import { mkdtemp, rm } from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { createLogger } from "@/log";
import { startRunnerServer, type RunnerServer } from "@/server";
import {
  connectProtocolClient,
  handshake,
  type ProtocolClient,
} from "./protocol-client";

/**
 * An in-process runner server plus one already-handshaken client, with
 * log capture (for the credential-leak assertions) and one-call
 * teardown. In-process so v8 coverage sees the server; the spawn suite
 * covers the real-child-process shape.
 */
export interface RunnerSession {
  client: ProtocolClient;
  workspaceDir: string;
  /** Every log line the runner emitted — greppable for leaks. */
  logLines: string[];
  close: () => Promise<void>;
}

export async function startRunnerSession(options: {
  token: string;
  tmpPrefix: string;
  heartbeatMs?: number;
}): Promise<RunnerSession> {
  const workspaceDir = await mkdtemp(path.join(os.tmpdir(), options.tmpPrefix));
  const logLines: string[] = [];
  const server: RunnerServer = await startRunnerServer({
    host: "127.0.0.1",
    port: 0,
    token: options.token,
    workspaceDir,
    heartbeatMs: options.heartbeatMs ?? 100,
    log: createLogger((line) => logLines.push(line)),
  });
  const client = await connectProtocolClient(server.port, options.token);
  await handshake(client);
  return {
    client,
    workspaceDir,
    logLines,
    close: async () => {
      client.close();
      await server.close();
      await rm(workspaceDir, { recursive: true, force: true });
    },
  };
}