const DEFAULT_UPGRADE_URL = "https://swiftcommerce.io/pricing/"

interface UpgradeAttribution {
  feature: string
  placement: string
}

function toCampaignToken(value: string): string {
  return value
    .trim()
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, "_")
    .replace(/^_+|_+$/g, "")
}

/**
 * Add anonymous dashboard attribution to an upgrade link while preserving any
 * query parameters already supplied by WordPress or the licensing provider.
 */
export function getTrackedUpgradeUrl(
  upgradeUrl: string,
  { feature, placement }: UpgradeAttribution,
): string {
  const url = new URL(upgradeUrl || DEFAULT_UPGRADE_URL)
  const content = [toCampaignToken(feature), toCampaignToken(placement)]
    .filter(Boolean)
    .join("_")

  url.searchParams.set("utm_source", "swift_commerce_plugin")
  url.searchParams.set("utm_medium", "plugin_dashboard")
  url.searchParams.set("utm_campaign", "upgrade_to_pro")
  url.searchParams.set("utm_content", content || "feature_header")

  return url.toString()
}