import type { BaseEvent } from "../types.js";
import type { BenchmarkSample } from "./evaluator.js";

function number(event: BaseEvent, key: string): number | undefined {
  const value = event[key];
  return typeof value === "number" && Number.isFinite(value) ? value : undefined;
}

export function collectBenchmarkSamples(events: readonly BaseEvent[], cohort: string): BenchmarkSample[] {
  const byTask = new Map<string, BaseEvent[]>();
  for (const event of events) {
    if (!event.taskId) continue;
    (byTask.get(event.taskId) ?? byTask.set(event.taskId, []).get(event.taskId)!).push(event);
  }
  const samples: BenchmarkSample[] = [];
  for (const [taskId, group] of byTask) {
    const ordered = [...group].sort((left, right) => left.timestamp.localeCompare(right.timestamp));
    const settled = [...ordered].reverse().find((event) => event.eventType === "result.completed");
    if (!settled) continue;
    const started = ordered.find((event) => event.eventType === "request.received") ?? ordered[0]!;
    const costToGreen = ordered.reduce((sum, event) => sum + (number(event, "creditsEstimated") ?? 0), 0);
    const timeToGreenMs = Math.max(0, Date.parse(settled.timestamp) - Date.parse(started.timestamp));
    if (!Number.isFinite(timeToGreenMs)) continue;
    samples.push({
      taskId,
      cohort,
      system: "ultrapi",
      verified: settled.success === true && settled.verified === true,
      costToGreen,
      timeToGreenMs,
    });
  }
  return samples.sort((left, right) => left.taskId.localeCompare(right.taskId));
}