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

namespace AsbCloudInfrastructure.Services
{
    class OperationParams
    {
        public OperationParams() { }

        public OperationParams(WellOperation operation)
        {
            Id = operation.Id;
            IdWellSectionType = operation.IdWellSectionType;
            IdCategory = operation.IdCategory;

            WellDepth = operation.WellDepth;
            StartDate = operation.StartDate;
            DurationHours = operation.DurationHours;

            WellDepthReal = operation.WellDepth;
            DeltaDepth = 0;
            DurationToNextOperationHours = operation.DurationHours;
        }

        public int Id { get; }
        public int IdWellSectionType { get; }
        public int IdCategory { get; }
        public double WellDepth { get; }
        public DateTime StartDate { get; }
        public double DurationHours { get; }
        public double WellDepthReal { get; set; }
        public double DeltaDepth { get; set; }
        public double DurationToNextOperationHours { get; set; }
    }

    class Race
    {
        public DateTime StartDate { get; set; }
        public double StartWellDepth { get; set; }
        public DateTime EndDate { get; set; }
        public double EndWellDepth { get; set; }
        public double DrillingTime { get; set; }
        public double NonProductiveHours { get; set; }
        public double DeltaDepth => EndWellDepth - StartWellDepth;
        public double DeltaHoursTimeNoNpt => (EndDate - StartDate).TotalHours - NonProductiveHours;
        public double Speed => DeltaDepth / (DeltaHoursTimeNoNpt + double.Epsilon);
    }

    class SectionStat
    {
        public DateTime StartDate { get; set; }
        public double StartWellDepth { get; set; }
        public DateTime EndDate { get; set; }
        public double EndWellDepth { get; set; }
        public double AvgRaceSpeed { get; set; }
        public double Rop { get; set; }
        public double BhaDownSpeed { get; set; }
        public double BhaUpSpeed { get; set; }
        public double CasingDownSpeed { get; set; }
        public int IdSectionType { get; internal set; }
        public double Hours => (EndDate - StartDate).TotalHours;
    }

    public class WellOperationsStatService
    {
        private readonly IAsbCloudDbContext db;
        private readonly CacheTable<WellSectionType> cachedSectionsTypes;
        const int idOperationBhaAssembly = 1025;
        const int idOperationBhaDisassembly = 1026;
        private const int idOperationNonProductiveTime = 1043;
        private const int idOperationDrilling = 1001;
        private const int idOperationBhaDown = 1046;
        private const int idOperationBhaUp = 1047;
        private const int IdOperationCasingDown = 1048;

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

        public async Task<IEnumerable<WellSectionDto>> GetSectionsByWellIdAsync(int idWell,
            CancellationToken token = default)
        {
            var operationsAll = await db.WellOperations
                .Where(o => o.IdWell == idWell)
                .OrderBy(o => o.StartDate) // ускорит дальнейшие сортировки
                .AsNoTracking()
                .ToListAsync(token);

            var operationsPlan = operationsAll
                .Where(o => o.IdType == 0);

            var sectionsPlan = CalcSectionsStats(operationsPlan);

            var operationsFact = operationsAll
                 .Where(o => o.IdType == 1);

            var sectionsFact = CalcSectionsStats(operationsFact);
            var sectionTypesIds = operationsAll.Select(o => o.IdWellSectionType).Distinct();
            var sections = new List<WellSectionDto>(sectionTypesIds.Count());
            foreach (var idSectionType in sectionTypesIds)
            {
                var statPlan = sectionsPlan.FirstOrDefault(s => s.IdSectionType == idSectionType);
                var statFact = sectionsFact.FirstOrDefault(s => s.IdSectionType == idSectionType);
                WellSectionDto section = MakeWellSectionDto(idSectionType, statPlan, statFact);
                sections.Add(section);
            }
            return sections;
        }

        private WellSectionDto MakeWellSectionDto(int idSectionType, SectionStat statPlan, SectionStat statFact)
        {
            return new WellSectionDto
            {
                Id = idSectionType,
                SectionType = cachedSectionsTypes.FirstOrDefault(s => s.Id == idSectionType)?.Caption,

                BhaDownSpeedPlan = statPlan?.BhaDownSpeed ?? double.NaN,
                BhaUpSpeedPlan = statPlan?.BhaUpSpeed ?? double.NaN,
                MechSpeedPlan = statPlan?.Rop ?? double.NaN,
                CasingDownSpeedPlan = statPlan?.CasingDownSpeed ?? double.NaN,
                RouteSpeedPlan = statPlan?.AvgRaceSpeed ?? double.NaN,
                WellDepthPlan = statPlan?.EndWellDepth ?? double.NaN,
                DurationPlan = statPlan?.Hours ?? double.NaN,

                BhaDownSpeedFact = statFact?.BhaDownSpeed ?? double.NaN,
                BhaUpSpeedFact = statFact?.BhaUpSpeed ?? double.NaN,
                MechSpeedFact = statFact?.Rop ?? double.NaN,
                CasingDownSpeedFact = statFact?.CasingDownSpeed ?? double.NaN,
                RouteSpeedFact = statFact?.AvgRaceSpeed ?? double.NaN,
                WellDepthFact = statFact?.EndWellDepth ?? double.NaN,
                DurationFact = statFact?.Hours ?? double.NaN,
            };
        }

        private static IEnumerable<SectionStat> CalcSectionsStats(IEnumerable<WellOperation> wellOperations)
        {
            var operations = MakeOperationsExt(wellOperations);
            var sectionTypesIds = operations.Select(o => o.IdWellSectionType).Distinct();
            var sectionsStats = new List<SectionStat>(sectionTypesIds.Count());
            foreach (var idSection in sectionTypesIds)
            {
                var section = CalcSectionStat(operations, idSection);
                sectionsStats.Add(section);
            }
            return sectionsStats;
        }

        private static SectionStat CalcSectionStat(IEnumerable<OperationParams> allOperations, int idSectionType)
        {
            var sectionOperations = allOperations
                .Where(o => o.IdWellSectionType == idSectionType)
                .OrderBy(o => o.StartDate)
                .ThenBy(o => o.WellDepth);
            var section = new SectionStat
            {
                IdSectionType = idSectionType,
                StartDate = sectionOperations.First().StartDate,
                EndDate = sectionOperations.Max(o => (o.StartDate.AddHours(o.DurationHours))),
                StartWellDepth = sectionOperations.Min(o => o.WellDepthReal),
                EndWellDepth = sectionOperations.Max(o => o.WellDepthReal),
                AvgRaceSpeed = CalcAvgRaceSpeed(sectionOperations),
                Rop = CalcROP(sectionOperations),
                BhaDownSpeed = CalcSpeedByOperation(sectionOperations, idOperationBhaDown),
                BhaUpSpeed = CalcSpeedByOperation(sectionOperations, idOperationBhaUp),
                CasingDownSpeed = CalcSpeedByOperation(sectionOperations, IdOperationCasingDown),
            };
            return section;
        }

        private static double CalcSpeedByOperation(IEnumerable<OperationParams> operationsProps, int idOperation)
        {
            var ops = operationsProps.Where(o => o.IdCategory == idOperation);
            var maxDepth = 0d;
            var dHours = 0d;
            foreach (var operation in ops)
            {
                if (maxDepth > operation.WellDepthReal)
                    maxDepth = operation.WellDepthReal;
                dHours += operation.DurationHours;
            }
            return maxDepth / (dHours + double.Epsilon);
        }

        private static double CalcROP(IEnumerable<OperationParams> operationsProps)
        {
            var drillingOperations = operationsProps.Where(o => o.IdCategory == idOperationDrilling);
            var dDepth = 0d;
            var dHours = 0d;
            foreach (var operation in drillingOperations)
            {
                dDepth += operation.DeltaDepth;
                dHours += operation.DurationHours;
            }
            return dDepth / (dHours + double.Epsilon);
        }

        // Метры в час
        private static double CalcAvgRaceSpeed(IEnumerable<OperationParams> operations)
        {
            var races = GetCompleteRaces(operations);
            var dDepth = 0d;
            var dHours = 0d;
            foreach (var race in races)
            {
                dHours += race.DeltaHoursTimeNoNpt;
                dDepth += race.DeltaDepth;
            }
            return dDepth / (dHours + double.Epsilon);
        }

        private static IEnumerable<OperationParams> MakeOperationsExt(IEnumerable<WellOperation> operations)
        {
            var count = operations.Count();
            var ops = new List<OperationParams>(count);
            var item = operations.ElementAt(0);
            var wellDepth = item.WellDepth;
            var pre = new OperationParams(item);
            var current = new OperationParams(item);
            for (int i = 1; i < count; i++)
            {
                item = operations.ElementAt(i);
                current = new OperationParams(item)
                {
                    WellDepthReal = Helper.Max(wellDepth, item.WellDepth) // TODO: учесть операциии с уменьшение глубины ствола.
                };
                pre.DeltaDepth = current.WellDepthReal - wellDepth;
                pre.DurationToNextOperationHours = (current.StartDate - pre.StartDate).TotalHours;
                ops.Add(pre);
                pre = current;
            }
            ops.Add(current);
            return ops;
        }

        private static IEnumerable<Race> GetCompleteRaces(IEnumerable<OperationParams> operations)
        {
            var races = new List<Race>(4);
            var iterator = operations.GetEnumerator();
            while (iterator.MoveNext())
            {
                if (iterator.Current.IdCategory == idOperationBhaAssembly)
                {
                    var race = new Race
                    {
                        StartDate = iterator.Current.StartDate.AddHours(iterator.Current.DurationHours),
                        StartWellDepth = iterator.Current.WellDepthReal
                    };
                    while (iterator.MoveNext())
                    {
                        if (iterator.Current.IdCategory == idOperationNonProductiveTime)
                        {
                            race.NonProductiveHours += iterator.Current.DurationHours;
                        }
                        if (iterator.Current.IdCategory == idOperationBhaDisassembly)
                        {
                            race.EndDate = iterator.Current.StartDate.AddHours(iterator.Current.DurationHours);
                            race.EndWellDepth = iterator.Current.WellDepthReal;
                            races.Add(race);
                        }
                    }
                }
            }
            return races;
        }

    }
}