Import export settings

Shared/Settings/Import/ImportSettingsSheetViewModel.swift

@@ -0,0 +1,77 @@
+import Foundation
+import SwiftUI
+
+class ImportSettingsSheetViewModel: ObservableObject {
+    static let shared = ImportSettingsSheetViewModel()
+
+    @Published var selectedInstances = Set<Instance.ID>()
+    @Published var selectedAccounts = Set<Account.ID>()
+
+    @Published var importableAccounts = Set<Account.ID>()
+    @Published var importableAccountsPasswords = [Account.ID: String]()
+
+    func toggleInstance(_ instance: Instance, accounts: [Account]) {
+        if selectedInstances.contains(instance.id) {
+            selectedInstances.remove(instance.id)
+        } else {
+            guard isImportable(instance) else { return }
+            selectedInstances.insert(instance.id)
+        }
+
+        removeNonImportableFromSelectedAccounts(accounts: accounts)
+    }
+
+    func toggleAccount(_ account: Account, accounts: [Account]) {
+        if selectedAccounts.contains(account.id) {
+            selectedAccounts.remove(account.id)
+        } else {
+            guard isImportable(account.id, accounts: accounts) else { return }
+            selectedAccounts.insert(account.id)
+        }
+    }
+
+    func isSelectedForImport(_ account: Account) -> Bool {
+        importableAccounts.contains(account.id) && selectedAccounts.contains(account.id)
+    }
+
+    func isImportable(_ accountID: Account.ID, accounts: [Account]) -> Bool {
+        guard let account = accounts.first(where: { $0.id == accountID }),
+              let instanceID = account.instanceID,
+              AccountsModel.shared.find(accountID) == nil
+        else { return false }
+
+        return ((account.password != nil && !account.password!.isEmpty) ||
+            importableAccounts.contains(account.id)) && (
+            (InstancesModel.shared.find(instanceID) != nil) ||
+                selectedInstances.contains(instanceID)
+        )
+    }
+
+    func isImportable(_ instance: Instance) -> Bool {
+        !isInstanceAlreadyAdded(instance)
+    }
+
+    func isInstanceAlreadyAdded(_ instance: Instance) -> Bool {
+        InstancesModel.shared.find(instance.id) != nil || InstancesModel.shared.findByURLString(instance.apiURLString) != nil
+    }
+
+    func removeNonImportableFromSelectedAccounts(accounts: [Account]) {
+        selectedAccounts = Set(selectedAccounts.filter { isImportable($0, accounts: accounts) })
+    }
+
+    func reset() {
+        selectedAccounts = []
+        selectedInstances = []
+        importableAccounts = []
+    }
+
+    func reset(_ importer: LocationsSettingsGroupImporter? = nil) {
+        reset()
+
+        guard let importer else { return }
+
+        selectedInstances = Set(importer.instances.filter { isImportable($0) }.map(\.id))
+        importableAccounts = Set(importer.accounts.filter { isImportable($0.id, accounts: importer.accounts) }.map(\.id))
+        selectedAccounts = importableAccounts
+    }
+}