using System;
using System.Linq;
using System.Threading.Tasks;
using Serilog;
using TINK.Model.Bikes;
using TINK.Model.Connector.Updater;
using TINK.Model.Services.CopriApi;
using TINK.Repository;

namespace TINK.Model.Connector
{
	/// <summary> Provides query functionality for a logged in user. </summary>
	public class CachedQueryLoggedIn : BaseLoggedIn, IQuery
	{
		/// <summary> Cached copri server. </summary>
		private ICachedCopriServer Server { get; }

		/// <summary>Constructs a copri query object.</summary>
		/// <param name="copriServer">Server which implements communication.</param>
		public CachedQueryLoggedIn(ICopriServerBase copriServer,
			string sessionCookie,
			string mail,
			Func<DateTime> dateTimeProvider) : base(copriServer, sessionCookie, mail, dateTimeProvider)
		{
			Server = copriServer as ICachedCopriServer;
			if (Server == null)
			{
				throw new ArgumentException($"Copri server is not of expected typ. Type detected is {copriServer.GetType()}.");
			}
		}

		/// <summary> Gets all stations including postions.</summary>
		public async Task<Result<StationsAndBikesContainer>> GetBikesAndStationsAsync()
		{
			var stationsResponse = await Server.GetStations();

			if (stationsResponse.Source == typeof(CopriCallsMonkeyStore)
				|| stationsResponse.Exception != null)
			{
				// Stations were read from cache ==> get bikes availbalbe and occupied from cache as well to avoid inconsistencies
				return new Result<StationsAndBikesContainer>(
					stationsResponse.Source,
					new StationsAndBikesContainer(
						stationsResponse.Response.GetStationsAllMutable(),
						UpdaterJSON.GetBikesAll(
							(await Server.GetBikesAvailable(true)).Response?.bikes?.Values,
							(await Server.GetBikesOccupied(true)).Response?.bikes_occupied?.Values,
							Mail,
							DateTimeProvider)),
					stationsResponse.GeneralData,
					stationsResponse.Exception);
			}

			var bikesAvailableResponse = await Server.GetBikesAvailable();
			if (bikesAvailableResponse.Source == typeof(CopriCallsMonkeyStore)
				|| bikesAvailableResponse.Exception != null)
			{
				// Bikes avilable were read from cache ==> get bikes occupied from cache as well to avoid inconsistencies
				return new Result<StationsAndBikesContainer>(
					bikesAvailableResponse.Source,
					new StationsAndBikesContainer(
						(await Server.GetStations(true)).Response.GetStationsAllMutable(),
						UpdaterJSON.GetBikesAll(bikesAvailableResponse.Response?.bikes?.Values,
						(await Server.GetBikesOccupied(true)).Response?.bikes_occupied?.Values,
						Mail,
						DateTimeProvider)),
					bikesAvailableResponse.GeneralData,
					bikesAvailableResponse.Exception);
			}

			var bikesOccupiedResponse = await Server.GetBikesOccupied();
			if (bikesOccupiedResponse.Source == typeof(CopriCallsMonkeyStore)
				|| bikesOccupiedResponse.Exception != null)
			{
				// Bikes occupied were read from cache ==> get bikes available from cache as well to avoid inconsistencies
				return new Result<StationsAndBikesContainer>(
					bikesOccupiedResponse.Source,
					new StationsAndBikesContainer(
						(await Server.GetStations(true)).Response.GetStationsAllMutable(),
						UpdaterJSON.GetBikesAll(
							(await Server.GetBikesAvailable(true)).Response?.bikes?.Values,
							bikesOccupiedResponse.Response?.bikes_occupied?.Values,
							Mail,
							DateTimeProvider)),
					bikesOccupiedResponse.GeneralData,
					bikesOccupiedResponse.Exception);
			}

			// Both types bikes could read from copri =>  update cache
			Server.AddToCache(stationsResponse);
			Server.AddToCache(bikesAvailableResponse);
			Server.AddToCache(bikesOccupiedResponse);

			var exceptions = new[] { stationsResponse?.Exception, bikesAvailableResponse?.Exception, bikesOccupiedResponse?.Exception }.Where(x => x != null).ToArray();

			var stationsMutable = stationsResponse.Response.GetStationsAllMutable();
			var bikesMutable = UpdaterJSON.GetBikesAll(
						bikesAvailableResponse.Response?.bikes?.Values,
						bikesOccupiedResponse.Response?.bikes_occupied?.Values,
						Mail,
						DateTimeProvider);

			return new Result<StationsAndBikesContainer>(
				stationsResponse.Source,
				new StationsAndBikesContainer(stationsMutable, bikesMutable),
				stationsResponse.GeneralData,
				exceptions.Length > 0 ? new AggregateException(exceptions) : null);
		}

		/// <summary> Gets bikes occupied. </summary>
		/// <returns>Collection of bikes.</returns>
		public async Task<Result<BikeCollection>> GetBikesOccupiedAsync()
		{
			var bikesAvailableResponse = await Server.GetBikesAvailable(false);
			if (bikesAvailableResponse.Source == typeof(CopriCallsMonkeyStore)
				|| bikesAvailableResponse.Exception != null)
			{
				// Bikes available were read from cache ==> get bikes occupied from cache as well to avoid inconsistencies.
				Log.ForContext<CachedQueryLoggedIn>().Debug("Bikes available read from cache. Reading bikes occupied from cache as well.");
				return new Result<BikeCollection>(
					bikesAvailableResponse.Source,
					UpdaterJSON.GetBikesAll(
						bikesAvailableResponse.Response?.bikes?.Values?.Where(bike => bike.GetState() == State.InUseStateEnum.FeedbackPending),
						(await Server.GetBikesOccupied(true))?.Response?.bikes_occupied?.Values,
						Mail,
						DateTimeProvider),
					bikesAvailableResponse.GeneralData,
					bikesAvailableResponse.Exception);
			}

			var bikesOccupiedResponse = await Server.GetBikesOccupied(false);
			if (bikesOccupiedResponse.Source == typeof(CopriCallsMonkeyStore)
				|| bikesOccupiedResponse.Exception != null)
			{
				// Bikes occupied were read from cache ==> get bikes available from cache as well to avoid inconsistencies
				Log.ForContext<CachedQueryLoggedIn>().Debug("Bikes occupied read from cache. Reread bikes available from cache as well.");
				return new Result<BikeCollection>(
					bikesOccupiedResponse.Source,
					UpdaterJSON.GetBikesAll(
						(await Server.GetBikesAvailable(true)).Response?.bikes?.Values?.Where(bike => bike.GetState() == State.InUseStateEnum.FeedbackPending),
						bikesOccupiedResponse.Response?.bikes_occupied?.Values,
						Mail,
						DateTimeProvider),
					bikesOccupiedResponse.GeneralData,
					bikesOccupiedResponse.Exception);
			}

			// Both types bikes could read from copri =>  update bikes occupied cache.
			// // Do not add bikes available to cache because this might lead to conflicts calls GetBikesAsync() and bikes with FeedbackPending state are of no use offline. 
			Server.AddToCache(bikesOccupiedResponse);

			return new Result<BikeCollection>(
				bikesOccupiedResponse.Source,
			   UpdaterJSON.GetBikesAll(
					bikesAvailableResponse?.Response.bikes?.Values?.Select(bike => bike)?.Where(bike => bike.GetState() == State.InUseStateEnum.FeedbackPending),
					bikesOccupiedResponse?.Response?.bikes_occupied?.Values,
					Mail,
					DateTimeProvider),
				bikesOccupiedResponse.GeneralData,
				bikesOccupiedResponse.Exception);
		}

		/// <summary> Gets bikes available and bikes occupied. </summary>
		/// <returns>Collection of bikes.</returns>
		public async Task<Result<BikeCollection>> GetBikesAsync()
		{
			var bikesAvailableResponse = await Server.GetBikesAvailable();

			if (bikesAvailableResponse.Source == typeof(CopriCallsMonkeyStore)
				|| bikesAvailableResponse.Exception != null)
			{
				// Bikes available were read from cache ==> get bikes occupied from cache as well to avoid inconsistencies.
				Log.ForContext<CachedQueryLoggedIn>().Debug("Bikes available read from cache. Reading bikes occupied from cache as well.");
				return new Result<BikeCollection>(
					bikesAvailableResponse.Source,
					UpdaterJSON.GetBikesAll(
						bikesAvailableResponse.Response?.bikes?.Values,
						(await Server.GetBikesOccupied(true)).Response?.bikes_occupied?.Values,
						Mail,
						DateTimeProvider),
					bikesAvailableResponse.GeneralData,
					bikesAvailableResponse.Exception);
			}

			var bikesOccupiedResponse = await Server.GetBikesOccupied();
			if (bikesOccupiedResponse.Source == typeof(CopriCallsMonkeyStore)
				|| bikesOccupiedResponse.Exception != null)
			{
				// Bikes occupied were read from cache ==> get bikes available from cache as well to avoid inconsistencies
				Log.ForContext<CachedQueryLoggedIn>().Debug("Bikes occupied read from cache. Reread bikes available from cache as well.");
				return new Result<BikeCollection>(
					bikesOccupiedResponse.Source,
					UpdaterJSON.GetBikesAll(
						(await Server.GetBikesAvailable(true)).Response?.bikes?.Values,
						bikesOccupiedResponse.Response?.bikes_occupied?.Values,
						Mail,
						DateTimeProvider),
					bikesOccupiedResponse.GeneralData,
					bikesOccupiedResponse.Exception);
			}

			// Both types bikes could read from copri =>  update cache
			Server.AddToCache(bikesAvailableResponse);
			Server.AddToCache(bikesOccupiedResponse);

			Log.ForContext<CachedQueryLoggedIn>().Debug("Bikes available and occupied read successfully from server.");
			return new Result<BikeCollection>(
				bikesAvailableResponse.Source,
				UpdaterJSON.GetBikesAll(
					bikesAvailableResponse.Response?.bikes?.Values,
					bikesOccupiedResponse.Response?.bikes_occupied?.Values,
					Mail,
					DateTimeProvider),
				bikesAvailableResponse.GeneralData,
				bikesAvailableResponse.Exception != null || bikesOccupiedResponse.Exception != null ? new AggregateException(new[] { bikesAvailableResponse.Exception, bikesOccupiedResponse.Exception }) : null);
		}
	}
}