using System;
using System.Threading.Tasks;
using Serilog;
using ShareeBike.Repository.Exception;
using ShareeBike.Services.CopriApi.Exception;
using ShareeBike.Model.Connector;
using ShareeBike.Model.Bikes.BikeInfoNS.BluetoothLock;

namespace ShareeBike.Model.Bikes.BikeInfoNS.BikeNS.Command
{
	/// <summary>
	/// Provides functionality to get the locked bike location.
	/// </summary>
	public static class AuthCommand
	{
		/// <summary>
		/// Possible steps of requesting a bike.
		/// </summary>
		public enum Step
		{
			Authenticate,
		}

		/// <summary>
		/// Possible steps of requesting a bike.
		/// </summary>
		public enum State
		{
			WebConnectFailed,
			GeneralAuthError,
		}

		/// <summary>
		/// Interface to notify view model about steps/ state changes of closing process.
		/// </summary>
		public interface IAuthCommandListener
		{
			/// <summary>
			/// Reports current step.
			/// </summary>
			/// <param name="currentStep">Current step to report.</param>
			void ReportStep(Step currentStep);

			/// <summary>
			/// Reports current state.
			/// </summary>
			/// <param name="currentState">Current state to report.</param>
			/// <param name="message">Message describing the current state.</param>
			/// <returns></returns>
			Task ReportStateAsync(State currentState, string message);
		}

		/// <summary>
		/// Get current location.
		/// </summary>
		/// <param name="listener"></param>
		/// <returns></returns>
		/// <exception cref="Exception"></exception>
		public static async Task InvokeAsync<T>(
			IBikeInfoMutable bike,
			Func<bool> isConnectedDelegate,
			Func<bool, IConnector> connectorFactory,
			IAuthCommandListener listener)
		{
			// Invokes member to notify about step being started.
			void InvokeCurrentStep(Step step)
			{
				if (listener == null)
					return;

				try
				{
					listener.ReportStep(step);
				}
				catch (Exception exception)
				{
					Log.ForContext<T>().Error("An exception {@exception} was thrown invoking step-action for step {step} ", exception, step);
				}
			}

			// Invokes member to notify about state change.
			async Task InvokeCurrentStateAsync(State state, string message)
			{
				if (listener == null)
					return;

				try
				{
					await listener.ReportStateAsync(state, message);
				}
				catch (Exception exception)
				{
					Log.ForContext<T>().Error("An exception {@exception} was thrown invoking state-action for state {state} ", exception, state);
				}
			}

			//// Start Action
			//// Step: Authenticate user
			InvokeCurrentStep(Step.Authenticate);

			try
			{
				// Repeat reservation to get a new seed/ k_user value.
				await connectorFactory(true).Command.CalculateAuthKeys(bike);
				Log.ForContext<T>().Information("Calculation of AuthKeys successfully.");
			}
			catch (Exception exception)
			{
				if (exception is WebConnectFailureException
					|| exception is RequestNotCachableException)
				{
					// Copri server is not reachable.
					Log.ForContext<T>().Error("Calculation of AuthKeys failed (Copri server not reachable).");
					await InvokeCurrentStateAsync(State.WebConnectFailed, exception.Message);
				}
				else
				{
					Log.ForContext<T>().Error("Calculation of AuthKeys failed. {@exception}", exception);
					await InvokeCurrentStateAsync(State.GeneralAuthError, exception.Message);
				}

				throw;
			}
		}
	}
}