feat: 提取常量和 Hooks 到独立文件（已完成）

src/views/Community/components/DynamicNewsCard/hooks/usePagination.js

@@ -0,0 +1,365 @@
+// src/views/Community/components/DynamicNewsCard/hooks/usePagination.js
+// 分页逻辑自定义 Hook
+
+import { useState, useMemo, useCallback } from 'react';
+import { fetchDynamicNews } from '../../../../../store/slices/communityDataSlice';
+import { logger } from '../../../../../utils/logger';
+import {
+  PAGINATION_CONFIG,
+  DISPLAY_MODES,
+  DEFAULT_MODE,
+  TOAST_CONFIG
+} from '../constants';
+
+/**
+ * 分页逻辑自定义 Hook
+ * @param {Object} options - Hook 配置选项
+ * @param {Array} options.allCachedEvents - 完整缓存事件列表
+ * @param {number} options.total - 服务端总数量
+ * @param {number} options.cachedCount - 已缓存数量
+ * @param {Function} options.dispatch - Redux dispatch 函数
+ * @param {Function} options.toast - Toast 通知函数
+ * @returns {Object} 分页状态和方法
+ */
+export const usePagination = ({ allCachedEvents, total, cachedCount, dispatch, toast }) => {
+  // 本地状态
+  const [currentPage, setCurrentPage] = useState(PAGINATION_CONFIG.INITIAL_PAGE);
+  const [loadingPage, setLoadingPage] = useState(null);
+  const [mode, setMode] = useState(DEFAULT_MODE);
+
+  // 根据模式决定每页显示数量
+  const pageSize = mode === DISPLAY_MODES.CAROUSEL
+    ? PAGINATION_CONFIG.CAROUSEL_PAGE_SIZE
+    : PAGINATION_CONFIG.GRID_PAGE_SIZE;
+
+  // 计算总页数（基于服务端总数据量）
+  const totalPages = Math.ceil(total / pageSize) || 1;
+
+  // 检查是否还有更多数据
+  const hasMore = cachedCount < total;
+
+  // 从缓存中切片获取当前页数据（过滤 null 占位符）
+  const currentPageEvents = useMemo(() => {
+    const startIndex = (currentPage - 1) * pageSize;
+    const endIndex = startIndex + pageSize;
+    return allCachedEvents.slice(startIndex, endIndex).filter(event => event !== null);
+  }, [allCachedEvents, currentPage, pageSize]);
+
+  /**
+   * 子函数1: 检查目标页缓存状态
+   * @param {number} targetPage - 目标页码
+   * @returns {Object} { isTargetPageCached, targetPageInfo }
+   */
+  const checkTargetPageCache = useCallback((targetPage) => {
+    const targetPageStartIndex = (targetPage - 1) * pageSize;
+    const targetPageEndIndex = targetPageStartIndex + pageSize;
+    const targetPageData = allCachedEvents.slice(targetPageStartIndex, targetPageEndIndex);
+    const validTargetData = targetPageData.filter(e => e !== null);
+    const expectedCount = Math.min(pageSize, total - targetPageStartIndex);
+    const isTargetPageCached = validTargetData.length >= expectedCount;
+
+    logger.debug('DynamicNewsCard', '目标页缓存检查', {
+      targetPage,
+      targetPageStartIndex,
+      targetPageEndIndex,
+      targetPageDataLength: targetPageData.length,
+      validTargetDataLength: validTargetData.length,
+      expectedCount,
+      isTargetPageCached
+    });
+
+    return {
+      isTargetPageCached,
+      targetPageInfo: {
+        startIndex: targetPageStartIndex,
+        endIndex: targetPageEndIndex,
+        validCount: validTargetData.length,
+        expectedCount
+      }
+    };
+  }, [allCachedEvents, pageSize, total]);
+
+  /**
+   * 子函数2: 计算预加载范围
+   * @param {number} targetPage - 目标页码
+   * @param {number} fromPage - 来源页码
+   * @returns {Array<number>} 预加载页码数组
+   */
+  const calculatePreloadRange = useCallback((targetPage, fromPage) => {
+    const isSequentialNavigation = Math.abs(targetPage - fromPage) === 1;
+
+    let preloadRange;
+    if (isSequentialNavigation) {
+      // 连续翻页：前后各N页（N = PRELOAD_RANGE）
+      const start = Math.max(1, targetPage - PAGINATION_CONFIG.PRELOAD_RANGE);
+      const end = Math.min(totalPages, targetPage + PAGINATION_CONFIG.PRELOAD_RANGE);
+      preloadRange = Array.from(
+        { length: end - start + 1 },
+        (_, i) => start + i
+      );
+    } else {
+      // 跳转翻页：只加载当前页
+      preloadRange = [targetPage];
+    }
+
+    logger.debug('DynamicNewsCard', '计算预加载范围', {
+      targetPage,
+      fromPage,
+      isSequentialNavigation,
+      preloadRange
+    });
+
+    return preloadRange;
+  }, [totalPages]);
+
+  /**
+   * 子函数3: 查找缺失页面
+   * @param {Array<number>} preloadRange - 预加载范围
+   * @returns {Array<number>} 缺失页码数组
+   */
+  const findMissingPages = useCallback((preloadRange) => {
+    const missingPages = preloadRange.filter(page => {
+      const pageStartIndex = (page - 1) * pageSize;
+      const pageEndIndex = pageStartIndex + pageSize;
+
+      // 如果该页超出数组范围，说明未缓存
+      if (pageEndIndex > allCachedEvents.length) {
+        logger.debug('DynamicNewsCard', `页面${page}超出数组范围`, {
+          pageStartIndex,
+          pageEndIndex,
+          allCachedEventsLength: allCachedEvents.length
+        });
+        return true;
+      }
+
+      // 检查该页的数据是否包含 null 占位符或数据不足
+      const pageData = allCachedEvents.slice(pageStartIndex, pageEndIndex);
+      const validData = pageData.filter(e => e !== null);
+      const expectedCount = Math.min(pageSize, total - pageStartIndex);
+      const hasNullOrIncomplete = validData.length < expectedCount;
+
+      logger.debug('DynamicNewsCard', `页面${page}数据检查`, {
+        pageStartIndex,
+        pageEndIndex,
+        pageDataLength: pageData.length,
+        validDataLength: validData.length,
+        expectedCount,
+        hasNullOrIncomplete
+      });
+
+      return hasNullOrIncomplete;
+    });
+
+    logger.debug('DynamicNewsCard', '缺失页面检测完成', {
+      preloadRange,
+      missingPages,
+      missingPagesCount: missingPages.length
+    });
+
+    return missingPages;
+  }, [allCachedEvents, pageSize, total]);
+
+  /**
+   * 子函数4: 加载页面数据
+   * @param {Array<number>} missingPages - 缺失页码数组
+   * @param {number} targetPage - 目标页码
+   * @param {boolean} silentMode - 静默模式（后台预加载）
+   * @returns {Promise<boolean>} 是否加载成功
+   */
+  const loadPages = useCallback(async (missingPages, targetPage, silentMode = false) => {
+    if (!silentMode) {
+      // 显示 loading 状态
+      setLoadingPage(targetPage);
+    }
+
+    try {
+      logger.debug('DynamicNewsCard', '开始加载页面数据', {
+        missingPages,
+        targetPage,
+        silentMode,
+        pageSize
+      });
+
+      // 拆分为单页请求，避免 per_page 动态值导致后端返回空数据
+      for (const page of missingPages) {
+        logger.debug('DynamicNewsCard', `开始加载第 ${page} 页`);
+
+        await dispatch(fetchDynamicNews({
+          page: page,
+          per_page: pageSize,  // 固定值（5或10），不使用动态计算
+          pageSize: pageSize,
+          clearCache: false
+        })).unwrap();
+
+        logger.debug('DynamicNewsCard', `第 ${page} 页加载完成`);
+      }
+
+      logger.debug('DynamicNewsCard', '所有页面加载完成', {
+        missingPages,
+        silentMode
+      });
+
+      return true;
+    } catch (error) {
+      logger.error('DynamicNewsCard', 'loadPages', error, {
+        targetPage,
+        silentMode,
+        missingPages
+      });
+
+      if (!silentMode) {
+        // 非静默模式下显示错误提示
+        toast({
+          title: '加载失败',
+          description: `无法加载第 ${targetPage} 页数据，请稍后重试`,
+          status: 'error',
+          duration: TOAST_CONFIG.DURATION_ERROR,
+          isClosable: true,
+          position: 'top'
+        });
+      }
+
+      return false;
+    } finally {
+      if (!silentMode) {
+        // 清除加载状态
+        setLoadingPage(null);
+      }
+    }
+  }, [dispatch, pageSize, toast]);
+
+  // 翻页处理（智能预加载）- 使用子函数重构
+  const handlePageChange = useCallback(async (newPage) => {
+    // 🔍 诊断日志 - 记录翻页开始状态
+    logger.debug('DynamicNewsCard', '开始翻页', {
+      currentPage,
+      newPage,
+      pageSize,
+      totalPages,
+      hasMore,
+      total,
+      allCachedEventsLength: allCachedEvents.length,
+      cachedCount
+    });
+
+    // 步骤1: 检查目标页缓存状态
+    const { isTargetPageCached } = checkTargetPageCache(newPage);
+
+    // 步骤2: 计算预加载范围
+    const preloadRange = calculatePreloadRange(newPage, currentPage);
+
+    // 步骤3: 查找缺失页面
+    const missingPages = findMissingPages(preloadRange);
+
+    // 步骤4: 根据情况加载数据
+    if (isTargetPageCached && missingPages.length > 0 && hasMore) {
+      // 场景A: 目标页已缓存，立即切换，后台静默预加载其他页
+      logger.debug('DynamicNewsCard', '目标页已缓存，立即切换 + 后台预加载', {
+        currentPage,
+        newPage,
+        缺失页面: missingPages
+      });
+
+      setCurrentPage(newPage);
+      await loadPages(missingPages, newPage, true); // 静默模式
+    } else if (missingPages.length > 0 && hasMore) {
+      // 场景B: 目标页未缓存，显示 loading 并等待加载完成
+      logger.debug('DynamicNewsCard', '目标页未缓存，显示 loading', {
+        currentPage,
+        newPage,
+        缺失页面: missingPages
+      });
+
+      const success = await loadPages(missingPages, newPage, false); // 非静默模式
+      if (success) {
+        setCurrentPage(newPage);
+      }
+    } else if (missingPages.length === 0) {
+      // 场景C: 所有页面均已缓存，直接切换
+      logger.debug('DynamicNewsCard', '无需加载，直接切换', {
+        currentPage,
+        newPage,
+        reason: '所有页面均已缓存'
+      });
+
+      setCurrentPage(newPage);
+    } else {
+      // 场景D: 意外分支（有缺失页面但 hasMore=false）
+      logger.warn('DynamicNewsCard', '意外分支：有缺失页面但无法加载', {
+        missingPages,
+        hasMore,
+        currentPage,
+        newPage,
+        total,
+        cachedCount
+      });
+
+      setCurrentPage(newPage);
+
+      toast({
+        title: '数据不完整',
+        description: `第 ${newPage} 页数据可能不完整`,
+        status: 'warning',
+        duration: TOAST_CONFIG.DURATION_WARNING,
+        isClosable: true,
+        position: 'top'
+      });
+    }
+  }, [
+    currentPage,
+    pageSize,
+    totalPages,
+    hasMore,
+    total,
+    allCachedEvents.length,
+    cachedCount,
+    checkTargetPageCache,
+    calculatePreloadRange,
+    findMissingPages,
+    loadPages,
+    toast
+  ]);
+
+  // 模式切换处理
+  const handleModeToggle = useCallback((newMode) => {
+    if (newMode === mode) return;
+
+    setMode(newMode);
+    setCurrentPage(PAGINATION_CONFIG.INITIAL_PAGE);
+
+    const newPageSize = newMode === DISPLAY_MODES.CAROUSEL
+      ? PAGINATION_CONFIG.CAROUSEL_PAGE_SIZE
+      : PAGINATION_CONFIG.GRID_PAGE_SIZE;
+
+    // 检查第1页的数据是否完整（排除 null）
+    const firstPageData = allCachedEvents.slice(0, newPageSize);
+    const validFirstPageCount = firstPageData.filter(e => e !== null).length;
+    const needsRefetch = validFirstPageCount < Math.min(newPageSize, total);
+
+    if (needsRefetch) {
+      // 第1页数据不完整，清空缓存重新请求
+      dispatch(fetchDynamicNews({
+        page: 1,
+        per_page: newPageSize,
+        pageSize: newPageSize,  // 传递 pageSize 确保索引计算一致
+        clearCache: true
+      }));
+    }
+    // 如果第1页数据完整，不发起请求，直接切换
+  }, [mode, allCachedEvents, total, dispatch]);
+
+  return {
+    // 状态
+    currentPage,
+    mode,
+    loadingPage,
+    pageSize,
+    totalPages,
+    hasMore,
+    currentPageEvents,
+
+    // 方法
+    handlePageChange,
+    handleModeToggle
+  };
+};