Add V2 database service integration with feature flag support

- Integrate V2 implementations for message operations (save, update, delete, clear) with feature flag control
- Add topic creation fallback in DexieMessageDataSource when loading non-existent topics
- Create integration status documentation tracking completed and pending V2 migrations
- Update Topic type to include TopicType enum for proper topic classification

src/renderer/src/services/db/DexieMessageDataSource.ts

@@ -23,6 +23,9 @@ export class DexieMessageDataSource implements MessageDataSource {
   }> {
     try {
       const topic = await db.topics.get(topicId)
+      if (!topic) {
+        await db.topics.add({ id: topicId, messages: [] })
+      }
       const messages = topic?.messages || []
 
       if (messages.length === 0) {

src/renderer/src/services/db/INTEGRATION_STATUS.md

@@ -0,0 +1,145 @@
+# V2 Database Service Integration Status
+
+## Overview
+The unified database service (DbService) has been successfully integrated into messageThunk.ts with feature flag support. This allows gradual rollout and easy rollback if issues occur.
+
+## Feature Flag Control
+```javascript
+// Enable V2 implementation
+VITE_USE_UNIFIED_DB_SERVICE=true yarn dev
+
+// Or via browser console
+localStorage.setItem('featureFlags', JSON.stringify({ USE_UNIFIED_DB_SERVICE: true }))
+location.reload()
+```
+
+## Integration Status
+
+### ✅ Completed Integrations
+
+#### Phase 2.1 - Read Operations (STABLE - Tested by user)
+- **loadTopicMessagesThunk** → `loadTopicMessagesThunkV2`
+  - Location: messageThunk.ts:843
+  - Status: ✅ STABLE (confirmed by user)
+  - Handles both regular topics and agent sessions
+
+#### Phase 2.2 - Helper Functions  
+- **updateFileCount** → `updateFileCountV2`
+  - Location: messageThunk.ts:1596
+  - Status: ✅ Integrated
+  - Used in cloneMessagesToNewTopicThunk
+
+#### Phase 2.3 - Delete Operations
+- **deleteSingleMessageThunk** → `deleteMessageFromDBV2`
+  - Location: messageThunk.ts:931
+  - Status: ✅ Integrated
+  
+- **deleteMessageGroupThunk** → `deleteMessagesFromDBV2`
+  - Location: messageThunk.ts:988
+  - Status: ✅ Integrated
+  
+- **clearTopicMessagesThunk** → `clearMessagesFromDBV2`
+  - Location: messageThunk.ts:1039
+  - Status: ✅ Integrated
+
+#### Phase 2.4 - Write Operations
+- **saveMessageAndBlocksToDB** → `saveMessageAndBlocksToDBV2`
+  - Location: messageThunk.ts:209
+  - Status: ✅ Integrated
+  - Used in sendMessage, branches, and resends
+
+#### Phase 2.5 - Update Operations
+- **updateSingleBlock** → `updateSingleBlockV2`
+  - Location: messageThunk.ts:326, 1351
+  - Status: ✅ Integrated
+  - Used in throttled block updates and translation updates
+  
+- **bulkAddBlocks** → `bulkAddBlocksV2`
+  - Location: messageThunk.ts:1587
+  - Status: ✅ Integrated
+  - Used in cloneMessagesToNewTopicThunk
+  
+- **updateBlocks (bulkPut)** → `updateBlocksV2`
+  - Location: messageThunk.ts:221, 259, 1684
+  - Status: ✅ Integrated
+  - Used in saveMessageAndBlocksToDB, updateExistingMessageAndBlocksInDB, updateMessageAndBlocksThunk
+
+- **updateMessage** → `updateMessageV2`
+  - Location: messageThunk.ts:1669
+  - Status: ✅ Integrated
+  - Used in updateMessageAndBlocksThunk
+
+## Not Yet Integrated
+
+### Functions Available but Not Used
+These V2 functions exist but haven't been integrated yet as their usage patterns are different:
+
+- **getRawTopicV2** - Available but not directly replacing db.topics.get() calls
+- **getTopicV2** - Available but not directly replacing db.topics.get() calls  
+- **persistExchangeV2** - Available for future use with message exchanges
+
+### Complex Operations Still Using Original Implementation
+These operations involve complex transactions and topic management that would need careful refactoring:
+
+1. **Topic message list updates** (db.topics.update with messages array)
+   - Used after delete operations
+   - Used in resendMessageThunk
+   - Used in regenerateAssistantMessageThunk
+   
+2. **Transaction-based operations**
+   - cloneMessagesToNewTopicThunk (partial integration)
+   - initiateTranslationThunk
+   - removeBlocksThunk
+
+## Testing Checklist
+
+### High Priority (Core Operations)
+- [x] Load messages for regular topic
+- [x] Load messages for agent session
+- [ ] Send message in regular chat
+- [ ] Send message in agent session
+- [ ] Delete single message
+- [ ] Delete message group
+- [ ] Clear all messages
+
+### Medium Priority (Edit Operations)
+- [ ] Update message content
+- [ ] Update message blocks
+- [ ] Update translation blocks
+- [ ] File reference counting
+
+### Low Priority (Advanced Features)
+- [ ] Clone messages to new topic
+- [ ] Resend messages
+- [ ] Regenerate assistant messages
+- [ ] Multi-model responses
+
+## Next Steps
+
+1. **Test Current Integrations**
+   - Enable feature flag and test all integrated operations
+   - Monitor for any errors or performance issues
+   - Verify data consistency
+
+2. **Phase 3 Consideration**
+   - Consider refactoring complex topic update operations
+   - Evaluate if persistExchangeV2 should be used for user+assistant pairs
+   - Plan migration of remaining db.topics operations
+
+3. **Performance Monitoring**
+   - Compare load times between original and V2
+   - Check memory usage with large message histories
+   - Verify agent session performance
+
+## Rollback Instructions
+If issues occur, disable the feature flag immediately:
+```javascript
+localStorage.setItem('featureFlags', JSON.stringify({ USE_UNIFIED_DB_SERVICE: false }))
+location.reload()
+```
+
+## Notes
+- All V2 implementations maintain backward compatibility
+- Agent session operations (IPC-based) are handled transparently
+- File operations only apply to Dexie storage, not agent sessions
+- Feature flag allows gradual rollout and A/B testing

src/renderer/src/store/thunk/messageThunk.ts

@@ -35,7 +35,18 @@ import { LRUCache } from 'lru-cache'
 import type { AppDispatch, RootState } from '../index'
 import { removeManyBlocks, updateOneBlock, upsertManyBlocks, upsertOneBlock } from '../messageBlock'
 import { newMessagesActions, selectMessagesForTopic } from '../newMessage'
-import { loadTopicMessagesThunkV2 } from './messageThunk.v2'
+import {
+  bulkAddBlocksV2,
+  clearMessagesFromDBV2,
+  deleteMessageFromDBV2,
+  deleteMessagesFromDBV2,
+  loadTopicMessagesThunkV2,
+  saveMessageAndBlocksToDBV2,
+  updateBlocksV2,
+  updateFileCountV2,
+  updateMessageV2,
+  updateSingleBlockV2
+} from './messageThunk.v2'
 
 const logger = loggerService.withContext('MessageThunk')
 
@@ -192,12 +203,23 @@ const createAgentMessageStream = async (
 }
 // TODO: 后续可以将db操作移到Listener Middleware中
 export const saveMessageAndBlocksToDB = async (message: Message, blocks: MessageBlock[], messageIndex: number = -1) => {
+  // Use V2 implementation if feature flag is enabled
+  if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+    return saveMessageAndBlocksToDBV2(message.topicId, message, blocks)
+  }
+
+  // Original implementation
   try {
     if (isAgentSessionTopicId(message.topicId)) {
       return
     }
     if (blocks.length > 0) {
-      await db.message_blocks.bulkPut(blocks)
+      // Use V2 implementation if feature flag is enabled
+      if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+        await updateBlocksV2(blocks)
+      } else {
+        await db.message_blocks.bulkPut(blocks)
+      }
     }
     const topic = await db.topics.get(message.topicId)
     if (topic) {
@@ -234,7 +256,12 @@ const updateExistingMessageAndBlocksInDB = async (
     await db.transaction('rw', db.topics, db.message_blocks, async () => {
       // Always update blocks if provided
       if (updatedBlocks.length > 0) {
-        await db.message_blocks.bulkPut(updatedBlocks)
+        // Use V2 implementation if feature flag is enabled
+        if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+          await updateBlocksV2(updatedBlocks)
+        } else {
+          await db.message_blocks.bulkPut(updatedBlocks)
+        }
       }
 
       // Check if there are message properties to update beyond id and topicId
@@ -303,7 +330,12 @@ const getBlockThrottler = (id: string) => {
       })
 
       blockUpdateRafs.set(id, rafId)
-      await db.message_blocks.update(id, blockUpdate)
+      // Use V2 implementation if feature flag is enabled
+      if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+        await updateSingleBlockV2(id, blockUpdate)
+      } else {
+        await db.message_blocks.update(id, blockUpdate)
+      }
     }, 150)
 
     blockUpdateThrottlers.set(id, throttler)
@@ -907,12 +939,19 @@ export const deleteSingleMessageThunk =
     try {
       dispatch(newMessagesActions.removeMessage({ topicId, messageId }))
       cleanupMultipleBlocks(dispatch, blockIdsToDelete)
-      await db.message_blocks.bulkDelete(blockIdsToDelete)
-      const topic = await db.topics.get(topicId)
-      if (topic) {
-        const finalMessagesToSave = selectMessagesForTopic(getState(), topicId)
-        await db.topics.update(topicId, { messages: finalMessagesToSave })
-        dispatch(updateTopicUpdatedAt({ topicId }))
+
+      // Use V2 implementation if feature flag is enabled
+      if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+        await deleteMessageFromDBV2(topicId, messageId)
+      } else {
+        // Original implementation
+        await db.message_blocks.bulkDelete(blockIdsToDelete)
+        const topic = await db.topics.get(topicId)
+        if (topic) {
+          const finalMessagesToSave = selectMessagesForTopic(getState(), topicId)
+          await db.topics.update(topicId, { messages: finalMessagesToSave })
+          dispatch(updateTopicUpdatedAt({ topicId }))
+        }
       }
     } catch (error) {
       logger.error(`[deleteSingleMessage] Failed to delete message ${messageId}:`, error as Error)
@@ -947,16 +986,24 @@ export const deleteMessageGroupThunk =
     }
 
     const blockIdsToDelete = messagesToDelete.flatMap((m) => m.blocks || [])
+    const messageIdsToDelete = messagesToDelete.map((m) => m.id)
 
     try {
       dispatch(newMessagesActions.removeMessagesByAskId({ topicId, askId }))
       cleanupMultipleBlocks(dispatch, blockIdsToDelete)
-      await db.message_blocks.bulkDelete(blockIdsToDelete)
-      const topic = await db.topics.get(topicId)
-      if (topic) {
-        const finalMessagesToSave = selectMessagesForTopic(getState(), topicId)
-        await db.topics.update(topicId, { messages: finalMessagesToSave })
-        dispatch(updateTopicUpdatedAt({ topicId }))
+
+      // Use V2 implementation if feature flag is enabled
+      if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+        await deleteMessagesFromDBV2(topicId, messageIdsToDelete)
+      } else {
+        // Original implementation
+        await db.message_blocks.bulkDelete(blockIdsToDelete)
+        const topic = await db.topics.get(topicId)
+        if (topic) {
+          const finalMessagesToSave = selectMessagesForTopic(getState(), topicId)
+          await db.topics.update(topicId, { messages: finalMessagesToSave })
+          dispatch(updateTopicUpdatedAt({ topicId }))
+        }
       }
     } catch (error) {
       logger.error(`[deleteMessageGroup] Failed to delete messages with askId ${askId}:`, error as Error)
@@ -983,10 +1030,16 @@ export const clearTopicMessagesThunk =
       dispatch(newMessagesActions.clearTopicMessages(topicId))
       cleanupMultipleBlocks(dispatch, blockIdsToDelete)
 
-      await db.topics.update(topicId, { messages: [] })
-      dispatch(updateTopicUpdatedAt({ topicId }))
-      if (blockIdsToDelete.length > 0) {
-        await db.message_blocks.bulkDelete(blockIdsToDelete)
+      // Use V2 implementation if feature flag is enabled
+      if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+        await clearMessagesFromDBV2(topicId)
+      } else {
+        // Original implementation
+        await db.topics.update(topicId, { messages: [] })
+        dispatch(updateTopicUpdatedAt({ topicId }))
+        if (blockIdsToDelete.length > 0) {
+          await db.message_blocks.bulkDelete(blockIdsToDelete)
+        }
       }
     } catch (error) {
       logger.error(`[clearTopicMessagesThunk] Failed to clear messages for topic ${topicId}:`, error as Error)
@@ -1309,7 +1362,12 @@ export const updateTranslationBlockThunk =
       dispatch(updateOneBlock({ id: blockId, changes }))
 
       // 更新数据库
-      await db.message_blocks.update(blockId, changes)
+      // Use V2 implementation if feature flag is enabled
+      if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+        await updateSingleBlockV2(blockId, changes)
+      } else {
+        await db.message_blocks.update(blockId, changes)
+      }
       // Logger.log(`[updateTranslationBlockThunk] Successfully updated translation block ${blockId}.`)
     } catch (error) {
       logger.error(`[updateTranslationBlockThunk] Failed to update translation block ${blockId}:`, error as Error)
@@ -1522,20 +1580,33 @@ export const cloneMessagesToNewTopicThunk =
 
         // Add the NEW blocks
         if (clonedBlocks.length > 0) {
-          await db.message_blocks.bulkAdd(clonedBlocks)
+          // Use V2 implementation if feature flag is enabled
+          if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+            await bulkAddBlocksV2(clonedBlocks)
+          } else {
+            await db.message_blocks.bulkAdd(clonedBlocks)
+          }
         }
         // Update file counts
         const uniqueFiles = [...new Map(filesToUpdateCount.map((f) => [f.id, f])).values()]
-        for (const file of uniqueFiles) {
-          await db.files
-            .where('id')
-            .equals(file.id)
-            .modify((f) => {
-              if (f) {
-                // Ensure file exists before modifying
-                f.count = (f.count || 0) + 1
-              }
-            })
+        if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+          // Use V2 implementation for file count updates
+          for (const file of uniqueFiles) {
+            await updateFileCountV2(file.id, 1, false)
+          }
+        } else {
+          // Original implementation
+          for (const file of uniqueFiles) {
+            await db.files
+              .where('id')
+              .equals(file.id)
+              .modify((f) => {
+                if (f) {
+                  // Ensure file exists before modifying
+                  f.count = (f.count || 0) + 1
+                }
+              })
+          }
         }
       })
 
@@ -1589,33 +1660,46 @@ export const updateMessageAndBlocksThunk =
       }
 
       // 2. 更新数据库 (在事务中)
-      await db.transaction('rw', db.topics, db.message_blocks, async () => {
-        // Only update topic.messages if there were actual message changes
-        if (messageUpdates && Object.keys(messageUpdates).length > 0) {
-          const topic = await db.topics.get(topicId)
-          if (topic && topic.messages) {
-            const messageIndex = topic.messages.findIndex((m) => m.id === messageId)
-            if (messageIndex !== -1) {
-              Object.assign(topic.messages[messageIndex], messageUpdates)
-              await db.topics.update(topicId, { messages: topic.messages })
+      // Use V2 implementation if feature flag is enabled
+      if (featureFlags.USE_UNIFIED_DB_SERVICE) {
+        // Update message properties if provided
+        if (messageUpdates && Object.keys(messageUpdates).length > 0 && messageId) {
+          await updateMessageV2(topicId, messageId, messageUpdates)
+        }
+        // Update blocks if provided
+        if (blockUpdatesList.length > 0) {
+          await updateBlocksV2(blockUpdatesList)
+        }
+      } else {
+        // Original implementation with transaction
+        await db.transaction('rw', db.topics, db.message_blocks, async () => {
+          // Only update topic.messages if there were actual message changes
+          if (messageUpdates && Object.keys(messageUpdates).length > 0) {
+            const topic = await db.topics.get(topicId)
+            if (topic && topic.messages) {
+              const messageIndex = topic.messages.findIndex((m) => m.id === messageId)
+              if (messageIndex !== -1) {
+                Object.assign(topic.messages[messageIndex], messageUpdates)
+                await db.topics.update(topicId, { messages: topic.messages })
+              } else {
+                logger.error(
+                  `[updateMessageAndBlocksThunk] Message ${messageId} not found in DB topic ${topicId} for property update.`
+                )
+                throw new Error(`Message ${messageId} not found in DB topic ${topicId} for property update.`)
+              }
             } else {
               logger.error(
-                `[updateMessageAndBlocksThunk] Message ${messageId} not found in DB topic ${topicId} for property update.`
+                `[updateMessageAndBlocksThunk] Topic ${topicId} not found or empty for message property update.`
               )
-              throw new Error(`Message ${messageId} not found in DB topic ${topicId} for property update.`)
+              throw new Error(`Topic ${topicId} not found or empty for message property update.`)
             }
-          } else {
-            logger.error(
-              `[updateMessageAndBlocksThunk] Topic ${topicId} not found or empty for message property update.`
-            )
-            throw new Error(`Topic ${topicId} not found or empty for message property update.`)
           }
-        }
 
-        if (blockUpdatesList.length > 0) {
-          await db.message_blocks.bulkPut(blockUpdatesList)
-        }
-      })
+          if (blockUpdatesList.length > 0) {
+            await db.message_blocks.bulkPut(blockUpdatesList)
+          }
+        })
+      }
 
       dispatch(updateTopicUpdatedAt({ topicId }))
     } catch (error) {

src/renderer/src/store/thunk/messageThunk.v2.ts

@@ -53,7 +53,7 @@ export const loadTopicMessagesThunkV2 =
       }
       dispatch(newMessagesActions.messagesReceived({ topicId, messages }))
     } catch (error) {
-      logger.error(`Failed to load messages for topic ${topicId}:`, error)
+      logger.error(`Failed to load messages for topic ${topicId}:`, error as Error)
       // Could dispatch an error action here if needed
     } finally {
       dispatch(newMessagesActions.setTopicLoading({ topicId, loading: false }))
@@ -95,7 +95,7 @@ export const getTopicV2 = async (topicId: string): Promise<Topic | undefined> =>
     // Construct the full Topic object
     const topic: Topic = {
       id: rawTopic.id,
-      type: isAgentSessionTopicId(topicId) ? TopicType.AgentSession : TopicType.Chat,
+      type: isAgentSessionTopicId(topicId) ? TopicType.Session : TopicType.Chat,
       messages: rawTopic.messages,
       assistantId: '', // These fields would need to be fetched from appropriate source
       name: '',
@@ -261,7 +261,7 @@ export const updateSingleBlockV2 = async (blockId: string, updates: Partial<Mess
 }
 
 /**
- * Bulk add message blocks
+ * Bulk add message blocks (for new blocks)
  */
 export const bulkAddBlocksV2 = async (blocks: MessageBlock[]): Promise<void> => {
   try {
@@ -272,3 +272,16 @@ export const bulkAddBlocksV2 = async (blocks: MessageBlock[]): Promise<void> =>
     throw error
   }
 }
+
+/**
+ * Update multiple message blocks (upsert operation)
+ */
+export const updateBlocksV2 = async (blocks: MessageBlock[]): Promise<void> => {
+  try {
+    await dbService.updateBlocks(blocks)
+    logger.info('Updated blocks via DbService', { count: blocks.length })
+  } catch (error) {
+    logger.error('Failed to update blocks:', { count: blocks.length, error })
+    throw error
+  }
+}

src/renderer/src/types/index.ts

@@ -198,8 +198,14 @@ export type Metrics = {
   time_thinking_millsec?: number
 }
 
+export enum TopicType {
+  Chat = 'chat',
+  Session = 'session'
+}
+
 export type Topic = {
   id: string
+  type: TopicType
   assistantId: string
   name: string
   createdAt: string