package {

    import flash.display.MovieClip;

    public class LevelSystem extends MovieClip {

        const MAX_LEVEL = 50;
        const XP_INCREMENT = 500;

        public var int iXP; // Total amount of gathered XP
        public var int iLevel; // Current level
        public var int iXPGatheredForNextLevel; // Amount of XP gathered for the next level
        public var int iXPRequiredForNextLevel; // Amount of XP required for the next level

        public function LevelSystem {
            CalculateLevelProgress();
        }

        public function GiveXP(int amount) {
            XP += amount;

            CalculateLevelProgress();

            while (XPGatheredForNextLevel >= XPRequiredForNextLevel && Level < MAX_LEVEL) {
                Level++;

                // Recalculate level progress after leveling up
                CalculateLevelProgress();
            }
        }

        public function CalculateLevelProgress() {
            local int xpToCurrentLevel; // Total amount of XP gathered with current and previous levels

            xpToCurrentLevel = 0.5 * Level * (Level-1) * XP_INCREMENT;
            XPGatheredForNextLevel = XP - xpToCurrentLevel;
            XPRequiredForNextLevel = Level * XP_INCREMENT;
        }
    }
}