using JD.TeaBoxAddinSystem.Addins.Description.Conditions;
using JD.TeaBoxAddinSystem.Addins.Internal;

namespace JD.TeaBoxAddinSystem.Addins
{
    /// <summary>
    /// A condition node is an object that evaluates to true or false.
    /// </summary>
    /// <remarks>
    /// Implementors must call <see cref="NotifyChanged"/> if the result of the evaluation could have changed.
    /// </remarks>
    public abstract class ConditionNode : Node
    {
        #region Properties

        /// <summary>
        /// Type of this condition node.
        /// </summary>
        public new ConditionType Type
        {
            get
            {
                return (ConditionType)base.Type;
            }
        }

        internal virtual bool Polled
        {
            get
            {
                return false;
            }
        }

        #endregion

        #region Methods

        /// <summary>
        /// Returns true if the condition is satisfied.
        /// </summary>
        /// <returns>True if the condition is satisfied, false otherwise.</returns>
        public abstract bool Evaluate();

        /// <summary>
        /// This method should be called when the result of <see cref="Evaluate"/> could have changed.
        /// </summary>
        protected void NotifyChanged()
        {
            AddinManager.SessionService.ConditionManager.OnConditionChanged(this);
        }

        #endregion
    }
}