Improve readability issues

This is only the first change of many changes.

* Remove redundant autogenerated comments
* Use the recommended file name style
* Use camelCase for variable names
* Don't introduce submodules for relevant types
* Don't introduce constants like modules, these are implementation details
* Remove empty files

1 files changed, 168 insertions, 0 deletions

diff --git a/packages/cli/src/core/history-updater.ts b/packages/cli/src/core/history-updater.ts
new file mode 100644
index 00000000..4013728f
--- /dev/null
+++ b/packages/cli/src/core/history-updater.ts
@@ -0,0 +1,168 @@
+import { Part } from "@google/genai";
+import { toolRegistry } from "../tools/tool-registry.js";
+import { HistoryItem, IndividualToolCallDisplay, ToolCallEvent, ToolCallStatus, ToolConfirmationOutcome, ToolEditConfirmationDetails, ToolExecuteConfirmationDetails } from "../ui/types.js";
+import { ToolResultDisplay } from "../tools/tool.js";
+
+/**
+ * Processes a tool call chunk and updates the history state accordingly.
+ * Manages adding new tool groups or updating existing ones.
+ * Resides here as its primary effect is updating history based on tool events.
+ */
+export const handleToolCallChunk = (
+    chunk: ToolCallEvent,
+    setHistory: React.Dispatch<React.SetStateAction<HistoryItem[]>>,
+    submitQuery: (query: Part) => Promise<void>,
+    getNextMessageId: () => number,
+    currentToolGroupIdRef: React.MutableRefObject<number | null>
+): void => {
+    const toolDefinition = toolRegistry.getTool(chunk.name);
+    const description = toolDefinition?.getDescription
+        ? toolDefinition.getDescription(chunk.args)
+        : '';
+    const toolDisplayName = toolDefinition?.displayName ?? chunk.name;
+    let confirmationDetails = chunk.confirmationDetails;
+    if (confirmationDetails) {
+        const originalConfirmationDetails = confirmationDetails;
+        const historyUpdatingConfirm = async (outcome: ToolConfirmationOutcome) => {
+            originalConfirmationDetails.onConfirm(outcome);
+
+            if (outcome === ToolConfirmationOutcome.Cancel) {
+                let resultDisplay: ToolResultDisplay | undefined;
+                if ('fileDiff' in originalConfirmationDetails) {
+                    resultDisplay = { fileDiff: (originalConfirmationDetails as ToolEditConfirmationDetails).fileDiff };
+                } else {
+                    resultDisplay = `~~${(originalConfirmationDetails as ToolExecuteConfirmationDetails).command}~~`;
+                }
+                handleToolCallChunk({ ...chunk, status: ToolCallStatus.Canceled, confirmationDetails: undefined, resultDisplay, }, setHistory, submitQuery, getNextMessageId, currentToolGroupIdRef);
+                const functionResponse: Part = {
+                    functionResponse: {
+                        name: chunk.name,
+                        response: { "error": "User rejected function call." },
+                    },
+                }
+                await submitQuery(functionResponse);
+            } else {
+                const tool = toolRegistry.getTool(chunk.name)
+                if (!tool) {
+                    throw new Error(`Tool "${chunk.name}" not found or is not registered.`);
+                }
+                handleToolCallChunk({ ...chunk, status: ToolCallStatus.Invoked, resultDisplay: "Executing...", confirmationDetails: undefined }, setHistory, submitQuery, getNextMessageId, currentToolGroupIdRef);
+                const result = await tool.execute(chunk.args);
+                handleToolCallChunk({ ...chunk, status: ToolCallStatus.Invoked, resultDisplay: result.returnDisplay, confirmationDetails: undefined }, setHistory, submitQuery, getNextMessageId, currentToolGroupIdRef);
+                const functionResponse: Part = {
+                    functionResponse: {
+                        name: chunk.name,
+                        id: chunk.callId,
+                        response: { "output": result.llmContent },
+                    },
+                }
+                await submitQuery(functionResponse);
+            }
+        }
+
+        confirmationDetails = {
+            ...originalConfirmationDetails,
+            onConfirm: historyUpdatingConfirm,
+        };
+    }
+    const toolDetail: IndividualToolCallDisplay = {
+        callId: chunk.callId,
+        name: toolDisplayName,
+        description,
+        resultDisplay: chunk.resultDisplay,
+        status: chunk.status,
+        confirmationDetails: confirmationDetails,
+    };
+
+    const activeGroupId = currentToolGroupIdRef.current;
+    setHistory(prev => {
+        if (chunk.status === ToolCallStatus.Pending) {
+            if (activeGroupId === null) {
+                // Start a new tool group
+                const newGroupId = getNextMessageId();
+                currentToolGroupIdRef.current = newGroupId;
+                return [
+                    ...prev,
+                    { id: newGroupId, type: 'tool_group', tools: [toolDetail] } as HistoryItem
+                ];
+            }
+
+            // Add to existing tool group
+            return prev.map(item =>
+                item.id === activeGroupId && item.type === 'tool_group'
+                    ? item.tools.some(t => t.callId === toolDetail.callId)
+                        ? item // Tool already listed as pending
+                        : { ...item, tools: [...item.tools, toolDetail] }
+                    : item
+            );
+        }
+
+        // Update the status of a pending tool within the active group
+        if (activeGroupId === null) {
+            // Log if an invoked tool arrives without an active group context
+            console.warn("Received invoked tool status without an active tool group ID:", chunk);
+            return prev;
+        }
+
+        return prev.map(item =>
+            item.id === activeGroupId && item.type === 'tool_group'
+                ? {
+                    ...item,
+                    tools: item.tools.map(t =>
+                        t.callId === toolDetail.callId
+                            ? { ...t, ...toolDetail, status: chunk.status } // Update details & status
+                            : t
+                    )
+                }
+                : item
+        );
+    });
+};
+
+/**
+ * Appends an error or informational message to the history, attempting to attach
+ * it to the last non-user message or creating a new entry.
+ */
+export const addErrorMessageToHistory = (
+    error: any,
+    setHistory: React.Dispatch<React.SetStateAction<HistoryItem[]>>,
+    getNextMessageId: () => number
+): void => {
+    const isAbort = error.name === 'AbortError';
+    const errorType = isAbort ? 'info' : 'error';
+    const errorText = isAbort
+        ? '[Request cancelled by user]'
+        : `[Error: ${error.message || 'Unknown error'}]`;
+
+    setHistory(prev => {
+        const reversedHistory = [...prev].reverse();
+        // Find the last message that isn't from the user to append the error/info to
+        const lastBotMessageIndex = reversedHistory.findIndex(item => item.type !== 'user');
+        const originalIndex = lastBotMessageIndex !== -1 ? prev.length - 1 - lastBotMessageIndex : -1;
+
+        if (originalIndex !== -1) {
+            // Append error to the last relevant message
+            return prev.map((item, index) => {
+                if (index === originalIndex) {
+                    let baseText = '';
+                    // Determine base text based on item type
+                    if (item.type === 'gemini') baseText = item.text ?? '';
+                    else if (item.type === 'tool_group') baseText = `Tool execution (${item.tools.length} calls)`;
+                    else if (item.type === 'error' || item.type === 'info') baseText = item.text ?? '';
+                    // Safely handle potential undefined text
+
+                    const updatedText = (baseText + (baseText && !baseText.endsWith('\n') ? '\n' : '') + errorText).trim();
+                    // Reuse existing ID, update type and text
+                    return { ...item, type: errorType, text: updatedText };
+                }
+                return item;
+            });
+        } else {
+            // No previous message to append to, add a new error item
+            return [
+                ...prev,
+                { id: getNextMessageId(), type: errorType, text: errorText } as HistoryItem
+            ];
+        }
+    });
+};
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