import * as fs from 'fs';
// Import DevTools trace engine and formatters from chrome-devtools-frontend
// We intentionally use deep imports to match the package structure.
// These modules are ESM and require NodeNext module resolution.
// Types are loosely typed to minimize coupling with DevTools internals.
// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-ignore
import * as TraceEngine from 'chrome-devtools-frontend/front_end/models/trace/trace.js';
// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-ignore
import { PerformanceTraceFormatter } from 'chrome-devtools-frontend/front_end/models/ai_assistance/data_formatters/PerformanceTraceFormatter.js';
// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-ignore
import { PerformanceInsightFormatter } from 'chrome-devtools-frontend/front_end/models/ai_assistance/data_formatters/PerformanceInsightFormatter.js';
// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-ignore
import { AgentFocus } from 'chrome-devtools-frontend/front_end/models/ai_assistance/performance/AIContext.js';
const engine = TraceEngine.TraceModel.Model.createWithAllHandlers();
function readJsonFile(path: string): any {
const text = fs.readFileSync(path, 'utf-8');
return JSON.parse(text);
}
export async function parseTrace(json: any): Promise<{
parsedTrace: any;
insights: any | null;
}> {
engine.resetProcessor();
const events = Array.isArray(json) ? json : json.traceEvents;
if (!events || !Array.isArray(events)) {
throw new Error('Invalid trace format: expected array or {traceEvents: []}');
}
await engine.parse(events);
const parsedTrace = engine.parsedTrace();
const insights = parsedTrace?.insights ?? null;
if (!parsedTrace) throw new Error('No parsed trace returned by engine');
return { parsedTrace, insights };
}
export function getTraceSummary(parsedTrace: any): string {
const focus = AgentFocus.fromParsedTrace(parsedTrace);
const formatter = new PerformanceTraceFormatter(focus);
return formatter.formatTraceSummary();
}
export function getInsightText(parsedTrace: any, insights: any, insightName: string): string {
if (!insights) throw new Error('No insights available for this trace');
const mainNavId = parsedTrace.data?.Meta?.mainFrameNavigations?.at(0)?.args?.data?.navigationId;
const NO_NAV = TraceEngine.Types.Events.NO_NAVIGATION;
const set = insights.get(mainNavId ?? NO_NAV);
if (!set) throw new Error('No insights for selected navigation');
const model = set.model || {};
if (!(insightName in model)) throw new Error(`Insight not found: ${insightName}`);
const formatter = new PerformanceInsightFormatter(
AgentFocus.fromParsedTrace(parsedTrace),
model[insightName],
);
return formatter.formatInsight();
}
export async function analyzeTraceFile(
filePath: string,
insightName?: string,
): Promise<{
summary: string;
insight?: string;
}> {
const json = readJsonFile(filePath);
const { parsedTrace, insights } = await parseTrace(json);
const summary = getTraceSummary(parsedTrace);
if (insightName) {
try {
const insight = getInsightText(parsedTrace, insights, insightName);
return { summary, insight };
} catch {
// If requested insight missing, still return summary
return { summary };
}
}
return { summary };
}
export default { analyzeTraceFile };
