// ==========================================
// OmniConvert: Utilities Processor Modules
// ==========================================

// 1. CHARACTER COUNTER MODULE
const CharCounterHub = {
  init() {
    const $ = (id) => document.getElementById(id);
    if (!$('charInputTextArea')) return;

    $('charInputTextArea').addEventListener('input', () => this.updateStats());
    
    // Quick Actions
    $('charBtnUpper').addEventListener('click', () => this.transformText('upper'));
    $('charBtnLower').addEventListener('click', () => this.transformText('lower'));
    $('charBtnTitle').addEventListener('click', () => this.transformText('title'));
    $('charBtnStrip').addEventListener('click', () => this.transformText('strip'));
    $('charBtnCopy').addEventListener('click', () => this.copyToClipboard());
    $('charBtnClear').addEventListener('click', () => this.clear());
  },

  updateStats() {
    const text = document.getElementById('charInputTextArea').value;
    
    // Counts
    const charCountWithSpaces = text.length;
    const charCountNoSpaces = text.replace(/\s/g, '').length;
    
    // Words
    const wordsArray = text.trim().split(/\s+/).filter(w => w.length > 0);
    const wordCount = wordsArray.length;
    
    // Lines
    const lineCount = text.length > 0 ? text.split('\n').length : 0;
    
    // Sentences
    const sentenceCount = text.length > 0 ? (text.split(/[.!?]+/).filter(s => s.trim().length > 0).length) : 0;
    
    // Paragraphs
    const paragraphCount = text.length > 0 ? (text.split(/\n\s*\n/).filter(p => p.trim().length > 0).length) : 0;
    
    // Time estimates
    const readingTimeSec = Math.ceil((wordCount / 200) * 60); // 200 words per minute
    const speakingTimeSec = Math.ceil((wordCount / 150) * 60); // 150 words per minute

    // Render Stats
    document.getElementById('charCountWithSpaces').textContent = charCountWithSpaces;
    document.getElementById('charCountNoSpaces').textContent = charCountNoSpaces;
    document.getElementById('charWordCount').textContent = wordCount;
    document.getElementById('charLineCount').textContent = lineCount;
    document.getElementById('charSentenceCount').textContent = sentenceCount;
    document.getElementById('charParagraphCount').textContent = paragraphCount;
    
    document.getElementById('charReadingTime').textContent = `~${readingTimeSec} ${I18n ? I18n.t('sec', 'сек') : 'сек'}`;
    document.getElementById('charSpeakingTime').textContent = `~${speakingTimeSec} ${I18n ? I18n.t('sec', 'сек') : 'сек'}`;

    // Word Frequency Analysis
    this.renderWordFrequency(wordsArray);
  },

  renderWordFrequency(words) {
    const listContainer = document.getElementById('charWordFreqList');
    
    if (words.length === 0) {
      listContainer.innerHTML = `<span style="color:var(--text-muted); font-style:italic;">${I18n ? I18n.t('placeholder_freq_empty', 'Введите текст для подсчета частоты слов...') : 'Введите текст для подсчета частоты слов...'}</span>`;
      return;
    }

    // Filter, lower case and tally frequencies
    const freq = {};
    words.forEach(w => {
      const cleanWord = w.toLowerCase().replace(/[.,\/#!$%\^&\*;:{}=\-_`~()?"'«»]/g, '');
      if (cleanWord.length > 2) { // only count words of length > 2
        freq[cleanWord] = (freq[cleanWord] || 0) + 1;
      }
    });

    const sortedWords = Object.keys(freq).map(w => ({ word: w, count: freq[w] }))
      .sort((a, b) => b.count - a.count)
      .slice(0, 5); // top 5

    if (sortedWords.length === 0) {
      listContainer.innerHTML = `<span style="color:var(--text-muted); font-style:italic;">${I18n ? I18n.t('no_popular_words', 'Нет популярных слов (учитываются слова длиннее 2 символов)') : 'Нет популярных слов (учитываются слова длиннее 2 символов)'}</span>`;
      return;
    }

    const maxCount = sortedWords[0].count;
    listContainer.innerHTML = '';

    sortedWords.forEach(item => {
      const pct = Math.round((item.count / maxCount) * 100);
      const row = document.createElement('div');
      row.className = 'freq-row';
      row.innerHTML = `
        <span class="freq-word" title="${item.word}">${item.word}</span>
        <div class="freq-bar-wrap">
          <div class="freq-bar" style="width: ${pct}%"></div>
        </div>
        <span class="freq-num">${item.count}</span>
      `;
      listContainer.appendChild(row);
    });
  },

  transformText(type) {
    const area = document.getElementById('charInputTextArea');
    let text = area.value;
    if (!text) return;

    if (type === 'upper') {
      text = text.toUpperCase();
    } else if (type === 'lower') {
      text = text.toLowerCase();
    } else if (type === 'title') {
      text = text.replace(/(^\s*|[.!?]\s+|\s+)([a-zа-я])/g, (m, p1, p2) => p1 + p2.toUpperCase());
    } else if (type === 'strip') {
      text = text.replace(/[ \t]+/g, ' ').replace(/\n\s*\n+/g, '\n\n').trim();
    }
    
    area.value = text;
    this.updateStats();
    App.showToast('Преобразование текста завершено', 'success');
  },

  copyToClipboard() {
    const text = document.getElementById('charInputTextArea').value;
    if (!text) return;
    navigator.clipboard.writeText(text)
      .then(() => App.showToast('Текст скопирован в буфер обмена', 'success'))
      .catch(() => App.showToast('Не удалось скопировать', 'error'));
  },

  clear() {
    document.getElementById('charInputTextArea').value = '';
    this.updateStats();
  }
};

// 2. PDF TOOLS MODULE
const PDFToolsHub = {
  mergeQueue: [], // Array of { id, file, name, pageCount }
  nextMergeId: 1,

  init() {
    const $ = (id) => document.getElementById(id);
    if (!$('pdfTabMergeBtn')) return;

    // Tabs toggler
    $('pdfTabMergeBtn').addEventListener('click', () => this.switchTab('merge'));
    $('pdfTabSplitBtn').addEventListener('click', () => this.switchTab('split'));

    // Merger bindings
    App.setupDropzone('pdfMergeDropzone', 'pdfMergeFileInput', (files) => {
      this.handleMergeFilesAdded(files);
    });
    $('pdfMergeSubmitBtn').addEventListener('click', () => this.executeMerge());

    // Splitter bindings
    App.setupDropzone('pdfSplitDropzone', 'pdfSplitFileInput', (files) => {
      if (files.length > 0) this.loadSplitFile(files[0]);
    });
    $('pdfSplitRangeToggle').addEventListener('change', (e) => {
      const row = $('pdfSplitRangeRow');
      if (e.target.checked) row.classList.remove('hidden');
      else row.classList.add('hidden');
      this.validateSplitBtn();
    });
    $('pdfSplitSubmitBtn').addEventListener('click', () => this.executeSplit());
  },

  switchTab(tab) {
    const $ = (id) => document.getElementById(id);
    if (tab === 'merge') {
      $('pdfTabMergeBtn').classList.add('active');
      $('pdfTabSplitBtn').classList.remove('active');
      $('pdfMergeContainer').classList.remove('hidden');
      $('pdfSplitContainer').classList.add('hidden');
    } else {
      $('pdfTabMergeBtn').classList.remove('active');
      $('pdfTabSplitBtn').classList.add('active');
      $('pdfMergeContainer').classList.add('hidden');
      $('pdfSplitContainer').classList.remove('hidden');
    }
  },

  // PDF Merger implementation
  async handleMergeFilesAdded(fileList) {
    const pdfjsLib = window.pdfjsLib || window['pdfjs-dist/build/pdf'];
    if (!pdfjsLib) {
      App.showToast('Библиотека PDF.js не найдена.', 'error');
      return;
    }
    pdfjsLib.GlobalWorkerOptions.workerSrc = 'lib/pdf.worker.min.js';

    App.showToast('Загрузка PDF-файлов...', 'info');

    for (const file of fileList) {
      if (file.type !== 'application/pdf' && !file.name.endsWith('.pdf')) {
        App.showToast(`Файл "${file.name}" не является PDF-документом`, 'warning');
        continue;
      }

      try {
        const arrayBuffer = await file.arrayBuffer();
        const pdf = await pdfjsLib.getDocument({ data: arrayBuffer }).promise;
        const pageCount = pdf.numPages;

        this.mergeQueue.push({
          id: this.nextMergeId++,
          file,
          name: file.name,
          pageCount
        });
      } catch (err) {
        console.error(err);
        App.showToast(`Ошибка разбора PDF "${file.name}": ${err.message}`, 'error');
      }
    }

    this.renderMergeList();
  },

  renderMergeList() {
    const list = document.getElementById('pdfMergeList');
    const container = document.getElementById('pdfMergeListCard');
    const submitBtn = document.getElementById('pdfMergeSubmitBtn');
    
    list.innerHTML = '';
    document.getElementById('pdfMergeCount').textContent = this.mergeQueue.length;

    if (this.mergeQueue.length === 0) {
      container.classList.add('hidden');
      submitBtn.disabled = true;
      return;
    }

    container.classList.remove('hidden');
    submitBtn.disabled = this.mergeQueue.length < 2;

    this.mergeQueue.forEach((item, index) => {
      const row = document.createElement('div');
      row.className = 'pdf-item';
      row.innerHTML = `
        <div class="pdf-item-title" title="${item.name}">${item.name}</div>
        <div class="pdf-item-meta">${item.pageCount} стр. (${App.formatBytes(item.file.size)})</div>
        <div class="pdf-item-actions">
          <button class="pdf-up-btn" data-idx="${index}">↑</button>
          <button class="pdf-down-btn" data-idx="${index}">↓</button>
          <button class="pdf-del-btn" style="color:var(--error); border-color:rgba(239,68,68,0.2);" data-idx="${index}">✕</button>
        </div>
      `;

      row.querySelector('.pdf-up-btn').addEventListener('click', () => this.moveMergeItem(index, -1));
      row.querySelector('.pdf-down-btn').addEventListener('click', () => this.moveMergeItem(index, 1));
      row.querySelector('.pdf-del-btn').addEventListener('click', () => this.deleteMergeItem(index));

      list.appendChild(row);
    });
  },

  moveMergeItem(index, direction) {
    const targetIdx = index + direction;
    if (targetIdx < 0 || targetIdx >= this.mergeQueue.length) return;
    
    // Swap
    const temp = this.mergeQueue[index];
    this.mergeQueue[index] = this.mergeQueue[targetIdx];
    this.mergeQueue[targetIdx] = temp;
    
    this.renderMergeList();
  },

  deleteMergeItem(index) {
    this.mergeQueue.splice(index, 1);
    this.renderMergeList();
  },

  async executeMerge() {
    if (this.mergeQueue.length < 2) return;
    if (typeof window.PDFLib === 'undefined') {
      App.showToast('Библиотека pdf-lib не найдена. Проверьте lib/pdf-lib.min.js', 'error');
      return;
    }

    const btn = document.getElementById('pdfMergeSubmitBtn');
    btn.disabled = true;
    btn.innerHTML = '<span class="loading-spinner"></span> Сшивание...';
    App.showToast('Начало сборки PDF документа...', 'info');

    try {
      const mergedPdf = await window.PDFLib.PDFDocument.create();
      
      for (const item of this.mergeQueue) {
        const bytes = await item.file.arrayBuffer();
        const pdf = await window.PDFLib.PDFDocument.load(bytes);
        const copiedPages = await mergedPdf.copyPages(pdf, pdf.getPageIndices());
        copiedPages.forEach((page) => mergedPdf.addPage(page));
      }

      const mergedPdfBytes = await mergedPdf.save();
      const blob = new Blob([mergedPdfBytes], { type: 'application/pdf' });
      const url = URL.createObjectURL(blob);

      const a = document.createElement('a');
      a.href = url;
      a.download = `omniconvert_merged_${Date.now()}.pdf`;
      document.body.appendChild(a);
      a.click();
      a.remove();

      setTimeout(() => URL.revokeObjectURL(url), 5000);
      App.showToast('Документы PDF успешно объединены и скачаны!', 'success');
      
      // Reset queue
      this.mergeQueue = [];
      this.renderMergeList();
    } catch (err) {
      console.error(err);
      App.showToast('Сбой слияния PDF: ' + err.message, 'error');
    } finally {
      btn.disabled = false;
      btn.innerHTML = '🔗 Склеить PDF-файлы';
    }
  },

  // PDF Splitter implementation
  currentSplitFile: null,

  async loadSplitFile(file) {
    const pdfjsLib = window.pdfjsLib || window['pdfjs-dist/build/pdf'];
    if (!pdfjsLib) {
      App.showToast('Библиотека PDF.js не найдена.', 'error');
      return;
    }
    pdfjsLib.GlobalWorkerOptions.workerSrc = 'lib/pdf.worker.min.js';

    App.showToast('Чтение страниц документа...', 'info');
    
    try {
      const arrayBuffer = await file.arrayBuffer();
      const pdf = await pdfjsLib.getDocument({ data: arrayBuffer }).promise;
      const totalPages = pdf.numPages;

      this.currentSplitFile = file;
      
      // UI setup
      document.getElementById('pdfSplitFilename').textContent = `${file.name} (${App.formatBytes(file.size)})`;
      document.getElementById('pdfSplitTotalPages').textContent = totalPages;
      
      // Populate Checklist
      const checklist = document.getElementById('pdfSplitPageChecklist');
      checklist.innerHTML = '';

      for (let i = 1; i <= totalPages; i++) {
        const label = document.createElement('label');
        label.className = 'page-chk-label';
        label.innerHTML = `
          <input type="checkbox" value="${i}" checked>
          <span>Стр. ${i}</span>
        `;
        
        label.querySelector('input').addEventListener('change', (e) => {
          if (e.target.checked) label.classList.add('selected');
          else label.classList.remove('selected');
          this.validateSplitBtn();
        });
        
        // Initial style
        label.classList.add('selected');
        
        checklist.appendChild(label);
      }

      document.getElementById('pdfSplitDetailsCard').classList.remove('hidden');
      this.validateSplitBtn();
      App.showToast('PDF успешно загружен в разделитель', 'success');

    } catch (err) {
      console.error(err);
      App.showToast('Ошибка чтения PDF: ' + err.message, 'error');
    }
  },

  validateSplitBtn() {
    const isRange = document.getElementById('pdfSplitRangeToggle').checked;
    const submitBtn = document.getElementById('pdfSplitSubmitBtn');
    
    if (!this.currentSplitFile) {
      submitBtn.disabled = true;
      return;
    }

    if (isRange) {
      submitBtn.disabled = false;
    } else {
      const checkedCount = document.querySelectorAll('#pdfSplitPageChecklist input:checked').length;
      submitBtn.disabled = checkedCount === 0;
    }
  },

  async executeSplit() {
    if (!this.currentSplitFile) return;
    if (typeof window.PDFLib === 'undefined') {
      App.showToast('Библиотека pdf-lib не найдена.', 'error');
      return;
    }

    const btn = document.getElementById('pdfSplitSubmitBtn');
    btn.disabled = true;
    btn.innerHTML = '<span class="loading-spinner"></span> Обработка...';
    App.showToast('Извлечение страниц...', 'info');

    try {
      const bytes = await this.currentSplitFile.arrayBuffer();
      const sourcePdf = await window.PDFLib.PDFDocument.load(bytes);
      const splitPdf = await window.PDFLib.PDFDocument.create();
      
      const totalPages = sourcePdf.getPageCount();
      let selectedPages = [];

      const isRange = document.getElementById('pdfSplitRangeToggle').checked;
      if (isRange) {
        // Parse range input (e.g. 1-3, 5)
        const rangeText = document.getElementById('pdfSplitRangeInput').value.trim();
        if (!rangeText) {
          throw new Error('Пожалуйста, введите корректный диапазон страниц.');
        }

        const parts = rangeText.split(',');
        for (const p of parts) {
          const range = p.trim().split('-');
          if (range.length === 1) {
            const val = parseInt(range[0], 10);
            if (!isNaN(val) && val >= 1 && val <= totalPages) {
              selectedPages.push(val - 1);
            }
          } else if (range.length === 2) {
            const start = parseInt(range[0], 10);
            const end = parseInt(range[1], 10);
            if (!isNaN(start) && !isNaN(end) && start <= end && start >= 1 && end <= totalPages) {
              for (let i = start; i <= end; i++) {
                selectedPages.push(i - 1);
              }
            }
          }
        }
      } else {
        // Read checked checkboxes
        const checkboxes = document.querySelectorAll('#pdfSplitPageChecklist input:checked');
        checkboxes.forEach((cb) => {
          selectedPages.push(parseInt(cb.value, 10) - 1);
        });
      }

      // Eliminate duplicates and sort indices
      selectedPages = Array.from(new Set(selectedPages)).sort((a, b) => a - b);

      if (selectedPages.length === 0) {
        throw new Error('Не выбрано ни одной страницы для извлечения');
      }

      const copiedPages = await splitPdf.copyPages(sourcePdf, selectedPages);
      copiedPages.forEach((page) => splitPdf.addPage(page));

      const splitBytes = await splitPdf.save();
      const blob = new Blob([splitBytes], { type: 'application/pdf' });
      const url = URL.createObjectURL(blob);

      const rawName = this.currentSplitFile.name.replace(/\.[^.]+$/, '');
      const a = document.createElement('a');
      a.href = url;
      a.download = `${rawName}_split_${Date.now()}.pdf`;
      document.body.appendChild(a);
      a.click();
      a.remove();

      setTimeout(() => URL.revokeObjectURL(url), 5000);
      App.showToast('Новый PDF документ успешно скачан!', 'success');
    } catch (err) {
      console.error(err);
      App.showToast('Ошибка разделения PDF: ' + err.message, 'error');
    } finally {
      btn.disabled = false;
      btn.innerHTML = '⚡ Извлечь страницы';
    }
  }
};

// 3. CRYPTOGRAPHY HUB MODULE (AES & Checksums)
const CryptoHub = {
  init() {
    const $ = (id) => document.getElementById(id);
    if (!$('hashDropzone')) return;

    // File Hash Checksums bindings
    App.setupDropzone('hashDropzone', 'hashFileInput', (files) => {
      if (files.length > 0) this.calculateFileHashes(files[0]);
    });

    // AES bindings
    $('cryptoEncryptBtn').addEventListener('click', () => this.encryptAction());
    $('cryptoDecryptBtn').addEventListener('click', () => this.decryptAction());
    $('cryptoCopyOutputBtn').addEventListener('click', () => this.copyCryptoOutput());
  },

  async calculateFileHashes(file) {
    if (typeof window.SparkMD5 === 'undefined') {
      App.showToast('Библиотека SparkMD5 не найдена. Проверьте lib/spark-md5.min.js', 'error');
      return;
    }

    const $ = (id) => document.getElementById(id);
    $('hashResultsWrap').classList.add('hidden');
    $('hashFileDetails').textContent = `Анализ: ${file.name} (${App.formatBytes(file.size)}) ...`;
    App.showToast('Вычисление хеш-сумм...', 'info');

    try {
      const buffer = await file.arrayBuffer();
      
      // Calculate MD5
      const spark = new window.SparkMD5.ArrayBuffer();
      spark.append(buffer);
      const md5Hash = spark.end();
      $('hashMD5').value = md5Hash;

      // Calculate SHA hashes natively via SubtleCrypto
      const sha1Buffer = await window.crypto.subtle.digest('SHA-1', buffer);
      $('hashSHA1').value = this.hex(sha1Buffer);

      const sha256Buffer = await window.crypto.subtle.digest('SHA-256', buffer);
      $('hashSHA256').value = this.hex(sha256Buffer);

      const sha512Buffer = await window.crypto.subtle.digest('SHA-512', buffer);
      $('hashSHA512').value = this.hex(sha512Buffer);

      $('hashFileDetails').textContent = `${file.name} (${App.formatBytes(file.size)})`;
      $('hashResultsWrap').classList.remove('hidden');
      App.showToast('Контрольные суммы вычислены успешно', 'success');
    } catch (e) {
      console.error(e);
      App.showToast('Ошибка вычисления хеша: ' + e.message, 'error');
    }
  },

  hex(buffer) {
    const hexCodes = [];
    const view = new DataView(buffer);
    for (let i = 0; i < view.byteLength; i += 4) {
      const value = view.getUint32(i);
      const stringValue = value.toString(16);
      const padding = '00000000';
      const paddedValue = (padding + stringValue).slice(-8);
      hexCodes.push(paddedValue);
    }
    return hexCodes.join('');
  },

  // AES Cryptography using PBKDF2 + AES-GCM 256-bit
  async encryptAction() {
    const text = document.getElementById('cryptoInputText').value.trim();
    const password = document.getElementById('cryptoPassword').value;
    
    if (!text || !password) {
      App.showToast('Пожалуйста, заполните поле ввода и введите пароль', 'warning');
      return;
    }

    try {
      const enc = new TextEncoder();
      const salt = window.crypto.getRandomValues(new Uint8Array(16));
      const iv = window.crypto.getRandomValues(new Uint8Array(12));
      
      const baseKey = await window.crypto.subtle.importKey(
        'raw', enc.encode(password), 'PBKDF2', false, ['deriveKey']
      );
      
      const key = await window.crypto.subtle.deriveKey(
        {
          name: 'PBKDF2',
          salt: salt,
          iterations: 100000,
          hash: 'SHA-256'
        },
        baseKey,
        { name: 'AES-GCM', length: 256 },
        false,
        ['encrypt']
      );
      
      const ciphertext = await window.crypto.subtle.encrypt(
        { name: 'AES-GCM', iv: iv }, key, enc.encode(text)
      );

      // Pack salt + iv + ciphertext
      const combined = new Uint8Array(salt.byteLength + iv.byteLength + ciphertext.byteLength);
      combined.set(salt, 0);
      combined.set(iv, salt.byteLength);
      combined.set(new Uint8Array(ciphertext), salt.byteLength + iv.byteLength);
      
      // Convert packed array to Base64
      let binary = '';
      for (let i = 0; i < combined.length; i++) {
        binary += String.fromCharCode(combined[i]);
      }
      const b64Result = btoa(binary);
      
      document.getElementById('cryptoOutputText').value = b64Result;
      App.showToast('Текст зашифрован!', 'success');
    } catch (e) {
      console.error(e);
      App.showToast('Сбой шифрования: ' + e.message, 'error');
    }
  },

  async decryptAction() {
    const b64Text = document.getElementById('cryptoInputText').value.trim();
    const password = document.getElementById('cryptoPassword').value;
    
    if (!b64Text || !password) {
      App.showToast('Пожалуйста, вставьте зашифрованный текст и введите пароль', 'warning');
      return;
    }

    try {
      const enc = new TextEncoder();
      const dec = new TextDecoder();
      
      // Unpack Base64 string
      const binaryString = atob(b64Text);
      const combined = new Uint8Array(binaryString.length);
      for (let i = 0; i < binaryString.length; i++) {
        combined[i] = binaryString.charCodeAt(i);
      }
      
      if (combined.byteLength < 28) {
        throw new Error('Зашифрованная строка имеет некорректный размер');
      }

      const salt = combined.slice(0, 16);
      const iv = combined.slice(16, 28);
      const ciphertext = combined.slice(28);

      const baseKey = await window.crypto.subtle.importKey(
        'raw', enc.encode(password), 'PBKDF2', false, ['deriveKey']
      );
      
      const key = await window.crypto.subtle.deriveKey(
        {
          name: 'PBKDF2',
          salt: salt,
          iterations: 100000,
          hash: 'SHA-256'
        },
        baseKey,
        { name: 'AES-GCM', length: 256 },
        false,
        ['decrypt']
      );

      const decrypted = await window.crypto.subtle.decrypt(
        { name: 'AES-GCM', iv: iv }, key, ciphertext
      );
      
      document.getElementById('cryptoOutputText').value = dec.decode(decrypted);
      App.showToast('Текст успешно расшифрован!', 'success');
    } catch (e) {
      console.error(e);
      App.showToast('Ошибка расшифровки: неверный пароль или поврежденная строка', 'error');
    }
  },

  copyCryptoOutput() {
    const text = document.getElementById('cryptoOutputText').value;
    if (!text) return;
    navigator.clipboard.writeText(text)
      .then(() => App.showToast('Результат скопирован', 'success'))
      .catch(() => App.showToast('Не удалось скопировать', 'error'));
  }
};

// 4. QR CODES & SVG MODULE
const QrSvgHub = {
  init() {
    const $ = (id) => document.getElementById(id);
    if (!$('qrTabGenBtn')) return;

    // Tabs toggle
    $('qrTabGenBtn').addEventListener('click', () => this.switchTab('gen'));
    $('qrTabScanBtn').addEventListener('click', () => this.switchTab('scan'));
    $('qrTabSvgBtn').addEventListener('click', () => this.switchTab('svg'));

    // QR Gen bindings
    $('qrGenBtn').addEventListener('click', () => this.generateQRCode());
    $('qrGenSizeSlider').addEventListener('input', (e) => {
      $('qrGenSizeDisplay').textContent = `${e.target.value} x ${e.target.value} px`;
    });
    $('qrGenDownloadBtn').addEventListener('click', () => this.downloadQRCode());

    // QR Scan bindings
    App.setupDropzone('qrScanDropzone', 'qrScanFileInput', (files) => {
      if (files.length > 0) this.scanQRImage(files[0]);
    });
    $('qrScanCopyBtn').addEventListener('click', () => {
      const txt = $('qrScanResultText').value;
      navigator.clipboard.writeText(txt)
        .then(() => App.showToast('Текст QR скопирован', 'success'));
    });

    // SVG Optimizer bindings
    $('svgOptimizeBtn').addEventListener('click', () => this.optimizeSVG());
    $('svgOptFileLoader').addEventListener('change', (e) => {
      const file = e.target.files[0];
      if (file) this.loadSVGFile(file);
    });
    $('svgOptDownloadBtn').addEventListener('click', () => this.downloadSVG());
  },

  switchTab(tab) {
    const $ = (id) => document.getElementById(id);
    const tabs = ['qrTabGenBtn', 'qrTabScanBtn', 'qrTabSvgBtn'];
    const containers = ['qrGenContainer', 'qrScanContainer', 'svgOptContainer'];
    
    tabs.forEach(t => $(t).classList.remove('active'));
    containers.forEach(c => $(c).classList.add('hidden'));

    if (tab === 'gen') {
      $('qrTabGenBtn').classList.add('active');
      $('qrGenContainer').classList.remove('hidden');
    } else if (tab === 'scan') {
      $('qrTabScanBtn').classList.add('active');
      $('qrScanContainer').classList.remove('hidden');
    } else {
      $('qrTabSvgBtn').classList.add('active');
      $('svgOptContainer').classList.remove('hidden');
    }
  },

  // QR Code generator using davidshimjs/qrcodejs
  generateQRCode() {
    const text = document.getElementById('qrGenInputText').value.trim();
    if (!text) {
      App.showToast('Введите текст или ссылку для QR-кода', 'warning');
      return;
    }

    if (typeof window.QRCode === 'undefined') {
      App.showToast('Библиотека QRCode.js не найдена.', 'error');
      return;
    }

    const container = document.getElementById('qrGenCanvasContainer');
    container.innerHTML = '';

    const size = parseInt(document.getElementById('qrGenSizeSlider').value, 10);
    const colorFore = document.getElementById('qrGenColorFore').value;
    const colorBack = document.getElementById('qrGenColorBack').value;

    try {
      new window.QRCode(container, {
        text: text,
        width: size,
        height: size,
        colorDark: colorFore,
        colorLight: colorBack,
        correctLevel: window.QRCode.CorrectLevel.H
      });

      document.getElementById('qrGenDownloadBtn').classList.remove('hidden');
      App.showToast('QR-Код сгенерирован', 'success');
    } catch (e) {
      console.error(e);
      App.showToast('Сбой генерации: ' + e.message, 'error');
    }
  },

  downloadQRCode() {
    // Find canvas rendered inside container
    const canvas = document.querySelector('#qrGenCanvasContainer canvas');
    if (!canvas) {
      // Fallback: search for image rendered
      const img = document.querySelector('#qrGenCanvasContainer img');
      if (img && img.src) {
        const a = document.createElement('a');
        a.href = img.src;
        a.download = `omniconvert_qr_${Date.now()}.png`;
        document.body.appendChild(a);
        a.click();
        a.remove();
        App.showToast('QR-Код скачан', 'success');
      } else {
        App.showToast('Изображение QR не готово', 'warning');
      }
      return;
    }

    const url = canvas.toDataURL('image/png');
    const a = document.createElement('a');
    a.href = url;
    a.download = `omniconvert_qr_${Date.now()}.png`;
    document.body.appendChild(a);
    a.click();
    a.remove();
    App.showToast('QR-Код скачан', 'success');
  },

  // QR Code scanning from image via jsQR
  scanQRImage(file) {
    if (typeof window.jsQR === 'undefined') {
      App.showToast('Библиотека jsQR не найдена. Проверьте lib/jsQR.min.js', 'error');
      return;
    }

    App.showToast('Анализ изображения...', 'info');

    const reader = new FileReader();
    reader.onload = (e) => {
      const img = new Image();
      img.onload = () => {
        const canvas = document.createElement('canvas');
        canvas.width = img.naturalWidth;
        canvas.height = img.naturalHeight;
        
        const ctx = canvas.getContext('2d');
        ctx.drawImage(img, 0, 0);
        
        const imgData = ctx.getImageData(0, 0, canvas.width, canvas.height);
        const code = window.jsQR(imgData.data, imgData.width, imgData.height);
        
        const area = document.getElementById('qrScanResultText');
        const copyBtn = document.getElementById('qrScanCopyBtn');
        
        if (code && code.data) {
          area.value = code.data;
          copyBtn.disabled = false;
          App.showToast('QR-Код успешно расшифрован!', 'success');
        } else {
          area.value = '';
          copyBtn.disabled = true;
          App.showToast('Не удалось обнаружить QR-Код на изображении', 'warning');
        }
      };
      img.src = e.target.result;
    };
    reader.readAsDataURL(file);
  },

  // SVG Optimizer implementation
  originalSVG: '',
  optimizedSVG: '',

  loadSVGFile(file) {
    const reader = new FileReader();
    reader.onload = (e) => {
      document.getElementById('svgOptTextArea').value = e.target.result;
      App.showToast('Файл SVG загружен', 'success');
    };
    reader.readAsText(file);
  },

  optimizeSVG() {
    let svg = document.getElementById('svgOptTextArea').value.trim();
    if (!svg) {
      App.showToast('Введите или загрузите SVG-код', 'warning');
      return;
    }

    const cleanMeta = document.getElementById('svgOptMeta').checked;
    const cleanXml = document.getElementById('svgOptXml').checked;
    const roundCoords = document.getElementById('svgOptRound').checked;

    const sizeBefore = new Blob([svg], { type: 'image/svg+xml' }).size;

    // Run cleanups
    try {
      if (cleanMeta) {
        // Comments
        svg = svg.replace(/<!--[\s\S]*?-->/g, '');
        // Adobe / Inkscape metadata
        svg = svg.replace(/<metadata>[\s\S]*?<\/metadata>/gi, '');
        svg = svg.replace(/sodipodi:[a-z-]+="[^"]*"/gi, '');
        svg = svg.replace(/inkscape:[a-z-]+="[^"]*"/gi, '');
      }

      if (cleanXml) {
        // XML declarations & doctype
        svg = svg.replace(/<\?xml[\s\S]*?\?>/i, '');
        svg = svg.replace(/<!DOCTYPE[\s\S]*?>/i, '');
      }

      if (roundCoords) {
        // Find float numbers in path data and round them to 2 decimals
        svg = svg.replace(/(-?\d+\.\d{3,})/g, (match) => {
          return parseFloat(parseFloat(match).toFixed(2));
        });
      }

      // Compact spacing
      svg = svg.replace(/\s+/g, ' ')
               .replace(/>\s+</g, '><')
               .trim();

      const sizeAfter = new Blob([svg], { type: 'image/svg+xml' }).size;
      const pct = (((sizeBefore - sizeAfter) / sizeBefore) * 100).toFixed(1);

      document.getElementById('svgOptSizeBefore').textContent = App.formatBytes(sizeBefore);
      document.getElementById('svgOptSizeAfter').textContent = App.formatBytes(sizeAfter);
      document.getElementById('svgOptSavings').textContent = `-${pct}%`;

      document.getElementById('svgOptStatsCard').classList.remove('hidden');
      document.getElementById('svgOptDownloadBtn').classList.remove('hidden');

      this.optimizedSVG = svg;
      App.showToast('SVG оптимизирован!', 'success');
    } catch (e) {
      console.error(e);
      App.showToast('Ошибка оптимизации SVG: ' + e.message, 'error');
    }
  },

  downloadSVG() {
    if (!this.optimizedSVG) return;
    const blob = new Blob([this.optimizedSVG], { type: 'image/svg+xml;charset=utf-8' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = `omniconvert_optimized_${Date.now()}.svg`;
    document.body.appendChild(a);
    a.click();
    a.remove();
    setTimeout(() => URL.revokeObjectURL(url), 5000);
    App.showToast('Оптимизированный SVG скачан', 'success');
  }
};

// Initialize modules on document ready
document.addEventListener('DOMContentLoaded', () => {
  CharCounterHub.init();
  PDFToolsHub.init();
  CryptoHub.init();
  QrSvgHub.init();
});