refactor(LocalDataSource, PostRepository, ChatScreen): enhance database handling and message loading

- Introduced a promise-based initialization mechanism in LocalDataSource to prevent concurrent initialization issues. - Updated PostRepository to utilize an enqueueWrite method for database operations, ensuring thread-safe writes. - Refactored ChatScreen to improve message loading logic, including preloading history and managing scroll behavior more effectively. - Enhanced message rendering logic to maintain correct indices in inverted lists and optimize user experience during scrolling.
2026-03-23 23:06:19 +08:00
parent 7305254e11
commit c98f1917f7
9 changed files with 396 additions and 185 deletions
--- a/src/screens/message/components/ChatScreen/useChatScreen.ts
+++ b/src/screens/message/components/ChatScreen/useChatScreen.ts
@@ -114,10 +114,15 @@ export const useChatScreen = () => {
  const flatListRef = useRef<any>(null);
  const textInputRef = useRef<any>(null);

-  // 防止重复加载的 ref
-  const shouldAutoScrollOnEnterRef = useRef(true);
-  const autoScrollTimersRef = useRef<ReturnType<typeof setTimeout>[]>([]);
-  const scrollPositionRef = useRef({ contentHeight: 0, scrollY: 0 });
+  // 滚动状态机 refs（Telegram/Element 风格：底部粘附 + 阅读锚点）
+  const scrollPositionRef = useRef({ contentHeight: 0, scrollY: 0, viewportHeight: 0 });
+  const hasInitialAnchorDoneRef = useRef(false);
+  const prevMessageCountRef = useRef(0);
+  const prevLatestSeqRef = useRef(0);
+  const prevMarkedReadSeqRef = useRef(0);
+  const isProgrammaticScrollRef = useRef(false);
+  const suppressAutoFollowRef = useRef(false);
+  const isBrowsingHistoryRef = useRef(false);

  // 回复消息状态
  const [replyingTo, setReplyingTo] = useState<GroupMessage | null>(null);
@@ -196,10 +201,13 @@ export const useChatScreen = () => {
    return '对方未关注你前：仅可发送1条文字消息，且不能发送图片';
  }, [followRestricted, myPrivateSentCount]);

-  // 【改造】同步加载状态
+  // 加载态语义修正：
+  // isLoadingMessages 在分页加载历史时也会短暂为 true。
+  // 若直接驱动 ChatScreen 的 loading，会导致消息列表被卸载重挂载，触发“回到底部”。
+  // 这里只在“首屏且尚无消息”时展示 loading 占位。
  useEffect(() => {
-    setLoading(isLoadingMessages);
-  }, [isLoadingMessages]);
+    setLoading(isLoadingMessages && messageManagerMessages.length === 0);
+  }, [isLoadingMessages, messageManagerMessages.length]);

  // 【改造】同步 hasMore 状态
  useEffect(() => {
@@ -263,32 +271,73 @@ export const useChatScreen = () => {
    };
  }, [isGroupChat, otherUserId]);

-  // 进入新会话时重置首次自动滚动标记
+  // 进入新会话时重置滚动状态
  useEffect(() => {
-    shouldAutoScrollOnEnterRef.current = true;
-    autoScrollTimersRef.current.forEach(clearTimeout);
-    autoScrollTimersRef.current = [];
+    hasInitialAnchorDoneRef.current = false;
+    prevMessageCountRef.current = 0;
+    prevLatestSeqRef.current = 0;
+    prevMarkedReadSeqRef.current = 0;
+    suppressAutoFollowRef.current = false;
+    isBrowsingHistoryRef.current = false;
  }, [conversationId]);

-  // 组件卸载时清理定时器
-  useEffect(() => {
-    return () => {
-      autoScrollTimersRef.current.forEach(clearTimeout);
-      autoScrollTimersRef.current = [];
-    };
-  }, []);
+  const scrollToLatest = useCallback((animated: boolean, force: boolean = false, reason: string = 'unknown') => {
+    if (!force && (suppressAutoFollowRef.current || isBrowsingHistoryRef.current)) return;
+    // inverted 列表下，最新消息端对应 offset=0
+    isProgrammaticScrollRef.current = true;
+    flatListRef.current?.scrollToOffset({
+      offset: 0,
+      animated,
+    });
+    setTimeout(() => {
+      isProgrammaticScrollRef.current = false;
+    }, animated ? 220 : 32);
+  }, [flatListRef, scrollPositionRef, messages.length]);

-  // 消息加载完成后滚动到底部
+  const isNearBottom = useCallback(() => {
+    const scrollY = scrollPositionRef.current.scrollY || 0;
+    // inverted 列表下，越接近 0 越靠近最新消息端
+    return scrollY <= 100;
+  }, [scrollPositionRef]);
+
+  // 首屏加载完成后仅锚定一次到最新消息端
  useEffect(() => {
-    if (!loading && !loadingMore && messages.length > 0 && shouldAutoScrollOnEnterRef.current) {
-      const timer = setTimeout(() => {
-        if (shouldAutoScrollOnEnterRef.current) {
-          flatListRef.current?.scrollToEnd({ animated: false });
-        }
-      }, 500);
-      return () => clearTimeout(timer);
+    if (
+      loading ||
+      loadingMore ||
+      messages.length === 0 ||
+      hasInitialAnchorDoneRef.current ||
+      scrollPositionRef.current.viewportHeight <= 0
+    ) {
+      return;
    }
-  }, [loading, loadingMore, messages.length]);
+    hasInitialAnchorDoneRef.current = true;
+    const timer = setTimeout(() => {
+      scrollToLatest(false, true, 'initial-anchor');
+    }, 0);
+    return () => clearTimeout(timer);
+  }, [loading, loadingMore, messages.length, scrollToLatest]);
+
+  // 新消息跟随策略（Telegram/QQ 风格）：
+  // 仅当“最新端消息 seq 增长”且用户在底部附近时才跟随；
+  // 历史加载只会增加旧消息，不会提升 latest seq，因此不会触发回底。
+  useEffect(() => {
+    const currentCount = messages.length;
+    const latestSeq = currentCount > 0 ? Math.max(...messages.map(m => m.seq || 0)) : 0;
+    const prevLatestSeq = prevLatestSeqRef.current;
+    prevMessageCountRef.current = currentCount;
+    prevLatestSeqRef.current = latestSeq;
+
+    if (loading || loadingMore) return;
+    if (latestSeq <= prevLatestSeq) return;
+    if (suppressAutoFollowRef.current) return;
+    if (!isNearBottom()) return;
+
+    const timer = setTimeout(() => {
+      scrollToLatest(false, false, 'new-message-follow');
+    }, 0);
+    return () => clearTimeout(timer);
+  }, [messages, loading, loadingMore, isNearBottom, scrollToLatest]);

  // 获取当前用户信息
  useEffect(() => {
@@ -384,22 +433,18 @@ export const useChatScreen = () => {
    };
  }, [routeUserId, conversationId, currentUserId, isGroupChat]);

-  // 【改造】加载更多历史消息
+  // 加载更多历史消息（inverted 下保持阅读锚点）
  const loadMoreHistory = useCallback(async () => {
    if (!conversationId || !hasMoreHistory || loadingMore) {
      return;
    }

-    // 禁用自动滚动到底部，防止加载历史消息后滚动位置跳转
-    shouldAutoScrollOnEnterRef.current = false;
-    // 清除所有待执行的自动滚动定时器
-    autoScrollTimersRef.current.forEach(clearTimeout);
-    autoScrollTimersRef.current = [];
+    // 历史加载期间禁止“新消息自动跟随到底”
+    suppressAutoFollowRef.current = true;

    // 保存加载前的滚动位置和内容高度
    const scrollYBefore = scrollPositionRef.current.scrollY;
    const contentHeightBefore = scrollPositionRef.current.contentHeight;
-
    setLoadingMore(true);

    try {
@@ -411,22 +456,8 @@ export const useChatScreen = () => {
        setFirstSeq(minSeq);
      }

-      // 加载完成后，恢复滚动位置
-      // 使用 setTimeout 确保 FlashList 已经更新
-      setTimeout(() => {
-        if (flatListRef.current) {
-          // 计算新的滚动位置，保持相对位置不变
-          const newContentHeight = scrollPositionRef.current.contentHeight;
-          const heightDiff = newContentHeight - contentHeightBefore;
-          const newScrollY = scrollYBefore + heightDiff;
-          
-          // 滚动到计算后的位置
-          flatListRef.current.scrollToOffset({
-            offset: newScrollY,
-            animated: false,
-          });
-        }
-      }, 100);
+      // inverted + maintainVisibleContentPosition 下由列表原生保持位置
+      // 不做手动 scrollToOffset，避免与原生锚点冲突导致回到底部
    } catch (error) {
      console.error('加载历史消息失败:', error);
    } finally {
@@ -434,48 +465,44 @@ export const useChatScreen = () => {
    }
  }, [conversationId, hasMoreHistory, loadingMore, loadMoreMessages, messages]);

-  // 列表内容尺寸变化后触发首次自动滚动
+  // 列表内容尺寸变化：仅同步内容高度，锚点补偿由 loadMoreHistory 统一处理
  const handleMessageListContentSizeChange = useCallback((contentWidth: number, contentHeight: number) => {
-    // 如果是加载更多历史消息，不要自动滚动
-    if (loadingMore) {
-      return;
-    }
-    
-    if (!shouldAutoScrollOnEnterRef.current) return;
-    if (loading) return;
-    if (messages.length === 0) return;
-
-    const prevContentHeight = scrollPositionRef.current.contentHeight;
    scrollPositionRef.current.contentHeight = contentHeight;
+  }, []);

-    // 如果内容高度增加（加载了更多消息），不要自动滚动到底部
-    if (prevContentHeight > 0 && contentHeight > prevContentHeight) {
-      return;
-    }
+  const handleReachLatestEdge = useCallback(() => {
+    suppressAutoFollowRef.current = false;
+    isBrowsingHistoryRef.current = false;
+  }, []);

-    shouldAutoScrollOnEnterRef.current = false;
-    autoScrollTimersRef.current.forEach(clearTimeout);
-    autoScrollTimersRef.current = [];
+  const setBrowsingHistory = useCallback((browsing: boolean) => {
+    isBrowsingHistoryRef.current = browsing;
+  }, []);

-    [100, 300, 500, 800, 1200].forEach(delay => {
-      const timer = setTimeout(() => {
-        flatListRef.current?.scrollToEnd({ animated: false });
-      }, delay);
-      autoScrollTimersRef.current.push(timer);
-    });
-  }, [loading, loadingMore, messages.length]);
-
-  // 【改造】自动标记已读 - 当有新消息且是当前会话时
+  // 自动标记已读（QQ/Telegram 风格）：
+  // 仅当出现更大的 latest seq，且用户在最新端附近时才上报。
+  // 历史加载/浏览历史不会触发 read。
  useEffect(() => {
    if (!conversationId || messages.length === 0) return;
+    if (loading || loadingMore) return;
+    if (suppressAutoFollowRef.current || isBrowsingHistoryRef.current) return;
+    if (!isNearBottom()) return;

-    const maxSeq = Math.max(...messages.map(m => m.seq), 0);
-    if (maxSeq > 0) {
-      markAsRead(maxSeq).catch(error => {
-        console.error('[ChatScreen] 自动标记已读失败:', error);
-      });
-    }
-  }, [messages, conversationId, markAsRead]);
+    const latestSeq = Math.max(...messages.map(m => m.seq), 0);
+    if (latestSeq <= 0) return;
+
+    // 没有新增最新消息，不重复上报
+    if (latestSeq <= prevLatestSeqRef.current) return;
+    prevLatestSeqRef.current = latestSeq;
+
+    // 避免对同一 seq 重复标记
+    if (latestSeq <= prevMarkedReadSeqRef.current) return;
+    prevMarkedReadSeqRef.current = latestSeq;
+
+    markAsRead(latestSeq).catch(error => {
+      console.error('[ChatScreen] 自动标记已读失败:', error);
+    });
+  }, [messages, conversationId, markAsRead, loading, loadingMore, isNearBottom]);

  // 使用 ref 存储 groupMembers
  const groupMembersRef = useRef(groupMembers);
@@ -494,16 +521,20 @@ export const useChatScreen = () => {
    const keyboardWillShow = (e: KeyboardEvent) => {
      setKeyboardHeight(e.endCoordinates.height);
      setActivePanel(prev => prev === 'mention' ? 'mention' : 'none');
-      setTimeout(() => {
-        flatListRef.current?.scrollToEnd({ animated: false });
-      }, 150);
+      if (isNearBottom()) {
+        setTimeout(() => {
+          scrollToLatest(false, false, 'keyboard-show');
+        }, 150);
+      }
    };

    const keyboardWillHide = () => {
      setKeyboardHeight(0);
-      setTimeout(() => {
-        flatListRef.current?.scrollToEnd({ animated: false });
-      }, 100);
+      if (isNearBottom()) {
+        setTimeout(() => {
+          scrollToLatest(false, false, 'keyboard-hide');
+        }, 100);
+      }
    };

    const showSubscription = Keyboard.addListener(
@@ -519,7 +550,7 @@ export const useChatScreen = () => {
      showSubscription.remove();
      hideSubscription.remove();
    };
-  }, []);
+  }, [scrollToLatest, isNearBottom]);

  // 格式化时间
  const formatTime = useCallback((dateString: string): string => {
@@ -773,7 +804,7 @@ export const useChatScreen = () => {
      }

      setTimeout(() => {
-        flatListRef.current?.scrollToEnd({ animated: true });
+        scrollToLatest(false, false, 'send-text');
      }, 100);
    } catch (error) {
      console.error('发送消息失败:', error);
@@ -781,7 +812,7 @@ export const useChatScreen = () => {
    } finally {
      setSending(false);
    }
-  }, [inputText, conversationId, isGroupChat, routeGroupId, selectedMentions, mentionAll, sendMessageViaManager, isMuted, muteAll, buildTextSegments, replyingTo, getSendErrorMessage, canSendFirstPrivateText]);
+  }, [inputText, conversationId, isGroupChat, routeGroupId, selectedMentions, mentionAll, sendMessageViaManager, isMuted, muteAll, buildTextSegments, replyingTo, getSendErrorMessage, canSendFirstPrivateText, scrollToLatest]);

  // 发送图片消息
  const handleSendImage = useCallback(async (imageUri: string, mimeType?: string) => {
@@ -823,7 +854,7 @@ export const useChatScreen = () => {
      }

      setTimeout(() => {
-        flatListRef.current?.scrollToEnd({ animated: true });
+        scrollToLatest(false, false, 'send-image');
      }, 100);
    } catch (error) {
      console.error('发送图片失败:', error);
@@ -831,7 +862,7 @@ export const useChatScreen = () => {
    } finally {
      setSendingImage(false);
    }
-  }, [conversationId, isGroupChat, routeGroupId, sendMessageViaManager, isMuted, muteAll, buildImageSegments, replyingTo, getSendErrorMessage, canSendPrivateImage]);
+  }, [conversationId, isGroupChat, routeGroupId, sendMessageViaManager, isMuted, muteAll, buildImageSegments, replyingTo, getSendErrorMessage, canSendPrivateImage, scrollToLatest]);

  // 选择图片
  const handlePickImage = useCallback(async () => {
@@ -950,7 +981,7 @@ export const useChatScreen = () => {
      }

      setTimeout(() => {
-        flatListRef.current?.scrollToEnd({ animated: true });
+        scrollToLatest(false, false, 'send-sticker');
      }, 100);
    } catch (error) {
      console.error('发送自定义表情失败:', error);
@@ -958,35 +989,35 @@ export const useChatScreen = () => {
    } finally {
      setSendingImage(false);
    }
-  }, [conversationId, isGroupChat, routeGroupId, sendMessageViaManager, isMuted, muteAll, buildImageSegments, replyingTo, canSendPrivateImage]);
+  }, [conversationId, isGroupChat, routeGroupId, sendMessageViaManager, isMuted, muteAll, buildImageSegments, replyingTo, canSendPrivateImage, scrollToLatest]);

  // 切换表情面板
  const toggleEmojiPanel = useCallback(() => {
    Keyboard.dismiss();
    setActivePanel(prev => {
      const newPanel = prev === 'emoji' ? 'none' : 'emoji';
-      if (newPanel !== 'none') {
+      if (newPanel !== 'none' && isNearBottom()) {
        setTimeout(() => {
-          flatListRef.current?.scrollToEnd({ animated: false });
+          scrollToLatest(false, false, 'open-emoji-panel');
        }, 200);
      }
      return newPanel;
    });
-  }, []);
+  }, [scrollToLatest, isNearBottom]);

  // 切换更多功能面板
  const toggleMorePanel = useCallback(() => {
    Keyboard.dismiss();
    setActivePanel(prev => {
      const newPanel = prev === 'more' ? 'none' : 'more';
-      if (newPanel !== 'none') {
+      if (newPanel !== 'none' && isNearBottom()) {
        setTimeout(() => {
-          flatListRef.current?.scrollToEnd({ animated: false });
+          scrollToLatest(false, false, 'open-more-panel');
        }, 200);
      }
      return newPanel;
    });
-  }, []);
+  }, [scrollToLatest, isNearBottom]);

  // 关闭面板
  const closePanel = useCallback(() => {
@@ -1245,5 +1276,7 @@ export const useChatScreen = () => {
    loadMoreHistory,
    handleClearConversation,
    handleMessageListContentSizeChange,
+    handleReachLatestEdge,
+    setBrowsingHistory,
  };
 };