fix: Model flag parsing and model args (#42)

src/agent/model.ts

@@ -0,0 +1,64 @@
+/**
+ * Model resolution and handling utilities
+ */
+import modelsData from "../models.json";
+
+export const models = modelsData;
+
+/**
+ * Resolve a model by ID or handle
+ * @param modelIdentifier - Can be either a model ID (e.g., "opus") or a full handle (e.g., "anthropic/claude-opus-4-1-20250805")
+ * @returns The model handle if found, null otherwise
+ */
+export function resolveModel(modelIdentifier: string): string | null {
+  const byId = models.find((m) => m.id === modelIdentifier);
+  if (byId) return byId.handle;
+
+  const byHandle = models.find((m) => m.handle === modelIdentifier);
+  if (byHandle) return byHandle.handle;
+
+  return null;
+}
+
+/**
+ * Get the default model handle
+ */
+export function getDefaultModel(): string {
+  const defaultModel = models.find((m) => m.isDefault);
+  return defaultModel?.handle || models[0].handle;
+}
+
+/**
+ * Format available models for error messages
+ */
+export function formatAvailableModels(): string {
+  return models.map((m) => `  ${m.id.padEnd(20)} ${m.handle}`).join("\n");
+}
+
+/**
+ * Get model info by ID or handle
+ * @param modelIdentifier - Can be either a model ID (e.g., "opus") or a full handle (e.g., "anthropic/claude-opus-4-1-20250805")
+ * @returns The model info if found, null otherwise
+ */
+export function getModelInfo(modelIdentifier: string) {
+  const byId = models.find((m) => m.id === modelIdentifier);
+  if (byId) return byId;
+
+  const byHandle = models.find((m) => m.handle === modelIdentifier);
+  if (byHandle) return byHandle;
+
+  return null;
+}
+
+/**
+ * Get updateArgs for a model by ID or handle
+ * @param modelIdentifier - Can be either a model ID (e.g., "opus") or a full handle (e.g., "anthropic/claude-opus-4-1-20250805")
+ * @returns The updateArgs if found, undefined otherwise
+ */
+export function getModelUpdateArgs(
+  modelIdentifier?: string,
+): Record<string, unknown> | undefined {
+  if (!modelIdentifier) return undefined;
+  const modelInfo = getModelInfo(modelIdentifier);
+  return modelInfo?.updateArgs;
+}