using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Runtime.Serialization;

using System.ComponentModel;

namespace SharpLib.Ear

{

    /// <summary>

    /// EAR object provides serialization support.

    /// It assumes most derived class is decorated with AttributeObject.

    /// </summary>

    [DataContract]

    [KnownType("DerivedTypes")]

    public abstract class Object: IComparable, INotifyPropertyChanged

    {

        private bool iConstructed = false;

        [DataMember]

        public List<Object> Objects = new List<Object>();

        /// <summary>

        /// </summary>

        [DataMember]

        [AttributeObjectProperty

            (

                Id = "Object.Name",

                Name = "Name",

                Description = "Given object name."

            )

        ]

        public string Name { get; set; } = "";

        protected Object()

        {

            Construct();

        }

        /// <summary>

        /// Needed as our constructor is not called following internalization.

        /// </summary>

        public void Construct()

        {

            //Construct ourselves first

            if (!iConstructed)

            {

                DoConstruct();

                iConstructed = true;

            }

            //Then construct our children

            foreach (Object o in Objects)

            {

                o.Construct();

            }

        }

        /// <summary>

        /// 

        /// </summary>

        protected virtual void DoConstruct()

        {

            //Make sure our name is not null

            if (Name == null)

            {

                Name = "";

            }

            // Makes sure our objects are not null

            if (Objects == null)

            {

                Objects = new List<Object>();

            }

        }

        public enum State

        {

            Rest=0,

            Edit

        }

        State iCurrentState = State.Rest;

        public State CurrentState { get { return iCurrentState; } set { OnStateLeave(); iCurrentState = value; OnStateEnter(); } }

        /// <summary>

        /// 

        /// </summary>

        protected virtual void OnStateLeave()

        {

        }

        /// <summary>

        /// 

        /// </summary>

        protected virtual void OnStateEnter()

        {

        }

        /// <summary>

        /// Static object name.

        /// </summary>

        public string AttributeName

        {

            //Get the name of this object attribute

            get { return Utils.Reflection.GetAttribute<AttributeObject>(GetType()).Name; }

            private set { }

        }

        /// <summary>

        /// Static object description.

        /// </summary>

        public string AttributeDescription

        {

            //Get the description of this object attribute

            get { return Utils.Reflection.GetAttribute<AttributeObject>(GetType()).Description; }

            private set { }

        }

        /// <summary>

        /// Dynamic object description.

        /// </summary>

        /// <returns></returns>

        public virtual string Brief()

        {

            return AttributeName;

        }

        /// <summary>

        /// Needed to make sure our sorting makes sense

        /// </summary>

        /// <param name="obj"></param>

        /// <returns></returns>

        public int CompareTo(object obj)

        {

            //Sort by object name

            return Utils.Reflection.GetAttribute<AttributeObject>(GetType()).Name.CompareTo(obj.GetType());

        }

        /// <summary>

        /// Tells whether the current object configuration is valid.

        /// </summary>

        /// <returns></returns>

        public virtual bool IsValid()

        {

            return true;

        }

        /// <summary>

        /// So that data contract knows all our types.

        /// </summary>

        /// <returns></returns>

        private static IEnumerable<Type> DerivedTypes()

        {

            return SharpLib.Utils.Reflection.GetDerivedTypes<Object>();

        }

        /// <summary>

        /// 

        /// </summary>

        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>

        /// Invoke our event.

        /// </summary>

        /// <param name="name"></param>

        protected void OnPropertyChanged(string name)

        {

            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));

        }

    }

}