using System;
using System.Linq;
using System.Threading.Tasks;
using TINK.Model.Bike;
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 readonly ICachedCopriServer server;

        /// <summary>Constructs a copri query object.</summary>
        /// <param name="p_oCopriServer">Server which implements communication.</param>
        public CachedQueryLoggedIn(ICopriServerBase p_oCopriServer,
            string p_strSessionCookie,
            string p_strMail,
            Func<DateTime> p_oDateTimeProvider) : base(p_oCopriServer, p_strSessionCookie, p_strMail, p_oDateTimeProvider)
        {
            server = p_oCopriServer as ICachedCopriServer;
            if (server == null)
            {
                throw new ArgumentException($"Copri server is not of expected typ. Type detected is {p_oCopriServer.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,
                            (await server.GetBikesOccupied(true)).Response,
                            Mail,
                            DateTimeProvider)),
                    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,
                        (await server.GetBikesOccupied(true)).Response,
                        Mail,
                        DateTimeProvider)),
                    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,
                            bikesOccupiedResponse.Response,
                            Mail,
                            DateTimeProvider)),
                    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,
                        bikesOccupiedResponse.Response,
                        Mail,
                        DateTimeProvider);

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

        /// <summary> Gets bikes occupied. </summary>
        /// <returns>Collection of bikes.</returns>
        public async Task<Result<BikeCollection>> GetBikesOccupiedAsync()
        {
            var result = await server.GetBikesOccupied();
            server.AddToCache(result);
            return new Result<BikeCollection>(result.Source, result.Response.GetBikesOccupied(Mail, DateTimeProvider), result.Exception);
        }

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

            if (l_oBikesAvailableResponse.Source == typeof(CopriCallsMonkeyStore)
                || l_oBikesAvailableResponse.Exception != null)
            {
                // Bikes avilable were read from cache ==> get bikes occupied from cache as well to avoid inconsistencies
                return new Result<BikeCollection>(
                    l_oBikesAvailableResponse.Source,
                    UpdaterJSON.GetBikesAll(
                        l_oBikesAvailableResponse.Response,
                        (await server.GetBikesOccupied(true)).Response,
                        Mail,
                        DateTimeProvider),
                    l_oBikesAvailableResponse.Exception);
            }

            var l_oBikesOccupiedResponse = await server.GetBikesOccupied();
            if (l_oBikesOccupiedResponse.Source == typeof(CopriCallsMonkeyStore)
                || l_oBikesOccupiedResponse.Exception != null)
            {
                // Bikes occupied were read from cache ==> get bikes available from cache as well to avoid inconsistencies
                return new Result<BikeCollection>(
                    l_oBikesOccupiedResponse.Source,
                    UpdaterJSON.GetBikesAll(
                        (await server.GetBikesAvailable(true)).Response,
                        l_oBikesOccupiedResponse.Response,
                        Mail,
                        DateTimeProvider),
                    l_oBikesOccupiedResponse.Exception);

            }

            // Both types bikes could read from copri =>  update cache
            server.AddToCache(l_oBikesAvailableResponse);
            server.AddToCache(l_oBikesOccupiedResponse);

            return new Result<BikeCollection>(
                l_oBikesAvailableResponse.Source,
                UpdaterJSON.GetBikesAll(l_oBikesAvailableResponse.Response, l_oBikesOccupiedResponse.Response, Mail, DateTimeProvider),
                l_oBikesAvailableResponse.Exception != null || l_oBikesOccupiedResponse.Exception != null ? new AggregateException(new[] { l_oBikesAvailableResponse.Exception, l_oBikesOccupiedResponse.Exception }) : null);
        }      
    }
}