Fix output of print not being used as message content

ChaosBot/Discord/Services/CustomCommandHandler.cs

@@ -34,8 +34,12 @@ namespace ChaosBot.Discord.Services
                 }
                 else if(customCommand.Type == CustomCommandType.CustomLua)
                 {
-                    if (!ProgrammingLanguageInterpreterFacade.TryInterpret(customCommand, out string errorReason))
+                    if (!ProgrammingLanguageInterpreterFacade.TryInterpret(context, customCommand,
-                        throw new Exception($"Could not execute code: {errorReason}");
+                        out string errorReason))
+                    {
+                        await context.Channel.SendMessageAsync(errorReason);
+                        throw new Exception($"Could not execute code for command '{customCommand.Command}': {errorReason}");
+                    }
                 }
                 else if (customCommand.Type == CustomCommandType.Embed)
                 {

ChaosBot/Services/ProgrammingLanguageInterpreter/IProgrammingLanguageInterpreter.cs

@@ -2,6 +2,6 @@ namespace ChaosBot.Services.ProgrammingLanguageInterpreter
 {
     public interface IProgrammingLanguageInterpreter
     {
-        void Interpret(string content, string command);
+        string Interpret(string content, string command);
     }
 }

ChaosBot/Services/ProgrammingLanguageInterpreter/LuaProgrammingLanguageInterpreter.cs

@@ -1,3 +1,5 @@
+using System;
+using System.Text;
 using System.Text.RegularExpressions;
 using Neo.IronLua;
 using NLog;
@@ -7,8 +9,9 @@ namespace ChaosBot.Services.ProgrammingLanguageInterpreter
     internal class LuaProgrammingLanguageInterpreter : IProgrammingLanguageInterpreter
     {
         private static readonly ILogger Logger = Program.GetLogger();
+        private readonly StringBuilder _outputBuilder = new StringBuilder();
         
-        public void Interpret(string content, string command)
+        public string Interpret(string content, string command)
         {
             using (Lua lua = new Lua())
             {
@@ -17,11 +20,27 @@ namespace ChaosBot.Services.ProgrammingLanguageInterpreter
                 // This is a runtime type check
                 dynamic env = lua.CreateEnvironment();
 
-                foreach (string line in (new Regex("\n")).Split(content))
+                ParamsDelegate printDel = Print;
+                env.print = printDel;
+
+                env.dochunk(content, $"{command}.lua");
+
+                return _outputBuilder.ToString();
+            }
+        }
+
+        private delegate void ParamsDelegate(params object[] parameters);
+
+        private void Print(params object[] parameters)
         {
-                    env.dochunk(line, $"{command}.lua");
+            StringBuilder sb = new StringBuilder();
-                }
+
+            foreach (object parameter in parameters)
+            {
+                sb.Append(parameter);
             }
+
+            _outputBuilder.Append(sb);
         }
     }
 }

ChaosBot/Services/ProgrammingLanguageInterpreter/ProgrammingLanguageInterpreterFacade.cs

@@ -1,10 +1,12 @@
+using System;
 using ChaosBot.Models;
+using Discord.Commands;
 
 namespace ChaosBot.Services.ProgrammingLanguageInterpreter
 {
     public static class ProgrammingLanguageInterpreterFacade
     {
-        public static bool TryInterpret(CustomCommand customCommand, out string errorReason)
+        public static bool TryInterpret(SocketCommandContext context, CustomCommand customCommand, out string errorReason)
         {
             errorReason = "";
             IProgrammingLanguageInterpreter interpreter =
@@ -15,8 +17,21 @@ namespace ChaosBot.Services.ProgrammingLanguageInterpreter
                 return false;
             }
 
-            interpreter.Interpret(customCommand.Content, customCommand.Command);
+            try
+            {
+                string output = interpreter.Interpret(customCommand.Content, customCommand.Command);
+                
+                if (output.Length > 0)
+                    context.Channel.SendMessageAsync(output);
+                else
+                    context.Channel.SendMessageAsync($"Command '{customCommand.Command}' had no output.");
                 return true;
             }
+            catch (Exception ex)
+            {
+                errorReason = $"There was an error with your code ({ex.GetType().Name}): {ex.Message}";
+                return false;
+            }
+        }
     }
 }