/**
 * How a customer gets an eSIM onto a phone, in every form we can offer.
 *
 * This lives apart from the pages because the activate page and the delivery
 * email have to say exactly the same thing. They did not, in the product this
 * template grew out of: the page learned about one-tap install and the email
 * kept telling people to scan a QR code on the device they were reading it on.
 * Two copies of install instructions drift, and the copy that drifts is the one
 * the customer is holding.
 */

/** Both halves of the credential, as a phone's manual-entry form asks for them. */
export interface ManualInstallDetails {
  /** e.g. consumer.rsp.example.com — the "SM-DP+ address" field. */
  smdpAddress?: string;
  /** e.g. K2-1A2B3C-4D5E6F — the "activation code" field. */
  matchingId?: string;
  /** The whole LPA string, which is what a QR code encodes. */
  activationCode?: string;
}

/**
 * The full LPA string, from whichever pieces the operator supplied.
 *
 * `LPA:1$<smdp>$<matchingId>` is the format every modern handset accepts, so
 * either the operator hands it over whole or we can rebuild it.
 */
export function manualActivationCode(details: ManualInstallDetails): string | null {
  if (details.activationCode) return details.activationCode;
  if (details.smdpAddress && details.matchingId) {
    return `LPA:1$${details.smdpAddress}$${details.matchingId}`;
  }
  return null;
}

/**
 * Apple's universal eSIM install link — iOS 17.4 and later hand the activation
 * string straight to Settings, so the customer never types anything.
 *
 * Nothing equivalent exists on Android: install there is Settings → Network →
 * add eSIM → enter manually, which is what the written steps below are for.
 * The link is harmless on a phone that cannot use it; it opens a page that
 * explains the manual route.
 */
export function directInstallUrl(activationCode: string): string {
  return `https://esimsetup.apple.com/esim_qrcode_provisioning?carddata=${encodeURIComponent(
    activationCode,
  )}`;
}

/**
 * The steps in words.
 *
 * A customer whose camera cannot reach a second screen, and whose phone is too
 * old for the one-tap link, otherwise has two credentials and no idea where to
 * type them. The SM-DP+ address and the activation code are named here exactly
 * as the handset names them, because "paste your activation string" does not
 * match any field on either operating system.
 */
export const IPHONE_INSTALL_STEPS: readonly string[] = [
  "Open Settings, then Cellular (or Mobile Service).",
  "Tap Add eSIM, then Use QR Code.",
  "Tap Enter Details Manually.",
  "Paste the SM-DP+ address and activation code from above.",
  "Leave data roaming on — that is how the plan connects abroad.",
];

export const ANDROID_INSTALL_STEPS: readonly string[] = [
  "Open Settings, then Network & internet.",
  "Tap SIMs, then Add SIM or Download a SIM instead.",
  "Choose Need help? then Enter it manually.",
  "Paste the activation code from above.",
  "Turn on roaming for this SIM once it appears.",
];