public class InsightLevel {

    public delegate void InsightLevelChangedAction();
    public event InsightLevelChangedAction OnChanged;
    private int level;

    public InsightLevel(int initialLevel) {
        this.level = initialLevel;
    }

    public void Modify(int amount) {
        int previousLevel = this.level;

        this.level += amount;
        if (this.level < 0) this.level = 0;

        if (this.level != previousLevel && this.OnChanged != null) {
            this.OnChanged();
        }
    }

    public int Level {get => this.level;}
}