import { chmodSync, mkdirSync, writeFileSync } from "node:fs";
import { dirname } from "node:path";
import type { Cookie } from "playwright";

function cookieField(value: string): string {
  return value.replace(/[\t\r\n]/g, "");
}

/** Serialize Playwright cookies in the Netscape cookies.txt format used by yt-dlp. */
export function serializeNetscapeCookies(cookies: readonly Cookie[]): string {
  const lines = ["# Netscape HTTP Cookie File", "# Generated by harn browse. Keep private.", ""];
  for (const cookie of [...cookies].sort((a, b) =>
    `${a.domain}\0${a.path}\0${a.name}`.localeCompare(`${b.domain}\0${b.path}\0${b.name}`),
  )) {
    const domain = `${cookie.httpOnly ? "#HttpOnly_" : ""}${cookieField(cookie.domain)}`;
    const includeSubdomains = cookie.domain.startsWith(".") ? "TRUE" : "FALSE";
    const secure = cookie.secure ? "TRUE" : "FALSE";
    const expires = cookie.expires > 0 ? String(Math.floor(cookie.expires)) : "0";
    lines.push(
      [
        domain,
        includeSubdomains,
        cookieField(cookie.path || "/"),
        secure,
        expires,
        cookieField(cookie.name),
        cookieField(cookie.value),
      ].join("\t"),
    );
  }
  return `${lines.join("\n")}\n`;
}

/** Write a credential-bearing cookie file with owner-only permissions. */
export function writeNetscapeCookieFile(path: string, cookies: readonly Cookie[]): void {
  mkdirSync(dirname(path), { recursive: true });
  writeFileSync(path, serializeNetscapeCookies(cookies), { mode: 0o600 });
  chmodSync(path, 0o600);
}