AnkiDroid only card design

[Helge]

I program fairly complex cards for AnkiDroid. If anybody is interested in what I learned along the way, I could post some stuff. Anyone interested?

[ferophila]

Always. Thank you!

[Helge]

Especially see last function.

Much of my code is Typescript, but that can easily be converted to JS.

class Statics {
  // ********  Config
  /** The date when the collection was created. Unconveniently, this is needed to calculate the due date from
   * the value the API returns. */
  private static dateOfCreationOfCollection = new Date(2023, 5, 12);

  public static daysSinceCardModified() {
    const unixTimestamp = window["AnkiDroidJS"].ankiGetCardMod();
    const dateFromTimestamp = new Date(unixTimestamp * 1000); // convert to milliseconds
    const today = new Date();
    const differenceInTime = today.getTime() - dateFromTimestamp.getTime();
    const differenceInDays = differenceInTime / (1000 * 3600 * 24);
    return differenceInDays;
  }
  public static daysSinceCreationOfCollection() {
    const diffTime = Math.abs(new Date().getTime() - Statics.dateOfCreationOfCollection.getTime());
    return Math.ceil(diffTime / (1000 * 60 * 60 * 24));
  }
  public static daysSinceCardWasDue() {
    let days = Statics.daysSinceCreationOfCollection() - window["AnkiDroidJS"].ankiGetCardDue();
    if (0 <= days && days < 10*365)
      return days;
    // Strange number of days. Thus, we assume that it is a new card, for which the API function above returns a random integer.
    return 0;
  }
  public static intervalOfCard() {
    return window["AnkiDroidJS"].ankiGetCardInterval();
  }
  /**
   * @return {string} the time since the card was last shown to the user
   * or "" if the card is due today or not due yet.
   *
   * I have lots of overdue cards and I find it very useful to display the number of
   * days since the card was last seen. */
  public static timeSinceLastSeenAsString(): string {
    const daysSinceCardWasDue = Statics.daysSinceCardWasDue();
    if (daysSinceCardWasDue === 0) {
      return "";
    }
    const daysSince = daysSinceCardWasDue + Statics.intervalOfCard();
    if (daysSince>=75) {
      return (daysSince/365.25).toFixed(1) + " y = " + daysSince + " d";
    }
    if (daysSince>=25) {
      return (daysSince/(365.25/12)).toFixed(1) + " m = " + daysSince + " d";
    }
    return daysSince + " d";
  }
}