Libation/Source/AudibleUtilities/AudibleApiStorage.cs

using LibationFileManager;
using Newtonsoft.Json;
using System;
using System.IO;

namespace AudibleUtilities;

public class AccountSettingsLoadErrorEventArgs : ErrorEventArgs
{
	/// <summary>
	/// Create a new, empty <see cref="AccountsSettings"/> file if true, otherwise throw
	/// </summary>
	public bool Handled { get; set; }
	/// <summary>
	/// The file path of the AccountsSettings.json file
	/// </summary>
	public string SettingsFilePath { get; }

	public AccountSettingsLoadErrorEventArgs(string path, Exception exception)
		: base(exception)
	{
		SettingsFilePath = path;
	}
}

public static class AudibleApiStorage
{
	public static string AccountsSettingsFile => Path.Combine(Configuration.Instance.LibationFiles.Location, "AccountsSettings.json");

	public static event EventHandler<AccountSettingsLoadErrorEventArgs>? LoadError;

	public static void EnsureAccountsSettingsFileExists()
	{
		// saves. BEWARE: this will overwrite an existing file
		if (!File.Exists(AccountsSettingsFile))
		{
			//Save the JSON file manually so that AccountsSettingsPersister.Saving and AccountsSettingsPersister.Saved
			//are not fired. There's no need to fire those events on an empty AccountsSettings file.
			var accountSerializerSettings = AudibleApi.Authorization.Identity.GetJsonSerializerSettings();
			File.WriteAllText(AccountsSettingsFile, JsonConvert.SerializeObject(new AccountsSettings(), Formatting.Indented, accountSerializerSettings));
		}
	}

	/// <summary>If you use this, be a good citizen and DISPOSE of it</summary>
	public static AccountsSettingsPersister GetAccountsSettingsPersister()
	{
		try
		{
			return new AccountsSettingsPersister(AccountsSettingsFile);
		}
		catch (Exception ex)
		{
			var args = new AccountSettingsLoadErrorEventArgs(AccountsSettingsFile, ex);
			LoadError?.Invoke(null, args);
			if (args.Handled)
				return GetAccountsSettingsPersister();
			throw;
		}
	}

	public static string GetIdentityTokensJsonPath(this Account account)
		=> GetIdentityTokensJsonPath(account.AccountId, account.Locale?.Name);
	public static string GetIdentityTokensJsonPath(string username, string? localeName)
	{
		var usernameEscaped = EscapeNewtonsoftJsonPathSingleQuotedLiteral(username);
		var localeNameEscaped = EscapeNewtonsoftJsonPathSingleQuotedLiteral(localeName ?? string.Empty);

		return $"$.Accounts[?(@.AccountId == '{usernameEscaped}' && @.IdentityTokens.LocaleName == '{localeNameEscaped}')].IdentityTokens";
	}

	/// <summary>
	/// Escape a value for use inside single-quoted Newtonsoft JSONPath filter literals.
	/// See https://www.newtonsoft.com/json/help/html/QueryJsonSelectTokenEscaped.htm
	/// </summary>
	internal static string EscapeNewtonsoftJsonPathSingleQuotedLiteral(string value)
		=> value.Replace("\\", @"\\").Replace("'", @"\'");
}