-    <!-- JSZip 3.x is required by epub.js -->
-    <script>
-        // Verify after script load
-        debugLog('Checking libraries after inline script...');
-    </script>
-    <script src="js/jszip.min.js" onload="debugLog('JSZip loaded: ' + typeof JSZip)" onerror="debugLog('ERROR: jszip.min.js failed to load')"></script>
-    <script>
-        // After JSZip loads, verify it
-        if (typeof JSZip !== 'undefined') {
-            debugLog('JSZip OK, version: ' + (JSZip.version || 'unknown'));
-        } else {
-            debugLog('JSZip NOT available after script tag');
-        }
-    </script>
-    <script src="js/epub.min.js" onload="debugLog('epub.js loaded: ' + typeof ePub)" onerror="debugLog('ERROR: epub.min.js failed to load')"></script>
-    <script>
-        if (typeof ePub !== 'undefined') {
-            debugLog('ePub OK');
-        } else {
-            debugLog('ePub NOT available after script tag');
-        }
+        })();
     </script>
 </body>
 </html>
\ No newline at end of file
diff --git a/BookReader/ViewModels/ReaderViewModel.cs b/BookReader/ViewModels/ReaderViewModel.cs
index edcfc5e..079d078 100644
--- a/BookReader/ViewModels/ReaderViewModel.cs
+++ b/BookReader/ViewModels/ReaderViewModel.cs
@@ -121,6 +121,9 @@ public partial class ReaderViewModel : BaseViewModel
     {
         if (Book == null) return;
 
+        // Важно: если CFI пустой, не перезаписываем старый прогресс (защита от багов JS)
+        if (string.IsNullOrEmpty(cfi) && progress <= 0) return;
+
         Book.ReadingProgress = progress;
         Book.LastCfi = cfi;
         Book.LastChapter = chapter;
@@ -128,6 +131,7 @@ public partial class ReaderViewModel : BaseViewModel
         Book.TotalPages = totalPages;
         Book.LastRead = DateTime.UtcNow;
 
+        // Сохраняем в базу данных
         await _databaseService.UpdateBookAsync(Book);
 
         await _databaseService.SaveProgressAsync(new ReadingProgress
diff --git a/BookReader/Views/ReaderPage.xaml b/BookReader/Views/ReaderPage.xaml
index bc9f88a..0c0651c 100644
--- a/BookReader/Views/ReaderPage.xaml
+++ b/BookReader/Views/ReaderPage.xaml
@@ -3,6 +3,7 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              xmlns:vm="clr-namespace:BookReader.ViewModels"
              xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
+             xmlns:converters="clr-namespace:BookReader.Converters"
              x:Class="BookReader.Views.ReaderPage"
              x:DataType="vm:ReaderViewModel"
              Shell.NavBarIsVisible="False"
diff --git a/BookReader/Views/ReaderPage.xaml.cs b/BookReader/Views/ReaderPage.xaml.cs
index 97d7033..0fa1d70 100644
--- a/BookReader/Views/ReaderPage.xaml.cs
+++ b/BookReader/Views/ReaderPage.xaml.cs
@@ -18,6 +18,10 @@ public partial class ReaderPage : ContentPage
         _viewModel = viewModel;
         BindingContext = viewModel;
         _viewModel.OnJavaScriptRequested += OnJavaScriptRequested;
+        //Microsoft.Maui.Controls.Application.Current.Deactivated += async (s, e) =>
+        //{
+        //    if (_isActive) await SaveCurrentProgress();
+        //};
     }
 
     protected override async void OnAppearing()
@@ -44,7 +48,13 @@ public partial class ReaderPage : ContentPage
         await SaveCurrentProgress();
     }
 
-   
+    protected override async void OnNavigatedFrom(NavigatedFromEventArgs args)
+    {
+        _isActive = false;
+        base.OnNavigatedFrom(args);
+        // Сохраняем немедленно при любом уходе со страницы
+        await SaveCurrentProgress();
+    }
 
     // ========== ЗАГРУЗКА КНИГИ ==========