Avoid fetching account when unnecessary

ServiceLayer/Sources/ServiceLayer/Services/AccountStatusesService.swift

@@ -7,25 +7,50 @@ import Mastodon
 import MastodonAPI
 
 public struct AccountStatusesService {
+    public let accountService: AnyPublisher<AccountService, Error>
+
     private let accountID: String
     private let mastodonAPIClient: MastodonAPIClient
     private let contentDatabase: ContentDatabase
 
+    init(account: Account, mastodonAPIClient: MastodonAPIClient, contentDatabase: ContentDatabase) {
+        self.init(
+            id: account.id,
+            account: account,
+            mastodonAPIClient: mastodonAPIClient,
+            contentDatabase: contentDatabase)
+    }
+
     init(id: String, mastodonAPIClient: MastodonAPIClient, contentDatabase: ContentDatabase) {
+        self.init(id: id, account: nil, mastodonAPIClient: mastodonAPIClient, contentDatabase: contentDatabase)
+    }
+
+    private init(
+        id: String,
+        account: Account?,
+        mastodonAPIClient: MastodonAPIClient,
+        contentDatabase: ContentDatabase) {
         accountID = id
         self.mastodonAPIClient = mastodonAPIClient
         self.contentDatabase = contentDatabase
+
+        var accountPublisher = contentDatabase.accountObservation(id: accountID)
+            .compactMap { $0 }
+            .eraseToAnyPublisher()
+
+        if let account = account {
+            accountPublisher = accountPublisher
+                .merge(with: Just(account).setFailureType(to: Error.self))
+                .eraseToAnyPublisher()
+        }
+
+        accountService = accountPublisher
+            .map { AccountService(account: $0, mastodonAPIClient: mastodonAPIClient, contentDatabase: contentDatabase) }
+            .eraseToAnyPublisher()
     }
 }
 
 public extension AccountStatusesService {
-    func accountService() -> AnyPublisher<AccountService, Error> {
-        contentDatabase.accountObservation(id: accountID)
-            .compactMap { $0 }
-            .map { AccountService(account: $0, mastodonAPIClient: mastodonAPIClient, contentDatabase: contentDatabase) }
-            .eraseToAnyPublisher()
-    }
-
     func statusListService(
         collectionPublisher: CurrentValueSubject<AccountStatusCollection, Never>) -> StatusListService {
         StatusListService(

ServiceLayer/Sources/ServiceLayer/Services/NavigationService.swift

@@ -63,6 +63,10 @@ public extension NavigationService {
         AccountStatusesService(id: id, mastodonAPIClient: mastodonAPIClient, contentDatabase: contentDatabase)
     }
 
+    func accountStatusesService(account: Account) -> AccountStatusesService {
+        AccountStatusesService(account: account, mastodonAPIClient: mastodonAPIClient, contentDatabase: contentDatabase)
+    }
+
     func statusService(status: Status) -> StatusService {
         StatusService(status: status, mastodonAPIClient: mastodonAPIClient, contentDatabase: contentDatabase)
     }
@@ -110,7 +114,7 @@ private extension NavigationService {
                             mastodonAPIClient: mastodonAPIClient,
                             contentDatabase: contentDatabase))
                 } else if let account = results.accounts.first {
-                    return .accountStatuses(accountStatusesService(id: account.id))
+                    return .accountStatuses(accountStatusesService(account: account))
                 } else if let status = results.statuses.first {
                     return .statusList(
                         StatusListService(

ViewModels/Sources/ViewModels/AccountListViewModel.swift

@@ -65,12 +65,19 @@ extension AccountListViewModel: CollectionViewModel {
     public func itemSelected(_ item: CollectionItem) {
         switch item.kind {
         case .account:
+            let navigationService = accountListService.navigationService
+            let accountStatusesService: AccountStatusesService
+
+            if let account = accounts[item.id] {
+                accountStatusesService = navigationService.accountStatusesService(account: account)
+            } else {
+                accountStatusesService = navigationService.accountStatusesService(id: item.id)
+            }
+
             navigationEventsSubject.send(
                 .collectionNavigation(
                     AccountStatusesViewModel(
-                        accountStatusesService: accountListService
-                            .navigationService
-                            .accountStatusesService(id: item.id))))
+                        accountStatusesService: accountStatusesService)))
         default:
             break
         }

ViewModels/Sources/ViewModels/AccountStatusesViewModel.swift

@@ -22,7 +22,7 @@ public class AccountStatusesViewModel: StatusListViewModel {
 
         $collection.sink(receiveValue: collectionSubject.send).store(in: &cancellables)
 
-        accountStatusesService.accountService()
+        accountStatusesService.accountService
             .map(AccountViewModel.init(accountService:))
             .assignErrorsToAlertItem(to: \.alertItem, on: self)
             .assign(to: &$accountViewModel)

ViewModels/Sources/ViewModels/StatusViewModel.swift

@@ -120,7 +120,7 @@ public extension StatusViewModel {
             Just(CollectionItemEvent.navigation(
                     .accountStatuses(
                         statusService.navigationService.accountStatusesService(
-                            id: statusService.status.displayStatus.account.id))))
+                            account: statusService.status.displayStatus.account))))
                 .setFailureType(to: Error.self)
                 .eraseToAnyPublisher())
     }