import type { GameConfig, Location, ShipModel } from "@deadhead/content";

/**
 * The distance pay and fuel are charged on (decision 0.5.84): the route distance
 * scaled down for long legs, `reference × (distance / reference)^exponent`.
 * A leg of the reference length (Earth–Moon) is unchanged; an exponent of 1
 * makes it the plain distance. Range, travel time and XP use the plain distance.
 */
export function economicDistance(distanceMillionKm: number, config: GameConfig): number {
  const { referenceMillionKm, exponent } = config.economicDistance;
  return referenceMillionKm * (distanceMillionKm / referenceMillionKm) ** exponent;
}

/**
 * Fuel cost in credits: economic distance × the ship's cost per million km ×
 * the origin's launch multiplier.
 */
export function fuelCost(
  ship: ShipModel,
  origin: Location,
  distanceMillionKm: number,
  config: GameConfig,
): number {
  return (
    economicDistance(distanceMillionKm, config) *
    ship.fuelCostPerMillionKm *
    origin.launchCostMultiplier
  );
}