/// <summary>
/// Initializes a new instance of the <see cref="FacebookAdapter"/> class using an existing Facebook client.
/// </summary>
/// /// <param name="facebookClient">Client used to interact with the Facebook API.</param>
/// <param name="options">Options for the Facebook Adapter.</param>
/// <param name="logger">The logger this adapter should use.</param>
/// <exception cref="ArgumentNullException"><paramref name="options"/> is null.</exception>
public FacebookAdapter(FacebookClientWrapper facebookClient, FacebookAdapterOptions options, ILogger logger = null)
{
_options = options ?? new FacebookAdapterOptions();
_facebookClient = facebookClient ?? throw new ArgumentNullException(nameof(facebookClient));
_logger = logger ?? NullLogger.Instance;
}
/// <summary>
/// Initializes a new instance of the <see cref="FacebookAdapter"/> class using configuration settings.
/// </summary>
/// <param name="configuration">An <see cref="IConfiguration"/> instance.</param>
/// <remarks>
/// The adapter uses these configuration keys:
/// - `VerifyToken`, the token to respond to the initial verification request.
/// - `AppSecret`, the secret used to validate incoming webhooks.
/// - `AccessToken`, an access token for the bot.
/// </remarks>
/// <param name="options">An instance of <see cref="FacebookAdapterOptions"/>.</param>
/// <param name="logger">The logger this adapter should use.</param>
public FacebookAdapter(IConfiguration configuration, FacebookAdapterOptions options = null, ILogger logger = null)
: this(new FacebookClientWrapper(new FacebookClientWrapperOptions(configuration[FacebookVerifyTokenSettingKey], configuration[FacebookAppSecretSettingKey], configuration[FacebookAccessTokenSettingKey])), options, logger)
{
}