// content.js - 核心功能实现
(function() {
  'use strict';

  console.log('[BlurText] Content script loaded');

  let isBlurMode = false;
  let blurMode = 'element'; // 'element', 'selection', or 'area'
  let blurIntensity = 10;
  let blurredElements = new Set();
  let hintElement = null;
  let blurButton = null; // 浮动模糊按钮
  let elementTooltip = null; // 元素模式悬停提示

  // 区域模式相关变量
  let isDrawing = false;
  let startX = 0;
  let startY = 0;
  let drawingBox = null;
  let areaOverlays = []; // 存储所有区域覆盖层

  // 初始化：从存储中加载配置
  chrome.storage.local.get(['blurIntensity'], (result) => {
    if (result.blurIntensity) {
      blurIntensity = result.blurIntensity;
      console.log('[BlurText] Loaded blur intensity:', blurIntensity);
    }
  });

  // 监听来自 popup 的消息
  chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
    console.log('[BlurText] Received message:', request);

    if (request.action === 'toggleBlurMode') {
      isBlurMode = request.enabled;
      blurMode = request.mode || 'element';
      blurIntensity = request.intensity || 10;

      console.log('[BlurText] Toggle blur mode:', isBlurMode, 'mode:', blurMode, 'intensity:', blurIntensity);

      if (isBlurMode) {
        enableBlurMode();
      } else {
        disableBlurMode();
      }
    } else if (request.action === 'clearAll') {
      console.log('[BlurText] Clear all blurs');
      clearAllBlurs();
    } else if (request.action === 'updateIntensity') {
      blurIntensity = request.intensity;
      console.log('[BlurText] Update intensity:', blurIntensity);
      updateAllBlurIntensity();
    } else if (request.action === 'switchMode') {
      blurMode = request.mode;
      console.log('[BlurText] Switch mode:', blurMode);
      updateModeUI();
    }
  });

  // 启用模糊模式
  function enableBlurMode() {
    console.log('[BlurText] Enabling blur mode, mode:', blurMode);

    let modeText = '元素模式 - 点击元素进行模糊';
    if (blurMode === 'selection') {
      modeText = '文本选择模式 - 拖动选择文字后点击模糊按钮';
    } else if (blurMode === 'area') {
      modeText = '区域模式 - 拖动鼠标绘制模糊区域';
    }
    showHint(`模糊模式已开启 - ${modeText}，按 ESC 退出`);

    // 根据模式添加对应的样式和事件
    if (blurMode === 'element') {
      document.body.classList.add('blurtext-mode');
      document.addEventListener('click', handleClick, true);
      document.addEventListener('mouseover', handleMouseOver, true);
      document.addEventListener('mouseout', handleMouseOut, true);
    } else if (blurMode === 'selection') {
      // 文本选择模式不需要 crosshair 光标
      document.addEventListener('mouseup', handleTextSelection, true);
    } else if (blurMode === 'area') {
      // 区域模式：使用 crosshair 光标并添加绘制事件
      document.body.classList.add('blurtext-mode');
      document.addEventListener('mousedown', handleAreaMouseDown, true);
      document.addEventListener('mousemove', handleAreaMouseMove, true);
      document.addEventListener('mouseup', handleAreaMouseUp, true);
    }

    // 键盘事件对所有模式都需要
    document.addEventListener('keydown', handleKeydown, true);

    console.log('[BlurText] Event listeners attached');
  }

  // 禁用模糊模式
  function disableBlurMode() {
    document.body.classList.remove('blurtext-mode');
    hideHint();
    hideBlurButton();
    hideDrawingBox();
    hideElementTooltip();

    // 移除所有事件监听
    document.removeEventListener('click', handleClick, true);
    document.removeEventListener('keydown', handleKeydown, true);
    document.removeEventListener('mouseover', handleMouseOver, true);
    document.removeEventListener('mouseout', handleMouseOut, true);
    document.removeEventListener('mouseup', handleTextSelection, true);
    document.removeEventListener('mousedown', handleAreaMouseDown, true);
    document.removeEventListener('mousemove', handleAreaMouseMove, true);
    document.removeEventListener('mouseup', handleAreaMouseUp, true);

    // 清除所有高亮和预览
    removeAllHighlights();
  }

  // 更新模式UI
  function updateModeUI() {
    if (!isBlurMode) return;

    console.log('[BlurText] Switching mode to:', blurMode);

    // 先移除所有旧的事件监听和样式
    document.body.classList.remove('blurtext-mode');
    document.removeEventListener('click', handleClick, true);
    document.removeEventListener('mouseover', handleMouseOver, true);
    document.removeEventListener('mouseout', handleMouseOut, true);
    document.removeEventListener('mouseup', handleTextSelection, true);
    document.removeEventListener('mousedown', handleAreaMouseDown, true);
    document.removeEventListener('mousemove', handleAreaMouseMove, true);
    document.removeEventListener('mouseup', handleAreaMouseUp, true);

    // 清除旧模式的UI元素
    hideBlurButton();
    removeAllHighlights();
    hideDrawingBox();
    hideElementTooltip();

    // 根据新模式添加事件监听和样式
    if (blurMode === 'element') {
      document.body.classList.add('blurtext-mode');
      document.addEventListener('click', handleClick, true);
      document.addEventListener('mouseover', handleMouseOver, true);
      document.addEventListener('mouseout', handleMouseOut, true);
      showHint('已切换到元素模式 - 点击元素进行模糊', 3000);
    } else if (blurMode === 'selection') {
      // 文本选择模式不需要 crosshair 光标
      document.addEventListener('mouseup', handleTextSelection, true);
      showHint('已切换到文本选择模式 - 拖动选择文字后点击模糊按钮', 3000);
    } else if (blurMode === 'area') {
      // 区域模式
      document.body.classList.add('blurtext-mode');
      document.addEventListener('mousedown', handleAreaMouseDown, true);
      document.addEventListener('mousemove', handleAreaMouseMove, true);
      document.addEventListener('mouseup', handleAreaMouseUp, true);
      showHint('已切换到区域模式 - 拖动鼠标绘制模糊区域', 3000);
    }

    console.log('[BlurText] Mode switched successfully');
  }

  // 处理点击事件
  function handleClick(e) {
    console.log('[BlurText] Click detected, isBlurMode:', isBlurMode, 'blurMode:', blurMode);

    if (!isBlurMode || blurMode !== 'element') return;

    // 阻止默认行为
    e.preventDefault();
    e.stopPropagation();

    let target = e.target;
    console.log('[BlurText] Target element:', target.tagName, target.className, 'text:', target.textContent?.substring(0, 20));

    // 如果是提示元素，忽略
    if (target.classList.contains('blurtext-hint')) {
      console.log('[BlurText] Ignored hint element');
      return;
    }

    // 切换模糊状态
    toggleBlur(target);
  }

  // 处理键盘事件（ESC 退出）
  function handleKeydown(e) {
    if (e.key === 'Escape' && isBlurMode) {
      isBlurMode = false;
      disableBlurMode();

      // 通知 popup
      chrome.runtime.sendMessage({ action: 'blurModeDisabled' });
    }
  }

  // 处理文本选择（文本选择模式）
  function handleTextSelection(e) {
    if (!isBlurMode || blurMode !== 'selection') return;

    // 避免点击模糊按钮时触发
    if (e.target.classList.contains('blurtext-blur-button')) {
      return;
    }

    // 避免点击已模糊的文本段落时触发（这些段落有自己的点击事件）
    if (e.target.classList.contains('blurtext-selection-wrapped')) {
      return;
    }

    const selection = window.getSelection();
    const selectedText = selection.toString().trim();

    console.log('[BlurText] Text selection:', selectedText);

    if (selectedText.length > 0) {
      // 显示模糊按钮
      showBlurButton(selection);
    } else {
      // 没有选中文本，隐藏按钮
      hideBlurButton();
    }
  }

  // 显示模糊按钮
  function showBlurButton(selection) {
    // 移除旧按钮
    hideBlurButton();

    // 获取选区的位置
    const range = selection.getRangeAt(0);
    const rect = range.getBoundingClientRect();

    // 创建模糊按钮
    blurButton = document.createElement('div');
    blurButton.className = 'blurtext-blur-button';
    blurButton.textContent = '🔒 模糊选中文本';
    blurButton.style.position = 'fixed';
    blurButton.style.left = `${rect.left + rect.width / 2}px`;
    blurButton.style.top = `${rect.bottom + 10}px`;
    blurButton.style.transform = 'translateX(-50%)';
    blurButton.style.zIndex = '2147483647';

    // 点击按钮模糊文本
    blurButton.addEventListener('click', (e) => {
      e.preventDefault();
      e.stopPropagation();
      blurSelectedText();
    });

    document.body.appendChild(blurButton);
  }

  // 隐藏模糊按钮
  function hideBlurButton() {
    if (blurButton && blurButton.parentNode) {
      blurButton.parentNode.removeChild(blurButton);
      blurButton = null;
    }
  }

  // 显示元素悬停提示
  function showElementTooltip(element, text) {
    // 移除旧提示
    hideElementTooltip();

    // 获取元素位置
    const rect = element.getBoundingClientRect();

    // 创建提示元素
    elementTooltip = document.createElement('div');
    elementTooltip.className = 'blurtext-element-tooltip';
    elementTooltip.textContent = text;
    elementTooltip.style.left = `${rect.left + rect.width / 2}px`;
    elementTooltip.style.top = `${rect.top + rect.height / 2}px`;
    elementTooltip.style.transform = 'translate(-50%, -50%)';

    document.body.appendChild(elementTooltip);
  }

  // 隐藏元素悬停提示
  function hideElementTooltip() {
    if (elementTooltip && elementTooltip.parentNode) {
      elementTooltip.parentNode.removeChild(elementTooltip);
      elementTooltip = null;
    }
  }

  // 模糊选中的文本
  function blurSelectedText() {
    const selection = window.getSelection();
    if (!selection.rangeCount) return;

    try {
      const range = selection.getRangeAt(0);

      // 获取选中的文本内容
      const selectedText = range.toString();

      // 验证选区是否符合要求
      if (!selectedText.trim()) {
        console.log('[BlurText] No text selected');
        hideBlurButton();
        return;
      }

      // 限制：不允许包含换行
      if (selectedText.includes('\n') || selectedText.includes('\r')) {
        console.log('[BlurText] Selection contains line breaks');
        showSelectionError(selection, '不支持跨行选择');
        hideBlurButton();
        return;
      }

      // 限制：不允许包含多个空格（允许单个空格）
      if (/\s{2,}/.test(selectedText)) {
        console.log('[BlurText] Selection contains multiple spaces');
        showSelectionError(selection, '不支持多个连续空格');
        hideBlurButton();
        return;
      }

      // 限制：检查是否跨越多个元素
      const startContainer = range.startContainer;
      const endContainer = range.endContainer;

      // 如果起始和结束容器不同，则跨越了多个节点
      if (startContainer !== endContainer) {
        console.log('[BlurText] Selection spans multiple elements');
        showSelectionError(selection, '不支持跨元素选择');
        hideBlurButton();
        return;
      }

      // 限制：只能选择文本节点
      if (startContainer.nodeType !== Node.TEXT_NODE) {
        console.log('[BlurText] Selection is not in a text node');
        showSelectionError(selection, '请选择纯文本内容');
        hideBlurButton();
        return;
      }

      // 创建 span 包裹选中的文本
      const span = document.createElement('span');
      span.className = 'blurtext-blurred blurtext-selection-wrapped';
      span.style.setProperty('--blur-intensity', `${blurIntensity}px`);
      span.style.cursor = 'pointer';

      // 添加鼠标悬停事件，显示恢复提示
      span.addEventListener('mouseenter', () => {
        showElementTooltip(span, '点击恢复此文本');
      });

      span.addEventListener('mouseleave', () => {
        hideElementTooltip();
      });

      // 添加点击事件，允许单独恢复
      span.addEventListener('click', (e) => {
        e.preventDefault();
        e.stopPropagation();
        hideElementTooltip(); // 点击后立即隐藏提示
        unblurSelectionSpan(span);
      });

      // 使用 surroundContents（在严格限制下应该不会失败）
      range.surroundContents(span);

      // 添加到模糊元素集合
      blurredElements.add(span);

      console.log('[BlurText] Text selection blurred, total elements:', blurredElements.size);

      // 清除选择
      selection.removeAllRanges();

      // 隐藏按钮
      hideBlurButton();
    } catch (error) {
      console.error('[BlurText] Error blurring selection:', error);
      showSelectionError(selection, '无法模糊该选区');
      hideBlurButton();
    }
  }

  // 在选区位置显示错误提示
  function showSelectionError(selection, message) {
    if (!selection.rangeCount) return;

    const range = selection.getRangeAt(0);
    const rect = range.getBoundingClientRect();

    // 创建错误提示元素
    const errorTooltip = document.createElement('div');
    errorTooltip.className = 'blurtext-selection-error';
    errorTooltip.textContent = message;
    errorTooltip.style.position = 'fixed';
    errorTooltip.style.left = `${rect.left + rect.width / 2}px`;
    errorTooltip.style.top = `${rect.bottom + 10}px`;
    errorTooltip.style.transform = 'translateX(-50%)';
    errorTooltip.style.zIndex = '2147483647';

    document.body.appendChild(errorTooltip);

    // 清除选择
    selection.removeAllRanges();

    // 2秒后自动移除
    setTimeout(() => {
      if (errorTooltip.parentNode) {
        errorTooltip.parentNode.removeChild(errorTooltip);
      }
    }, 2000);
  }

  // 恢复单个选择模式的模糊段落
  function unblurSelectionSpan(span) {
    if (!span || !span.parentNode) return;

    console.log('[BlurText] Unblurring selection span');

    // 从集合中移除
    blurredElements.delete(span);

    // 获取 span 的内容（保持子节点结构）
    const fragment = document.createDocumentFragment();
    while (span.firstChild) {
      fragment.appendChild(span.firstChild);
    }

    // 用原内容替换 span
    span.parentNode.replaceChild(fragment, span);

    console.log('[BlurText] Selection span removed, remaining elements:', blurredElements.size);
  }

  // 鼠标悬停高亮
  function handleMouseOver(e) {
    if (!isBlurMode || blurMode !== 'element') return;

    const target = e.target;
    if (target.classList.contains('blurtext-hint')) {
      return;
    }

    // 如果是已模糊的元素，显示恢复提示（不添加高亮）
    if (target.classList.contains('blurtext-blurred')) {
      removeAllHighlights(); // 移除其他高亮
      showElementTooltip(target, '点击取消模糊');
      return;
    }

    // 移除之前的高亮和提示
    removeAllHighlights();
    hideElementTooltip();

    // 直接高亮元素
    target.classList.add('blurtext-highlight');
  }

  // 移除所有高亮
  function removeAllHighlights() {
    const highlighted = document.querySelectorAll('.blurtext-highlight');
    highlighted.forEach(el => {
      el.classList.remove('blurtext-highlight');
    });
  }

  // 鼠标移出取消高亮
  function handleMouseOut(e) {
    if (!isBlurMode || blurMode !== 'element') return;

    // 隐藏提示
    hideElementTooltip();

    // 延迟移除，避免在元素间移动时闪烁
    setTimeout(() => {
      // 检查鼠标是否还在模糊模式下的元素上
      const hoveredElement = document.elementFromPoint(e.clientX, e.clientY);
      if (!hoveredElement ||
          hoveredElement.classList.contains('blurtext-hint') ||
          hoveredElement.classList.contains('blurtext-blurred')) {
        return;
      }

      // 如果鼠标不在任何高亮元素上，清除所有高亮
      const highlighted = document.querySelector('.blurtext-highlight:hover');
      if (!highlighted) {
        removeAllHighlights();
      }
    }, 100);
  }

  // 切换元素模糊状态
  function toggleBlur(element) {
    if (blurredElements.has(element)) {
      // 取消模糊
      console.log('[BlurText] Removing blur from element');
      element.classList.remove('blurtext-blurred');
      element.style.removeProperty('--blur-intensity');
      blurredElements.delete(element);

      // 隐藏提示气泡（因为元素已不再模糊）
      hideElementTooltip();
    } else {
      // 添加模糊
      console.log('[BlurText] Adding blur to element, intensity:', blurIntensity);
      element.classList.add('blurtext-blurred');
      element.style.setProperty('--blur-intensity', `${blurIntensity}px`);
      blurredElements.add(element);
    }
    console.log('[BlurText] Total blurred elements:', blurredElements.size);
  }

  // 清除所有模糊
  function clearAllBlurs() {
    blurredElements.forEach(element => {
      element.classList.remove('blurtext-blurred');
      element.style.removeProperty('--blur-intensity');
    });
    blurredElements.clear();

    // 清除所有区域覆盖层
    areaOverlays.forEach(overlay => {
      if (overlay.parentNode) {
        overlay.parentNode.removeChild(overlay);
      }
    });
    areaOverlays = [];

    // 如果在模糊模式下，显示提示
    if (isBlurMode) {
      showHint('已清除所有模糊效果', 2000);
    }
  }

  // ========== 区域模式相关函数 ==========

  // 处理区域模式鼠标按下
  function handleAreaMouseDown(e) {
    if (!isBlurMode || blurMode !== 'area') return;

    // 忽略提示元素和已有的区域覆盖层
    if (e.target.classList.contains('blurtext-hint') ||
        e.target.classList.contains('blurtext-area-overlay') ||
        e.target.classList.contains('blurtext-area-close')) {
      return;
    }

    // 检查是否点击了关闭按钮
    if (e.target.classList.contains('blurtext-area-close')) {
      const overlay = e.target.parentElement;
      removeAreaOverlay(overlay);
      e.preventDefault();
      e.stopPropagation();
      return;
    }

    isDrawing = true;
    startX = e.pageX;
    startY = e.pageY;

    // 创建绘制框
    drawingBox = document.createElement('div');
    drawingBox.className = 'blurtext-drawing-box';
    drawingBox.style.position = 'absolute';
    drawingBox.style.left = startX + 'px';
    drawingBox.style.top = startY + 'px';
    drawingBox.style.width = '0px';
    drawingBox.style.height = '0px';
    drawingBox.style.zIndex = '2147483646';
    document.body.appendChild(drawingBox);

    e.preventDefault();
    e.stopPropagation();
  }

  // 处理区域模式鼠标移动
  function handleAreaMouseMove(e) {
    if (!isBlurMode || blurMode !== 'area' || !isDrawing || !drawingBox) return;

    const currentX = e.pageX;
    const currentY = e.pageY;

    const width = Math.abs(currentX - startX);
    const height = Math.abs(currentY - startY);
    const left = Math.min(currentX, startX);
    const top = Math.min(currentY, startY);

    drawingBox.style.left = left + 'px';
    drawingBox.style.top = top + 'px';
    drawingBox.style.width = width + 'px';
    drawingBox.style.height = height + 'px';
  }

  // 处理区域模式鼠标释放
  function handleAreaMouseUp(e) {
    if (!isBlurMode || blurMode !== 'area' || !isDrawing || !drawingBox) return;

    isDrawing = false;

    const width = parseInt(drawingBox.style.width);
    const height = parseInt(drawingBox.style.height);

    // 只有当区域足够大时才创建模糊覆盖层（至少 20x20 像素）
    if (width > 20 && height > 20) {
      createAreaOverlay(
        parseInt(drawingBox.style.left),
        parseInt(drawingBox.style.top),
        width,
        height
      );
    }

    // 移除绘制框
    if (drawingBox.parentNode) {
      drawingBox.parentNode.removeChild(drawingBox);
    }
    drawingBox = null;

    e.preventDefault();
    e.stopPropagation();
  }

  // 创建区域覆盖层
  function createAreaOverlay(left, top, width, height) {
    const overlay = document.createElement('div');
    overlay.className = 'blurtext-area-overlay';
    overlay.style.position = 'absolute';
    overlay.style.left = left + 'px';
    overlay.style.top = top + 'px';
    overlay.style.width = width + 'px';
    overlay.style.height = height + 'px';
    overlay.style.setProperty('--blur-intensity', `${blurIntensity}px`);
    overlay.style.zIndex = '2147483645';

    // 点击覆盖层恢复区域
    overlay.addEventListener('click', (e) => {
      e.preventDefault();
      e.stopPropagation();
      removeAreaOverlay(overlay);
    });

    document.body.appendChild(overlay);
    areaOverlays.push(overlay);

    // 添加到模糊元素集合（用于统一管理强度）
    blurredElements.add(overlay);

    console.log('[BlurText] Area overlay created, total overlays:', areaOverlays.length);
  }

  // 移除区域覆盖层
  function removeAreaOverlay(overlay) {
    const index = areaOverlays.indexOf(overlay);
    if (index > -1) {
      areaOverlays.splice(index, 1);
    }
    blurredElements.delete(overlay);
    if (overlay.parentNode) {
      overlay.parentNode.removeChild(overlay);
    }
    console.log('[BlurText] Area overlay removed, remaining:', areaOverlays.length);
  }

  // 隐藏绘制框
  function hideDrawingBox() {
    if (drawingBox && drawingBox.parentNode) {
      drawingBox.parentNode.removeChild(drawingBox);
      drawingBox = null;
    }
    isDrawing = false;
  }

  // ========== 区域模式函数结束 ==========

  // 更新所有已模糊元素的强度
  function updateAllBlurIntensity() {
    blurredElements.forEach(element => {
      element.style.setProperty('--blur-intensity', `${blurIntensity}px`);
    });
  }

  // 显示提示
  function showHint(message, duration = null) {
    // 移除旧提示
    hideHint();

    // 创建新提示
    hintElement = document.createElement('div');
    hintElement.className = 'blurtext-hint';
    hintElement.textContent = message;
    document.body.appendChild(hintElement);

    // 如果指定了持续时间，自动隐藏
    if (duration) {
      setTimeout(() => {
        hideHint();
      }, duration);
    }
  }

  // 隐藏提示
  function hideHint() {
    if (hintElement && hintElement.parentNode) {
      hintElement.parentNode.removeChild(hintElement);
      hintElement = null;
    }
  }

  // 页面加载完成后，恢复之前的模糊状态（未来功能）
  // 这里可以添加持久化存储功能

})();