import os from "node:os";
import path from "node:path";

export const SERVICE_NAME = "triggershell";

export interface UnitOptions {
  execPath: string;
  binPath: string;
  configPath: string;
  configDir: string;
  port?: number;
  host?: string;
  scope: "user" | "system";
}

export function renderUnit(opts: UnitOptions): string {
  const args = ["start", "--config", opts.configPath, "--no-browser"];
  if (opts.port !== undefined) args.push("--port", String(opts.port));
  if (opts.host !== undefined) args.push("--host", opts.host);

  const execStart = [opts.execPath, opts.binPath, ...args]
    .map((part) => (part.includes(" ") ? `"${part}"` : part))
    .join(" ");

  const wantedBy =
    opts.scope === "user" ? "default.target" : "multi-user.target";

  return `[Unit]
Description=TriggerShell - self-hosted script runner
After=network.target

[Service]
Type=simple
ExecStart=${execStart}
WorkingDirectory=${opts.configDir}
Restart=on-failure
RestartSec=2
Environment=NODE_ENV=production

[Install]
WantedBy=${wantedBy}
`;
}

export function userUnitPath(): string {
  return path.join(
    os.homedir(),
    ".config",
    "systemd",
    "user",
    `${SERVICE_NAME}.service`,
  );
}

export function systemUnitPath(): string {
  return path.join("/etc", "systemd", "system", `${SERVICE_NAME}.service`);
}

export function isRoot(): boolean {
  return process.getuid?.() === 0;
}