User tagging and autocompletion

Co-authored-by: William Casarin <jb55@jb55.com>
Changelog-Added: User tagging and autocompletion in posts
Closes: #347
Fixes: #411, #63

damus.xcodeproj/project.pbxproj

@@ -171,6 +171,7 @@
 		4CF0ABEC29844B4700D66079 /* AnyDecodable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4CF0ABEB29844B4700D66079 /* AnyDecodable.swift */; };
 		4CF0ABEE29844B5500D66079 /* AnyEncodable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4CF0ABED29844B5500D66079 /* AnyEncodable.swift */; };
 		4CF0ABF029857E9200D66079 /* Bech32Object.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4CF0ABEF29857E9200D66079 /* Bech32Object.swift */; };
+		4CF0ABF62985CD5500D66079 /* UserSearch.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4CF0ABF52985CD5500D66079 /* UserSearch.swift */; };
 		4FE60CDD295E1C5E00105A1F /* Wallet.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4FE60CDC295E1C5E00105A1F /* Wallet.swift */; };
 		5C513FCC2984ACA60072348F /* QRCodeView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5C513FCB2984ACA60072348F /* QRCodeView.swift */; };
 		6439E014296790CF0020672B /* ProfileZoomView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6439E013296790CF0020672B /* ProfileZoomView.swift */; };
@@ -426,6 +427,7 @@
 		4CF0ABEB29844B4700D66079 /* AnyDecodable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AnyDecodable.swift; sourceTree = "<group>"; };
 		4CF0ABED29844B5500D66079 /* AnyEncodable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AnyEncodable.swift; sourceTree = "<group>"; };
 		4CF0ABEF29857E9200D66079 /* Bech32Object.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Bech32Object.swift; sourceTree = "<group>"; };
+		4CF0ABF52985CD5500D66079 /* UserSearch.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UserSearch.swift; sourceTree = "<group>"; };
 		4FE60CDC295E1C5E00105A1F /* Wallet.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Wallet.swift; sourceTree = "<group>"; };
 		5C513FCB2984ACA60072348F /* QRCodeView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QRCodeView.swift; sourceTree = "<group>"; };
 		6439E013296790CF0020672B /* ProfileZoomView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ProfileZoomView.swift; sourceTree = "<group>"; };
@@ -587,6 +589,7 @@
 		4C75EFA227FA576C0006080F /* Views */ = {
 			isa = PBXGroup;
 			children = (
+				4CF0ABF42985CD4200D66079 /* Posting */,
 				4CF0ABDF2981A83000D66079 /* Muting */,
 				4CC7AAEE297F11B300430951 /* Events */,
 				3AA24800297E3DAE0090C62D /* Reposts */,
@@ -846,6 +849,14 @@
 			path = AnyCodable;
 			sourceTree = "<group>";
 		};
+		4CF0ABF42985CD4200D66079 /* Posting */ = {
+			isa = PBXGroup;
+			children = (
+				4CF0ABF52985CD5500D66079 /* UserSearch.swift */,
+			);
+			path = Posting;
+			sourceTree = "<group>";
+		};
 		F7F0BA23297892AE009531F3 /* Modifiers */ = {
 			isa = PBXGroup;
 			children = (
@@ -1014,6 +1025,7 @@
 				4C216F34286F5ACD00040376 /* DMView.swift in Sources */,
 				4C3EA64428FF558100C48A62 /* sha256.c in Sources */,
 				4CE4F9E1285287B800C00DD9 /* TextFieldAlert.swift in Sources */,
+				4CF0ABF62985CD5500D66079 /* UserSearch.swift in Sources */,
 				4C363AA828297703006E126D /* InsertSort.swift in Sources */,
 				4C285C86283892E7008A31F1 /* CreateAccountModel.swift in Sources */,
 				4C64987C286D03E000EAE2B3 /* DirectMessagesView.swift in Sources */,

damus/ContentView.swift

@@ -302,7 +302,7 @@ struct ContentView: View {
             case .report(let target):
                 MaybeReportView(target: target)
             case .post:
-                PostView(replying_to: nil, references: [])
+                PostView(replying_to: nil, references: [], damus_state: damus_state!)
             case .reply(let event):
                 ReplyView(replying_to: event, damus: damus_state!)
             }

damus/Views/PostView.swift

@@ -16,10 +16,11 @@ let POST_PLACEHOLDER = NSLocalizedString("Type your post here...", comment: "Tex
 
 struct PostView: View {
     @State var post: String = ""
-
-    let replying_to: NostrEvent?
     @FocusState var focus: Bool
+    
+    let replying_to: NostrEvent?
     let references: [ReferencedId]
+    let damus_state: DamusState
 
     @Environment(\.presentationMode) var presentationMode
 
@@ -74,6 +75,7 @@ struct PostView: View {
                 TextEditor(text: $post)
                     .focused($focus)
                     .textInputAutocapitalization(.sentences)
+
                 if post.isEmpty {
                     Text(POST_PLACEHOLDER)
                         .padding(.top, 8)
@@ -82,6 +84,14 @@ struct PostView: View {
                         .allowsHitTesting(false)
                 }
             }
+
+            // This if-block observes @ for tagging
+            if let searching = get_searching_string(post) {
+                VStack {
+                    Spacer()
+                    UserSearch(damus_state: damus_state, search: searching, post: $post)
+                }.zIndex(1)
+            }
         }
         .onAppear() {
             DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
@@ -92,3 +102,23 @@ struct PostView: View {
     }
 }
 
+func get_searching_string(_ post: String) -> String? {
+    guard let last_word = post.components(separatedBy: .whitespacesAndNewlines).last else {
+        return nil
+    }
+    
+    guard last_word.count >= 2 else {
+        return nil
+    }
+    
+    guard last_word.first! == "@" else {
+        return nil
+    }
+    
+    // don't include @npub... strings
+    guard last_word.count != 64 else {
+        return nil
+    }
+    
+    return String(last_word.dropFirst())
+}

damus/Views/Posting/UserSearch.swift

@@ -0,0 +1,87 @@
+//
+//  UserAutocompletion.swift
+//  damus
+//
+//  Created by William Casarin on 2023-01-28.
+//
+
+import SwiftUI
+
+struct SearchedUser: Identifiable {
+    let petname: String?
+    let profile: Profile?
+    let pubkey: String
+    
+    var id: String {
+        return pubkey
+    }
+}
+
+struct UserSearch: View {
+    let damus_state: DamusState
+    let search: String
+    @Binding var post: String
+    
+    var users: [SearchedUser] {
+        guard let contacts = damus_state.contacts.event else {
+            return []
+        }
+        
+        return search_users(profiles: damus_state.profiles, tags: contacts.tags, search: search)
+    }
+    
+    var body: some View {
+        ScrollView {
+            LazyVStack {
+                ForEach(users) { user in
+                    UserView(damus_state: damus_state, pubkey: user.pubkey)
+                        .onTapGesture {
+                            guard let pk = bech32_pubkey(user.pubkey) else {
+                                return
+                            }
+                            post = post.replacingOccurrences(of: "@"+search, with: "@"+pk)
+                        }
+                }
+            }
+        }
+    }
+}
+
+struct UserSearch_Previews: PreviewProvider {
+    static let search: String = "jb55"
+    @State static var post: String = "some @jb55"
+    
+    static var previews: some View {
+        UserSearch(damus_state: test_damus_state(), search: search, post: $post)
+    }
+}
+
+
+func search_users(profiles: Profiles, tags: [[String]], search: String) -> [SearchedUser] {
+    var seen_user = Set<String>()
+    return tags.reduce(into: Array<SearchedUser>()) { arr, tag in
+        guard tag.count >= 2 && tag[0] == "p" else {
+            return
+        }
+        
+        let pubkey = tag[1]
+        guard !seen_user.contains(pubkey) else {
+            return
+        }
+        seen_user.insert(pubkey)
+        
+        var petname: String? = nil
+        if tag.count >= 4 {
+            petname = tag[3]
+        }
+        
+        let profile = profiles.lookup(id: pubkey)
+        
+        guard ((petname?.hasPrefix(search) ?? false) || (profile?.name?.hasPrefix(search) ?? false)) else {
+            return
+        }
+        
+        let searched_user = SearchedUser(petname: petname, profile: profile, pubkey: pubkey)
+        arr.append(searched_user)
+    }
+}

damus/Views/ReplyView.swift

@@ -47,7 +47,7 @@ struct ReplyView: View {
             ScrollView {
                 EventView(damus: damus, event: replying_to, has_action_bar: false)
             }
-            PostView(replying_to: replying_to, references: references)
+            PostView(replying_to: replying_to, references: gather_reply_ids(our_pubkey: damus.pubkey, from: replying_to), damus_state: damus)
         }
         .onAppear {
             references =  gather_reply_ids(our_pubkey: damus.pubkey, from: replying_to)