Precise custom model selection & simplify language model/provider log… (#147)

…ic (no merging)

src/ipc/utils/token_utils.ts

@@ -20,13 +20,7 @@ const DEFAULT_CONTEXT_WINDOW = 128_000;
 
 export async function getContextWindow() {
   const settings = readSettings();
-  const model = settings.selectedModel;
-
-  const models = await getLanguageModels({
-    providerId: model.provider,
-  });
-
-  const modelOption = models.find((m) => m.apiName === model.name);
+  const modelOption = await findLanguageModel(settings.selectedModel);
   return modelOption?.contextWindow || DEFAULT_CONTEXT_WINDOW;
 }
 
@@ -34,10 +28,23 @@ export async function getContextWindow() {
 const DEFAULT_MAX_TOKENS = 8_000;
 
 export async function getMaxTokens(model: LargeLanguageModel) {
+  const modelOption = await findLanguageModel(model);
+  return modelOption?.maxOutputTokens || DEFAULT_MAX_TOKENS;
+}
+
+async function findLanguageModel(model: LargeLanguageModel) {
   const models = await getLanguageModels({
     providerId: model.provider,
   });
 
-  const modelOption = models.find((m) => m.apiName === model.name);
-  return modelOption?.maxOutputTokens || DEFAULT_MAX_TOKENS;
+  if (model.customModelId) {
+    const customModel = models.find(
+      (m) => m.type === "custom" && m.id === model.customModelId,
+    );
+    if (customModel) {
+      return customModel;
+    }
+  }
+
+  return models.find((m) => m.apiName === model.name);
 }