const axios = require("axios")

async function subdomain(domain) {
  const url = `https://crt.sh/?q=${encodeURIComponent(domain)}&output=json`

  try {
    const res = await axios.get(url, {
      timeout: 30000,
      headers: {
        "User-Agent":
          "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120 Safari/537.36",
      },
    })
    if (!Array.isArray(res.data)) return []
    const subs = res.data
      .map(v => v.name_value)
      .flatMap(v => v.split("\n"))
      .filter(v => v.endsWith(domain))
    return [...new Set(subs)].sort()
  } catch (e) {
    throw new Error("Failed fetching subdomains")
  }
}

module.exports = { subdomain }