using System;
using System.Collections.Generic;

namespace LinFu.Reflection
{
    /// <summary>
    ///     Represents a generic interface for an abstract loader
    ///     that can read configuration information from disk
    ///     and apply it to a <typeparamref name="TTarget" /> instance.
    /// </summary>
    /// <typeparam name="TTarget">The class type being configured.</typeparam>
    public interface ILoader<TTarget>
    {
        /// <summary>
        ///     The list of <see cref="ILoaderPlugin{TTarget}" />
        ///     instances that will be used to
        ///     signal the beginning and end of the
        ///     load sequence.
        /// </summary>
        IList<ILoaderPlugin<TTarget>> Plugins { get; }

        /// <summary>
        ///     The list of <see cref="IActionLoader{TTarget, TInput}" />
        ///     instances responsible for configuring the <typeparamref name="TTarget" /> instance.
        /// </summary>
        IList<IActionLoader<TTarget, string>> FileLoaders { get; }

        /// <summary>
        ///     Gets or sets the <see cref="IDirectoryListing" /> instance
        ///     responsible for returning a list of filenames
        ///     to the loader for processing.
        /// </summary>
        IDirectoryListing DirectoryLister { get; set; }

        /// <summary>
        ///     The custom list of actions that will be
        ///     performed prior to the beginning of a load operation.
        /// </summary>
        IList<Action<ILoader<TTarget>>> CustomLoaderActions { get; }

        /// <summary>
        ///     The list of actions that will execute
        ///     every time a target instance is configured.
        /// </summary>
        IList<Action<TTarget>> QueuedActions { get; }

        /// <summary>
        ///     Loads the configuration using the files listed in
        ///     the target <paramref name="directory" /> that match
        ///     the given <paramref name="filespec">file pattern</paramref>.
        /// </summary>
        /// <param name="directory">The full path of the location to scan.</param>
        /// <param name="filespec">The wildcard file pattern string to use when specifying the target files.</param>
        void LoadDirectory(string directory, string filespec);

        /// <summary>
        ///     Configures the <paramref name="target" /> instance
        ///     using the configuration currently loaded from disk.
        /// </summary>
        /// <param name="target">The <typeparamref name="TTarget" /> instance to be configured.</param>
        void LoadInto(TTarget target);

        /// <summary>
        ///     Clears the currently loaded configuration
        ///     and resets the loader back to its defaults.
        /// </summary>
        void Reset();
    }
}