Added factory architecture to assist with creating factories of item …

…types. Courtesy of Thraka and the GoRogue-SadConsole integration library for the original code :D

GoRogue/Factory/BlueprintConfig.cs

@@ -0,0 +1,13 @@
+namespace SadConsole.Factory
+{
+    /// <summary>
+    /// Base class for a settings object that contains parameters to pass to the Create function of a factory.
+    /// </summary>
+    public class BlueprintConfig
+    {
+        /// <summary>
+        /// Represents no arguments -- pass as the config parameter to Create if there are no parameters you wish to pass.
+        /// </summary>
+        public static readonly BlueprintConfig Empty = new BlueprintConfig();
+    }
+}

GoRogue/Factory/Factory.cs

@@ -0,0 +1,109 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace SadConsole.Factory
+{
+    /// <summary>
+    /// A factory that produces a type of object based on a blueprint and a set of configuration parameters.
+    /// </summary>
+    /// <typeparam name="TBlueprintConfig">The type of parameter passed to the <see cref="Create(string, TBlueprintConfig)"/> function each time an object is created.</typeparam>
+    /// <typeparam name="TProduced">The type of object this factory creates.</typeparam>
+    public class Factory<TBlueprintConfig, TProduced> : IEnumerable<IBlueprint<TBlueprintConfig, TProduced>>
+        where TBlueprintConfig : BlueprintConfig
+    {
+        private readonly Dictionary<string, IBlueprint<TBlueprintConfig, TProduced>> _blueprints = new Dictionary<string, IBlueprint<TBlueprintConfig, TProduced>>();
+
+        /// <summary>
+        /// Adds a blueprint to the factory.
+        /// </summary>
+        /// <param name="blueprint">The blueprint to add.</param>
+        public void Add(IBlueprint<TBlueprintConfig, TProduced> blueprint) => _blueprints[blueprint.Id] = blueprint;
+
+        /// <summary>
+        /// Creates a <typeparamref name="TProduced"/> object using the blueprint with the given factory id, and the given settings object.
+        /// </summary>
+        /// <param name="factoryId">The factory id of a blueprint.</param>
+        /// <param name="blueprintConfig">A settings object passed to the Create function of the blueprint.</param>
+        /// <returns>A new object.</returns>
+        public TProduced Create(string factoryId, TBlueprintConfig blueprintConfig)
+        {
+            if (!_blueprints.ContainsKey(factoryId))
+            {
+                throw new ItemNotDefinedException(factoryId);
+            }
+
+            TProduced obj = _blueprints[factoryId].Create(blueprintConfig);
+            if (obj is IFactoryObject factoryObj)
+            {
+                factoryObj.DefinitionId = factoryId;
+            }
+
+            return obj;
+        }
+
+        /// <summary>
+        /// Checks if a blueprint exists.
+        /// </summary>
+        /// <param name="factoryId">The blueprint to check for.</param>
+        /// <returns>Returns true when the specified <paramref name="factoryId"/> exists; otherwise false.</returns>
+        public bool BlueprintExists(string factoryId) => _blueprints.ContainsKey(factoryId);
+
+        /// <summary>
+        /// Gets a blueprint by identifier.
+        /// </summary>
+        /// <param name="factoryId">The blueprint identifier to get.</param>
+        /// <returns>The blueprint of the object.</returns>
+        /// <exception cref="ItemNotDefinedException">Thrown if the factory identifier does not exist.</exception>
+        public IBlueprint<TBlueprintConfig, TProduced> GetBlueprint(string factoryId)
+        {
+            if (!_blueprints.ContainsKey(factoryId))
+            {
+                throw new ItemNotDefinedException(factoryId);
+            }
+
+            return _blueprints[factoryId];
+        }
+
+        /// <summary>
+        /// Gets an enumerator of all of the blueprints in the factory.
+        /// </summary>
+        /// <returns>An enumeration of the blueprints.</returns>
+        public IEnumerator<IBlueprint<TBlueprintConfig, TProduced>> GetEnumerator() => _blueprints.Values.GetEnumerator();
+
+        /// <summary>
+        /// Gets an enumerator of all of the blueprints in the factory.
+        /// </summary>
+        /// <returns>An enumeration of the blueprints.</returns>
+        IEnumerator IEnumerable.GetEnumerator() => _blueprints.Values.GetEnumerator();
+    }
+
+    /// <summary>
+    /// Exception thrown by <see cref="Factory{TBlueprintConfig, TProduced}"/> objects when a blueprint that doesn't exist is used.
+    /// </summary>
+    [Serializable]
+    public class ItemNotDefinedException : Exception
+    {
+        /// <summary>
+        /// Creates an exception.
+        /// </summary>
+        /// <param name="factoryId">Factory id that caused the error.</param>
+        public ItemNotDefinedException(string factoryId)
+            : base($"The item '{factoryId}' has not been added to this factory.")
+        { }
+    }
+
+    /// <summary>
+    /// A factory that produces a type of object based on a blueprint.
+    /// </summary>
+    /// <typeparam name="TProduced">The type of object this factory creates.</typeparam>
+    public class Factory<TProduced> : Factory<BlueprintConfig, TProduced>
+    {
+        /// <summary>
+        /// Creates a <typeparamref name="TProduced"/> object using the blueprint with the given factory id.
+        /// </summary>
+        /// <param name="factoryId">The factory id of a blueprint.</param>
+        /// <returns>A new object.</returns>
+        public TProduced Create(string factoryId) => Create(factoryId, BlueprintConfig.Empty);
+    }
+}

GoRogue/Factory/IBlueprint.cs

@@ -0,0 +1,22 @@
+namespace SadConsole.Factory
+{
+    /// <summary>
+    /// Defines how to create a <typeparamref name="TProduced"/> object.
+    /// </summary>
+    /// <typeparam name="TBlueprintConfig">The type of the parameter to pass to the <see cref="Create(TBlueprintConfig)"/> function.</typeparam>
+    /// <typeparam name="TProduced">The type of object to create.</typeparam>
+    public interface IBlueprint<in TBlueprintConfig, out TProduced> where TBlueprintConfig : BlueprintConfig
+    {
+        /// <summary>
+        /// A unique identifier of this factory definition.
+        /// </summary>
+        string Id { get; }
+
+        /// <summary>
+        /// Creates a <typeparamref name="TProduced"/> object.
+        /// </summary>
+        /// <param name="config">Configuration parameters used to create the object.</param>
+        /// <returns>The created object.</returns>
+        TProduced Create(TBlueprintConfig config);
+    }
+}

GoRogue/Factory/IFactoryObject.cs

@@ -0,0 +1,15 @@
+namespace SadConsole.Factory
+{
+    /// <summary>
+    /// Interface that can optionally be implemented by objects created via a <see cref="Factory{TBlueprintConfig, TProduced}"/>.  The <see cref="DefinitionId"/> property
+    /// will be automatically set to the ID of the blueprint used to create the object when the Factory's Create function is called.
+    /// </summary>
+    public interface IFactoryObject
+    {
+        /// <summary>
+        /// The identifier of the <see cref="IBlueprint{TBlueprintConfig, TProduced}"/> that created this object. Do not set manually -- <see cref="Factory{TBlueprintConfig, TProduced}"/>
+        /// will automatically set this field when the object is created.
+        /// </summary>
+        string DefinitionId { get; set; }
+    }
+}

GoRogue/Factory/SimpleBlueprint.cs

@@ -0,0 +1,34 @@
+namespace SadConsole.Factory
+{
+    /// <summary>
+    /// A simple <see cref="IBlueprint{TBlueprintConfig, TProduced}"/> that can be used when no configuration object is necessary to create the object.
+    /// Implements <see cref="IBlueprint{BlueprintConfig, TProduced}"/>.
+    /// </summary>
+    /// <typeparam name="TProduced">The type of object to create.</typeparam>
+    public abstract class SimpleBlueprint<TProduced> : IBlueprint<BlueprintConfig, TProduced>
+    {
+        /// <summary>
+        /// A unique identifier of this factory definition.
+        /// </summary>
+        public string Id { get; }
+
+        /// <summary>
+        /// Creates a SimpleBlueprint with the given blueprint id.
+        /// </summary>
+        /// <param name="id">ID for the blueprint.</param>
+        public SimpleBlueprint(string id) => Id = id;
+
+        /// <summary>
+        /// Calls <see cref="Create()"/>.
+        /// </summary>
+        /// <param name="config">Unused.</param>
+        /// <returns>The created object.</returns>
+        public TProduced Create(BlueprintConfig config) => Create();
+
+        /// <summary>
+        /// Creates a <typeparamref name="TProduced"/> object.
+        /// </summary>
+        /// <returns>The created object.</returns>
+        public abstract TProduced Create();
+    }
+}