using System;
using Chernobyl.Event;

namespace Chernobyl.Mathematics.Mechanics
{
    /// <summary>
    /// A mechanism that can be moved in a negative or positive direction in 1 
    /// dimension.
    /// </summary>
    public interface IAxis
    {
        /// <summary>
        /// The amount the axis was in a certain direction (the previous value 
        /// of <see cref="CurrentValue"/>).
        /// </summary>
        float PreviousValue { get; }

        /// <summary>
        /// The amount the axis is in a certain direction currently.
        /// </summary>
        float CurrentValue { get; }

        /// <summary>
        /// The amount of change, from the axis' <see cref="PreviousValue"/> to 
        /// its <see cref="CurrentValue"/>.
        /// </summary>
        float ChangeAmount { get; }

        /// <summary>
        /// The sensitivity of this axis. A sensitivity of 1 is the default. 
        /// A lower sensitivity (between 0.0 and 1.0) causes this axis to report 
        /// a smaller number for it's current value while a greater sensitivity 
        /// (greater than 1.0) causes the value reported to be greater.
        /// </summary>
        float Sensitivity { get; set; }

        /// <summary>
        /// Invoked when this axis moves.
        /// </summary>
        event EventHandler<EventArgs<IAxis>> OnMove;

        /// <summary>
        /// Invoked when this axis moves up.
        /// </summary>
        event EventHandler<EventArgs<IAxis>> OnUp;

        /// <summary>
        /// Invoked when this axis moves down.
        /// </summary>
        event EventHandler<EventArgs<IAxis>> OnDown;
    }
}