import { run } from "../db";
import { randomId } from "../crypto";

type UsageKind = "cache_bytes_stored" | "cache_bytes_freed";

/**
 * Audit trail of Actions cache writes and frees. Billing does not read it: self-hosted runner seconds are
 * metered at job completion (src/server/metering/ci.ts) and cache storage is a gauge over action_caches.
 * Single seam for usage metering of Actions cache storage. Events land in `runner_usage_events` until the
 * shared metering API exists; swapping this function body is the only change needed to forward them there.
 */
async function recordRunnerUsage(repoId: string, kind: UsageKind, quantity: number, subjectId: string | null) {
  if (!Number.isFinite(quantity) || quantity <= 0) return;
  try {
    await run(
      `INSERT INTO runner_usage_events (id, owner_id, repo_id, kind, quantity, subject_id, created_at)
       SELECT ?, owner_id, id, ?, ?, ?, ? FROM repos WHERE id = ?`,
      randomId(),
      kind,
      Math.round(quantity),
      subjectId,
      Date.now(),
      repoId,
    );
  } catch (error) {
    console.error("Failed to record usage", kind, repoId, error);
  }
}

export async function meterCacheStorage(repoId: string, bytes: number): Promise<void> {
  await recordRunnerUsage(repoId, "cache_bytes_stored", bytes, null);
}

export async function meterCacheFreed(repoId: string, bytes: number): Promise<void> {
  await recordRunnerUsage(repoId, "cache_bytes_freed", bytes, null);
}