import { spawn } from "node:child_process";

const SINGLE_QUOTE_ESCAPE = "'\"'\"'";

export function quoteScpPath(value: string): string {
  return `'${value.replace(/'/g, SINGLE_QUOTE_ESCAPE)}'`;
}

export function formatScpSource(remoteHost: string, remotePath: string): string {
  return `${remoteHost}:${quoteScpPath(remotePath)}`;
}

export async function copyRemoteFileViaScp(params: {
  remoteHost: string;
  remotePath: string;
  localPath: string;
}): Promise<void> {
  return await new Promise((resolve, reject) => {
    const child = spawn(
      "/usr/bin/scp",
      [
        "-o",
        "BatchMode=yes",
        "-o",
        "StrictHostKeyChecking=accept-new",
        formatScpSource(params.remoteHost, params.remotePath),
        params.localPath,
      ],
      { stdio: ["ignore", "ignore", "pipe"] },
    );

    let stderr = "";
    child.stderr?.setEncoding("utf8");
    child.stderr?.on("data", (chunk) => {
      stderr += chunk;
    });

    child.once("error", reject);
    child.once("exit", (code) => {
      if (code === 0) resolve();
      else reject(new Error(`scp failed (${code}): ${stderr.trim()}`));
    });
  });
}