Make AccountsSettings and Persister more clear

InternalUtilities/Account.cs

@@ -0,0 +1,95 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using AudibleApi;
+using AudibleApi.Authorization;
+using Dinah.Core;
+using Newtonsoft.Json;
+
+namespace InternalUtilities
+{
+	public class Account : IUpdatable
+	{
+		public event EventHandler Updated;
+		private void update(object sender = null, EventArgs e = null)
+			=> Updated?.Invoke(this, new EventArgs());
+
+		// canonical. immutable. email or phone number
+		public string AccountId { get; }
+
+		// user-friendly, non-canonical name. mutable
+		private string _accountName;
+		public string AccountName
+		{
+			get => _accountName;
+			set
+			{
+				if (string.IsNullOrWhiteSpace(value))
+					return;
+				var v = value.Trim();
+				if (v == _accountName)
+					return;
+				_accountName = v;
+				update();
+			}
+		}
+
+		// whether to include this account when scanning libraries.
+		// technically this is an app setting; not an attribute of account. but since it's managed with accounts, it makes sense to put this exception-to-the-rule here
+		private bool _libraryScan = true;
+		public bool LibraryScan
+		{
+			get => _libraryScan;
+			set
+			{
+				if (value == _libraryScan)
+					return;
+				_libraryScan = value;
+				update();
+			}
+		}
+
+		private string _decryptKey = "";
+		public string DecryptKey
+		{
+			get => _decryptKey;
+			set
+			{
+				var v = (value ?? "").Trim();
+				if (v == _decryptKey)
+					return;
+				_decryptKey = v;
+				update();
+			}
+		}
+
+		private Identity _identity;
+		public Identity IdentityTokens
+		{
+			get => _identity;
+			set
+			{
+				if (_identity is null && value is null)
+					return;
+
+				if (_identity != null)
+					_identity.Updated -= update;
+
+				if (value != null)
+					value.Updated += update;
+
+				_identity = value;
+				update();
+			}
+		}
+
+		[JsonIgnore]
+		public Locale Locale => IdentityTokens?.Locale;
+
+		public Account(string accountId)
+		{
+			ArgumentValidator.EnsureNotNullOrWhiteSpace(accountId, nameof(accountId));
+			AccountId = accountId.Trim();
+		}
+	}
+}

InternalUtilities/AccountsSettings.cs

@@ -1,32 +1,14 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 using AudibleApi;
 using AudibleApi.Authorization;
 using Dinah.Core;
-using Dinah.Core.IO;
 using Newtonsoft.Json;
 
 namespace InternalUtilities
 {
-	public class AccountsSettingsPersister : JsonFilePersister<AccountsSettings>
-	{
-		/// <summary>Alias for Target </summary>
-		public AccountsSettings AccountsSettings => Target;
-
-		/// <summary>uses path. create file if doesn't yet exist</summary>
-		public AccountsSettingsPersister(AccountsSettings target, string path, string jsonPath = null)
-			: base(target, path, jsonPath) { }
-
-		/// <summary>load from existing file</summary>
-		public AccountsSettingsPersister(string path, string jsonPath = null)
-			: base(path, jsonPath) { }
-
-		protected override JsonSerializerSettings GetSerializerSettings()
-			=> Identity.GetJsonSerializerSettings();
-	}
-	// 'AccountsSettings' is intentionally not IEnumerable<> so that properties can be added/extended
+	// 'AccountsSettings' is intentionally NOT IEnumerable<> so that properties can be added/extended
 	// from newtonsoft (https://www.newtonsoft.com/json/help/html/SerializationGuide.htm):
 	//   .NET :  IList, IEnumerable, IList<T>, Array
 	//   JSON :  Array (properties on the collection will not be serialized)
@@ -49,7 +31,7 @@ namespace InternalUtilities
 
 		#region Accounts
 		private List<Account> _accounts_backing = new List<Account>();
-		[JsonProperty(PropertyName = "Accounts")]
+		[JsonProperty(PropertyName = nameof(Accounts))]
 		private List<Account> _accounts_json
 		{
 			get => _accounts_backing;
@@ -141,84 +123,16 @@ namespace InternalUtilities
 
 			var acct = GetAccount(accountId, locale);
 
-			if (acct is null || account is null)
+			// new: ok
+			if (acct is null)
 				return;
 
-			if (acct != account)
-				throw new InvalidOperationException("Cannot add an account with the same account Id and Locale");
-		}
-	}
-	public class Account : IUpdatable
-	{
-		public event EventHandler Updated;
-		private void update(object sender = null, EventArgs e = null)
-			=> Updated?.Invoke(this, new EventArgs());
-
-		// canonical. immutable. email or phone number
-		public string AccountId { get; }
-
-		// user-friendly, non-canonical name. mutable
-		private string _accountName;
-		public string AccountName
-		{
-			get => _accountName;
-			set
-			{
-				if (string.IsNullOrWhiteSpace(value))
-					return;
-				var v = value.Trim();
-				if (v == _accountName)
-					return;
-				_accountName = v;
-				update();
-			}
-		}
-
-		// whether to include this account when scanning libraries.
-		// technically this is an app setting; not an attribute of account. but since it's managed with accounts, it makes sense to put this exception-to-the-rule here
-		public bool LibraryScan { get; set; }
-
-		private string _decryptKey = "";
-		public string DecryptKey
-		{
-			get => _decryptKey;
-			set
-			{
-				var v = (value ?? "").Trim();
-				if (v == _decryptKey)
-					return;
-				_decryptKey = v;
-				update();
-			}
-		}
-
-		private Identity _identity;
-		public Identity IdentityTokens
-		{
-			get => _identity;
-			set
-			{
-				if (_identity is null && value is null)
-					return;
-
-				if (_identity != null)
-					_identity.Updated -= update;
-
-				if (value != null)
-					value.Updated += update;
-
-				_identity = value;
-				update();
-			}
-		}
-
-		[JsonIgnore]
-		public Locale Locale => IdentityTokens?.Locale;
-
-		public Account(string accountId)
-		{
-			ArgumentValidator.EnsureNotNullOrWhiteSpace(accountId, nameof(accountId));
-			AccountId = accountId.Trim();
+			// same account instance: ok
+			if (acct == account)
+				return;
+			
+			// same account id + locale, different instance: bad
+			throw new InvalidOperationException("Cannot add an account with the same account Id and Locale");
 		}
 	}
 }

InternalUtilities/AccountsSettingsPersister.cs

@@ -0,0 +1,24 @@
+using System;
+using AudibleApi.Authorization;
+using Dinah.Core.IO;
+using Newtonsoft.Json;
+
+namespace InternalUtilities
+{
+	public class AccountsSettingsPersister : JsonFilePersister<AccountsSettings>
+	{
+		/// <summary>Alias for Target </summary>
+		public AccountsSettings AccountsSettings => Target;
+
+		/// <summary>uses path. create file if doesn't yet exist</summary>
+		public AccountsSettingsPersister(AccountsSettings target, string path, string jsonPath = null)
+			: base(target, path, jsonPath) { }
+
+		/// <summary>load from existing file</summary>
+		public AccountsSettingsPersister(string path, string jsonPath = null)
+			: base(path, jsonPath) { }
+
+		protected override JsonSerializerSettings GetSerializerSettings()
+			=> Identity.GetJsonSerializerSettings();
+	}
+}

InternalUtilities/UNTESTED/AudibleApiStorage.cs

@@ -24,9 +24,9 @@ namespace InternalUtilities
 			=> TEST_GetFirstAccount().GetIdentityTokensJsonPath();
 		// convenience for for tests and demos. don't use in production Libation
 		public static Account TEST_GetFirstAccount()
-			=> GetAccountsSettings().GetAll().FirstOrDefault();
+			=> GetPersistentAccountsSettings().GetAll().FirstOrDefault();
 
-		public static AccountsSettings GetAccountsSettings()
+		public static AccountsSettings GetPersistentAccountsSettings()
 			=> new AccountsSettingsPersister(AccountsSettingsFile).AccountsSettings;
 
 		public static string GetIdentityTokensJsonPath(this Account account)