Complete builders, start work on using them

src/Discord.Net.Commands/Info/ModuleInfo.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+
+using Discord.Commands.Builders;
+
+namespace Discord.Commands
+{
+    public class ModuleInfo
+    {
+        public CommandService Service { get; }
+        public string Name { get; }
+        public string Summary { get; }
+        public string Remarks { get; }
+
+        public IReadOnlyList<string> Aliases { get; }
+        public IEnumerable<CommandInfo> Commands { get; }
+        public IReadOnlyList<PreconditionAttribute> Preconditions { get; }
+
+        internal ModuleInfo(ModuleBuilder builder, CommandService service)
+        {
+            Service = service;
+
+            Name = builder.Name;
+            Summary = builder.Summary;
+            Remarks = builder.Remarks;
+
+            Aliases = BuildAliases(builder).ToImmutableArray();
+            Commands = builder.Commands.Select(x => x.Build(this, service));
+            Preconditions = BuildPreconditions(builder).ToImmutableArray();
+        }
+
+        private static List<string> BuildAliases(ModuleBuilder builder)
+        {
+            IEnumerable<string> result = null;
+
+            Stack<ModuleBuilder> builderStack = new Stack<ModuleBuilder>();
+
+            ModuleBuilder parent = builder;
+            while (parent.ParentModule != null)
+            {
+                builderStack.Push(parent);
+                parent = parent.ParentModule;
+            }
+
+            while (builderStack.Count() > 0)
+            {
+                ModuleBuilder level = builderStack.Pop(); // get the topmost builder
+                if (result == null)
+                    result = level.Aliases.ToList(); // create a shallow copy so we don't overwrite the builder unexpectedly
+                else
+                    result = result.Permutate(level.Aliases, (first, second) => first + " " + second);
+            }
+
+            return result.ToList();
+        }
+
+        private static List<PreconditionAttribute> BuildPreconditions(ModuleBuilder builder)
+        {
+            var result = new List<PreconditionAttribute>();
+
+
+            ModuleBuilder parent = builder;
+            while (parent.ParentModule != null)
+            {
+                result.AddRange(parent.Preconditions);
+                parent = parent.ParentModule;
+            }
+
+            return result;
+        }
+    }
+}