fix(chat): Prune history if it's too large, ignore log window as active file (aws#6989)

## Problem
```
An error occurred while processing your request.This error is reported to the team automatically. We will attempt to fix it as soon as possible.Details: Input is too long.
```
- A bug where status code is not being populated in error message
- A bug where output log window can be considered as active file which
can cause waste of tokens
- A bug where toolUse JSON.parse is not being handled correctly

## Solution
- Prune history if it's too large
- Fix status code bug in error message
- Fix active file bug
- Fix JSON.parse handling

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: jguoamz

packages/core/src/codewhispererChat/controllers/chat/chatRequest/converter.ts

@@ -148,6 +148,12 @@ export function triggerPayloadToChatRequest(triggerPayload: TriggerPayload): {
                 },
             }
         }
+
+        if (document.relativeFilePath === 'amazonwebservices.amazon-q-vscode.Amazon Q Logs') {
+            getLogger().debug('Active file is Amazon Q Logs, filter it out in the chat request')
+            document = undefined
+            cursorState = undefined
+        }
     }
 
     // service will throw validation exception if string is empty

packages/core/src/codewhispererChat/controllers/chat/controller.ts

@@ -698,7 +698,10 @@ export class ChatController {
                 this.messenger.sendAsyncEventProgress(tabID, true, '')
                 const session = this.sessionStorage.getSession(tabID)
                 const toolUseWithError = session.toolUseWithError
-                if (!toolUseWithError || !toolUseWithError.toolUse || !toolUseWithError.toolUse.input) {
+                getLogger().debug(
+                    `processToolUseMessage: ${toolUseWithError?.toolUse.name}:${toolUseWithError?.toolUse.toolUseId} with error: ${toolUseWithError?.error}`
+                )
+                if (!toolUseWithError || !toolUseWithError.toolUse) {
                     // Turn off AgentLoop flag if there's no tool use
                     this.sessionStorage.setAgentLoopInProgress(tabID, false)
                     return
@@ -780,7 +783,7 @@ export class ChatController {
                         toolResults: toolResults,
                         profile: AuthUtil.instance.regionProfileManager.activeRegionProfile,
                         origin: Origin.IDE,
-                        context: session.context ?? [],
+                        context: [],
                         relevantTextDocuments: [],
                         additionalContents: [],
                         documentReferences: [],
@@ -996,6 +999,7 @@ export class ChatController {
     private processException(e: any, tabID: string) {
         let errorMessage = ''
         let requestID = undefined
+        let statusCode = undefined
         const defaultMessage = 'Failed to get response'
         if (typeof e === 'string') {
             errorMessage = e.toUpperCase()
@@ -1005,6 +1009,7 @@ export class ChatController {
         } else if (e instanceof CodeWhispererStreamingServiceException) {
             errorMessage = e.message
             requestID = e.$metadata.requestId
+            statusCode = e.$metadata.httpStatusCode
         } else if (e instanceof Error) {
             errorMessage = e.message
         }
@@ -1014,11 +1019,11 @@ export class ChatController {
             this.sessionStorage.setAgentLoopInProgress(tabID, false)
         }
 
-        this.messenger.sendErrorMessage(errorMessage, tabID, requestID)
+        this.messenger.sendErrorMessage(errorMessage, tabID, requestID, statusCode)
         getLogger().error(`error: ${errorMessage} tabID: ${tabID} requestID: ${requestID}`)
 
         this.sessionStorage.deleteSession(tabID)
-        this.chatHistoryStorage.getTabHistory(tabID).clearRecentHistory()
+        this.chatHistoryStorage.getTabHistory(tabID).clear()
     }
 
     private async processContextMenuCommand(command: EditorContextCommand) {

packages/core/src/codewhispererChat/controllers/chat/messenger/messenger.ts

@@ -269,10 +269,9 @@ export class Messenger {
                     }
 
                     if (cwChatEvent.toolUseEvent?.stop) {
-                        let toolError = undefined
+                        toolUse.toolUseId = cwChatEvent.toolUseEvent.toolUseId ?? ''
+                        toolUse.name = cwChatEvent.toolUseEvent.name ?? ''
                         try {
-                            toolUse.toolUseId = cwChatEvent.toolUseEvent.toolUseId ?? ''
-                            toolUse.name = cwChatEvent.toolUseEvent.name ?? ''
                             toolUse.input = JSON.parse(toolUseInput)
                             const availableToolsNames = (session.pairProgrammingModeOn ? tools : noWriteTools).map(
                                 (item) => item.toolSpecification?.name
@@ -332,6 +331,10 @@ export class Messenger {
                                 ) {
                                     session.setMessageIdToUpdateListDirectory(toolUse.toolUseId)
                                 }
+                                getLogger().debug(
+                                    `SetToolUseWithError: ${toolUse.name}:${toolUse.toolUseId} with no error`
+                                )
+                                session.setToolUseWithError({ toolUse, error: undefined })
 
                                 if (!validation.requiresAcceptance) {
                                     // Need separate id for read tool and safe bash command execution as 'run-shell-command' id is required to state in cwChatConnector.ts which will impact generic tool execution.
@@ -350,12 +353,19 @@ export class Messenger {
                                     }
                                 }
                             } else {
-                                toolError = new Error('Tool not found')
+                                throw new Error('Tool not found')
                             }
                         } catch (error: any) {
-                            toolError = error
-                        } finally {
-                            session.setToolUseWithError({ toolUse, error: toolError })
+                            getLogger().error(
+                                `toolUseId: ${toolUse.toolUseId}, toolUseName: ${toolUse.name}, error: ${error}`
+                            )
+                            session.setToolUseWithError({ toolUse, error })
+                            // trigger processToolUseMessage to handle the error
+                            this.dispatcher.sendCustomFormActionMessage(
+                                new CustomFormActionMessage(tabID, {
+                                    id: 'generic-tool-execution',
+                                })
+                            )
                         }
                         // TODO: Add a spinner component for fsWrite, previous implementation is causing lag in mynah UX.
                     }
@@ -571,12 +581,17 @@ export class Messenger {
         )
     }
 
-    public sendErrorMessage(errorMessage: string | undefined, tabID: string, requestID: string | undefined) {
+    public sendErrorMessage(
+        errorMessage: string | undefined,
+        tabID: string,
+        requestID: string | undefined,
+        statusCode?: number
+    ) {
         this.showChatExceptionMessage(
             {
                 errorMessage: errorMessage,
                 sessionID: undefined,
-                statusCode: undefined,
+                statusCode: statusCode?.toString(),
             },
             tabID,
             requestID

packages/core/src/codewhispererChat/storages/chatHistory.ts

@@ -6,8 +6,8 @@ import { ChatMessage, ToolResult, ToolResultStatus, ToolUse } from '@amzn/codewh
 import { randomUUID } from '../../shared/crypto'
 import { getLogger } from '../../shared/logger/logger'
 
-// Maximum number of messages to keep in history
-const MaxConversationHistoryLength = 100
+// Maximum number of characters to keep in history
+const MaxConversationHistoryCharacters = 600_000
 
 /**
  * ChatHistoryManager handles the storage and manipulation of chat history
@@ -70,9 +70,6 @@ export class ChatHistoryManager {
      */
     public appendUserMessage(newMessage: ChatMessage): void {
         this.lastUserMessage = newMessage
-        if (!newMessage.userInputMessage?.content || newMessage.userInputMessage?.content.trim() === '') {
-            this.logger.warn('input must not be empty when adding new messages')
-        }
         this.history.push(this.formatChatHistoryMessage(this.lastUserMessage))
     }
 
@@ -118,22 +115,69 @@ export class ChatHistoryManager {
             this.clearRecentHistory()
         }
 
-        if (this.history.length <= MaxConversationHistoryLength) {
-            return
+        // Check if we need to trim based on character count
+        const totalCharacters = this.calculateHistoryCharacterCount()
+        if (totalCharacters > MaxConversationHistoryCharacters) {
+            this.logger.debug(
+                `History size (${totalCharacters} chars) exceeds limit of ${MaxConversationHistoryCharacters} chars`
+            )
+            // Keep removing messages from the beginning until we're under the limit
+            do {
+                // Find the next valid user message to start from
+                const indexToTrim = this.findIndexToTrim()
+                if (indexToTrim !== undefined && indexToTrim > 0) {
+                    this.logger.debug(
+                        `Removing the first ${indexToTrim} elements in the history due to character count limit`
+                    )
+                    this.history.splice(0, indexToTrim)
+                } else {
+                    // If we can't find a valid starting point, reset it
+                    this.logger.debug('Could not find a valid point to trim, reset history to reduce character count')
+                    this.history = []
+                }
+            } while (
+                this.calculateHistoryCharacterCount() > MaxConversationHistoryCharacters &&
+                this.history.length > 2
+            )
         }
+    }
 
-        const indexToTrim = this.findIndexToTrim()
-        if (indexToTrim !== undefined) {
-            this.logger.debug(`Removing the first ${indexToTrim} elements in the history`)
-            this.history.splice(0, indexToTrim)
-        } else {
-            this.logger.debug('No valid starting user message found in the history, clearing')
-            this.history = []
+    private calculateHistoryCharacterCount(): number {
+        let count = 0
+        for (const message of this.history) {
+            // Count characters in user messages
+            if (message.userInputMessage?.content) {
+                count += message.userInputMessage.content.length
+            }
+
+            // Count characters in assistant messages
+            if (message.assistantResponseMessage?.content) {
+                count += message.assistantResponseMessage.content.length
+            }
+
+            try {
+                // Count characters in tool uses and results
+                if (message.assistantResponseMessage?.toolUses) {
+                    for (const toolUse of message.assistantResponseMessage.toolUses) {
+                        count += JSON.stringify(toolUse).length
+                    }
+                }
+
+                if (message.userInputMessage?.userInputMessageContext?.toolResults) {
+                    for (const toolResult of message.userInputMessage.userInputMessageContext.toolResults) {
+                        count += JSON.stringify(toolResult).length
+                    }
+                }
+            } catch (error: any) {
+                this.logger.error(`Error calculating character count for tool uses/results: ${error.message}`)
+            }
         }
+        this.logger.debug(`Current history characters: ${count}`)
+        return count
     }
 
     private findIndexToTrim(): number | undefined {
-        for (let i = 1; i < this.history.length; i++) {
+        for (let i = 2; i < this.history.length; i++) {
             const message = this.history[i]
             if (this.isValidUserMessageWithoutToolResults(message)) {
                 return i
@@ -162,6 +206,12 @@ export class ChatHistoryManager {
     private ensureCurrentMessageIsValid(newUserMessage: ChatMessage): void {
         const lastHistoryMessage = this.history[this.history.length - 1]
         if (!lastHistoryMessage) {
+            if (newUserMessage.userInputMessage?.userInputMessageContext?.toolResults) {
+                this.logger.debug('No history message found, but new user message has tool results.')
+                newUserMessage.userInputMessage.userInputMessageContext.toolResults = undefined
+                // tool results are empty, so content must not be empty
+                newUserMessage.userInputMessage.content = 'Conversation history was too large, so it was cleared.'
+            }
             return
         }
 
@@ -198,8 +248,8 @@ export class ChatHistoryManager {
                 userInputMessage: {
                     ...message.userInputMessage,
                     userInputMessageContext: {
-                        ...message.userInputMessage.userInputMessageContext,
-                        tools: undefined,
+                        // Only keep toolResults in history
+                        toolResults: message.userInputMessage.userInputMessageContext?.toolResults,
                     },
                 },
             }

packages/core/src/codewhispererChat/tools/chatStream.ts

@@ -33,7 +33,7 @@ export class ChatStream extends Writable {
     ) {
         super()
         this.logger.debug(
-            `ChatStream created for tabID: ${tabID}, triggerID: ${triggerID}, session: ${session.readFiles}, emitEvent to mynahUI: ${emitEvent}`
+            `ChatStream created for tabID: ${tabID}, triggerID: ${triggerID}, emitEvent to mynahUI: ${emitEvent}`
         )
         if (!emitEvent) {
             return