import { spawn } from "node:child_process";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";

/**
 * Resume an existing run by launching `smithers up ... --resume` as a detached process.
 * Returns the spawned PID when available.
 */
export function resumeRunDetached(
  workflowPath: string,
  runId: string,
  claim?: {
    claimOwnerId: string;
    claimHeartbeatAtMs: number;
    restoreRuntimeOwnerId?: string | null;
    restoreHeartbeatAtMs?: number | null;
  },
) {
  const cliPath = fileURLToPath(new URL("./index.ts", import.meta.url));
  const args = [cliPath, "up", workflowPath, "--resume", "--run-id", runId, "-d", "--force"];
  if (claim) {
    args.push("--resume-claim-owner", claim.claimOwnerId);
    args.push("--resume-claim-heartbeat", String(claim.claimHeartbeatAtMs));
    if (claim.restoreRuntimeOwnerId !== undefined && claim.restoreRuntimeOwnerId !== null) {
      args.push("--resume-restore-owner", claim.restoreRuntimeOwnerId);
    }
    if (claim.restoreHeartbeatAtMs !== undefined && claim.restoreHeartbeatAtMs !== null) {
      args.push("--resume-restore-heartbeat", String(claim.restoreHeartbeatAtMs));
    }
  }
  const child = spawn(
    "bun",
    args,
    {
      cwd: dirname(resolve(workflowPath)),
      stdio: "ignore",
      env: process.env,
      detached: true,
    },
  );
  child.unref();
  return child.pid ?? null;
}