Add basic markdown support for assist chat messages (#3689)

Author: krsilas

Sources/App/Assist/AssistView.swift

@@ -112,14 +112,15 @@ struct AssistView: View {
                 AssistTypingIndicator()
                     .padding(.vertical, Spaces.half)
             } else {
-                Text(item.content)
+                Text(item.markdown)
             }
         }
         .padding(8)
         .padding(.horizontal, 8)
         .background(backgroundForChatItemType(item.itemType))
         .roundedCorner(10, corners: roundedCornersForChatItemType(item.itemType))
-        .foregroundColor(.white)
+        .foregroundColor(foregroundForChatItemType(item.itemType))
+        .tint(tintForChatItemType(item.itemType))
         .frame(maxWidth: .infinity, alignment: alignmentForChatItemType(item.itemType))
         .textSelection(.enabled)
     }
@@ -252,15 +253,35 @@ struct AssistView: View {
         switch itemType {
         case .input:
             .haPrimary
-        case .output:
-            .gray
+        case .output, .typing:
+            .secondaryBackground
         case .error:
             .red
-        case .info, .typing:
+        case .info:
             .gray.opacity(0.5)
         }
     }
 
+    private func foregroundForChatItemType(_ itemType: AssistChatItem.ItemType) -> Color {
+        switch itemType {
+        case .input, .error:
+            .white
+        case .info:
+            .secondary
+        default:
+            .primary
+        }
+    }
+
+    private func tintForChatItemType(_ itemType: AssistChatItem.ItemType) -> Color {
+        switch itemType {
+        case .input, .error:
+            .white
+        default:
+            .haPrimary
+        }
+    }
+
     private func alignmentForChatItemType(_ itemType: AssistChatItem.ItemType) -> Alignment {
         switch itemType {
         case .input:

Sources/Extensions/Watch/Assist/Views/ChatBubbleView.swift

@@ -10,14 +10,15 @@ struct ChatBubbleView: View {
                 AssistTypingIndicator()
                     .padding(.vertical, Spaces.half)
             } else {
-                Text(item.content)
+                Text(item.markdown)
             }
         }
         .padding(4)
         .padding(.horizontal, 4)
         .background(backgroundForChatItemType(item.itemType))
         .roundedCorner(6, corners: roundedCornersForChatItemType(item.itemType))
-        .foregroundColor(.white)
+        .foregroundColor(foregroundForChatItemType(item.itemType))
+        .tint(tintForChatItemType(item.itemType))
         .frame(maxWidth: .infinity, alignment: alignmentForChatItemType(item.itemType))
         .listRowBackground(Color.clear)
         .id(item.id)
@@ -28,14 +29,34 @@ struct ChatBubbleView: View {
         case .input:
             .haPrimary
         case .output, .typing:
-            .gray
+            .secondaryBackground
         case .error:
             .red
         case .info:
             .gray.opacity(0.5)
         }
     }
 
+    private func foregroundForChatItemType(_ itemType: AssistChatItem.ItemType) -> Color {
+        switch itemType {
+        case .input, .error:
+            .white
+        case .info:
+            .secondary
+        default:
+            .primary
+        }
+    }
+
+    private func tintForChatItemType(_ itemType: AssistChatItem.ItemType) -> Color {
+        switch itemType {
+        case .input, .error:
+            .white
+        default:
+            .haPrimary
+        }
+    }
+
     private func alignmentForChatItemType(_ itemType: AssistChatItem.ItemType) -> Alignment {
         switch itemType {
         case .input:

Sources/Shared/Assets/Colors.xcassets/Background/secondaryBackground.colorset/Contents.json

@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0xE5",
+          "green" : "0xE5",
+          "red" : "0xE5"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0x28",
+          "green" : "0x28",
+          "red" : "0x28"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Sources/Shared/Assist/AssistChatItem.swift

@@ -9,6 +9,21 @@ public struct AssistChatItem: Equatable {
 
     public var id: String = UUID().uuidString
     public let content: String
+    public var markdown: AttributedString {
+        var content = (try? AttributedString(
+            markdown: content,
+            options: AttributedString
+                .MarkdownParsingOptions(
+                    interpretedSyntax: .inlineOnlyPreservingWhitespace,
+                    failurePolicy: .returnPartiallyParsedIfPossible
+                )
+        )) ?? AttributedString(content)
+        for run in content.runs where run.attributes.link != nil {
+            content[run.range].underlineStyle = .single
+        }
+        return content
+    }
+
     public let itemType: ItemType
 
     public enum ItemType {