/* Sparx
 * Copyright August Zinsser 2007
 * This program is distributed under the terms of the GNU General Public License
 */


using System;
using System.Collections.Generic;
using System.Text;


namespace Pina3D.Particles
{
    /// <summary>
    /// All objects that can be saved to and loaded from a .spx file
    /// </summary>
    public abstract class SparxEntity : ICloneable
    {
        protected string mName;         // Used for bookeeping

        public string Name { set { mName = value; } get { return mName; } }


        public SparxEntity()
            : this ("")
        {
        }


        public SparxEntity(string name)
        {
            mName = name;
        }


        /// <summary>
        /// Returns a new instance that is like this one was when it was created
        /// </summary>
        /// <returns></returns>
        public abstract Object Clone();
    }


    /// <summary>
    /// Sparx entities that are born and may die
    /// </summary>
    public class SparxMortalEntity : SparxEntity
    {
        protected float mLifeExpectancy;                // Varies, whereas some children's "lifeSpan" variable serves as an initializer for mLifeExpectancy
        protected float mAge;
        protected bool mAlive;
        protected bool mImmortal;


        /// <summary>
        /// Time from birth to expected death. This value may vary as the entity exists.
        /// </summary>
        public virtual float LifeExpectancy { set { mLifeExpectancy = value; } get { return mLifeExpectancy; } }
        /// <summary>
        /// The time that has elapsed since this emission was created.
        /// </summary>
        public virtual float Age { set { mAge = value; } get { return mAge; } }
        public bool Alive { set { mAlive = value; } get { return mAlive; } }
        public bool Immortal { set { mImmortal = value; } get { return mImmortal; } }


        public SparxMortalEntity(string name, float lifeSpan, bool immortal)
            : base (name)
        {
            mLifeExpectancy = lifeSpan;
            mAge = 0;
            mImmortal = immortal;
            mAlive = true;
        }

        /// <summary>
        /// Allows children to instantiate blank copies of themselves for cloning
        /// </summary>
        protected SparxMortalEntity() { }


        /// <summary>
        /// Ages the entity and kills it if it gets too old
        /// </summary>
        public virtual void Update()
        {
            mAge += Pina.ElapsedSeconds;

            // Death
            if (!mImmortal && mAge > mLifeExpectancy)
            {
                mAlive = false;
            }
        }


        public override Object Clone()
        {
            return new SparxMortalEntity(mName, mLifeExpectancy, mImmortal);
        }
    }
}