Add a simple markdown to plain text converter (#210)

* Add Alexa Auth Handler.

* Fix crazyness in merge.

* again.

* Add Alexa Skill Id validation check.

* Tabs to spaces

* Add a couple tests.

* Separate skill id check.

* Set ExpectReplies and add more tests.

* Dont NRE when activities is null.

* Make methods virutal for mocking

* Add check for Request being null so we don't throw NRE on bad requests from Alexa.

* Add simple markdown formatter

Co-authored-by: Gary Pretty <gary@garypretty.co.uk>

libraries/Bot.Builder.Community.Adapters.Alexa.Core/AlexaRequestMapper.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Security;
 using System.Xml;
@@ -7,6 +8,7 @@
 using Alexa.NET.Request.Type;
 using Alexa.NET.Response;
 using Bot.Builder.Community.Adapters.Alexa.Core.Attachments;
+using Bot.Builder.Community.Adapters.Alexa.Core.Utility;
 using Microsoft.Bot.Schema;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
@@ -91,18 +93,13 @@ public SkillResponse ActivityToResponse(Activity activity, SkillRequest alexaReq
                 return response;
             }
 
-            if (!SecurityElement.IsValidText(activity.Text))
-            {
-                activity.Text = SecurityElement.Escape(activity.Text);
-            }
-
             if (!string.IsNullOrEmpty(activity.Speak))
             {
                 response.Response.OutputSpeech = new SsmlOutputSpeech(activity.Speak);
             }
             else
             {
-                response.Response.OutputSpeech = new PlainTextOutputSpeech(activity.Text ?? string.Empty);
+                response.Response.OutputSpeech = new PlainTextOutputSpeech(NormalizeActivityText(activity.TextFormat, activity.Text));
             }
 
             ProcessActivityAttachments(activity, response);
@@ -116,7 +113,7 @@ public SkillResponse ActivityToResponse(Activity activity, SkillRequest alexaReq
                         break;
                     case InputHints.ExpectingInput:
                         response.Response.ShouldEndSession = false;
-                        response.Response.Reprompt = new Reprompt(activity.Text);
+                        response.Response.Reprompt = new Reprompt(NormalizeActivityText(activity.TextFormat, activity.Text));
                         break;
                     default:
                         response.Response.ShouldEndSession = _options.ShouldEndSessionByDefault;
@@ -278,6 +275,40 @@ private string StripSpeakTag(string speakText)
             {
                 return speakText;
             }
+        }
+
+        private string NormalizeActivityText(string textFormat, string text)
+        {
+            if (string.IsNullOrWhiteSpace(text))
+            {
+                return string.Empty;
+            }
+
+            // Default to plain text if it isn't specified.
+            if (textFormat == null)
+            {
+                textFormat = TextFormatTypes.Plain;
+            }
+
+            string plainText;
+            if (textFormat.Equals(TextFormatTypes.Plain, StringComparison.Ordinal))
+            {
+                plainText = text;
+            }
+            else if (textFormat.Equals(TextFormatTypes.Markdown, StringComparison.Ordinal))
+            {
+                plainText = AlexaMarkdownToPlaintextRenderer.Render(text);
+            }
+            else // xml format or other unknown and unsupported format.
+            {
+                plainText = string.Empty;
+            }
+
+            if (!SecurityElement.IsValidText(plainText))
+            {
+                plainText = SecurityElement.Escape(plainText);
+            }
+            return plainText;
         }
 
         /// <summary>
@@ -373,4 +404,4 @@ private ICard CreateAlexaCardFromHeroCard(HeroCard heroCard)
             }
         }
     }
-}
+}

libraries/Bot.Builder.Community.Adapters.Alexa.Core/Bot.Builder.Community.Adapters.Alexa.Core.csproj

@@ -21,6 +21,7 @@
   <ItemGroup>
     <PackageReference Include="Alexa.NET" Version="1.13.0" />
     <PackageReference Include="Alexa.NET.CustomerProfile" Version="2.1.1" />
+    <PackageReference Include="Microsoft.MarkedNet" Version="1.0.13" />
     <PackageReference Include="Microsoft.Bot.Builder" Version="4.8.0" />
     <PackageReference Include="Microsoft.Bot.Schema" Version="4.8.0" />
   </ItemGroup>

libraries/Bot.Builder.Community.Adapters.Alexa.Core/Utility/AlexaMarkdownToPlaintextRenderer.cs

@@ -0,0 +1,53 @@
+using System;
+using Microsoft.MarkedNet;
+
+namespace Bot.Builder.Community.Adapters.Alexa.Core.Utility
+{
+    /// <summary>
+    /// Simple Markdown renderer to turn markdown into plain text for Alexa.
+    /// </summary>
+    public static class AlexaMarkdownToPlaintextRenderer
+    {
+        private static readonly Marked _marked = new Marked(new Options { Renderer = new RemoveMarkupRenderer() });
+
+        public static string Render(string source) => _marked.Parse(source);
+
+        private class RemoveMarkupRenderer : MarkdownRenderer
+        {
+            private const string ListItemMarker = "$$ListItemMarker$$";
+
+            public override string Blockquote(string quote) => string.Concat(Environment.NewLine, quote, Environment.NewLine);
+            public override string Br() => Environment.NewLine;
+            public override string Code(string code, string lang, bool escaped) => code;
+            public override string Codespan(string text) => text;
+            public override string Del(string text) => text;
+            public override string Em(string text) => text;
+            public override string Heading(string text, int level, string raw) => string.Concat(Environment.NewLine, text, Environment.NewLine);
+            public override string Hr() => Environment.NewLine;
+            public override string Html(string html) => string.Empty;
+            public override string Image(string href, string title, string text) => title ?? text;
+            public override string Link(string href, string title, string text) => $"{title ?? text} {href}";
+            public override string List(string body, bool ordered, int start)
+            {
+                if (ordered)
+                {
+                    for (int marker = start, markerIndex = body.IndexOf(ListItemMarker); markerIndex >= 0; markerIndex = body.IndexOf(ListItemMarker), ++marker)
+                    {
+                        body = body.Substring(0, markerIndex) + Environment.NewLine + marker + " " + body.Substring(markerIndex + ListItemMarker.Length);
+                    }
+                }
+                else
+                {
+                    body = body.Replace(ListItemMarker, Environment.NewLine);
+                }
+                return body;
+            }
+            public override string ListItem(string text) => $"{ListItemMarker}{text}";
+            public override string Paragraph(string text) => string.Concat(Environment.NewLine, text, Environment.NewLine);
+            public override string Strong(string text) => text;
+            public override string Table(string header, string body) => string.Empty;
+            public override string TableCell(string content, TableCellFlags flags) => string.Empty;
+            public override string TableRow(string content) => string.Empty;
+        }
+    }
+}