/**
 * Credits. The whole economy is four numbers and a losing streak, and all of
 * it is pure: the match calls these and stores what comes back.
 */

export const START_CREDITS = 800;
export const CREDIT_CAP = 9000;
export const KILL_REWARD = 200;
export const PLANT_REWARD = 300;
export const WIN_REWARD = 3000;
/** Rising with the streak, and capped at the third step. */
export const LOSS_BONUS = [1900, 2400, 2900];

export const clampCredits = (credits: number): number =>
  Math.max(0, Math.min(CREDIT_CAP, Math.floor(credits)));

export const award = (credits: number, amount: number): number => clampCredits(credits + amount);

/** The loss bonus for a team that has now lost `streak` rounds in a row. */
export const lossBonus = (streak: number): number =>
  LOSS_BONUS[Math.min(Math.max(streak, 1), LOSS_BONUS.length) - 1]!;

/** What a round's end pays each member of a team. */
export function roundReward(won: boolean, lossStreak: number, planted: boolean): number {
  if (won) return WIN_REWARD;
  // A team that lost the round but got the spike down keeps a little more.
  return lossBonus(lossStreak) + (planted ? PLANT_REWARD : 0);
}

/** A purchase either happens at a price or is refused; never a debt. */
export function spend(credits: number, cost: number): { ok: boolean; credits: number } {
  if (!Number.isFinite(cost) || cost < 0 || cost > credits) return { ok: false, credits };
  return { ok: true, credits: clampCredits(credits - cost) };
}