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

namespace AsbCloudInfrastructure.Services
{
    public class TelemetryAnalyticsService : ITelemetryAnalyticsService
    {
        private readonly IAsbCloudDbContext db;
        private readonly ITelemetryService telemetryService;
        private readonly ISaubDataCache saubDataCache;
        private readonly CacheTable<WellOperationCategory> cacheOperations;
        private readonly TelemetryOperationDetectorService operationDetectorService;
        private readonly IEnumerable<WellOperationCategory> operations;

        public TelemetryAnalyticsService(IAsbCloudDbContext db, ITelemetryService telemetryService,
            ISaubDataCache saubDataCache, CacheDb cacheDb)
        {
            this.db = db;
            this.telemetryService = telemetryService;
            this.saubDataCache = saubDataCache;
            cacheOperations = cacheDb.GetCachedTable<WellOperationCategory>((AsbCloudDbContext)db);
            operations = cacheOperations.Where();
            operationDetectorService = new TelemetryOperationDetectorService(operations);
        }

        public async Task<IEnumerable<WellDepthToDayDto>> GetWellDepthToDayAsync(int idWell, CancellationToken token = default)
        {
            var telemetryId = telemetryService.GetIdTelemetryByIdWell(idWell);

            if (telemetryId is null)
                return null;

            var depthToTimeData = (from d in db.DataSaubBases
                                   where d.IdTelemetry == telemetryId
                                   select new
                                   {
                                       d.Id,
                                       d.WellDepth,
                                       d.BitDepth,
                                       d.Date
                                   });

            var m = (int)Math.Round(1d * depthToTimeData.Count() / 2048);

            if (m > 1)
                depthToTimeData = depthToTimeData.Where(d => d.Id % m == 0);

            return await depthToTimeData.Select(d => new WellDepthToDayDto
            {
                WellDepth = d.WellDepth ?? 0.0,
                BitDepth = d.BitDepth ?? 0.0,
                Date = d.Date
            }).AsNoTracking().ToListAsync(token).ConfigureAwait(false);
        }

        public async Task<IEnumerable<WellDepthToIntervalDto>> GetWellDepthToIntervalAsync(int idWell,
            int intervalSeconds, int workBeginSeconds, CancellationToken token = default)
        {
            intervalSeconds = intervalSeconds == 0 ? 86400 : intervalSeconds;

            var telemetryId = telemetryService.GetIdTelemetryByIdWell(idWell);

            if (telemetryId is null)
                return null;

            var timezoneOffset = telemetryService.GetTimezoneOffsetByTelemetryId((int)telemetryId);

            var drillingPeriodsInfo = await db.GetDepthToIntervalAsync((int)telemetryId, intervalSeconds,
                workBeginSeconds, timezoneOffset, token).ConfigureAwait(false);

            var wellDepthToIntervalData = drillingPeriodsInfo.Select(d => new WellDepthToIntervalDto
            {
                IntervalStartDate = d.BeginPeriodDate,
                IntervalDepthProgress = (d.MaxDepth - d.MinDepth) ?? 0.0 / intervalSeconds
            }).OrderBy(d => d.IntervalStartDate).ToList();

            return wellDepthToIntervalData;
        }

        public async Task<PaginationContainer<TelemetryOperationDto>> GetOperationsByWellAsync(int idWell,
            IEnumerable<int> categoryIds = default, DateTime begin = default,
            DateTime end = default, int skip = 0, int take = 32, CancellationToken token = default)
        {
            var telemetryId = telemetryService.GetIdTelemetryByIdWell(idWell);

            if (telemetryId is null)
                return null;

            var operations = from a in db.TelemetryAnalysis.Include(t => t.Operation)
                             where a.IdTelemetry == telemetryId
                             select a;

            if ((categoryIds != default) && (categoryIds.Any()))
                operations = operations.Where(o => categoryIds.Contains(o.IdOperation));

            var result = new PaginationContainer<TelemetryOperationDto>
            {
                Skip = skip,
                Take = take
            };

            operations = operations.OrderBy(o => o.UnixDate);

            if (begin != default)
            {
                var unixBegin = (begin - new DateTime(1970, 1, 1)).TotalSeconds;
                operations = operations.Where(o => o.UnixDate >= unixBegin);
            }

            if (end != default)
            {
                var unixEnd = (end - new DateTime(1970, 1, 1)).TotalSeconds;
                operations = operations.Where(m => (m.UnixDate + m.DurationSec) <= unixEnd);
            }

            result.Count = await operations.CountAsync(token).ConfigureAwait(false);

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

            var operationsList = await operations.Take(take)
                .AsNoTracking()
                .ToListAsync(token)
                .ConfigureAwait(false);

            if (operationsList.Count == 0)
                return result;

            foreach (var operation in operations)
            {
                var operationDto = new TelemetryOperationDto
                {
                    Id = operation.Id,
                    Name = operation.Operation.Name,
                    BeginDate = DateTimeOffset.FromUnixTimeSeconds(operation.UnixDate).DateTime,
                    EndDate = DateTimeOffset.FromUnixTimeSeconds(operation.UnixDate + operation.DurationSec).DateTime,
                    StartWellDepth = operation.OperationStartDepth ?? 0.0,
                    EndWellDepth = operation.OperationEndDepth ?? 0.0
                };

                result.Items.Add(operationDto);
            }

            return result;
        }

        public async Task<IEnumerable<TelemetryOperationDurationDto>> GetOperationsSummaryAsync(int idWell,
            DateTime begin = default, DateTime end = default, CancellationToken token = default)
        {
            var telemetryId = telemetryService.GetIdTelemetryByIdWell(idWell);

            if (telemetryId is null)
                return null;

            var unixBegin = (begin - new DateTime(1970, 1, 1)).TotalSeconds;
            var unixEnd = (end - new DateTime(1970, 1, 1)).TotalSeconds;

            return await (from a in db.TelemetryAnalysis
                            where a.IdTelemetry == telemetryId &&
                            a.UnixDate > unixBegin && a.UnixDate < unixEnd
                            join o in db.TelemetryOperations on a.IdOperation equals o.Id
                            group a by new { a.IdOperation, o.Name } into g
                            select new TelemetryOperationDurationDto
                            {
                                OperationName = g.Key.Name,
                                Duration = g.Where(g => g.DurationSec > 0)
                                            .Sum(a => a.DurationSec)
                            }).AsNoTracking().ToListAsync(token)
                            .ConfigureAwait(false);
        }

        // This method is not finished (only half done). It returns not correct Dtos. 
        public async Task<IEnumerable<TelemetryOperationInfoDto>> GetOperationsToIntervalAsync(int idWell,
            int intervalSeconds, int workBeginSeconds, CancellationToken token = default)
        {
            intervalSeconds = intervalSeconds == 0 ? 86400 : intervalSeconds;

            var telemetryId = telemetryService.GetIdTelemetryByIdWell(idWell);

            if (telemetryId is null)
                return null;

            var timezoneOffset = telemetryService.GetTimezoneOffsetByTelemetryId((int)telemetryId);

            // Get'n'Group all operations only by start date and by name (if there were several operations in interval).
            // Without dividing these operations duration by given interval
            var ops = await (from a in db.TelemetryAnalysis
                            where a.IdTelemetry == telemetryId
                            join o in db.TelemetryOperations on a.IdOperation equals o.Id
                            group a by new
                            {
                                Interval = Math.Floor((a.UnixDate - workBeginSeconds + timezoneOffset) / intervalSeconds),
                                o.Name
                            } into g
                            select new
                            {
                                IntervalStart = g.Min(d => d.UnixDate),
                                OperationName = g.Key.Name,
                                OperationDuration = g.Sum(an => an.DurationSec)
                            }).AsNoTracking()
                            .OrderBy(op => op.IntervalStart)
                            .ToListAsync(token)
                            .ConfigureAwait(false);


            var groupedOperationsList = new List<TelemetryOperationInfoDto>();


            if (operations is not null && operations.Any())
            {
                var operations = ops.Select(o => (o.IntervalStart, o.OperationName, o.OperationDuration));

                var splittedOperationsByInterval = DivideOperationsByIntervalLength(operations, intervalSeconds); // divides good

                groupedOperationsList = UniteOperationsInDto(splittedOperationsByInterval, intervalSeconds).ToList(); // unites not good
            }

            return groupedOperationsList;
        }

        public void SaveAnalytics(DataSaubBaseDto dataSaubDto)
        {
            saubDataCache.AddData(dataSaubDto);

            if (saubDataCache.GetOrCreateCache(dataSaubDto.IdTelemetry).Count() > 1)
            {
                var dataSaubs = saubDataCache.GetOrCreateCache(dataSaubDto.IdTelemetry)
                    .OrderBy(d => d.Date);

                var telemetryAnalysisDto = GetDrillingAnalysis(dataSaubs);

                if (saubDataCache.CurrentAnalysis is null)
                    saubDataCache.CurrentAnalysis = telemetryAnalysisDto;

                if (saubDataCache.CurrentAnalysis.IdOperation == telemetryAnalysisDto.IdOperation)
                {
                    saubDataCache.CurrentAnalysis.DurationSec +=
                        telemetryAnalysisDto.DurationSec;
                    saubDataCache.CurrentAnalysis.OperationEndDepth = dataSaubDto.WellDepth;
                }
                else
                {
                    db.TelemetryAnalysis.Add(saubDataCache.CurrentAnalysis.Adapt<TelemetryAnalysis>());
                    saubDataCache.CurrentAnalysis = telemetryAnalysisDto;
                    saubDataCache.CurrentAnalysis.OperationStartDepth = dataSaubDto.WellDepth;
                }
            }
        }

        private static IEnumerable<(long IntervalStart, string OperationName, int OperationDuration)> DivideOperationsByIntervalLength(
            IEnumerable<(long IntervalStart, string OperationName, int OperationDuration)> operations, int intervalSeconds)
        {
            var splittedOperationsByInterval = new List<(long IntervalStart, string OperationName, int OperationDuration)>();

            var operationDurationTimeCounter = 0;

            foreach (var op in operations)
            {
                if (op.OperationDuration < (intervalSeconds - operationDurationTimeCounter))
                {
                    splittedOperationsByInterval.Add((op.IntervalStart, op.OperationName, op.OperationDuration));
                    operationDurationTimeCounter += op.OperationDuration;
                }
                else
                {   // if operation duration overflows current interval it shoud be divided into 2 or more parts for this and next intervals
                    var remainingIntervalTime = intervalSeconds - operationDurationTimeCounter;
                    splittedOperationsByInterval.Add((op.IntervalStart, op.OperationName, remainingIntervalTime)); // first part of long operation

                    var operationDurationAfterDividing = op.OperationDuration - remainingIntervalTime; // second part of long operation. Can be less or more than interval

                    // If operation duration even after dividing is still more than interval,
                    // it should be divided several times to several intervals.
                    if (operationDurationAfterDividing > intervalSeconds)
                    {
                        var counter = 0;
                        var updatedIntervalStartTime = op.IntervalStart + remainingIntervalTime;

                        while (operationDurationAfterDividing > intervalSeconds)
                        {
                            splittedOperationsByInterval.Add((updatedIntervalStartTime + intervalSeconds * counter, op.OperationName, intervalSeconds));
                            operationDurationAfterDividing -= intervalSeconds;
                            counter++;
                        }

                        splittedOperationsByInterval.Add((updatedIntervalStartTime + operationDurationAfterDividing, op.OperationName, operationDurationAfterDividing));

                        operationDurationTimeCounter = operationDurationAfterDividing;
                    }
                    else
                    {
                        splittedOperationsByInterval.Add((op.IntervalStart, op.OperationName, operationDurationAfterDividing));
                        operationDurationTimeCounter = operationDurationAfterDividing;
                    }
                }
            }

            return splittedOperationsByInterval;
        }

        private static IEnumerable<TelemetryOperationInfoDto> UniteOperationsInDto(
            IEnumerable<(long IntervalStart, string OperationName, int OperationDuration)> operations, int intervalSeconds)
        {
            var groupedOperationsList = new List<TelemetryOperationInfoDto>();

            var groupedOperationsObj = new TelemetryOperationInfoDto
            {
                IntervalBegin = DateTimeOffset.FromUnixTimeSeconds(operations.First().IntervalStart),
                Operations = new List<TelemetryOperationDetailsDto>()
            };

            var intervalEndDate = operations.First().IntervalStart + intervalSeconds;

            foreach (var op in operations)
            {
                if (op.IntervalStart < intervalEndDate)
                {
                    groupedOperationsObj.Operations.Add(new TelemetryOperationDetailsDto
                    {
                        OperationName = op.OperationName,
                        DurationSec = op.OperationDuration
                    });
                }
                else
                {
                    groupedOperationsList.Add(groupedOperationsObj);

                    intervalEndDate = op.IntervalStart + intervalSeconds;
                    groupedOperationsObj = new TelemetryOperationInfoDto
                    {
                        IntervalBegin = DateTimeOffset.FromUnixTimeSeconds(op.IntervalStart),
                        Operations = new List<TelemetryOperationDetailsDto>()
                    };

                    groupedOperationsObj.Operations.Add(new TelemetryOperationDetailsDto
                    {
                        OperationName = op.OperationName,
                        DurationSec = op.OperationDuration
                    });
                }
            }

            groupedOperationsList.Add(groupedOperationsObj);

            return groupedOperationsList;
        }

        private TelemetryAnalysisDto GetDrillingAnalysis(IEnumerable<DataSaubBaseDto> dataSaubBases)
        {
            var lastSaubDate = dataSaubBases.Last().Date;

            var saubWellDepths = dataSaubBases.Where(sw => sw.WellDepth is not null)
                .Select(s => (Value: (double)s.WellDepth,
                (s.Date - dataSaubBases.First().Date).TotalSeconds));
            var saubBitDepths = dataSaubBases.Where(sw => sw.BitDepth is not null)
                .Select(s => (Value: (double)s.BitDepth,
                (s.Date - dataSaubBases.First().Date).TotalSeconds));
            var saubBlockPositions = dataSaubBases.Where(sw => sw.BlockPosition is not null)
                .Select(s => (Value: (double)s.BlockPosition,
                (s.Date - dataSaubBases.First().Date).TotalSeconds));
            var saubRotorSpeeds = dataSaubBases.Where(sw => sw.RotorSpeed is not null)
                .Select(s => (Value: (double)s.RotorSpeed,
                (s.Date - dataSaubBases.First().Date).TotalSeconds));
            var saubPressures = dataSaubBases.Where(sw => sw.Pressure is not null)
                .Select(s => (Value: (double)s.Pressure,
                (s.Date - dataSaubBases.First().Date).TotalSeconds));
            var saubHookWeights = dataSaubBases.Where(sw => sw.HookWeight is not null)
                .Select(s => (Value: (double)s.HookWeight,
                (s.Date - dataSaubBases.First().Date).TotalSeconds));

            var wellDepthChangingIndex = new InterpolationLine(saubWellDepths).GetAForLinearFormula();
            var bitPositionChangingIndex = new InterpolationLine(saubBitDepths).GetAForLinearFormula();
            var blockPositionChangingIndex = new InterpolationLine(saubBlockPositions).GetAForLinearFormula();
            var rotorSpeedChangingIndex = new InterpolationLine(saubRotorSpeeds).GetAForLinearFormula();
            var pressureChangingIndex = new InterpolationLine(saubPressures).GetAForLinearFormula();
            var hookWeightChangingIndex = new InterpolationLine(saubHookWeights).GetAForLinearFormula();

            var IsBlockRising = InterpolationLine.IsValueDecreases(blockPositionChangingIndex, -0.0001);
            var IsBlockGoesDown = InterpolationLine.IsValueIncreases(blockPositionChangingIndex, 0.0001);
            var IsBlockStandsStill = InterpolationLine.IsValueNotChanges(blockPositionChangingIndex, (0.0001, -0.0001));

            var drillingAnalysis = new TelemetryAnalysisDto
            {
                IdTelemetry = dataSaubBases.First().IdTelemetry,
                UnixDate = (long)(lastSaubDate - new DateTime(1970, 1, 1, 0, 0, 0)).TotalSeconds,
                DurationSec = (int)(dataSaubBases.Last().Date - dataSaubBases.ElementAt(dataSaubBases.Count() - 2).Date).TotalSeconds,
                OperationStartDepth = null,
                OperationEndDepth = null,
                IsWellDepthDecreasing = InterpolationLine.IsValueDecreases(wellDepthChangingIndex, -0.0001),
                IsWellDepthIncreasing = InterpolationLine.IsValueIncreases(wellDepthChangingIndex, 0.0001),
                IsBitPositionDecreasing = InterpolationLine.IsValueDecreases(bitPositionChangingIndex, -0.0001),
                IsBitPositionIncreasing = InterpolationLine.IsValueIncreases(bitPositionChangingIndex, 0.0001),
                IsBitPositionLt20 = InterpolationLine.IsAverageLessThanBound(saubBitDepths, 20),
                IsBlockPositionDecreasing = InterpolationLine.IsValueDecreases(blockPositionChangingIndex, -0.0001),
                IsBlockPositionIncreasing = InterpolationLine.IsValueIncreases(blockPositionChangingIndex, 0.0001),
                IsRotorSpeedLt3 = InterpolationLine.IsAverageLessThanBound(saubRotorSpeeds, 3),
                IsRotorSpeedGt3 = InterpolationLine.IsAverageMoreThanBound(saubRotorSpeeds, 3),
                IsPressureLt20 = InterpolationLine.IsAverageLessThanBound(saubPressures, 20),
                IsPressureGt20 = InterpolationLine.IsAverageMoreThanBound(saubPressures, 20),
                IsHookWeightNotChanges = InterpolationLine.IsValueNotChanges(hookWeightChangingIndex, (0.0001, -0.0001)),
                IsHookWeightLt3 = InterpolationLine.IsAverageLessThanBound(saubHookWeights, 3),
                IdOperation = 1
            };

            drillingAnalysis.IdOperation = operationDetectorService.DetectOperation(drillingAnalysis).Id;

            return drillingAnalysis;
        }
    }
}