using System;
using System.Linq;
using System.Threading.Tasks;
using FarmmapsApi.Models;
using FarmmapsApi.Services;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json.Linq;
using static FarmmapsApi.Extensions;

namespace FarmmapsApiSamples
{
    public class NbsApp : IApp
    {
        private const string USERINPUT_ITEMTYPE = "vnd.farmmaps.itemtype.user.input";
        private const string VRANBS_TASK = "vnd.farmmaps.task.vranbs";
        
        private readonly ILogger<NbsApp> _logger;
        private readonly FarmmapsApiService _farmmapsApiService;

        public NbsApp(ILogger<NbsApp> logger, FarmmapsApiService farmmapsApiService)
        {
            _logger = logger;
            _farmmapsApiService = farmmapsApiService;

            farmmapsApiService.EventCallback += OnEvent;
        }

        private void OnEvent(EventMessage @event)
        {
            _logger.LogInformation(@event.EventType);
        }

        public async Task RunAsync()
        {
            try
            {
                _logger.LogInformation("NBS sample app started");
                
                await _farmmapsApiService.AuthenticateAsync();

                _logger.LogInformation("Authenticated client credentials");

                var roots = await _farmmapsApiService.GetCurrentUserRootsAsync();
                var myDriveRoot = roots.SingleOrDefault(r => r.Name == "My drive");

                if (myDriveRoot != null)
                {
                    var cropfieldItem = await GetOrCreateCropfieldItem(myDriveRoot.Code);
                    var targetN = await CalculateTargetN(cropfieldItem, 60);
                    
                    _logger.LogInformation($"TargetN: {targetN}");
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
            }
        }

        private async Task<Item> GetOrCreateCropfieldItem(string parentItemCode)
        {
            var cropfieldItems = await
                _farmmapsApiService.GetItemChildrenAsync(parentItemCode, "vnd.farmmaps.itemtype.cropfield");

            if (cropfieldItems.Count > 0) 
                return cropfieldItems[0];

            var currentYear = new DateTime(DateTime.UtcNow.Year, 1, 1);
            var cropfieldItemRequest = new ItemRequest()
            {
                ParentCode = parentItemCode,
                ItemType = "vnd.farmmaps.itemtype.cropfield",
                Name = "cropfield for VRA",
                DataDate = currentYear,
                DataEndDate = currentYear.AddYears(1),
                Data = JObject.FromObject(new
                    {startDate = currentYear, endDate = currentYear.AddYears(1)}),
                Geometry = JObject.Parse(
                    @"{""type"":""Polygon"",""coordinates"":[[[6.09942873984307,53.070025028087],[6.09992507404607,53.0705617890585],[6.10036959220086,53.0710679529031],[6.10065149010421,53.0714062774307],[6.10087493644271,53.0716712354474],[6.10091082982487,53.0716936039203],[6.10165087441291,53.0712041549161],[6.10204994718318,53.0709349338005],[6.10263143118855,53.0705789370018],[6.10311578125011,53.0702657538294],[6.10331686552072,53.0701314102389],[6.103326530575,53.070119463569],[6.10309137950343,53.0699829669055],[6.10184241586523,53.0692902201371],[6.10168497998891,53.0691984306747],[6.10092987659869,53.0694894453514],[6.09942873984307,53.070025028087]]]}")
            };

            return await _farmmapsApiService.CreateItemAsync(cropfieldItemRequest);
        }

        private async Task<double> CalculateTargetN(Item cropfieldItem, int targetYield)
        {
            var targetNItems = await
                _farmmapsApiService.GetItemChildrenAsync(cropfieldItem.ParentCode, USERINPUT_ITEMTYPE);

            Item targetNItem;
            if (targetNItems.Count == 0)
            {
                _logger.LogInformation("Creating targetN item");
                var itemRequest = CreateTargetNItemRequest(cropfieldItem.ParentCode);
                targetNItem = await _farmmapsApiService.CreateItemAsync(itemRequest);
            }
            else
            {
                targetNItem = targetNItems[0];
            }

            _logger.LogInformation($"Calculating targetN with targetYield: {targetYield}");
            
            var nbsTargetNRequest = new TaskRequest {TaskType = VRANBS_TASK};
            nbsTargetNRequest.attributes["operation"] = "targetn";
            nbsTargetNRequest.attributes["inputCode"] = targetNItem.Code;
            nbsTargetNRequest.attributes["inputType"] = "irmi";
            nbsTargetNRequest.attributes["purposeType"] = "consumption";
            nbsTargetNRequest.attributes["targetYield"] = targetYield.ToString();
            string itemTaskCode = await _farmmapsApiService.QueueTaskAsync(cropfieldItem.Code, nbsTargetNRequest);
            
            await PollTask(TimeSpan.FromSeconds(3), async (tokenSource) =>
            {
                var itemTask = await _farmmapsApiService.GetTaskStatusAsync(cropfieldItem.Code, itemTaskCode);

                if (itemTask.State != ItemTaskState.Processing && itemTask.State != ItemTaskState.Scheduled)
                    tokenSource.Cancel();
            });

            var item = await _farmmapsApiService.GetItemAsync(targetNItem.Code);
            if (item.Data.ContainsKey("TargetN"))
                return item.Data["TargetN"].Value<double>();
            
            return 0;
        }

        private ItemRequest CreateTargetNItemRequest(string parentItemCode)
        {
            return new ItemRequest()
            {
                ParentCode = parentItemCode,
                ItemType = USERINPUT_ITEMTYPE,
                Name = "TargetN",
                DataDate = DateTime.UtcNow
            };
        }
    }
}