Implement bot that performs time-series metric analysis and suggests repo management improvements (#25945)

tools/gemini-cli-bot/metrics/history-helper.ts

@@ -0,0 +1,61 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { readFileSync, existsSync } from 'node:fs';
+import { join } from 'node:path';
+
+const TIMESERIES_FILE = join(
+  process.cwd(),
+  'tools',
+  'gemini-cli-bot',
+  'history',
+  'metrics-timeseries.csv',
+);
+
+/**
+ * Calculates the historical average of a metric over a given number of days.
+ */
+export function getHistoricalAverage(
+  metric: string,
+  days: number,
+): number | null {
+  if (!existsSync(TIMESERIES_FILE)) return null;
+
+  try {
+    const content = readFileSync(TIMESERIES_FILE, 'utf-8');
+    const lines = content.split('\n').slice(1); // skip header
+    const now = new Date();
+    const threshold = new Date(now.getTime() - days * 24 * 60 * 60 * 1000);
+
+    const values: number[] = [];
+    for (const line of lines) {
+      if (!line.trim()) continue;
+      const parts = line.split(',');
+      if (parts.length < 3) continue;
+
+      const timestamp = parts[0];
+      const m = parts[1];
+      const value = parts[2];
+
+      if (m === metric) {
+        const date = new Date(timestamp);
+        if (date >= threshold) {
+          const numValue = parseFloat(value);
+          if (!isNaN(numValue)) {
+            values.push(numValue);
+          }
+        }
+      }
+    }
+
+    if (values.length === 0) return null;
+    const sum = values.reduce((a, b) => a + b, 0);
+    return sum / values.length;
+  } catch (error) {
+    console.error(`Error reading historical average for ${metric}:`, error);
+    return null;
+  }
+}

tools/gemini-cli-bot/metrics/index.ts

@@ -4,9 +4,10 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { readdirSync, writeFileSync } from 'node:fs';
+import { readdirSync, writeFileSync, existsSync, readFileSync } from 'node:fs';
 import { join } from 'node:path';
-import { execSync } from 'node:child_process';
+import { execFileSync } from 'node:child_process';
+import { getHistoricalAverage } from './history-helper.js';
 
 const SCRIPTS_DIR = join(
   process.cwd(),
@@ -15,12 +16,35 @@ const SCRIPTS_DIR = join(
   'metrics',
   'scripts',
 );
-const OUTPUT_FILE = join(process.cwd(), 'metrics-before.csv');
+const SYNC_SCRIPT = join(
+  process.cwd(),
+  'tools',
+  'gemini-cli-bot',
+  'history',
+  'sync.ts',
+);
+const OUTPUT_FILE = join(
+  process.cwd(),
+  'tools',
+  'gemini-cli-bot',
+  'history',
+  'metrics-before.csv',
+);
+const TIMESERIES_FILE = join(
+  process.cwd(),
+  'tools',
+  'gemini-cli-bot',
+  'history',
+  'metrics-timeseries.csv',
+);
 
 function processOutputLine(line: string, results: string[]) {
   const trimmedLine = line.trim();
   if (!trimmedLine) return;
 
+  let metricName = '';
+  let metricValue = 0;
+
   try {
     const parsed = JSON.parse(trimmedLine);
     if (
@@ -29,16 +53,59 @@ function processOutputLine(line: string, results: string[]) {
       'metric' in parsed &&
       'value' in parsed
     ) {
-      results.push(`${parsed.metric},${parsed.value}`);
+      metricName = parsed.metric;
+      metricValue = parseFloat(parsed.value);
+      results.push(`${metricName},${metricValue}`);
     } else {
-      results.push(trimmedLine);
+      const parts = trimmedLine.split(',');
+      if (parts.length === 2) {
+        metricName = parts[0];
+        metricValue = parseFloat(parts[1]);
+        results.push(trimmedLine);
+      } else {
+        results.push(trimmedLine);
+        return; // Unable to parse for deltas
+      }
     }
   } catch {
-    results.push(trimmedLine);
+    const parts = trimmedLine.split(',');
+    if (parts.length === 2) {
+      metricName = parts[0];
+      metricValue = parseFloat(parts[1]);
+      results.push(trimmedLine);
+    } else {
+      results.push(trimmedLine);
+      return; // Unable to parse for deltas
+    }
+  }
+
+  // Calculate and append deltas if the metric is a valid number
+  if (metricName && !isNaN(metricValue)) {
+    const avg7d = getHistoricalAverage(metricName, 7);
+    if (avg7d !== null) {
+      results.push(
+        `${metricName}_delta_7d,${(metricValue - avg7d).toFixed(2)}`,
+      );
+    }
+
+    const avg30d = getHistoricalAverage(metricName, 30);
+    if (avg30d !== null) {
+      results.push(
+        `${metricName}_delta_30d,${(metricValue - avg30d).toFixed(2)}`,
+      );
+    }
   }
 }
 
 async function run() {
+  // Sync history first
+  console.log('Syncing history...');
+  try {
+    execFileSync('npx', ['tsx', SYNC_SCRIPT], { stdio: 'inherit' });
+  } catch (error) {
+    console.error('History sync failed, continuing without history:', error);
+  }
+
   const scripts = readdirSync(SCRIPTS_DIR).filter(
     (file) => file.endsWith('.ts') || file.endsWith('.js'),
   );
@@ -49,8 +116,9 @@ async function run() {
     console.log(`Running metric script: ${script}`);
     try {
       const scriptPath = join(SCRIPTS_DIR, script);
-      const output = execSync(`npx tsx ${JSON.stringify(scriptPath)}`, {
+      const output = execFileSync('npx', ['tsx', scriptPath], {
         encoding: 'utf-8',
+        shell: process.platform === 'win32',
       });
 
       const lines = output.trim().split('\n');
@@ -64,6 +132,29 @@ async function run() {
 
   writeFileSync(OUTPUT_FILE, results.join('\n'));
   console.log(`Saved metrics to ${OUTPUT_FILE}`);
+
+  // Update timeseries with rolling window (keep last 100 lines)
+  const timestamp = new Date().toISOString();
+  let timeseriesLines: string[] = [];
+  if (existsSync(TIMESERIES_FILE)) {
+    timeseriesLines = readFileSync(TIMESERIES_FILE, 'utf-8').trim().split('\n');
+  } else {
+    timeseriesLines = ['timestamp,metric,value'];
+  }
+
+  const newRows = results.slice(1).map((row) => `${timestamp},${row}`);
+  if (newRows.length > 0) {
+    timeseriesLines.push(...newRows);
+
+    // Keep header + last 100 data rows
+    if (timeseriesLines.length > 101) {
+      const header = timeseriesLines[0];
+      timeseriesLines = [header, ...timeseriesLines.slice(-100)];
+    }
+
+    writeFileSync(TIMESERIES_FILE, timeseriesLines.join('\n') + '\n');
+    console.log(`Updated timeseries at ${TIMESERIES_FILE} (rolling window)`);
+  }
 }
 
 run().catch(console.error);

tools/gemini-cli-bot/metrics/scripts/domain_expertise.ts

@@ -6,7 +6,7 @@
  * @license
  */
 
-import { GITHUB_OWNER, GITHUB_REPO, MetricOutput } from '../types.js';
+import { GITHUB_OWNER, GITHUB_REPO, type MetricOutput } from '../types.js';
 import { execSync } from 'node:child_process';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';

tools/gemini-cli-bot/metrics/scripts/latency.ts

@@ -6,7 +6,7 @@
  * @license
  */
 
-import { GITHUB_OWNER, GITHUB_REPO, MetricOutput } from '../types.js';
+import { GITHUB_OWNER, GITHUB_REPO, type MetricOutput } from '../types.js';
 import { execSync } from 'node:child_process';
 
 try {

tools/gemini-cli-bot/metrics/scripts/review_distribution.ts

@@ -6,7 +6,7 @@
  * @license
  */
 
-import { GITHUB_OWNER, GITHUB_REPO, MetricOutput } from '../types.js';
+import { GITHUB_OWNER, GITHUB_REPO, type MetricOutput } from '../types.js';
 import { execSync } from 'node:child_process';
 
 try {

tools/gemini-cli-bot/metrics/scripts/throughput.ts

@@ -6,7 +6,7 @@
  * @license
  */
 
-import { GITHUB_OWNER, GITHUB_REPO, MetricOutput } from '../types.js';
+import { GITHUB_OWNER, GITHUB_REPO, type MetricOutput } from '../types.js';
 import { execSync } from 'node:child_process';
 
 try {

tools/gemini-cli-bot/metrics/scripts/time_to_first_response.ts

@@ -6,7 +6,7 @@
  * @license
  */
 
-import { GITHUB_OWNER, GITHUB_REPO, MetricOutput } from '../types.js';
+import { GITHUB_OWNER, GITHUB_REPO, type MetricOutput } from '../types.js';
 import { execSync } from 'node:child_process';
 
 try {