using System.Linq;
using System.Reflection;
using LinFu.IoC.Configuration.Interfaces;
using LinFu.IoC.Interfaces;

namespace LinFu.IoC.Configuration
{
    /// <summary>
    ///     A class that automatically invokes methods using arguments
    ///     derived from existing instances from within a <see cref="IServiceContainer" />
    ///     instance.
    /// </summary>
    public class AutoMethodInjector : AutoMemberInjector<MethodInfo>
    {
        /// <summary>
        ///     Injects services from the <paramref name="container" /> into the target <see cref="MethodInfo" /> instance.
        /// </summary>
        /// <param name="target">The target object.</param>
        /// <param name="method">The <see cref="MethodInfo" /> instance that will store the service instance.</param>
        /// <param name="resolver">
        ///     The <see cref="IArgumentResolver" /> that will determine which arguments will be assigned to the
        ///     target member.
        /// </param>
        /// <param name="additionalArguments">
        ///     The additional arguments that were passed to the <see cref="IServiceRequestResult" />
        ///     during the instantiation process.
        /// </param>
        /// <param name="container">The container that will provide the service instances.</param>
        protected override void Inject(object target, MethodInfo method,
            IArgumentResolver resolver, IServiceContainer container,
            object[] additionalArguments)
        {
            var parameterTypes = from p in method.GetParameters()
                select new NamedType(p) as INamedType;

            var arguments = resolver.ResolveFrom(parameterTypes, container, additionalArguments);

            // Invoke the target method
            method.Invoke(target, arguments);
        }
    }
}