using System;
using System.Linq;
using System.Reflection;

namespace Chernobyl.Attribution
{
    /// <summary>
    /// An <see cref="Attribute"/> that is applied to methods. When executed, 
    /// instances of this type will execute any 
    /// <see cref="IProcessAttribute{TCustomAttributeProvider}"/> types found on 
    /// any parameters of the method attributed.
    /// </summary>
    [AttributeUsage(AttributeTargets.Method)]
    public class ProcessParametersAttribute
        : Attribute, IProcessAttribute<MethodInfo>
    {
        /// <summary>
        /// Performs the task requested on the <see cref="ICustomAttributeProvider" />
        /// passed in.
        /// </summary>
        /// <param name="attributeProvider">The <see cref="ICustomAttributeProvider" />
        /// this <see cref="Attribute" /> was applied to and that is to be
        /// processed.</param>
        /// <exception cref="System.NotImplementedException"></exception>
        public void Process(MethodInfo attributeProvider)
        {
            var parameters = attributeProvider.GetParameters().Concat(
                attributeProvider.ReturnParameter.ToEnumerable());
            parameters.Process(Inherited);
        }

        /// <summary>
        /// True if this instance should look up the hierarchy chain of each
        /// <see cref="ICustomAttributeProvider"/> for 
        /// <see cref="IProcessAttribute{TCustomAttributeProvider}"/> attributes.
        /// </summary>
        public bool Inherited { get; set; }
    }
}