refactor: simplify useModelLRU hook and ModelSelector handlers

Author: ammar-agent

src/browser/components/ModelSelector.tsx

@@ -17,7 +17,7 @@ interface ModelSelectorProps {
   onRemoveModel?: (model: string) => void;
   onComplete?: () => void;
   defaultModel?: string | null;
-  onSetDefaultModel?: (model: string | null) => void;
+  onSetDefaultModel?: (model: string) => void;
 }
 
 export interface ModelSelectorRef {
@@ -186,6 +186,14 @@ export const ModelSelector = forwardRef<ModelSelectorRef, ModelSelectorProps>(
       setHighlightedIndex(currentIndex);
     }, [recentModels, value]);
 
+    const handleSetDefault = (e: React.MouseEvent, model: string) => {
+      e.preventDefault();
+      e.stopPropagation();
+      if (defaultModel !== model && onSetDefaultModel) {
+        onSetDefaultModel(model);
+      }
+    };
+
     // Expose open method to parent via ref
     useImperativeHandle(
       ref,
@@ -256,15 +264,7 @@ export const ModelSelector = forwardRef<ModelSelectorRef, ModelSelectorProps>(
                         <button
                           type="button"
                           onMouseDown={(e) => e.preventDefault()}
-                          onClick={(event) => {
-                            event.preventDefault();
-                            event.stopPropagation();
-                            const isDefault = defaultModel === model;
-                            // If it's already the default, do nothing (cannot unset)
-                            if (!isDefault) {
-                              onSetDefaultModel(model);
-                            }
-                          }}
+                          onClick={(e) => handleSetDefault(e, model)}
                           className={cn(
                             "rounded-sm border px-1 py-0.5 transition-colors duration-150 flex items-center justify-center",
                             defaultModel === model
@@ -276,12 +276,12 @@ export const ModelSelector = forwardRef<ModelSelectorRef, ModelSelectorProps>(
                           }
                           disabled={defaultModel === model}
                         >
-                          <Star
-                            className={cn("h-3 w-3")}
-                          />
+                          <Star className={cn("h-3 w-3")} />
                         </button>
                         <Tooltip className="tooltip" align="center">
-                          {defaultModel === model ? "Current default model" : "Set as default model"}
+                          {defaultModel === model
+                            ? "Current default model"
+                            : "Set as default model"}
                         </Tooltip>
                       </TooltipWrapper>
                     )}

src/browser/hooks/useAIViewKeybinds.ts

@@ -6,7 +6,7 @@ import { updatePersistedState, readPersistedState } from "@/browser/hooks/usePer
 import type { ThinkingLevel, ThinkingLevelOn } from "@/common/types/thinking";
 import { DEFAULT_THINKING_LEVEL } from "@/common/types/thinking";
 import { getThinkingPolicyForModel } from "@/browser/utils/thinking/policy";
-import { getDefaultModelFromLRU } from "@/browser/hooks/useModelLRU";
+import { getDefaultModel } from "@/browser/hooks/useModelLRU";
 import type { StreamingMessageAggregator } from "@/browser/utils/messages/StreamingMessageAggregator";
 import { isCompactingStream, cancelCompaction } from "@/browser/utils/compaction/handler";
 
@@ -116,7 +116,7 @@ export function useAIViewKeybinds({
         // Fall back to message history model, then to most recent model from LRU
         // This matches the same logic as useSendMessageOptions
         const selectedModel = readPersistedState<string | null>(getModelKey(workspaceId), null);
-        const modelToUse = selectedModel ?? currentModel ?? getDefaultModelFromLRU();
+        const modelToUse = selectedModel ?? currentModel ?? getDefaultModel();
 
         // Storage key for remembering this model's last-used active thinking level
         const lastThinkingKey = getLastThinkingByModelKey(modelToUse);

src/browser/hooks/useModelLRU.ts

@@ -33,21 +33,11 @@ export function evictModelFromLRU(model: string): void {
   persistModels(nextList);
 }
 
-export function getExplicitDefaultModel(): string {
+export function getDefaultModel(): string {
   const persisted = readPersistedState<string | null>(DEFAULT_MODEL_KEY, null);
   return persisted ?? FALLBACK_MODEL;
 }
 
-/**
- * Get the default model.
- * Prioritizes the explicit default model if set.
- * Otherwise, falls back to LRU behavior (most recently used).
- */
-export function getDefaultModelFromLRU(): string {
-  // Always return the explicit default (which falls back to hardcoded default)
-  return getExplicitDefaultModel();
-}
-
 /**
  * Hook to manage a Least Recently Used (LRU) cache of AI models.
  * Stores up to 8 recently used models in localStorage.
@@ -60,24 +50,12 @@ export function useModelLRU() {
     { listener: true }
   );
 
-  const [defaultModel, setDefaultModel] = usePersistedState<string | null>(
+  const [defaultModel, setDefaultModel] = usePersistedState<string>(
     DEFAULT_MODEL_KEY,
-    null,
+    FALLBACK_MODEL,
     { listener: true }
   );
 
-  // Return the effective default model (never null)
-  const effectiveDefaultModel = defaultModel ?? FALLBACK_MODEL;
-
-  // Wrapper for setDefaultModel that prevents null/clearing
-  const handleSetDefaultModel = useCallback(
-    (model: string | null) => {
-      if (!model) return;
-      setDefaultModel(model);
-    },
-    [setDefaultModel]
-  );
-
   // Merge any new defaults from MODEL_ABBREVIATIONS (only once on mount)
   useEffect(() => {
     setRecentModels((prev) => {
@@ -131,7 +109,7 @@ export function useModelLRU() {
     evictModel,
     getRecentModels,
     recentModels,
-    defaultModel: effectiveDefaultModel,
-    setDefaultModel: handleSetDefaultModel,
+    defaultModel,
+    setDefaultModel,
   };
 }

src/browser/hooks/useSendMessageOptions.ts

@@ -1,7 +1,7 @@
 import { useThinkingLevel } from "./useThinkingLevel";
 import { useMode } from "@/browser/contexts/ModeContext";
 import { usePersistedState } from "./usePersistedState";
-import { getDefaultModelFromLRU } from "./useModelLRU";
+import { getDefaultModel } from "./useModelLRU";
 import { modeToToolPolicy, PLAN_MODE_INSTRUCTION } from "@/common/utils/ui/modeUtils";
 import { getModelKey } from "@/common/constants/storage";
 import type { SendMessageOptions } from "@/common/types/ipc";
@@ -56,7 +56,7 @@ export function useSendMessageOptions(workspaceId: string): SendMessageOptions {
   const [thinkingLevel] = useThinkingLevel();
   const [mode] = useMode();
   const { options: providerOptions } = useProviderOptions();
-  const defaultModel = getDefaultModelFromLRU();
+  const defaultModel = getDefaultModel();
   const [preferredModel] = usePersistedState<string>(
     getModelKey(workspaceId),
     defaultModel, // Default to most recently used model

src/browser/utils/messages/sendOptions.ts

@@ -1,7 +1,7 @@
 import { getModelKey, getThinkingLevelKey, getModeKey } from "@/common/constants/storage";
 import { modeToToolPolicy, PLAN_MODE_INSTRUCTION } from "@/common/utils/ui/modeUtils";
 import { readPersistedState } from "@/browser/hooks/usePersistedState";
-import { getDefaultModelFromLRU } from "@/browser/hooks/useModelLRU";
+import { getDefaultModel } from "@/browser/hooks/useModelLRU";
 import type { SendMessageOptions } from "@/common/types/ipc";
 import type { UIMode } from "@/common/types/mode";
 import type { ThinkingLevel } from "@/common/types/thinking";
@@ -38,7 +38,7 @@ function getProviderOptions(): MuxProviderOptions {
  */
 export function getSendOptionsFromStorage(workspaceId: string): SendMessageOptions {
   // Read model preference (workspace-specific), fallback to LRU default
-  const model = readPersistedState<string>(getModelKey(workspaceId), getDefaultModelFromLRU());
+  const model = readPersistedState<string>(getModelKey(workspaceId), getDefaultModel());
 
   // Read thinking level (workspace-specific)
   const thinkingLevel = readPersistedState<ThinkingLevel>(