using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using FarmmapsApi.Models;
using FarmmapsApi.Services;
using FarmmapsHaulmkilling.Models;
using Microsoft.Extensions.Logging;
using static FarmmapsApi.Extensions;
using static FarmmapsApiSamples.Constants;

namespace FarmmapsHaulmkilling
{
    public class HaulmkillingService
    {
        private readonly ILogger<HaulmkillingService> _logger;
        private readonly FarmmapsApiService _farmmapsApiService;
        private readonly GeneralService _generalService;

        public HaulmkillingService(ILogger<HaulmkillingService> logger, FarmmapsApiService farmmapsApiService,
            GeneralService generalService)
        {
            _logger = logger;
            _farmmapsApiService = farmmapsApiService;
            _generalService = generalService;
        }
        
        /// <summary>
        /// Gets the list of available haulmkilling agents
        /// </summary>
        /// <returns>List of haulmkilling agents</returns>
        public async Task<List<HaulmkillingAgent>> GetHaulmkillingAgents()
        {
            var itemType = "vnd.farmmaps.package.vra.haulmkilling";
            var vraHerbicideDataItems = await _farmmapsApiService.GetItemsAsync(string.Empty, itemType);

            var item = vraHerbicideDataItems.FirstOrDefault();
            if (item == null)
                return null;

            return item.Data.ContainsKey("agents") ? item.Data["agents"].ToObject<List<HaulmkillingAgent>>() : null;
        }
        
        /// <summary>
        /// Creates an haulmkilling application map
        /// </summary>
        /// <param name="cropfieldItem">The context cropfield item to use</param>
        /// <param name="inputItem">The geotiff item to use</param>
        /// <param name="inputType">WDVI or NDVI</param>
        /// <param name="agentName">One of the available agents</param>
        /// <param name="selectedOption">One of the available options</param>
        /// <returns>Haulmkilling application map item</returns>
        public async Task<Item> CalculateApplicationMapAsync(Item cropfieldItem, Item inputItem, string inputType,
            string agentName, string selectedOption)
        {
            var taskRequest = new TaskRequest()
            {
                TaskType = "vnd.farmmaps.task.vrahaulmkilling"
            };
            taskRequest.attributes["inputCode"] = inputItem.Code;
            taskRequest.attributes["inputType"] = inputType;
            taskRequest.attributes["agentName"] = agentName;
            taskRequest.attributes["selectedOption"] = selectedOption;

            var taskCode = await _farmmapsApiService.QueueTaskAsync(cropfieldItem.Code, taskRequest);
            await PollTask(TimeSpan.FromSeconds(3), async (tokenSource) =>
            {
                _logger.LogInformation("Checking vrahaulmkilling task status");
                var itemTaskStatus = await _farmmapsApiService.GetTaskStatusAsync(cropfieldItem.Code, taskCode);
                if (itemTaskStatus.IsFinished)
                    tokenSource.Cancel();
            });
            
            var itemTask = await _farmmapsApiService.GetTaskStatusAsync(cropfieldItem.Code, taskCode);
            if (itemTask.State == ItemTaskState.Error)
            {
                _logger.LogError($"Something went wrong with task execution: {itemTask.Message}");
                return null;
            }

            var itemName = $"VRAHaulmkilling {agentName}";
            var applianceMapItem = await _generalService.FindChildItemAsync(cropfieldItem.Code,
                GEOTIFF_PROCESSED_ITEMTYPE, itemName, 
                i => i.Updated >= itemTask.Finished &&
                            i.Name.ToLower().Contains(itemName.ToLower()));
            
            if (applianceMapItem == null)
            {
                _logger.LogError("Could not find the VRAHaulmkilling geotiff child item under cropfield");
                return null;
            }

            return applianceMapItem;
        }
    }
}