feat: Change /stats to include more detailed breakdowns (#2615)

packages/cli/src/ui/utils/computeStats.ts

@@ -0,0 +1,84 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  SessionMetrics,
+  ComputedSessionStats,
+  ModelMetrics,
+} from '../contexts/SessionContext.js';
+
+export function calculateErrorRate(metrics: ModelMetrics): number {
+  if (metrics.api.totalRequests === 0) {
+    return 0;
+  }
+  return (metrics.api.totalErrors / metrics.api.totalRequests) * 100;
+}
+
+export function calculateAverageLatency(metrics: ModelMetrics): number {
+  if (metrics.api.totalRequests === 0) {
+    return 0;
+  }
+  return metrics.api.totalLatencyMs / metrics.api.totalRequests;
+}
+
+export function calculateCacheHitRate(metrics: ModelMetrics): number {
+  if (metrics.tokens.prompt === 0) {
+    return 0;
+  }
+  return (metrics.tokens.cached / metrics.tokens.prompt) * 100;
+}
+
+export const computeSessionStats = (
+  metrics: SessionMetrics,
+): ComputedSessionStats => {
+  const { models, tools } = metrics;
+  const totalApiTime = Object.values(models).reduce(
+    (acc, model) => acc + model.api.totalLatencyMs,
+    0,
+  );
+  const totalToolTime = tools.totalDurationMs;
+  const agentActiveTime = totalApiTime + totalToolTime;
+  const apiTimePercent =
+    agentActiveTime > 0 ? (totalApiTime / agentActiveTime) * 100 : 0;
+  const toolTimePercent =
+    agentActiveTime > 0 ? (totalToolTime / agentActiveTime) * 100 : 0;
+
+  const totalCachedTokens = Object.values(models).reduce(
+    (acc, model) => acc + model.tokens.cached,
+    0,
+  );
+  const totalPromptTokens = Object.values(models).reduce(
+    (acc, model) => acc + model.tokens.prompt,
+    0,
+  );
+  const cacheEfficiency =
+    totalPromptTokens > 0 ? (totalCachedTokens / totalPromptTokens) * 100 : 0;
+
+  const totalDecisions =
+    tools.totalDecisions.accept +
+    tools.totalDecisions.reject +
+    tools.totalDecisions.modify;
+  const successRate =
+    tools.totalCalls > 0 ? (tools.totalSuccess / tools.totalCalls) * 100 : 0;
+  const agreementRate =
+    totalDecisions > 0
+      ? (tools.totalDecisions.accept / totalDecisions) * 100
+      : 0;
+
+  return {
+    totalApiTime,
+    totalToolTime,
+    agentActiveTime,
+    apiTimePercent,
+    toolTimePercent,
+    cacheEfficiency,
+    totalDecisions,
+    successRate,
+    agreementRate,
+    totalCachedTokens,
+    totalPromptTokens,
+  };
+};