using AsbCloudApp.Data;
using AsbCloudApp.Services;
using AsbCloudDb.Model;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace AsbCloudInfrastructure.Services
{
    public class WellSectionService : IWellSectionService
    {
        private readonly IAsbCloudDbContext db;

        public WellSectionService(IAsbCloudDbContext db)
        {
            this.db = db;
        }

        public async Task<IEnumerable<WellSectionDto>> GetSectionsByWellIdAsync(int idWell,
            CancellationToken token = default)
        {
            var wellOperations = await (from w in db.WellOperations
                                        where w.IdWell == idWell
                                        select w)
                                        .Include(w => w.WellSectionType)
                                        .ToListAsync(token)
                                        .ConfigureAwait(false);

            if (!wellOperations.Any())
                return null;

            var wellOperationsGroupedBySections = wellOperations
                .GroupBy(op => op.IdWellSectionType).ToList();

            var wellOperationsClone = wellOperations.Select(o => o.ShallowCopy()).ToList();

            wellOperationsClone.ForEach(op =>
            {
                op.IdWellSectionType = 1;
                op.WellSectionType = new WellSectionType { Caption = "Обобщенное по скважине" };
            });

            var groupedWellOperationsClone = wellOperationsClone.GroupBy(o => o.IdWell);

            wellOperationsGroupedBySections.Add(groupedWellOperationsClone.First());

            var depthsPlanList = GetWellDepthStats(wellOperationsGroupedBySections, 0).ToList();

            var depthsFactList = GetWellDepthStats(wellOperationsGroupedBySections, 1).ToList();

            var durationsPlanList = GetWellDurationStats(wellOperationsGroupedBySections, 0).ToList();

            var durationsFactList = GetWellDurationStats(wellOperationsGroupedBySections, 1).ToList();

            var mechSpeedsPlanList = GetWellStats(wellOperationsGroupedBySections, 1001, 0).ToList();

            var mechSpeedsFactList = GetWellStats(wellOperationsGroupedBySections, 1001, 1).ToList();

            var bhaUpSpeedPlanList = GetWellStats(wellOperationsGroupedBySections, 1046, 0).ToList();

            var bhaUpSpeedFactList = GetWellStats(wellOperationsGroupedBySections, 1046, 1).ToList();

            var bhaDownSpeedPlanList = GetWellStats(wellOperationsGroupedBySections, 1047, 0).ToList();

            var bhaDownSpeedFactList = GetWellStats(wellOperationsGroupedBySections, 1047, 1).ToList();

            var casingDownPlanList = GetWellStats(wellOperationsGroupedBySections, 1048, 0).ToList();

            var casingDownFactList = GetWellStats(wellOperationsGroupedBySections, 1048, 1).ToList();

            var routeSpeedsPlan = GetWellRouteSpeedStats(wellOperationsGroupedBySections, 0).ToList();

            var routeSpeedsFact = GetWellRouteSpeedStats(wellOperationsGroupedBySections, 1).ToList();

            var dtos = new List<WellSectionDto>();

            for (int i = 0; i < wellOperationsGroupedBySections.Count; i++)
            {
                var dto = new WellSectionDto
                {
                    SectionType = wellOperationsGroupedBySections[i]
                                  .FirstOrDefault().WellSectionType.Caption,
                    WellDepthPlan = depthsPlanList[i],
                    WellDepthFact = depthsFactList[i],
                    DurationPlan = durationsPlanList[i],
                    DurationFact = durationsFactList[i],
                    MechSpeedPlan = mechSpeedsPlanList[i],
                    MechSpeedFact = mechSpeedsFactList[i],
                    BhaUpSpeedPlan = bhaUpSpeedPlanList[i],
                    BhaUpSpeedFact = bhaUpSpeedFactList[i],
                    BhaDownSpeedPlan = bhaDownSpeedPlanList[i],
                    BhaDownSpeedFact = bhaDownSpeedFactList[i],
                    CasingDownSpeedPlan = casingDownPlanList[i],
                    CasingDownSpeedFact = casingDownFactList[i],
                    RouteSpeedPlan = routeSpeedsPlan[i],
                    RouteSpeedFact = routeSpeedsFact[i]
                };

                dtos.Add(dto);
            }

            return dtos.OrderBy(d => d.WellDepthPlan);
        }

        private static IEnumerable<double> GetWellDepthStats(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations, int type)
        {
            return groupedOperations.Select(group => group.Where(o => o.IdType == type)
                .DefaultIfEmpty().Max(w => w?.WellDepth ?? 0.0));
        }


        private static IEnumerable<double> GetWellDurationStats(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations, int type)
        {
            var durationsPlanFactsBase = groupedOperations.Select(group => new
            {
                DurationMax = group.Where(o => o.IdType == type).DefaultIfEmpty()
                    .Max(op => op?.StartDate + TimeSpan.FromHours(op?.DurationHours ?? 0)) ?? default,

                DurationMin = group.Where(o => o.IdType == type).DefaultIfEmpty()
                    .Min(op => op?.StartDate) ?? default
            });

            return durationsPlanFactsBase.Select(o =>
                (o.DurationMax - o.DurationMin).TotalHours);
        }

        private static IEnumerable<double> GetWellStats(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations, int idCategory, int type)
        {
            var mechSpeedBase = groupedOperations.Select(g =>
            (
                DepthDifferenceSum: g.Where(o => o.IdType == type && o.IdCategory == idCategory)
                    .Select((el, i) => i > 0 ? el.WellDepth - g.ElementAt(i - 1).WellDepth : 0).Sum(),
                DurationDifferenceSum: g.Where(o => o.IdType == type && o.IdCategory == idCategory)
                    .Select(el => el.DurationHours).Sum()
            ));

            return CalculateResult(mechSpeedBase);
        }

        private static IEnumerable<double> GetWellRouteSpeedStats(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations, int type)
        {
            var bhaRaiseDecreaseCollection = new List<(WellOperation FirstBhaPositionDecrease,
                                                       WellOperation LastBhaPositionIncrease)>();

            foreach (var group in groupedOperations)
            {
                var firstBhaPositionDecrease = group.Any(o => o.IdCategory == 1046 && o.IdType == type)
                                               ? group.First(o => o.IdCategory == 1046 && o.IdType == type)
                                               : null;

                var lastBhaPositionIncrease = group.Any(o => o.IdCategory == 1047 && o.IdType == type)
                                              ? group.Last(o => o.IdCategory == 1047 && o.IdType == type)
                                              : null;

                bhaRaiseDecreaseCollection.Add((firstBhaPositionDecrease, lastBhaPositionIncrease));
            }

            var routeSpeedsBase = bhaRaiseDecreaseCollection.Select(el =>
            (
                RouteDepth: (el.LastBhaPositionIncrease?.WellDepth - el.FirstBhaPositionDecrease?.WellDepth) ?? 0,
                RouteDuration: (el.LastBhaPositionIncrease?.StartDate +
                                     TimeSpan.FromHours(el.LastBhaPositionIncrease?.DurationHours ?? 0) -
                                     el.FirstBhaPositionDecrease?.StartDate)?.TotalHours ?? 0
            ));

            return CalculateResult(routeSpeedsBase);
        }

        private static IEnumerable<double> CalculateResult(IEnumerable<(double,
            double)> rawData)
        {
            return rawData.Select(el =>
                (el.Item1 / el.Item2) is double.NaN
                ? 0
                : (el.Item1 / el.Item2)
            );
        }

    }
}