Refactor (#109)

utils/agent.ts

@@ -0,0 +1,70 @@
+import { type Agent, agents } from "../agents/index.ts";
+import type { AgentName } from "../external.ts";
+import { log } from "./cli.ts";
+import type { ResolvedPayload } from "./payload.ts";
+import type { RepoSettings } from "./repoSettings.ts";
+
+/**
+ * Check if an agent has API keys available (from process.env)
+ */
+function agentHasApiKeys(agent: Agent): boolean {
+  // empty apiKeyNames means agent accepts any *API_KEY* env var
+  if (agent.apiKeyNames.length === 0) {
+    return Object.keys(process.env).some((key) => key.includes("API_KEY") && process.env[key]);
+  }
+  return agent.apiKeyNames.some((envKey) => !!process.env[envKey]);
+}
+
+function getAvailableAgents(): Agent[] {
+  return Object.values(agents).filter((agent) => agentHasApiKeys(agent));
+}
+
+export function resolveAgent(params: {
+  payload: ResolvedPayload;
+  repoSettings: RepoSettings;
+}): Agent {
+  const agentOverride = process.env.AGENT_OVERRIDE as AgentName | undefined;
+  log.debug(
+    `» determineAgent: agentOverride=${agentOverride}, payload.agent=${params.payload.agent}, repoSettings.defaultAgent=${params.repoSettings.defaultAgent}`
+  );
+  const configuredAgentName =
+    agentOverride || params.payload.agent || params.repoSettings.defaultAgent || null;
+
+  if (configuredAgentName) {
+    const agent = agents[configuredAgentName];
+    if (!agent) {
+      throw new Error(`invalid agent name: ${configuredAgentName}`);
+    }
+
+    // if explicitly configured (via override or payload), respect it even without matching keys
+    // this allows users to force an agent selection (will fail later with clear error if no keys)
+    const isExplicitOverride = agentOverride !== undefined || params.payload.agent !== null;
+    if (isExplicitOverride) {
+      log.info(`» selected configured agent: ${agent.name}`);
+      return agent;
+    }
+
+    // for repo-level defaults, check if agent has matching keys before selecting
+    if (agentHasApiKeys(agent)) {
+      log.info(`» selected configured agent: ${agent.name}`);
+      return agent;
+    }
+
+    // fall through to auto-selection
+    const availableAgents = getAvailableAgents();
+    log.warning(
+      `Repo default agent ${agent.name} has no matching API keys. Available: ${
+        availableAgents.map((a) => a.name).join(", ") || "none"
+      }`
+    );
+  }
+
+  const availableAgents = getAvailableAgents();
+  if (availableAgents.length === 0) {
+    throw new Error("no agents available - missing API keys");
+  }
+
+  const agent = availableAgents[0];
+  log.info(`» no agent configured, defaulting to first available agent: ${agent.name}`);
+  return agent;
+}