using BeWo.Data.Access;
using BeWo.Data.Entities;
using BeWo.Service.Core;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Globalization;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using Task = System.Threading.Tasks.Task;

namespace BeWo.Service.ServiceUtils.DistanceCalculator
{
    public class OpenrouteServiceAPI : IDistanceAPI
    {
        public class ResponseGeo
        {
            public Feature[] Features { get; set; }

            public class Feature
            {
                public string Type { get; set; }
                public Geometry Geometry { get; set; }
            }

            public class Geometry
            {
                public string Type { get; set; }
                public decimal[] Coordinates { get; set; }
            }
        }

        public class ResponseMatrix
        {
            public decimal[,] Durations { get; set; }
            public decimal[,] Distances { get; set; }
        }

        private string Key { get; set; }
        private string GeoUrl { get; set; }
        private string Url { get; set; }

        private AddressRouteMatrix Matrix { get; set; }

        private Address[] OriginAddresses { get; set; }
        private Address[] DestinationAddresses { get; set; }

        public OpenrouteServiceAPI()
        {
            var appSettings = ConfigurationManager.AppSettings;

			Url = appSettings["OpenrouteServiceApiUrl"];
			if (string.IsNullOrEmpty(Url))
            {
                throw new Exception("OpenrouteServiceApiUrl is not set in AppSettings.");
            }

            Key = MergedConfig.GetSecretSetting("OpenrouteServiceApiKey");
			if (string.IsNullOrEmpty(Key))
            {
                throw new Exception("OpenrouteServiceApiKey is not set.");
            }

			GeoUrl = appSettings["OpenrouteServiceApiUrlGeocode"];
			if (string.IsNullOrEmpty(GeoUrl))
            {
                throw new Exception("OpenrouteServiceApiUrlGeocode is not set in AppSettings.");
			}			
        }

        public void RequestMissingData(ref AddressRouteMatrix matrix, IEnumerable<Address> origins, IEnumerable<Address> destinations)
        {
            Matrix = matrix;
            OriginAddresses = origins.ToArray();
            DestinationAddresses = destinations.ToArray();

            if (!(origins.Any() && destinations.Any()))
                throw new NotImplementedException("Keine Addresse angefragt");

            LoadCoordinates().Wait();

            var task = GetMatrix();

            task.Wait();

            if (task.Exception is object)
            {
                throw task.Exception;
            }
        }

        public async Task LoadCoordinates()
        {
            // Update Koordinaten
            var items = OriginAddresses.Union(DestinationAddresses).ToHashSet();
            foreach (var item in items)
            {
                if (item.L_Version is object && item.L_Version == item.Version)
                    continue;

                await LoadCoordinate(item);

                DAOFactory.GenericDAO.Update(item);
            }
        }

        public async Task LoadCoordinate(Address address)
        {
            using (var client = new HttpClient())
            {
                var uri = new Uri(GetGeocodeUrl(address));

                client.DefaultRequestHeaders.Clear();
                client.DefaultRequestHeaders.TryAddWithoutValidation("accept", "application/json; charset=utf-8");
                client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json; charset=utf-8");

                using (var response = await client.GetAsync(uri))
                {
                    string responseData = await response.Content.ReadAsStringAsync();

                    if (response.IsSuccessStatusCode)
                    {
                        try
                        {
                            var data = JsonConvert.DeserializeObject<ResponseGeo>(responseData);

                            address.Longitude = data.Features[0].Geometry.Coordinates[0];
                            address.Latitude = data.Features[0].Geometry.Coordinates[1];
                            address.L_Version = address.Version.Value + 1;

                            return;
                        }
                        catch (Exception e)
                        {
                            throw e;
                        }

                    }
                    else
                    {
                        throw new Exception("OpenrouteServiceAPI failed with status code: " + response.StatusCode + " |||Data: " + responseData);
                    }
                }
            }
        }

        public async Task<AddressRouteMatrix> GetMatrix()
        {
            using (var client = new HttpClient())
            {
                var uri = new Uri(Url);

                client.DefaultRequestHeaders.Clear();
                client.DefaultRequestHeaders.TryAddWithoutValidation("accept", "application/json; charset=utf-8");
                client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json; charset=utf-8");
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", Key);

                using (var content = new StringContent(GetMatrixBodyContentString()))
                //using (var content = new StringContent("{\"locations\":[[48.477473,9.70093],[49.153868,9.207916]]}"))
                {
                    content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
                    using (var response = await client.PostAsync(uri, content))
                    {
                        string responseData = await response.Content.ReadAsStringAsync();

                        if (response.IsSuccessStatusCode)
                        {
                            var data = JsonConvert.DeserializeObject<ResponseMatrix>(responseData);

                            return FillMatrix(data);
                        }
                        else
                        {
                            throw new Exception("OpenrouteServiceAPI failed with status code: " + response.StatusCode + " |||Data: " + responseData);
                        }
                    }
                }
            }
        }

        public AddressRouteMatrix FillMatrix(ResponseMatrix response)
        {
            for (int i = 0; i < response.Durations.GetLength(0); i++)
            {
                for (int j = 0; j < response.Durations.GetLength(1); j++)
                {
                    var distance = response.Distances[i, j];
                    var duration = response.Durations[i, j];

                    var origin = OriginAddresses[i];
                    var destination = DestinationAddresses[j];

                    var route = Matrix.GetRoute(origin, destination);

                    route.Distance_in_meter = (int) (distance * 1000);
                    route.Time_in_seconds = (int) duration;
                }
            }

            return Matrix;
        }

        private string GetGeocodeUrl(Address address)
        {
            var html = HttpUtility.UrlEncode(AddressRouteManager.AddressToString(address));
            return $"{GeoUrl}?api_key={Key}&text={html}&sources=openstreetmap&size=1";
        }

        private string GetMatrixBodyContentString()
        {
            var sb = new StringBuilder();

            var origins = OriginAddresses.Select(GetCoordinates);
            var olen = OriginAddresses.Count();
            var destination = DestinationAddresses.Select(GetCoordinates);
            var dlen = DestinationAddresses.Count();

            sb.Append("{\"locations\":");
            sb.Append("[");
            sb.Append(string.Join(",", origins.Union(destination)));
            sb.Append("]");

            sb.Append(",\"metrics\":[\"distance\",\"duration\"]");
            sb.Append(",\"units\":\"km\"");

            sb.Append(",\"sources\":");
            sb.Append(GetList(0, olen - 1));

            sb.Append(",\"destinations\":");
            sb.Append(GetList(olen, olen + dlen - 1));

            sb.Append("}");

            return sb.ToString();
        }

        private string GetCoordinates(Address add) => $"[{add.Longitude.Value.ToString(new CultureInfo("en-US"))},{add.Latitude.Value.ToString(new CultureInfo("en-US"))}]";

        private string GetList(int x, int y)
        {
            if (y < x)
                throw new ArgumentException($"y({y}) darf nicht kleiner als x({x}) sein");

            var diff = y - x;
            var list = new int[diff + 1];

            for (int i = 0; i <= diff; i++)
            {
                list[i] = x + i;
            }

            return "[" + string.Join(",", list) + "]";
        }
    }
}