refactor: break submitQuery into smaller functions (#350)

1 files changed, 487 insertions, 394 deletions

diff --git a/packages/cli/src/ui/hooks/useGeminiStream.ts b/packages/cli/src/ui/hooks/useGeminiStream.ts
index 2b18f0a1..035f3e85 100644
--- a/packages/cli/src/ui/hooks/useGeminiStream.ts
+++ b/packages/cli/src/ui/hooks/useGeminiStream.ts
@@ -9,6 +9,12 @@ import { useInput } from 'ink';
 import {
   GeminiClient,
   GeminiEventType as ServerGeminiEventType,
+  ServerGeminiStreamEvent as GeminiEvent,
+  ServerGeminiContentEvent as ContentEvent,
+  ServerGeminiToolCallRequestEvent as ToolCallRequestEvent,
+  ServerGeminiToolCallResponseEvent as ToolCallResponseEvent,
+  ServerGeminiToolCallConfirmationEvent as ToolCallConfirmationEvent,
+  ServerGeminiErrorEvent as ErrorEvent,
   getErrorMessage,
   isNodeError,
   Config,
@@ -26,6 +32,7 @@ import {
   IndividualToolCallDisplay,
   ToolCallStatus,
   HistoryItemWithoutId,
+  HistoryItemToolGroup,
   MessageType,
 } from '../types.js';
 import { isAtCommand } from '../utils/commandUtils.js';
@@ -35,6 +42,17 @@ import { findLastSafeSplitPoint } from '../utils/markdownUtilities.js';
 import { useStateAndRef } from './useStateAndRef.js';
 import { UseHistoryManagerReturn } from './useHistoryManager.js';
 
+enum StreamProcessingStatus {
+  Completed,
+  PausedForConfirmation,
+  UserCancelled,
+  Error,
+}
+
+/**
+ * Hook to manage the Gemini stream, handle user input, process commands,
+ * and interact with the Gemini API and history manager.
+ */
 export const useGeminiStream = (
   addItem: UseHistoryManagerReturn['addItem'],
   _clearItems: UseHistoryManagerReturn['clearItems'],
@@ -82,240 +100,490 @@ export const useGeminiStream = (
     }
   });
 
-  const submitQuery = useCallback(
-    async (query: PartListUnion) => {
-      if (streamingState === StreamingState.Responding) return;
-      if (typeof query === 'string' && query.trim().length === 0) return;
-
-      const userMessageTimestamp = Date.now();
-      let queryToSendToGemini: PartListUnion | null = null;
-
-      setShowHelp(false);
+  const prepareQueryForGemini = async (
+    query: PartListUnion,
+    userMessageTimestamp: number,
+    signal: AbortSignal,
+  ): Promise<{ queryToSend: PartListUnion | null; shouldProceed: boolean }> => {
+    if (typeof query === 'string' && query.trim().length === 0) {
+      return { queryToSend: null, shouldProceed: false };
+    }
 
-      abortControllerRef.current ??= new AbortController();
-      const signal = abortControllerRef.current.signal;
+    let localQueryToSendToGemini: PartListUnion | null = null;
 
-      if (typeof query === 'string') {
-        const trimmedQuery = query.trim();
-        onDebugMessage(`User query: '${trimmedQuery}'`);
+    if (typeof query === 'string') {
+      const trimmedQuery = query.trim();
+      onDebugMessage(`User query: '${trimmedQuery}'`);
 
-        if (handleSlashCommand(trimmedQuery)) return;
-        if (handleShellCommand(trimmedQuery)) return;
+      // Handle UI-only commands first
+      if (handleSlashCommand(trimmedQuery)) {
+        return { queryToSend: null, shouldProceed: false };
+      }
+      if (handleShellCommand(trimmedQuery)) {
+        return { queryToSend: null, shouldProceed: false };
+      }
 
-        if (isAtCommand(trimmedQuery)) {
-          const atCommandResult = await handleAtCommand({
-            query: trimmedQuery,
-            config,
-            addItem,
-            onDebugMessage,
-            messageId: userMessageTimestamp,
-            signal,
-          });
-          if (!atCommandResult.shouldProceed) return;
-          queryToSendToGemini = atCommandResult.processedQuery;
-        } else {
-          addItem(
-            { type: MessageType.USER, text: trimmedQuery },
-            userMessageTimestamp,
-          );
-          queryToSendToGemini = trimmedQuery;
+      // Handle @-commands (which might involve tool calls)
+      if (isAtCommand(trimmedQuery)) {
+        const atCommandResult = await handleAtCommand({
+          query: trimmedQuery,
+          config,
+          addItem,
+          onDebugMessage,
+          messageId: userMessageTimestamp,
+          signal,
+        });
+        if (!atCommandResult.shouldProceed) {
+          return { queryToSend: null, shouldProceed: false };
         }
+        localQueryToSendToGemini = atCommandResult.processedQuery;
       } else {
-        queryToSendToGemini = query;
-      }
-
-      if (queryToSendToGemini === null) {
-        onDebugMessage(
-          'Query processing resulted in null, not sending to Gemini.',
+        // Normal query for Gemini
+        addItem(
+          { type: MessageType.USER, text: trimmedQuery },
+          userMessageTimestamp,
         );
-        return;
+        localQueryToSendToGemini = trimmedQuery;
       }
+    } else {
+      // It's a function response (PartListUnion that isn't a string)
+      localQueryToSendToGemini = query;
+    }
 
-      const client = geminiClientRef.current;
-      if (!client) {
-        const errorMsg = 'Gemini client is not available.';
+    if (localQueryToSendToGemini === null) {
+      onDebugMessage(
+        'Query processing resulted in null, not sending to Gemini.',
+      );
+      return { queryToSend: null, shouldProceed: false };
+    }
+    return { queryToSend: localQueryToSendToGemini, shouldProceed: true };
+  };
+
+  const ensureChatSession = async (): Promise<{
+    client: GeminiClient | null;
+    chat: Chat | null;
+  }> => {
+    const currentClient = geminiClientRef.current;
+    if (!currentClient) {
+      const errorMsg = 'Gemini client is not available.';
+      setInitError(errorMsg);
+      addItem({ type: MessageType.ERROR, text: errorMsg }, Date.now());
+      return { client: null, chat: null };
+    }
+
+    if (!chatSessionRef.current) {
+      try {
+        chatSessionRef.current = await currentClient.startChat();
+      } catch (err: unknown) {
+        const errorMsg = `Failed to start chat: ${getErrorMessage(err)}`;
         setInitError(errorMsg);
         addItem({ type: MessageType.ERROR, text: errorMsg }, Date.now());
-        return;
+        setStreamingState(StreamingState.Idle);
+        return { client: currentClient, chat: null };
+      }
+    }
+    return { client: currentClient, chat: chatSessionRef.current };
+  };
+
+  // --- UI Helper Functions (used by event handlers) ---
+  const updateFunctionResponseUI = (
+    toolResponse: ToolCallResponseInfo,
+    status: ToolCallStatus,
+  ) => {
+    setPendingHistoryItem((item) =>
+      item?.type === 'tool_group'
+        ? {
+            ...item,
+            tools: item.tools.map((tool) => {
+              if (tool.callId === toolResponse.callId) {
+                return {
+                  ...tool,
+                  status,
+                  resultDisplay: toolResponse.resultDisplay,
+                };
+              } else {
+                return tool;
+              }
+            }),
+          }
+        : null,
+    );
+  };
+
+  const updateConfirmingFunctionStatusUI = (
+    callId: string,
+    confirmationDetails: ToolCallConfirmationDetails | undefined,
+  ) => {
+    if (pendingHistoryItemRef.current?.type !== 'tool_group') return;
+    setPendingHistoryItem((item) =>
+      item?.type === 'tool_group'
+        ? {
+            ...item,
+            tools: item.tools.map((tool) =>
+              tool.callId === callId
+                ? {
+                    ...tool,
+                    status: ToolCallStatus.Confirming,
+                    confirmationDetails,
+                  }
+                : tool,
+            ),
+          }
+        : null,
+    );
+  };
+
+  // This function will be fully refactored in a later step
+  const wireConfirmationSubmission = (
+    confirmationDetails: ServerToolCallConfirmationDetails,
+  ): ToolCallConfirmationDetails => {
+    const originalConfirmationDetails = confirmationDetails.details;
+    const request = confirmationDetails.request;
+    const resubmittingConfirm = async (outcome: ToolConfirmationOutcome) => {
+      originalConfirmationDetails.onConfirm(outcome);
+      if (pendingHistoryItemRef?.current?.type === 'tool_group') {
+        setPendingHistoryItem((item) =>
+          item?.type === 'tool_group'
+            ? {
+                ...item,
+                tools: item.tools.map((tool) =>
+                  tool.callId === request.callId
+                    ? {
+                        ...tool,
+                        confirmationDetails: undefined,
+                        status: ToolCallStatus.Executing,
+                      }
+                    : tool,
+                ),
+              }
+            : item,
+        );
+        refreshStatic();
       }
 
-      if (!chatSessionRef.current) {
+      if (outcome === ToolConfirmationOutcome.Cancel) {
+        declineToolExecution(
+          'User rejected function call.',
+          ToolCallStatus.Error,
+          request,
+          originalConfirmationDetails,
+        );
+      } else {
+        const tool = toolRegistry.getTool(request.name);
+        if (!tool) {
+          throw new Error(
+            `Tool "${request.name}" not found or is not registered.`,
+          );
+        }
         try {
-          chatSessionRef.current = await client.startChat();
-        } catch (err: unknown) {
-          const errorMsg = `Failed to start chat: ${getErrorMessage(err)}`;
-          setInitError(errorMsg);
-          addItem({ type: MessageType.ERROR, text: errorMsg }, Date.now());
+          abortControllerRef.current = new AbortController();
+          const result = await tool.execute(
+            request.args,
+            abortControllerRef.current.signal,
+          );
+          if (abortControllerRef.current.signal.aborted) {
+            declineToolExecution(
+              result.llmContent,
+              ToolCallStatus.Canceled,
+              request,
+              originalConfirmationDetails,
+            );
+            return;
+          }
+          const functionResponse: Part = {
+            functionResponse: {
+              name: request.name,
+              id: request.callId,
+              response: { output: result.llmContent },
+            },
+          };
+          const responseInfo: ToolCallResponseInfo = {
+            callId: request.callId,
+            responsePart: functionResponse,
+            resultDisplay: result.returnDisplay,
+            error: undefined,
+          };
+          updateFunctionResponseUI(responseInfo, ToolCallStatus.Success);
+          if (pendingHistoryItemRef.current) {
+            addItem(pendingHistoryItemRef.current, Date.now());
+            setPendingHistoryItem(null);
+          }
           setStreamingState(StreamingState.Idle);
-          return;
+          await submitQuery(functionResponse); // Recursive call
+        } finally {
+          if (streamingState !== StreamingState.WaitingForConfirmation) {
+            abortControllerRef.current = null;
+          }
         }
       }
+    };
 
-      setStreamingState(StreamingState.Responding);
-      setInitError(null);
-      const chat = chatSessionRef.current;
+    // Extracted declineToolExecution to be part of wireConfirmationSubmission's closure
+    // or could be a standalone helper if more params are passed.
+    function declineToolExecution(
+      declineMessage: string,
+      status: ToolCallStatus,
+      request: ServerToolCallConfirmationDetails['request'],
+      originalDetails: ServerToolCallConfirmationDetails['details'],
+    ) {
+      let resultDisplay: ToolResultDisplay | undefined;
+      if ('fileDiff' in originalDetails) {
+        resultDisplay = {
+          fileDiff: (originalDetails as ToolEditConfirmationDetails).fileDiff,
+        };
+      } else {
+        resultDisplay = `~~${(originalDetails as ToolExecuteConfirmationDetails).command}~~`;
+      }
+      const functionResponse: Part = {
+        functionResponse: {
+          id: request.callId,
+          name: request.name,
+          response: { error: declineMessage },
+        },
+      };
+      const responseInfo: ToolCallResponseInfo = {
+        callId: request.callId,
+        responsePart: functionResponse,
+        resultDisplay,
+        error: new Error(declineMessage),
+      };
+      const history = chatSessionRef.current?.getHistory();
+      if (history) {
+        history.push({ role: 'model', parts: [functionResponse] });
+      }
+      updateFunctionResponseUI(responseInfo, status);
+      if (pendingHistoryItemRef.current) {
+        addItem(pendingHistoryItemRef.current, Date.now());
+        setPendingHistoryItem(null);
+      }
+      setStreamingState(StreamingState.Idle);
+    }
 
-      try {
-        const stream = client.sendMessageStream(
-          chat,
-          queryToSendToGemini,
-          signal,
+    return { ...originalConfirmationDetails, onConfirm: resubmittingConfirm };
+  };
+
+  // --- Stream Event Handlers ---
+  const handleContentEvent = (
+    eventValue: ContentEvent['value'],
+    currentGeminiMessageBuffer: string,
+    userMessageTimestamp: number,
+  ): string => {
+    let newGeminiMessageBuffer = currentGeminiMessageBuffer + eventValue;
+    if (
+      pendingHistoryItemRef.current?.type !== 'gemini' &&
+      pendingHistoryItemRef.current?.type !== 'gemini_content'
+    ) {
+      if (pendingHistoryItemRef.current) {
+        addItem(pendingHistoryItemRef.current, userMessageTimestamp);
+      }
+      setPendingHistoryItem({ type: 'gemini', text: '' });
+      newGeminiMessageBuffer = eventValue;
+    }
+    // Split large messages for better rendering performance. Ideally,
+    // we should maximize the amount of output sent to <Static />.
+    const splitPoint = findLastSafeSplitPoint(newGeminiMessageBuffer);
+    if (splitPoint === newGeminiMessageBuffer.length) {
+      // Update the existing message with accumulated content
+      setPendingHistoryItem((item) => ({
+        type: item?.type as 'gemini' | 'gemini_content',
+        text: newGeminiMessageBuffer,
+      }));
+    } else {
+      // This indicates that we need to split up this Gemini Message.
+      // Splitting a message is primarily a performance consideration. There is a
+      // <Static> component at the root of App.tsx which takes care of rendering
+      // content statically or dynamically. Everything but the last message is
+      // treated as static in order to prevent re-rendering an entire message history
+      // multiple times per-second (as streaming occurs). Prior to this change you'd
+      // see heavy flickering of the terminal. This ensures that larger messages get
+      // broken up so that there are more "statically" rendered.
+      const beforeText = newGeminiMessageBuffer.substring(0, splitPoint);
+      const afterText = newGeminiMessageBuffer.substring(splitPoint);
+      addItem(
+        {
+          type: pendingHistoryItemRef.current?.type as
+            | 'gemini'
+            | 'gemini_content',
+          text: beforeText,
+        },
+        userMessageTimestamp,
+      );
+      setPendingHistoryItem({ type: 'gemini_content', text: afterText });
+      newGeminiMessageBuffer = afterText;
+    }
+    return newGeminiMessageBuffer;
+  };
+
+  const handleToolCallRequestEvent = (
+    eventValue: ToolCallRequestEvent['value'],
+    userMessageTimestamp: number,
+  ) => {
+    const { callId, name, args } = eventValue;
+    const cliTool = toolRegistry.getTool(name);
+    if (!cliTool) {
+      console.error(`CLI Tool "${name}" not found!`);
+      return; // Skip this event if tool is not found
+    }
+    if (pendingHistoryItemRef.current?.type !== 'tool_group') {
+      if (pendingHistoryItemRef.current) {
+        addItem(pendingHistoryItemRef.current, userMessageTimestamp);
+      }
+      setPendingHistoryItem({ type: 'tool_group', tools: [] });
+    }
+    let description: string;
+    try {
+      description = cliTool.getDescription(args);
+    } catch (e) {
+      description = `Error: Unable to get description: ${getErrorMessage(e)}`;
+    }
+    const toolCallDisplay: IndividualToolCallDisplay = {
+      callId,
+      name: cliTool.displayName,
+      description,
+      status: ToolCallStatus.Pending,
+      resultDisplay: undefined,
+      confirmationDetails: undefined,
+    };
+    setPendingHistoryItem((pending) =>
+      pending?.type === 'tool_group'
+        ? { ...pending, tools: [...pending.tools, toolCallDisplay] }
+        : null,
+    );
+  };
+
+  const handleToolCallResponseEvent = (
+    eventValue: ToolCallResponseEvent['value'],
+  ) => {
+    const status = eventValue.error
+      ? ToolCallStatus.Error
+      : ToolCallStatus.Success;
+    updateFunctionResponseUI(eventValue, status);
+  };
+
+  const handleToolCallConfirmationEvent = (
+    eventValue: ToolCallConfirmationEvent['value'],
+  ) => {
+    const confirmationDetails = wireConfirmationSubmission(eventValue);
+    updateConfirmingFunctionStatusUI(
+      eventValue.request.callId,
+      confirmationDetails,
+    );
+    setStreamingState(StreamingState.WaitingForConfirmation);
+  };
+
+  const handleUserCancelledEvent = (userMessageTimestamp: number) => {
+    if (pendingHistoryItemRef.current) {
+      if (pendingHistoryItemRef.current.type === 'tool_group') {
+        const updatedTools = pendingHistoryItemRef.current.tools.map((tool) =>
+          tool.status === ToolCallStatus.Pending ||
+          tool.status === ToolCallStatus.Confirming ||
+          tool.status === ToolCallStatus.Executing
+            ? { ...tool, status: ToolCallStatus.Canceled }
+            : tool,
         );
+        const pendingItem: HistoryItemToolGroup = {
+          ...pendingHistoryItemRef.current,
+          tools: updatedTools,
+        };
+        addItem(pendingItem, userMessageTimestamp);
+      } else {
+        addItem(pendingHistoryItemRef.current, userMessageTimestamp);
+      }
+      setPendingHistoryItem(null);
+    }
+    addItem(
+      { type: MessageType.INFO, text: 'User cancelled the request.' },
+      userMessageTimestamp,
+    );
+    setStreamingState(StreamingState.Idle);
+  };
 
-        let geminiMessageBuffer = '';
+  const handleErrorEvent = (
+    eventValue: ErrorEvent['value'],
+    userMessageTimestamp: number,
+  ) => {
+    if (pendingHistoryItemRef.current) {
+      addItem(pendingHistoryItemRef.current, userMessageTimestamp);
+      setPendingHistoryItem(null);
+    }
+    addItem(
+      { type: MessageType.ERROR, text: `[API Error: ${eventValue.message}]` },
+      userMessageTimestamp,
+    );
+  };
 
-        for await (const event of stream) {
-          if (event.type === ServerGeminiEventType.Content) {
-            if (
-              pendingHistoryItemRef.current?.type !== 'gemini' &&
-              pendingHistoryItemRef.current?.type !== 'gemini_content'
-            ) {
-              if (pendingHistoryItemRef.current) {
-                addItem(pendingHistoryItemRef.current, userMessageTimestamp);
-              }
-              setPendingHistoryItem({
-                type: 'gemini',
-                text: '',
-              });
-              geminiMessageBuffer = '';
-            }
+  const processGeminiStreamEvents = async (
+    stream: AsyncIterable<GeminiEvent>,
+    userMessageTimestamp: number,
+  ): Promise<StreamProcessingStatus> => {
+    let geminiMessageBuffer = '';
 
-            geminiMessageBuffer += event.value;
+    for await (const event of stream) {
+      if (event.type === ServerGeminiEventType.Content) {
+        geminiMessageBuffer = handleContentEvent(
+          event.value,
+          geminiMessageBuffer,
+          userMessageTimestamp,
+        );
+      } else if (event.type === ServerGeminiEventType.ToolCallRequest) {
+        handleToolCallRequestEvent(event.value, userMessageTimestamp);
+      } else if (event.type === ServerGeminiEventType.ToolCallResponse) {
+        handleToolCallResponseEvent(event.value);
+      } else if (event.type === ServerGeminiEventType.ToolCallConfirmation) {
+        handleToolCallConfirmationEvent(event.value);
+        return StreamProcessingStatus.PausedForConfirmation; // Explicit return as this pauses the stream
+      } else if (event.type === ServerGeminiEventType.UserCancelled) {
+        handleUserCancelledEvent(userMessageTimestamp);
+        return StreamProcessingStatus.UserCancelled;
+      } else if (event.type === ServerGeminiEventType.Error) {
+        handleErrorEvent(event.value, userMessageTimestamp);
+        return StreamProcessingStatus.Error;
+      }
+    }
+    return StreamProcessingStatus.Completed;
+  };
 
-            // Split large messages for better rendering performance. Ideally,
-            // we should maximize the amount of output sent to <Static />.
-            const splitPoint = findLastSafeSplitPoint(geminiMessageBuffer);
-            if (splitPoint === geminiMessageBuffer.length) {
-              // Update the existing message with accumulated content
-              setPendingHistoryItem((item) => ({
-                type: item?.type as 'gemini' | 'gemini_content',
-                text: geminiMessageBuffer,
-              }));
-            } else {
-              // This indicates that we need to split up this Gemini Message.
-              // Splitting a message is primarily a performance consideration. There is a
-              // <Static> component at the root of App.tsx which takes care of rendering
-              // content statically or dynamically. Everything but the last message is
-              // treated as static in order to prevent re-rendering an entire message history
-              // multiple times per-second (as streaming occurs). Prior to this change you'd
-              // see heavy flickering of the terminal. This ensures that larger messages get
-              // broken up so that there are more "statically" rendered.
-              const beforeText = geminiMessageBuffer.substring(0, splitPoint);
-              const afterText = geminiMessageBuffer.substring(splitPoint);
-              geminiMessageBuffer = afterText;
-              addItem(
-                {
-                  type: pendingHistoryItemRef.current?.type as
-                    | 'gemini'
-                    | 'gemini_content',
-                  text: beforeText,
-                },
-                userMessageTimestamp,
-              );
-              setPendingHistoryItem({
-                type: 'gemini_content',
-                text: afterText,
-              });
-            }
-          } else if (event.type === ServerGeminiEventType.ToolCallRequest) {
-            const { callId, name, args } = event.value;
-            const cliTool = toolRegistry.getTool(name);
-            if (!cliTool) {
-              console.error(`CLI Tool "${name}" not found!`);
-              continue;
-            }
+  const submitQuery = useCallback(
+    async (query: PartListUnion) => {
+      if (streamingState === StreamingState.Responding) return;
 
-            if (pendingHistoryItemRef.current?.type !== 'tool_group') {
-              if (pendingHistoryItemRef.current) {
-                addItem(pendingHistoryItemRef.current, userMessageTimestamp);
-              }
-              setPendingHistoryItem({
-                type: 'tool_group',
-                tools: [],
-              });
-            }
+      const userMessageTimestamp = Date.now();
+      setShowHelp(false);
 
-            let description: string;
-            try {
-              description = cliTool.getDescription(args);
-            } catch (e) {
-              description = `Error: Unable to get description: ${getErrorMessage(e)}`;
-            }
+      abortControllerRef.current ??= new AbortController();
+      const signal = abortControllerRef.current.signal;
 
-            const toolCallDisplay: IndividualToolCallDisplay = {
-              callId,
-              name: cliTool.displayName,
-              description,
-              status: ToolCallStatus.Pending,
-              resultDisplay: undefined,
-              confirmationDetails: undefined,
-            };
+      const { queryToSend, shouldProceed } = await prepareQueryForGemini(
+        query,
+        userMessageTimestamp,
+        signal,
+      );
 
-            setPendingHistoryItem((pending) =>
-              pending?.type === 'tool_group'
-                ? {
-                    ...pending,
-                    tools: [...pending.tools, toolCallDisplay],
-                  }
-                : null,
-            );
-          } else if (event.type === ServerGeminiEventType.ToolCallResponse) {
-            const status = event.value.error
-              ? ToolCallStatus.Error
-              : ToolCallStatus.Success;
-            updateFunctionResponseUI(event.value, status);
-          } else if (
-            event.type === ServerGeminiEventType.ToolCallConfirmation
-          ) {
-            const confirmationDetails = wireConfirmationSubmission(event.value);
-            updateConfirmingFunctionStatusUI(
-              event.value.request.callId,
-              confirmationDetails,
-            );
-            setStreamingState(StreamingState.WaitingForConfirmation);
-            return;
-          } else if (event.type === ServerGeminiEventType.UserCancelled) {
-            if (pendingHistoryItemRef.current) {
-              if (pendingHistoryItemRef.current.type === 'tool_group') {
-                const updatedTools = pendingHistoryItemRef.current.tools.map(
-                  (tool) => {
-                    if (
-                      tool.status === ToolCallStatus.Pending ||
-                      tool.status === ToolCallStatus.Confirming ||
-                      tool.status === ToolCallStatus.Executing
-                    ) {
-                      return { ...tool, status: ToolCallStatus.Canceled };
-                    }
-                    return tool;
-                  },
-                );
-                const pendingHistoryItem = pendingHistoryItemRef.current;
-                pendingHistoryItem.tools = updatedTools;
-                addItem(pendingHistoryItem, userMessageTimestamp);
-              } else {
-                addItem(pendingHistoryItemRef.current, userMessageTimestamp);
-              }
-              setPendingHistoryItem(null);
-            }
-            addItem(
-              { type: MessageType.INFO, text: 'User cancelled the request.' },
-              userMessageTimestamp,
-            );
-            setStreamingState(StreamingState.Idle);
-            return;
-          } else if (event.type === ServerGeminiEventType.Error) {
-            if (pendingHistoryItemRef.current) {
-              addItem(pendingHistoryItemRef.current, userMessageTimestamp);
-              setPendingHistoryItem(null);
-            }
-            addItem(
-              {
-                type: MessageType.ERROR,
-                text: `[API Error: ${event.value.message}]`,
-              },
-              userMessageTimestamp,
-            );
-          }
+      if (!shouldProceed || queryToSend === null) {
+        return;
+      }
+
+      const { client, chat } = await ensureChatSession();
+
+      if (!client || !chat) {
+        return;
+      }
+
+      setStreamingState(StreamingState.Responding);
+      setInitError(null);
+
+      try {
+        const stream = client.sendMessageStream(chat, queryToSend, signal);
+        const processingStatus = await processGeminiStreamEvents(
+          stream,
+          userMessageTimestamp,
+        );
+
+        if (
+          processingStatus === StreamProcessingStatus.PausedForConfirmation ||
+          processingStatus === StreamProcessingStatus.UserCancelled
+        ) {
+          return;
         }
 
         if (pendingHistoryItemRef.current) {
@@ -323,7 +591,12 @@ export const useGeminiStream = (
           setPendingHistoryItem(null);
         }
 
-        setStreamingState(StreamingState.Idle);
+        if (
+          processingStatus === StreamProcessingStatus.Completed ||
+          processingStatus === StreamProcessingStatus.Error
+        ) {
+          setStreamingState(StreamingState.Idle);
+        }
       } catch (error: unknown) {
         if (!isNodeError(error) || error.name !== 'AbortError') {
           addItem(
@@ -336,191 +609,12 @@ export const useGeminiStream = (
         }
         setStreamingState(StreamingState.Idle);
       } finally {
-        abortControllerRef.current = null;
-      }
-
-      function updateConfirmingFunctionStatusUI(
-        callId: string,
-        confirmationDetails: ToolCallConfirmationDetails | undefined,
-      ) {
-        if (pendingHistoryItemRef.current?.type !== 'tool_group') return;
-        setPendingHistoryItem((item) =>
-          item?.type === 'tool_group'
-            ? {
-                ...item,
-                tools: item.tools.map((tool) =>
-                  tool.callId === callId
-                    ? {
-                        ...tool,
-                        status: ToolCallStatus.Confirming,
-                        confirmationDetails,
-                      }
-                    : tool,
-                ),
-              }
-            : null,
-        );
-      }
-
-      function updateFunctionResponseUI(
-        toolResponse: ToolCallResponseInfo,
-        status: ToolCallStatus,
-      ) {
-        setPendingHistoryItem((item) =>
-          item?.type === 'tool_group'
-            ? {
-                ...item,
-                tools: item.tools.map((tool) => {
-                  if (tool.callId === toolResponse.callId) {
-                    return {
-                      ...tool,
-                      status,
-                      resultDisplay: toolResponse.resultDisplay,
-                    };
-                  } else {
-                    return tool;
-                  }
-                }),
-              }
-            : null,
-        );
-      }
-
-      function wireConfirmationSubmission(
-        confirmationDetails: ServerToolCallConfirmationDetails,
-      ): ToolCallConfirmationDetails {
-        const originalConfirmationDetails = confirmationDetails.details;
-        const request = confirmationDetails.request;
-        const resubmittingConfirm = async (
-          outcome: ToolConfirmationOutcome,
-        ) => {
-          originalConfirmationDetails.onConfirm(outcome);
-
-          if (pendingHistoryItemRef?.current?.type === 'tool_group') {
-            setPendingHistoryItem((item) =>
-              item?.type === 'tool_group'
-                ? {
-                    ...item,
-                    tools: item.tools.map((tool) =>
-                      tool.callId === request.callId
-                        ? {
-                            ...tool,
-                            confirmationDetails: undefined,
-                            status: ToolCallStatus.Executing,
-                          }
-                        : tool,
-                    ),
-                  }
-                : item,
-            );
-            refreshStatic();
-          }
-
-          if (outcome === ToolConfirmationOutcome.Cancel) {
-            declineToolExecution(
-              'User rejected function call.',
-              ToolCallStatus.Error,
-            );
-          } else {
-            const tool = toolRegistry.getTool(request.name);
-            if (!tool) {
-              throw new Error(
-                `Tool "${request.name}" not found or is not registered.`,
-              );
-            }
-
-            try {
-              abortControllerRef.current = new AbortController();
-              const result = await tool.execute(
-                request.args,
-                abortControllerRef.current.signal,
-              );
-
-              if (abortControllerRef.current.signal.aborted) {
-                declineToolExecution(
-                  result.llmContent,
-                  ToolCallStatus.Canceled,
-                );
-                return;
-              }
-
-              const functionResponse: Part = {
-                functionResponse: {
-                  name: request.name,
-                  id: request.callId,
-                  response: { output: result.llmContent },
-                },
-              };
-
-              const responseInfo: ToolCallResponseInfo = {
-                callId: request.callId,
-                responsePart: functionResponse,
-                resultDisplay: result.returnDisplay,
-                error: undefined,
-              };
-              updateFunctionResponseUI(responseInfo, ToolCallStatus.Success);
-              if (pendingHistoryItemRef.current) {
-                addItem(pendingHistoryItemRef.current, Date.now());
-                setPendingHistoryItem(null);
-              }
-              setStreamingState(StreamingState.Idle);
-              await submitQuery(functionResponse);
-            } finally {
-              abortControllerRef.current = null;
-            }
-          }
-
-          function declineToolExecution(
-            declineMessage: string,
-            status: ToolCallStatus,
-          ) {
-            let resultDisplay: ToolResultDisplay | undefined;
-            if ('fileDiff' in originalConfirmationDetails) {
-              resultDisplay = {
-                fileDiff: (
-                  originalConfirmationDetails as ToolEditConfirmationDetails
-                ).fileDiff,
-              };
-            } else {
-              resultDisplay = `~~${(originalConfirmationDetails as ToolExecuteConfirmationDetails).command}~~`;
-            }
-            const functionResponse: Part = {
-              functionResponse: {
-                id: request.callId,
-                name: request.name,
-                response: { error: declineMessage },
-              },
-            };
-            const responseInfo: ToolCallResponseInfo = {
-              callId: request.callId,
-              responsePart: functionResponse,
-              resultDisplay,
-              error: new Error(declineMessage),
-            };
-
-            const history = chatSessionRef.current?.getHistory();
-            if (history) {
-              history.push({
-                role: 'model',
-                parts: [functionResponse],
-              });
-            }
-
-            updateFunctionResponseUI(responseInfo, status);
-            if (pendingHistoryItemRef.current) {
-              addItem(pendingHistoryItemRef.current, Date.now());
-              setPendingHistoryItem(null);
-            }
-            setStreamingState(StreamingState.Idle);
-          }
-        };
-
-        return {
-          ...originalConfirmationDetails,
-          onConfirm: resubmittingConfirm,
-        };
+        if (streamingState !== StreamingState.WaitingForConfirmation) {
+          abortControllerRef.current = null;
+        }
       }
     },
+    // eslint-disable-next-line react-hooks/exhaustive-deps
     [
       streamingState,
       setShowHelp,
@@ -528,11 +622,10 @@ export const useGeminiStream = (
       handleShellCommand,
       config,
       addItem,
-      pendingHistoryItemRef,
-      setPendingHistoryItem,
-      toolRegistry,
-      refreshStatic,
       onDebugMessage,
+      refreshStatic,
+      setInitError,
+      setStreamingState,
     ],
   );