import { existsSync, mkdirSync, readFileSync, unlinkSync, writeFileSync } from "node:fs";
import { join } from "node:path";
import { resolveDataDir } from "../data-dir.mjs";

const SERVICES = ["server", "mitm", "tunnel/cloudflared", "tunnel/tailscale"];

function getServicePidPath(service) {
  return join(resolveDataDir(), service, ".pid");
}

export function writePidFile(service, pid) {
  try {
    const dir = join(resolveDataDir(), service);
    mkdirSync(dir, { recursive: true });
    writeFileSync(getServicePidPath(service), String(pid), "utf8");
    return true;
  } catch {
    return false;
  }
}

export function readPidFile(service) {
  try {
    const file = getServicePidPath(service);
    if (!existsSync(file)) return null;
    const pid = parseInt(readFileSync(file, "utf8").trim(), 10);
    return Number.isFinite(pid) ? pid : null;
  } catch {
    return null;
  }
}

export function cleanupPidFile(service) {
  try {
    unlinkSync(getServicePidPath(service));
  } catch {}
}

export function killAllSubprocesses() {
  for (const service of SERVICES) {
    const pid = readPidFile(service);
    if (!pid) continue;
    try {
      process.kill(pid, "SIGTERM");
    } catch {}
    cleanupPidFile(service);
  }
}

export function isPidRunning(pid) {
  if (!pid) return false;
  try {
    process.kill(pid, 0);
    return true;
  } catch {
    return false;
  }
}

export function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

export async function waitForServer(port, timeout = 15000) {
  const start = Date.now();
  while (Date.now() - start < timeout) {
    try {
      const res = await fetch(`http://localhost:${port}/api/health`, {
        signal: AbortSignal.timeout(2000),
      });
      if (res.ok) return true;
    } catch {}
    await sleep(500);
  }
  return false;
}