using System;

namespace LinFu.AOP.Interfaces
{
    /// <summary>
    ///     An extension class that adds helper methods to the <see cref="IActivator{T}" /> interface.
    /// </summary>
    public static class ActivatorExtensions
    {
        /// <summary>
        ///     Instantiates the <paramref name="targetType" /> with the given <paramref name="activator" /> and
        ///     <paramref name="constructorArguments" />.
        /// </summary>
        /// <param name="activator">
        ///     The <see cref="IActivator{T}" /> instance that will be responsible for creating the
        ///     <paramref name="targetType" />.
        /// </param>
        /// <param name="targetType">The type to be created.</param>
        /// <param name="constructorArguments">The arguments that will be passed to the constructor.</param>
        /// <returns>An object reference that matches the given <paramref name="targetType" />.</returns>
        public static object CreateInstance(this IActivator<IActivationContext> activator, Type targetType,
            object[] constructorArguments)
        {
            var context = new ActivationContext(targetType, constructorArguments);
            return activator.CreateInstance(context);
        }

        /// <summary>
        ///     Instantiates the target type with the given <paramref name="activator" /> and
        ///     <paramref name="constructorArguments" />.
        /// </summary>
        /// <param name="activator">
        ///     The <see cref="IActivator{T}" /> instance that will be responsible for creating the target
        ///     type.
        /// </param>
        /// <param name="constructorArguments">The arguments that will be passed to the constructor.</param>
        /// <typeparam name="T">The target type that will be instantiated by the activator.</typeparam>
        /// <returns>An object reference that matches the given target type.</returns>
        public static T CreateInstance<T>(this IActivator<IActivationContext> activator, object[] constructorArguments)
        {
            return (T) activator.CreateInstance(typeof(T), constructorArguments);
        }
    }
}