Get servers and choose one randomly for signup (IOS-171)

Server list from backend has a weight which plays a role in which server gets selected.
mastodon.social is the fallback in case something goes wrong

Localization/app.json

@@ -270,7 +270,7 @@
         "welcome": {
             "log_in": "Log In",
             "learn_more": "Learn more",
-            "join_default_server": "Join mastodon.social",
+            "join_default_server": "Join %@",
             "pick_server": "Pick another server",
             "separator": {
                 "or": "or"

Mastodon/Scene/Onboarding/Welcome/WelcomeViewController.swift

@@ -47,10 +47,6 @@ final class WelcomeViewController: UIViewController, NeedsDependency {
 
     private(set) lazy var joinDefaultServerButton: UIButton = {
         var buttonConfiguration = UIButton.Configuration.filled()
-        buttonConfiguration.attributedTitle = AttributedString(
-            L10n.Scene.Welcome.joinDefaultServer,
-            attributes: .init([.font: UIFontMetrics(forTextStyle: .headline).scaledFont(for: .systemFont(ofSize: 17, weight: .semibold))])
-        )
         buttonConfiguration.baseForegroundColor = .white
         buttonConfiguration.background.backgroundColor = Asset.Colors.Brand.blurple.color
         buttonConfiguration.background.cornerRadius = 14
@@ -217,6 +213,23 @@ extension WelcomeViewController {
             .store(in: &disposeBag)
 
         setupIllustrationLayout()
+
+        joinDefaultServerButton.configuration?.showsActivityIndicator = true
+        joinDefaultServerButton.isEnabled = false
+        joinDefaultServerButton.configuration?.title = nil
+
+        viewModel.downloadDefaultServer { [weak self] in
+            guard let selectedDefaultServer = self?.viewModel.randomDefaultServer else { return }
+
+            DispatchQueue.main.async {
+                self?.joinDefaultServerButton.configuration?.showsActivityIndicator = false
+                self?.joinDefaultServerButton.isEnabled = true
+                self?.joinDefaultServerButton.configuration?.attributedTitle = AttributedString(
+                    L10n.Scene.Welcome.joinDefaultServer(selectedDefaultServer.domain),
+                    attributes: .init([.font: UIFontMetrics(forTextStyle: .headline).scaledFont(for: .systemFont(ofSize: 17, weight: .semibold))])
+                )
+            }
+        }
     }
     
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
@@ -262,12 +275,12 @@ extension WelcomeViewController {
     //MARK: - Actions
     @objc
     private func joinDefaultServer(_ sender: UIButton) {
+
+        guard let server = viewModel.randomDefaultServer else { return }
         sender.configuration?.title = nil
         sender.isEnabled = false
         sender.configuration?.showsActivityIndicator = true
 
-        let server = Mastodon.Entity.Server.mastodonDotSocial
-
         authenticationViewModel.isAuthenticating.send(true)
 
         context.apiService.instance(domain: server.domain)
@@ -320,19 +333,26 @@ extension WelcomeViewController {
                 self.authenticationViewModel.isAuthenticating.send(false)
 
                 switch completion {
-                    case .failure(let error):
+                case .failure(let error ):
-                        //TODO: show an alert or something
+                    guard let randomServer = self.viewModel.pickRandomDefaultServer() else { return }
-                        break
+
-                    case .finished:
+                    viewModel.randomDefaultServer = randomServer
-                        break
+
+                    sender.isEnabled = true
+                    sender.configuration?.showsActivityIndicator = false
+                    sender.configuration?.attributedTitle = AttributedString(
+                        L10n.Scene.Welcome.joinDefaultServer(randomServer.domain),
+                        attributes: .init([.font: UIFontMetrics(forTextStyle: .headline).scaledFont(for: .systemFont(ofSize: 17, weight: .semibold))])
+                    )
+                case .finished:
+                    sender.isEnabled = true
+                    sender.configuration?.showsActivityIndicator = false
+                    sender.configuration?.attributedTitle = AttributedString(
+                        L10n.Scene.Welcome.joinDefaultServer(server.domain),
+                        attributes: .init([.font: UIFontMetrics(forTextStyle: .headline).scaledFont(for: .systemFont(ofSize: 17, weight: .semibold))])
+                    )
                 }
 
-                sender.isEnabled = true
-                sender.configuration?.showsActivityIndicator = false
-                sender.configuration?.attributedTitle = AttributedString(
-                    L10n.Scene.Welcome.joinDefaultServer,
-                    attributes: .init([.font: UIFontMetrics(forTextStyle: .headline).scaledFont(for: .systemFont(ofSize: 17, weight: .semibold))])
-                )
             } receiveValue: { [weak self] response in
                 guard let self = self else { return }
                 if let rules = response.instance.value.rules, !rules.isEmpty {

Mastodon/Scene/Onboarding/Welcome/WelcomeViewModel.swift

@@ -8,11 +8,14 @@
 import Foundation
 import Combine
 import MastodonCore
+import MastodonSDK
 
 final class WelcomeViewModel {
  
     var disposeBag = Set<AnyCancellable>()
-    
+    private(set) var defaultServers: [Mastodon.Entity.DefaultServer]?
+    var randomDefaultServer: Mastodon.Entity.Server?
+
     // input
     let context: AppContext
     
@@ -26,5 +29,40 @@ final class WelcomeViewModel {
             .map { !$0.isEmpty }
             .assign(to: &$needsShowDismissEntry)
     }
-    
+
+    func downloadDefaultServer(completion: (() -> Void)? = nil) {
+            context.apiService.defaultServers()
+            .timeout(.milliseconds(500) , scheduler: DispatchQueue.main)
+            .sink { [weak self] result in
+
+                switch result {
+                case .finished:
+                    if let defaultServers = self?.defaultServers, defaultServers.isEmpty == false {
+                        self?.randomDefaultServer = self?.pickRandomDefaultServer()
+                    } else {
+                        self?.randomDefaultServer = Mastodon.Entity.Server.mastodonDotSocial
+                    }
+                case .failure(_):
+                    self?.randomDefaultServer = Mastodon.Entity.Server.mastodonDotSocial
+                }
+
+                completion?()
+            } receiveValue: { [weak self] servers in
+                self?.defaultServers = servers.value
+            }
+            .store(in: &disposeBag)
+    }
+
+    func pickRandomDefaultServer() -> Mastodon.Entity.Server? {
+        guard let defaultServers else { return nil }
+
+        let weightedServers = defaultServers
+            .compactMap { [Mastodon.Entity.DefaultServer](repeating: $0, count: $0.weight) }
+            .reduce([], +)
+
+        let randomServer = weightedServers.randomElement()
+            .map { Mastodon.Entity.Server(domain: $0.domain, instance: Mastodon.Entity.Instance(domain: $0.domain)) }
+
+        return randomServer
+    }
 }

MastodonSDK/Sources/MastodonLocalization/Generated/Strings.swift

@@ -1510,8 +1510,10 @@ public enum L10n {
       }
     }
     public enum Welcome {
-      /// Join mastodon.social
+      /// Join %@
-      public static let joinDefaultServer = L10n.tr("Localizable", "Scene.Welcome.JoinDefaultServer", fallback: "Join mastodon.social")
+      public static func joinDefaultServer(_ p1: Any) -> String {
+        return L10n.tr("Localizable", "Scene.Welcome.JoinDefaultServer", String(describing: p1), fallback: "Join %@")
+      }
       /// Learn more
       public static let learnMore = L10n.tr("Localizable", "Scene.Welcome.LearnMore", fallback: "Learn more")
       /// Log In

MastodonSDK/Sources/MastodonLocalization/Resources/Base.lproj/Localizable.strings

@@ -530,7 +530,7 @@ uploaded to Mastodon.";
 "Scene.Welcome.Education.Mastodon.Title" = "Welcome to Mastodon";
 "Scene.Welcome.Education.Servers.Description" = "Every Mastodon account is hosted on a server — each with its own values, rules, & admins. No matter which one you pick, you can follow and interact with people on any server.";
 "Scene.Welcome.Education.Servers.Title" = "What are servers?";
-"Scene.Welcome.JoinDefaultServer" = "Join mastodon.social";
+"Scene.Welcome.JoinDefaultServer" = "Join %@";
 "Scene.Welcome.LearnMore" = "Learn more";
 "Scene.Welcome.LogIn" = "Log In";
 "Scene.Welcome.PickServer" = "Pick another server";
@@ -556,4 +556,4 @@ uploaded to Mastodon.";
 "Widget.MultipleFollowers.ConfigurationDescription" = "Show number of followers for multiple accounts.";
 "Widget.MultipleFollowers.ConfigurationDisplayName" = "Multiple followers";
 "Widget.MultipleFollowers.MockUser.AccountName" = "another@follower.social";
-"Widget.MultipleFollowers.MockUser.DisplayName" = "Another follower";
+"Widget.MultipleFollowers.MockUser.DisplayName" = "Another follower";

MastodonSDK/Sources/MastodonLocalization/Resources/en.lproj/Localizable.strings

@@ -530,7 +530,7 @@ uploaded to Mastodon.";
 "Scene.Welcome.Education.Mastodon.Title" = "Welcome to Mastodon";
 "Scene.Welcome.Education.Servers.Description" = "Every Mastodon account is hosted on a server — each with its own values, rules, & admins. No matter which one you pick, you can follow and interact with people on any server.";
 "Scene.Welcome.Education.Servers.Title" = "What are servers?";
-"Scene.Welcome.JoinDefaultServer" = "Join mastodon.social";
+"Scene.Welcome.JoinDefaultServer" = "Join %@";
 "Scene.Welcome.LearnMore" = "Learn more";
 "Scene.Welcome.LogIn" = "Log In";
 "Scene.Welcome.PickServer" = "Pick another server";
@@ -556,4 +556,4 @@ uploaded to Mastodon.";
 "Widget.MultipleFollowers.ConfigurationDescription" = "Show number of followers for multiple accounts.";
 "Widget.MultipleFollowers.ConfigurationDisplayName" = "Multiple followers";
 "Widget.MultipleFollowers.MockUser.AccountName" = "another@follower.social";
-"Widget.MultipleFollowers.MockUser.DisplayName" = "Another follower";
+"Widget.MultipleFollowers.MockUser.DisplayName" = "Another follower";

MastodonSDK/Sources/MastodonSDK/Entity/Mastodon+Entity+DefaultServer.swift

@@ -4,7 +4,12 @@ import Foundation
 
 extension Mastodon.Entity {
     public struct DefaultServer: Codable {
-        let domain: String
+        public let domain: String
-        let weight: Int
+        public let weight: Int
+
+        public init(domain: String, weight: Int) {
+            self.domain = domain
+            self.weight = weight
+        }
     }
 }