import "server-only";
import { unlinkSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";

const state = globalThis as typeof globalThis & { __aiChatbotActiveWork?: number };
const path = join(process.platform === "win32" ? tmpdir() : "/tmp", `ai-chatbot-active-work-${process.pid}.json`);

function update(delta: number) {
  state.__aiChatbotActiveWork = (state.__aiChatbotActiveWork || 0) + delta;
  try {
    writeFileSync(path, JSON.stringify({ pid: process.pid, active: state.__aiChatbotActiveWork }), { mode: 0o600 });
  } catch (error) {
    try { unlinkSync(path); } catch {}
    console.warn("[Active Work] Failed to record running work:", error);
  }
}

/** Includes generation that continues after the client connection closes. */
export async function trackRuntimeWork<T>(execute: () => T | Promise<T>): Promise<T> {
  update(1);
  try { return await execute(); } finally { update(-1); }
}