using System;
using Chernobyl.Event;

namespace Chernobyl.Game.Destruction
{
    /// <summary>
    /// Represents an object that can be killed or destroyed such as life forms,
    /// buildings, etc.
    /// </summary>
    public interface IDestroyable : Chernobyl.Destruction.IDestroyable
    {
        /// <summary>
        /// A 0 to 1 value that represents the health of this instance. If this
        /// value is 0 then this instance has been destroyed. If this value is
        /// 1 then this instance has full health.
        /// </summary>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the value
        /// set on this property is below zero or above 1.</exception>
        float Health { get; set; }

        /// <summary>
        /// The maximum amount of health this instance can have. This value is
        /// NOT clamped between 0 and 1 but cannot go below 0 (for example it
        /// could be 100). Note that the minimum amount of health is always 0.
        /// </summary>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the value
        /// set on this property is zero or below.</exception>
        float MaxHealth { get; set; }

        /// <summary>
        /// An event that is raised when this instance is damaged. The 
        /// <see cref="ValueChangedEventArgs{T}"/> type passed as the event
        /// argument represents the old value and the new value of the
        /// <see cref="Health"/> property.
        /// </summary>
        event EventHandler<ValueChangedEventArgs<float>> Damaged;

        /// <summary>
        /// An event that occurs when this instance gains health.  The 
        /// <see cref="ValueChangedEventArgs{T}"/> type passed as the event
        /// argument represents the old value and the new value of the
        /// <see cref="Health"/> property.
        /// </summary>
        event EventHandler<ValueChangedEventArgs<float>> Healed;

        /// <summary>
        /// An event that is raised when this object has been fully restored 
        /// back to life. In other words, when <see cref="Health"/> is zero and
        /// then becomes a number greater than zero. The 
        /// <see cref="ValueChangedEventArgs{T}"/> type passed as the event
        /// argument represents the old value (always 0) and the new value of 
        /// the <see cref="Health"/> property.
        /// </summary>
        event EventHandler<ValueChangedEventArgs<float>> Revived;
    }
}