DD.WellWorkover.Cloud/AsbCloudInfrastructure/Services/TelemetryDataBaseService.cs

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

namespace AsbCloudInfrastructure.Services
{
    public abstract class TelemetryDataBaseService<TDto, TModel> : ITelemetryDataService<TDto>
        where TDto : AsbCloudApp.Data.ITelemetryData
        where TModel : class, AsbCloudDb.Model.ITelemetryData
    {
        private readonly IAsbCloudDbContext db;
        private readonly ITelemetryService telemetryService;
        protected readonly CacheTable<Telemetry> cacheTelemetry;
        protected readonly CacheTable<TelemetryUser> cacheTelemetryUsers;
        protected readonly CacheTable<Well> cacheWells;

        public TelemetryDataBaseService(
            IAsbCloudDbContext db,
            ITelemetryService telemetryService,
            CacheDb cacheDb)
        {
            this.db = db;
            this.telemetryService = telemetryService;
            cacheTelemetry = cacheDb.GetCachedTable<Telemetry>((AsbCloudDbContext)db);
            cacheTelemetryUsers = cacheDb.GetCachedTable<TelemetryUser>((AsbCloudDbContext)db);
            cacheWells = cacheDb.GetCachedTable<Well>((AsbCloudDbContext)db);
        }

        public virtual async Task<int> UpdateDataAsync(string uid, IEnumerable<TDto> dtos, CancellationToken token = default)
        {
            if (dtos == default || !dtos.Any())
                return 0;

            var dtosList = dtos.OrderBy(d => d.DateTime).ToList();

            var dtoMinDate = dtosList.First().DateTime;
            var dtoMaxDate = dtosList.Last().DateTime;

            if (dtosList.Count > 1)
            {
                var duplicates = new List<TDto>(8);
                for (int i = 1; i < dtosList.Count; i++)
                    if (dtosList[i].DateTime - dtosList[i-1].DateTime < TimeSpan.FromMilliseconds(100))
                        duplicates.Add(dtosList[i - 1]);
                foreach (var duplicate in duplicates)
                    dtosList.Remove(duplicate);
            }

            var idTelemetry = telemetryService.GetOrCreateTelemetryIdByUid(uid);
            var timezone = telemetryService.GetTimezone(idTelemetry);

            var entities = dtosList.Select(dto => {
                    var entity = Convert(dto, timezone.Hours);                    
                    entity.IdTelemetry = idTelemetry;
                    return entity;
                });

            var entityMaxDate = entities.Max(e => e.DateTime);
            telemetryService.SaveRequestDate(uid, entityMaxDate);

            var dbset = db.Set<TModel>();
            var stopwatch = Stopwatch.StartNew();
            try
            {
                return await db.Database.ExecInsertOrUpdateAsync(dbset, entities, token).ConfigureAwait(false);
            }
            catch(Exception ex)
            {
                stopwatch.Stop();
                Trace.WriteLine($"Fail to save data telemetry " +
                    $"uid: {uid}, " +
                    $"idTelemetry {idTelemetry}, " +
                    $"count: {entities.Count()}, " +
                    $"dataDate: {entities.FirstOrDefault()?.DateTime}, " +
                    $"dbSaveDurationTime:{stopwatch.ElapsedMilliseconds}ms. " +
                    $"Message: {ex.Message}");
                return 0;
            }
        }

        public virtual async Task<IEnumerable<TDto>> GetAsync(int idWell,
            DateTime dateBegin = default, double intervalSec = 600d,
            int approxPointsCount = 1024, CancellationToken token = default)
        {
            var well = cacheWells.FirstOrDefault(w => w.Id == idWell);
            if (well?.IdTelemetry is null)
                return default;

            var idTelemetry = well?.IdTelemetry ?? default;

            var timezone = telemetryService.GetTimezone(idTelemetry);

            var filterByDateEnd = dateBegin != default;
            DateTimeOffset dateBeginUtc;
            if (dateBegin == default)
            {
                dateBeginUtc = telemetryService.GetLastTelemetryDate(idTelemetry, true);
                if (dateBeginUtc != default)
                    dateBeginUtc = dateBeginUtc.AddSeconds(-intervalSec);
            }
            else
            {
                dateBeginUtc = dateBegin.ToUtcDateTimeOffset(timezone.Hours);
            }

            if (dateBeginUtc == default)
                dateBeginUtc = DateTime.UtcNow.AddSeconds(-intervalSec);
            
            var dateEnd = dateBeginUtc.AddSeconds(intervalSec);
            var dbSet = db.Set<TModel>();

            var query = dbSet
                .Where(d => d.IdTelemetry == idTelemetry
                    && d.DateTime >= dateBeginUtc);

            if (filterByDateEnd)
                query = query.Where(d => d.DateTime <= dateEnd);

            var fullDataCount = await query.CountAsync(token)
                .ConfigureAwait(false);

            if (fullDataCount == 0)
                return default;

            if (fullDataCount > 1.75 * approxPointsCount)
            {
                var m = (int)Math.Round(1d * fullDataCount / approxPointsCount);

                switch (m)
                {
                    //case var i when i <= 1: // тут для полноты, но никогда не сработает из-за условия выше
                    //    break;
                    case var i when i < 10:
                        query = query.Where((d) => d.DateTime.Second % m == 0);
                        break;
                    case var i when i < 30:
                        query = query.Where((d) => (d.DateTime.Minute * 60 + d.DateTime.Second) % m == 0);
                        break;
                    case var i when i < 600:
                        query = query.Where((d) => ((d.DateTime.Hour * 60 + d.DateTime.Minute) * 60 + d.DateTime.Second) % m == 0);
                        break;
                    default:
                        query = query.Where((d) => (((d.DateTime.DayOfYear * 24 + d.DateTime.Hour) * 60 + d.DateTime.Minute) * 60 + d.DateTime.Second) % m == 0);
                        break;
                }

                if (m > 1)
                    query = query.Where((d) => (((d.DateTime.DayOfYear*24 + d.DateTime.Hour)*60 + d.DateTime.Minute)*60 + d.DateTime.Second) % m == 0);
            }

            var entities = await query
                .OrderBy(d=>d.DateTime)
                .AsNoTracking()
                .ToListAsync(token)
                .ConfigureAwait(false);

            var dtos = entities.Select(e => Convert(e, timezone.Hours));
                            
            return dtos;
        }

        public abstract TDto Convert(TModel src, double timezoneOffset);

        public abstract TModel Convert(TDto src, double timezoneOffset);

        private static double AssumeTimezoneOffset(DateTime nearToCurrentDate)
        {
            var offset = 5d;
            if (nearToCurrentDate.Kind == DateTimeKind.Unspecified)
            {
                var now = DateTime.UtcNow;
                var minutes = 60 * (now.Hour - nearToCurrentDate.Hour) + now.Minute - nearToCurrentDate.Minute;
                var minutesPositive = (1440_0000 + minutes) % 1440; //60*24
                var halfsHours = Math.Round(1d * minutesPositive / 30d); // quarters are ignored
                var hours = halfsHours / 2;
                offset = hours < 12 ? hours : 24 - hours;
            }
            if (nearToCurrentDate.Kind == DateTimeKind.Local)
                offset = TimeZoneInfo.Local.BaseUtcOffset.TotalHours;

            return offset;
        }
    }
}