Improve detection and logging of download capabilities

- Check if the Api supports widevine before trying to download
- Additional logging

Source/AudibleUtilities/AccountsSettings.cs

@@ -6,6 +6,7 @@ using AudibleApi.Authorization;
 using Dinah.Core;
 using Newtonsoft.Json;
 
+#nullable enable
 namespace AudibleUtilities
 {
 	// 'AccountsSettings' is intentionally NOT IEnumerable<> so that properties can be added/extended
@@ -14,8 +15,8 @@ namespace AudibleUtilities
 	//   JSON :  Array (properties on the collection will not be serialized)
 	public class AccountsSettings : IUpdatable
 	{
-		public event EventHandler Updated;
-		private void update(object sender = null, EventArgs e = null)
+		public event EventHandler? Updated;
+		private void update(object? sender = null, EventArgs? e = null)
 		{
 			foreach (var account in Accounts)
 				validate(account);
@@ -48,9 +49,9 @@ namespace AudibleUtilities
 			}
 		}
 
-		private string _cdm;
+		private string? _cdm;
 		[JsonProperty]
-		public string Cdm
+		public string? Cdm
 		{
 			get => _cdm;
 			set
@@ -68,7 +69,7 @@ namespace AudibleUtilities
 		#endregion
 
 		#region de/serialize
-		public static AccountsSettings FromJson(string json)
+		public static AccountsSettings? FromJson(string json)
 			=> JsonConvert.DeserializeObject<AccountsSettings>(json, Identity.GetJsonSerializerSettings());
 
 		public string ToJson(Formatting formatting = Formatting.Indented)
@@ -107,7 +108,7 @@ namespace AudibleUtilities
 			account.Updated += update;
 		}
 
-		public Account GetAccount(string accountId, string locale)
+		public Account? GetAccount(string accountId, string? locale)
 		{
 			if (locale is null)
 				return null;

Source/FileLiberator/DownloadOptions.Factory.cs

@@ -3,6 +3,7 @@ using AudibleApi;
 using AudibleApi.Common;
 using AudibleUtilities.Widevine;
 using DataLayer;
+using Dinah.Core;
 using LibationFileManager;
 using NAudio.Lame;
 using System;
@@ -24,6 +25,16 @@ public partial class DownloadOptions
 	public static async Task<DownloadOptions> InitiateDownloadAsync(Api api, Configuration config, LibraryBook libraryBook, CancellationToken token)
 	{
 		var license = await ChooseContent(api, libraryBook, config, token);
+		Serilog.Log.Logger.Debug("Content License {@License}", new
+		{
+			license.DrmType,
+			license.ContentMetadata.ContentReference.Codec,
+			license.ContentMetadata.ContentReference.Marketplace,
+			license.ContentMetadata.ContentReference.ContentSizeInBytes,
+			license.ContentMetadata.ContentReference.Version,
+			license.ContentMetadata.ContentReference.FileVersion
+		});
+
 		token.ThrowIfCancellationRequested();
 
 		//Some audiobooks will have incorrect chapters in the metadata returned from the license request,
@@ -56,10 +67,28 @@ public partial class DownloadOptions
 
 	private static async Task<LicenseInfo> ChooseContent(Api api, LibraryBook libraryBook, Configuration config, CancellationToken token)
 	{
+		Serilog.Log.Logger.Debug("Download Settings {@Settings}", new
+		{
+			config.FileDownloadQuality,
+			config.UseWidevine,
+			config.Request_xHE_AAC,
+			config.RequestSpatial,
+			config.SpatialAudioCodec
+		});
+
 		var dlQuality = config.FileDownloadQuality == Configuration.DownloadQuality.Normal ? DownloadQuality.Normal : DownloadQuality.High;
 
-		if (!config.UseWidevine || await Cdm.GetCdmAsync() is not Cdm cdm)
+		bool canUseWidevine = api.SupportsWidevine();
+		if (!config.UseWidevine || !canUseWidevine || await Cdm.GetCdmAsync() is not Cdm cdm)
 		{
+			if (config.UseWidevine)
+			{
+				if (canUseWidevine)
+					Serilog.Log.Logger.Information("Unable to get a Widevine CDM. Falling back to ADRM.");
+				else
+					Serilog.Log.Logger.Information("Account {@account} is not registered as an android device, so content will not be downloaded with Widevine DRM. Remove and re-add the account in Libation to fix.", libraryBook.Account.ToMask());
+			}
+
 			token.ThrowIfCancellationRequested();
 			var license = await api.GetDownloadLicenseAsync(libraryBook.Book.AudibleProductId, dlQuality);
 			return new LicenseInfo(license);

Source/FileLiberator/UtilityExtensions.cs

@@ -7,6 +7,7 @@ using DataLayer;
 using Dinah.Core;
 using LibationFileManager;
 using LibationFileManager.Templates;
+using System.Security.Authentication;
 
 #nullable enable
 namespace FileLiberator
@@ -25,14 +26,22 @@ namespace FileLiberator
 
 		public static async Task<AudibleApi.Api> GetApiAsync(this LibraryBook libraryBook)
 		{
-			Account account;
-			using (var accounts = AudibleApiStorage.GetAccountsSettingsPersister())
-				account = accounts.AccountsSettings.GetAccount(libraryBook.Account, libraryBook.Book.Locale);
+			using var accounts = AudibleApiStorage.GetAccountsSettingsPersister();
+			var account = accounts.AccountsSettings.GetAccount(libraryBook.Account, libraryBook.Book.Locale)
+				?? throw new InvalidCredentialException($"No account found for '{libraryBook.Account}' and locale '{libraryBook.Book.Locale}'");
 
 			var apiExtended = await ApiExtended.CreateAsync(account);
 			return apiExtended.Api;
 		}
 
+		public static bool SupportsWidevine(this AudibleApi.Api api)
+		{
+			//TODO: Expose Api's identity maintainer directly instead of using reflection.
+			var identityProperty = api.GetType().GetProperty("_identityMaintainer", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
+			return identityProperty?.GetValue(api) is AudibleApi.Authorization.IIdentityMaintainer identityMaintainer
+				&& identityMaintainer.DeviceType == AudibleApi.Resources.DeviceType;
+		}
+
 		public static LibraryBookDto ToDto(this LibraryBook libraryBook)
 		{
 			using var persister = AudibleApiStorage.GetAccountsSettingsPersister();

Source/LibationAvalonia/Controls/Settings/Audio.axaml.cs

@@ -39,7 +39,7 @@ namespace LibationAvalonia.Controls.Settings
 			{
 				using var accounts = AudibleApiStorage.GetAccountsSettingsPersister();
 
-				if (!accounts.AccountsSettings.Accounts.Any(a => a.IdentityTokens.DeviceType == AudibleApi.Resources.DeviceType))
+				if (!accounts.AccountsSettings.Accounts.All(a => a.IdentityTokens.DeviceType == AudibleApi.Resources.DeviceType))
 				{
 					if (VisualRoot is Window parent)
 					{

Source/LibationWinForms/Dialogs/SettingsDialog.AudioSettings.cs

@@ -224,7 +224,7 @@ namespace LibationWinForms.Dialogs
 			{
 				using var accounts = AudibleApiStorage.GetAccountsSettingsPersister();
 
-				if (!accounts.AccountsSettings.Accounts.Any(a => a.IdentityTokens.DeviceType == AudibleApi.Resources.DeviceType))
+				if (!accounts.AccountsSettings.Accounts.All(a => a.IdentityTokens.DeviceType == AudibleApi.Resources.DeviceType))
 				{
 					var choice = MessageBox.Show(this,
 						"In order to enable widevine content, Libation will need to log into your accounts again.\r\n\r\n" +