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

function update(delta: number, durable: boolean) {
  state.__aiChatbotActiveWork = (state.__aiChatbotActiveWork || 0) + delta;
  if (durable) state.__aiChatbotDurableWork = (state.__aiChatbotDurableWork || 0) + delta;
  try {
    writeFileSync(path, JSON.stringify({ pid: process.pid, active: state.__aiChatbotActiveWork, durable: state.__aiChatbotDurableWork || 0 }), { 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>, options: { durable?: boolean } = {}): Promise<T> {
  update(1, options.durable === true);
  try { return await execute(); } finally { update(-1, options.durable === true); }
}