Parse links in profiles

Changelog-Added: Parse links in profiles

damus/Util/Markdown.swift

@@ -0,0 +1,43 @@
+//
+//  Markdown.swift
+//  damus
+//
+//  Created by Lionello Lunesu on 2022-12-28.
+//
+
+import Foundation
+
+public struct Markdown {
+    private let detector = try! NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
+
+    /// Ensure the specified URL has a scheme by prepending "https://" if it's absent.
+    static func withScheme(_ url: any StringProtocol) -> any StringProtocol {
+        return url.contains("://") ? url : "https://" + url
+    }
+
+    public static func parse(content: String) -> AttributedString {
+        // Similar to the parsing in NoteContentView
+        let md_opts: AttributedString.MarkdownParsingOptions =
+            .init(interpretedSyntax: .inlineOnlyPreservingWhitespace)
+
+        if let txt = try? AttributedString(markdown: content, options: md_opts) {
+            return txt
+        } else {
+            return AttributedString(stringLiteral: content)
+        }
+    }
+
+    /// Process the input text and add markdown for any embedded URLs.
+    public func process(_ input: String) -> AttributedString {
+        let matches = detector.matches(in: input, options: [], range: NSRange(location: 0, length: input.utf16.count))
+        var output = input
+        // Start with the last match, because replacing the first would invalidate all subsequent indices
+        for match in matches.reversed() {
+            guard let range = Range(match.range, in: input) else { continue }
+            let url = input[range]
+            output.replaceSubrange(range, with: "[\(url)](\(Markdown.withScheme(url)))")
+        }
+        // TODO: escape unintentional markdown
+        return Markdown.parse(content: output)
+    }
+}

damus/Views/FollowingView.swift

@@ -10,7 +10,9 @@ import SwiftUI
 struct FollowUserView: View {
     let target: FollowTarget
     let damus_state: DamusState
-    
+
+    static let markdown = Markdown()
+
     var body: some View {
         HStack {
             let pmodel = ProfileModel(pubkey: target.pubkey, damus: damus_state)
@@ -23,8 +25,8 @@ struct FollowUserView: View {
                 VStack(alignment: .leading) {
                     let profile = damus_state.profiles.lookup(id: target.pubkey)
                     ProfileName(pubkey: target.pubkey, profile: profile, contacts: damus_state.contacts, show_friend_confirmed: false)
-                    if let about = profile.flatMap { $0.about } {
-                        Text(about)
+                    if let about = profile?.about {
+                        Text(FollowUserView.markdown.process(about))
                             .lineLimit(3)
                             .font(.footnote)
                     }

damus/Views/NoteContentView.swift

@@ -70,17 +70,10 @@ struct NoteContentView: View {
     let size: EventViewKind
     
     func MainContent() -> some View {
-        let md_opts: AttributedString.MarkdownParsingOptions =
-            .init(interpretedSyntax: .inlineOnlyPreservingWhitespace)
-        
         return VStack(alignment: .leading) {
-            if let txt = try? AttributedString(markdown: artifacts.content, options: md_opts) {
-                Text(txt)
-                    .font(eventviewsize_to_font(size))
-            } else {
-                Text(artifacts.content)
-                    .font(eventviewsize_to_font(size))
-            }
+            Text(Markdown.parse(content: artifacts.content))
+                .font(eventviewsize_to_font(size))
+
             if show_images && artifacts.images.count > 0 {
                 ImageCarousel(urls: artifacts.images)
             } else if !show_images && artifacts.images.count > 0 {

damus/Views/ProfileView.swift

@@ -152,7 +152,9 @@ struct ProfileView: View {
                 .environmentObject(user_settings)
         }
     }
-    
+
+    static let markdown = Markdown()
+
     var DMButton: some View {
         let dm_model = damus_state.dms.lookup_or_create(profile.pubkey)
         let dmview = DMChatView(damus_state: damus_state, pubkey: profile.pubkey)
@@ -188,7 +190,6 @@ struct ProfileView: View {
                 
                 DMButton
                 
-                
                 if profile.pubkey != damus_state.pubkey {
                     FollowButtonView(
                         target: profile.get_follow_target(),
@@ -205,7 +206,7 @@ struct ProfileView: View {
             ProfileNameView(pubkey: profile.pubkey, profile: data, contacts: damus_state.contacts)
                 .padding(.bottom)
             
-            Text(data?.about ?? "")
+            Text(ProfileView.markdown.process(data?.about ?? ""))
                 .font(.subheadline)
         
             Divider()