import type { Difficulty } from "./schemas";

/**
 * Base XP for a correct answer. Harder decks are worth more, and the
 * multi-part activity types get a small bonus.
 */
export const XP_BY_DIFFICULTY: Record<Difficulty, number> = {
  easy: 10,
  medium: 15,
  hard: 20,
};

const TYPE_BONUS: Record<string, number> = {
  matching: 5,
  ordering: 5,
  short_answer: 5,
};

export function xpForActivity(type: string, difficulty: Difficulty): number {
  return XP_BY_DIFFICULTY[difficulty] + (TYPE_BONUS[type] ?? 0);
}

/** Consecutive-correct streak multiplier (capped at 3x). */
export function streakMultiplier(streak: number): number {
  return Math.min(1 + Math.max(0, streak) * 0.1, 3);
}