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

namespace AsbCloudInfrastructure.Services
{
    public class WellSectionService: IWellSectionService
    {
        private readonly IAsbCloudDbContext db;
        private readonly CacheTable<WellSectionType> cachedSectionsTypes;

        public WellSectionService(IAsbCloudDbContext db, Cache.CacheDb cache)
        {
            this.db = db;
            cachedSectionsTypes = cache.GetCachedTable<WellSectionType>((DbContext)db);
        }

        public Task<string[]> GetTypesAsync(CancellationToken token) =>
            db.WellSectionTypes.Select(e => e.Caption).Distinct().AsNoTracking().ToArrayAsync(token);

        public async Task<PaginationContainer<WellSectionDto>> GetSectionsByWellIdAsync(int idWell,
            int skip, int take, CancellationToken token = default)
        {
            var groupedWellOperationsQuery = (from w in db.WellOperations
                                              where w.IdWell == idWell
                                              select w)
                                              .Include(w => w.WellSectionType)
                                              .GroupBy(op => op.IdWellSectionType);

            if (skip > 0)
                groupedWellOperationsQuery = groupedWellOperationsQuery.Skip(skip);

            var wellOperationsGroupedBySections = await groupedWellOperationsQuery
                .Take(take).ToListAsync(token)
                .ConfigureAwait(false);

            var result = new PaginationContainer<WellSectionDto>
            {
                Skip = skip,
                Take = take,
                Count = wellOperationsGroupedBySections.Count
            };

            if (!wellOperationsGroupedBySections.Any())
                return result;

            // TODO: Подставить нормальные ID операций спускоа, подъема и т.д.
            var depthsPlanFactList = GetWellDepthPlanFact(wellOperationsGroupedBySections).ToList();

            var durationsPlanFactList = GetWellDurationPlanFact(wellOperationsGroupedBySections).ToList();

            var mechSpeedsList = GetWellMechSpeedPlanFact(wellOperationsGroupedBySections).ToList();

            var bhaUpSpeedList = GetWellBhaUpSpeedPlanFact(wellOperationsGroupedBySections).ToList();

            var bhaDownSpeedList = GetWellBhaDownSpeedPlanFact(wellOperationsGroupedBySections).ToList();

            var casingDownList = GetWellCasingDownPlanFact(wellOperationsGroupedBySections).ToList();

            var routeSpeeds = GetWellRouteSpeedsPlanFact(wellOperationsGroupedBySections).ToList();

            var dtos = new List<WellSectionDto>();

            for(int i = 0; i <= wellOperationsGroupedBySections.Count; i++)
            {
                var dto = new WellSectionDto
                {
                    SectionType = wellOperationsGroupedBySections[i].FirstOrDefault().OperationCategory.Name,
                    WellDepthPlan = depthsPlanFactList[i].DepthPlan,
                    WellDepthFact = depthsPlanFactList[i].DepthFact,
                    DurationPlan = durationsPlanFactList[i].DurationPlan,
                    DurationFact = durationsPlanFactList[i].DurationFact,
                    MechSpeedPlan = mechSpeedsList[i].MechSpeedPlan,
                    MechSpeedFact = mechSpeedsList[i].MechSpeedFact,
                    BhaUpSpeedPlan = bhaUpSpeedList[i].BhaUpSpeedPlan,
                    BhaUpSpeedFact = bhaUpSpeedList[i].BhaUpSpeedFact,
                    BhaDownSpeedPlan = bhaDownSpeedList[i].BhaDownSpeedPlan,
                    BhaDownSpeedFact = bhaDownSpeedList[i].BhaDownSpeedFact,
                    CasingDownSpeedPlan = casingDownList[i].CasingDownSpeedPlan,
                    CasingDownSpeedFact = casingDownList[i].CasingDownSpeedFact,
                    RouteSpeedPlan = routeSpeeds[i].RouteSpeedPlan,
                    RouteSpeedFact = routeSpeeds[i].RouteSpeedFact
                };

                dtos.Add(dto);
            }

            result.Items = dtos;

            return result;
        }

        public async Task<WellSectionDto> GetSectionByWellIdAsync(int id, CancellationToken token = default)
        {
            var entity = await db.WellSections
                .Include(s => s.WellSectionType)
                .FirstOrDefaultAsync(e => e.Id == id, token)
                .ConfigureAwait(false);

            if (entity is null)
                return null;
            
            var dto = entity.Adapt<WellSectionDto>();
            dto.SectionType = entity.WellSectionType.Caption;
            return dto;
        }

        //public async Task<WellSectionDto> InsertAsync(WellSectionDto item, int idWell, CancellationToken token = default)
        //{
        //    var sectionType = await GetWellSectionTypeFromCacheAndAssertAsync(item.SectionType);

        //    var entity = item.Adapt<WellSection>();
        //    entity.Id = default;
        //    entity.IdWell = idWell;
        //    entity.IdWellSectionType = sectionType.Id;
        //    var dbEntity = dbSet.Add(entity);
        //    await context.SaveChangesAsync(token).ConfigureAwait(false);

        //    var dto = dbEntity.Entity.Adapt<WellSectionDto>();
        //    dto.SectionType = sectionType.Caption;
        //    return dto;
        //}

        //public async Task<IEnumerable<WellSectionDto>> InsertRangeAsync(int idWell, IEnumerable<WellSectionDto> items, CancellationToken token = default)
        //{
        //    var dbEntities = new Microsoft.EntityFrameworkCore.ChangeTracking.EntityEntry<WellSection>[items.Count()];

        //    for (int i = 0; i < dbEntities.Length; i++)
        //    {
        //        var sectionType = await GetWellSectionTypeFromCacheAndAssertAsync(items.ElementAt(i).SectionType, token);
        //        var item = items.ElementAt(i).Adapt<WellSection>();
        //        item.IdWell = idWell;
        //        item.IdWellSectionType = sectionType.Id;
        //        dbEntities[i] = dbSet.Add(item);
        //    }

        //    await context.SaveChangesAsync(token).ConfigureAwait(false);

        //    var dtos = dbEntities.Select((e) => {
        //        var dto = e.Entity.Adapt<WellSectionDto>();
        //        var sectionType = cachedSectionsTypes.FirstOrDefault(s => s.Id == e.Entity.IdWellSectionType);
        //        dto.SectionType = sectionType.Caption;
        //        return dto;
        //    });

        //    return dtos;
        //}

        //public async Task<WellSectionDto> UpdateAsync(int idWell, int idSection, WellSectionDto item, CancellationToken token = default)
        //{
        //    var sectionType = await GetWellSectionTypeFromCacheAndAssertAsync(item.SectionType, token)
        //        .ConfigureAwait(false);

        //    var entity = item.Adapt<WellSection>();
        //    entity.Id = idSection;
        //    entity.IdWell = idWell;
        //    entity.IdWellSectionType = sectionType.Id;
        //    var dbEntity = dbSet.Update(entity);
        //    await context.SaveChangesAsync(token).ConfigureAwait(false);

        //    var dto = dbEntity.Entity.Adapt<WellSectionDto>();
        //    dto.SectionType = sectionType.Caption;
        //    return dto;
        //}

        //public Task<int> DeleteAsync(IEnumerable<int> ids, CancellationToken token = default)
        //{
        //    var entities = dbSet.Where(e => ids.Contains(e.Id));            
        //    dbSet.RemoveRange(entities);
        //    return context.SaveChangesAsync(token);
        //}

        private static IEnumerable<(double DepthPlan, double DepthFact)> GetWellDepthPlanFact(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations)
        {
            return groupedOperations
                .Select(group =>
                (
                    DepthPlan: group.Where(o => o.Type == 0).Max(w => w.WellDepth),
                    DepthFact: group.Where(o => o.Type == 1).Max(w => w.WellDepth)
                ));
        }

        private static IEnumerable<(double DurationPlan, double DurationFact)> GetWellDurationPlanFact(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations)
        {
            var durationsPlanFactsBase = groupedOperations.Select(group => new
            {
                DurationMaxPlan = group.Where(o => o.Type == 0).Select(op => op.StartDate +
                    TimeSpan.FromHours(op.DurationHours)).Max(),

                DurationMinPlan = group.Where(o => o.Type == 0).Min(i => i.StartDate),

                DurationMaxFact = group.Where(o => o.Type == 1).Select(op => op.StartDate +
                    TimeSpan.FromHours(op.DurationHours)).Max(),

                DurationMinFact = group.Where(o => o.Type == 1).Min(i => i.StartDate)
            });

            return durationsPlanFactsBase.Select(o =>
            (
                DurationPlan: (o.DurationMaxPlan - o.DurationMinPlan).TotalHours,
                DurationFact: (o.DurationMaxFact - o.DurationMinFact).TotalHours
            ));
        }

        private static IEnumerable<(double MechSpeedPlan, double MechSpeedFact)> GetWellMechSpeedPlanFact(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations)
        {
            var mechSpeedBase = groupedOperations.Select(g => new
            {
                DepthChangePlanSum = g.Where(o => o.Type == 0 && o.IdOperationCategory == 1)
                    .Select((el, i) => i > 0 ? el.WellDepth - g.ElementAt(i - 1).WellDepth : 0).Sum(),
                DurationsPlanSum = g.Where(o => o.Type == 0 && o.IdOperationCategory == 1)
                    .Select(el => el.DurationHours).Sum(),
                DepthChangeFactSum = g.Where(o => o.Type == 1 && o.IdOperationCategory == 1)
                    .Select((el, i) => i > 0 ? el.WellDepth - g.ElementAt(i - 1).WellDepth : 0).Sum(),
                DurationsFactSum = g.Where(o => o.Type == 1 && o.IdOperationCategory == 1)  
                    .Select(el => el.DurationHours).Sum()
            });

            return mechSpeedBase.Select(el =>
            (
                MechSpeedPlan: el.DepthChangePlanSum / el.DurationsPlanSum,
                MechSpeedFact: el.DepthChangeFactSum / el.DurationsFactSum
            ));
        }

        private static IEnumerable<(double BhaUpSpeedPlan, double BhaUpSpeedFact)> GetWellBhaUpSpeedPlanFact(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations)
        {
            var bhaUpSpeedBase = GetParams(groupedOperations, 2);

            return bhaUpSpeedBase.Select(el =>
            (
                BhaUpSpeedPlan: el.DepthDifferencePlanSum / el.DurationDifferencePlanSum,
                BhaUpSpeedFact: el.DepthDifferenceFactSum / el.DurationDifferenceFactSum
            ));
        }

        private static IEnumerable<(double BhaDownSpeedPlan, double BhaDownSpeedFact)> GetWellBhaDownSpeedPlanFact(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations)
        {
            var bhaDownSpeedBase = GetParams(groupedOperations, 3);

            return bhaDownSpeedBase.Select(el =>
            (
                BhaDownSpeedPlan: el.DepthDifferencePlanSum / el.DurationDifferencePlanSum,
                BhaDownSpeedFact: el.DepthDifferenceFactSum / el.DurationDifferenceFactSum
            ));
        }

        private static IEnumerable<(double CasingDownSpeedPlan, double CasingDownSpeedFact)> GetWellCasingDownPlanFact(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations)
        {
            var casingDownBase = GetParams(groupedOperations, 4);

            return casingDownBase.Select(el =>
            (
                CasingDownSpeedPlan: el.DepthDifferencePlanSum / el.DurationDifferencePlanSum,
                CasingDownSpeedFact: el.DepthDifferenceFactSum / el.DurationDifferenceFactSum
            )).ToList();
        }

        private static IEnumerable<(double DepthDifferencePlanSum, 
            double DurationDifferencePlanSum, double DepthDifferenceFactSum, 
            double DurationDifferenceFactSum)> GetParams(IEnumerable<IGrouping<int, WellOperation>> items, 
                int idOperationCategory)
        {
            return items.Select(g =>
            (
                DepthDifferencePlanSum: g.Where(o => o.Type == 0 && o.IdOperationCategory == idOperationCategory)
                    .Select((el, i) => i > 0 ? el.WellDepth - g.ElementAt(i - 1).WellDepth : 0).Sum(),
                DurationDifferencePlanSum: g.Where(o => o.Type == 0 && o.IdOperationCategory == idOperationCategory)
                    .Select(el => el.DurationHours).Sum(),
                DepthDifferenceFactSum: g.Where(o => o.Type == 1 && o.IdOperationCategory == idOperationCategory)
                    .Select((el, i) => i > 0 ? el.WellDepth - g.ElementAt(i - 1).WellDepth : 0).Sum(),
                DurationDifferenceFactSum: g.Where(o => o.Type == 1 && o.IdOperationCategory == idOperationCategory)
                    .Select(el => el.DurationHours).Sum()
            ));
        }

        private static IEnumerable<(double RouteSpeedPlan, double RouteSpeedFact)> GetWellRouteSpeedsPlanFact(
            IEnumerable<IGrouping<int, WellOperation>> groupedOperations)
        {
            var bhaRaiseDecreaseCollection = new List<(WellOperation FirstDecreasePlan, WellOperation LastIncreasePlan,
                                            WellOperation FirstDecreaseFact, WellOperation LastIncreaseFact)>();

            foreach (var group in groupedOperations)
            {
                var firstBhaPositionDecreasePlan = group.Any(o => o.IdOperationCategory == 5 && o.Type == 0)
                                                ? group.First(o => o.IdOperationCategory == 5 && o.Type == 0)
                                                : null;

                var lastBhaPositionIncreasePlan = group.Any(o => o.IdOperationCategory == 6 && o.Type == 0)
                                                ? group.First(o => o.IdOperationCategory == 5 && o.Type == 0)
                                                : null;

                var firstBhaPositionDecreaseFact = group.Any(o => o.IdOperationCategory == 5 && o.Type == 1)
                                                    ? group.First(o => o.IdOperationCategory == 5 && o.Type == 1)
                                                    : null;

                var lastBhaPositionIncreaseFact = group.Any(o => o.IdOperationCategory == 6 && o.Type == 1)
                                                   ? group.First(o => o.IdOperationCategory == 5 && o.Type == 1)
                                                   : null;

                bhaRaiseDecreaseCollection.Add((firstBhaPositionDecreasePlan,
                    lastBhaPositionIncreasePlan, firstBhaPositionDecreaseFact,
                    lastBhaPositionIncreaseFact));
            }

            var routeSpeedsBase = bhaRaiseDecreaseCollection.Select(el => new // TODO: check value for null
            {
                RouteDepthPlan = el.FirstDecreasePlan.WellDepth - el.LastIncreasePlan.WellDepth,
                RouteDepthFact = el.FirstDecreaseFact.WellDepth - el.LastIncreaseFact.WellDepth,
                RouteDurationPlan = (el.LastIncreasePlan.StartDate + 
                    TimeSpan.FromHours(el.LastIncreasePlan.DurationHours) - 
                    el.FirstDecreasePlan.StartDate).TotalHours,
                RouteDurationFact = (el.LastIncreaseFact.StartDate + 
                    TimeSpan.FromHours(el.LastIncreaseFact.DurationHours) - 
                    el.FirstDecreaseFact.StartDate).TotalHours
            });

            return routeSpeedsBase.Select(el =>
            (
                RouteSpeedPlan: el.RouteDepthPlan / el.RouteDurationPlan,
                RouteSpeedFact: el.RouteDepthFact / el.RouteDurationFact
            )).ToList();
        }

        private async Task<WellSectionType> GetWellSectionTypeFromCacheAndAssertAsync(string wellSectionType, CancellationToken token = default)
        {
            if (string.IsNullOrEmpty(wellSectionType))
                throw new ArgumentException("Тип секции должен быть указан", nameof(WellSectionDto.SectionType));

            var sectionType = await cachedSectionsTypes
                .FirstOrDefaultAsync(s => s.Caption.Equals(wellSectionType, StringComparison.OrdinalIgnoreCase), token)
                .ConfigureAwait(false);

            if (sectionType is null)
            {
                throw new ArgumentException($"Тип секции '{wellSectionType}' отсутствует в справочнике", nameof(WellSectionDto.SectionType));
                //sectionType = await cachedSectionsTypes.InsertAsync(new WellSectionType { Caption = item.SectionType}, token);
            }

            return sectionType;
        }
    }
}