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

namespace AsbCloudInfrastructure.Repository
{
#nullable enable
    public class GtrWitsRepository<TEntity, T> : IGtrRepository <T>       
        where TEntity : WitsItemBase<T>   
    {
        private readonly IAsbCloudDbContext db;
        private readonly ITelemetryService telemetryService;
        private readonly DbSet<TEntity> dbset;
        private static Random random = new Random((int)(DateTime.Now.Ticks % 0xFFFFFFFF));

        public GtrWitsRepository(
            IAsbCloudDbContext db,
            ITelemetryService telemetryService)
        {
            dbset = db.Set<TEntity>();
            this.db = db;
            this.telemetryService = telemetryService;
        }

        public async Task<IEnumerable<WitsRecordDto>> GetAsync(int idWell, DateTime dateBegin = default, double intervalSec = 600, int approxPointsCount = 1024, CancellationToken token = default)
        {
            var telemetry = telemetryService.GetOrDefaultTelemetryByIdWell(idWell);
            if (telemetry is null)
                return Enumerable.Empty<WitsRecordDto>();

            var timezone = telemetryService.GetTimezone(telemetry.Id);

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

            if (dateBeginUtc == default)
                dateBeginUtc = DateTime.UtcNow.AddSeconds(-intervalSec);

            //var cacheData = telemetryDataCache.GetOrDefault(telemetry.Id, dateBeginUtc.ToRemoteDateTime(timezone.Hours), intervalSec, approxPointsCount);
            //if (cacheData is not null)
            //    return cacheData;

            var dateEnd = dateBeginUtc.AddSeconds(intervalSec);
            var dbSet = db.Set<TEntity>();

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

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

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

            //if (fullDataCount == 0)
            //    return Enumerable.Empty<WitsRecordDto>();

            //if (fullDataCount > 1.75 * approxPointsCount)
            //{
            //    var m = (int)Math.Round(1d * fullDataCount / approxPointsCount);
            //    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 groupRecord = entities
                .GroupBy(g => g.IdRecord)
                .ToList();
            var dtos = new List<WitsRecordDto>();
            foreach(var group in groupRecord)
            {
                var dto = GetDto(group, telemetry.Id, timezone.Hours);
                dtos.Add(dto);
            }
            return dtos;
        }



        public async Task SaveDataAsync(int idTelemetry, WitsRecordDto dto, CancellationToken token)
        {
            if (dto is null)
                return;
            var timezoneHours = telemetryService.GetTimezone(idTelemetry).Hours;
            var entities = GetEntities(dto,idTelemetry,timezoneHours);
            var dateMin = entities.Min(e => e.DateTime);
            var dateMax = entities.Max(e => e.DateTime);
            var existingEntities = await dbset
                .Where(e => e.IdTelemetry == idTelemetry)
                .Where(e => e.DateTime >= dateMin && e.DateTime <= dateMax)
                .Select(e => e.DateTime)
                .OrderBy(d => d)
                .ToArrayAsync(token);
            foreach (var entity in entities)
            {
                if (!existingEntities.Any(e => e == entity.DateTime))
                {
                    dbset.Add((TEntity)entity);
                }
                else
                {
                    var dt = entity.DateTime;
                    entity.DateTime = new DateTimeOffset(
                        dt.Year,
                        dt.Month,
                        dt.Day,
                        dt.Hour,
                        dt.Minute,
                        dt.Second,
                        (dt.Millisecond + random.Next(1, 283)) % 1000,
                        dt.Offset);
                    dbset.Add((TEntity)entity);
                }
            }
            await db.SaveChangesAsync(token);
        }

        private static IEnumerable<WitsItemBase<T>> GetEntities(WitsRecordDto recordItems, int idTelemetry, double timezoneHours)
        {            
            var itemsCount = recordItems.Items.Count;
            var entities = new List<WitsItemBase<T>>(itemsCount);
            
            foreach (var dtoItems in recordItems.Items)
            {
                var entityItems = new WitsItemBase<T>
                {
                    IdTelemetry = idTelemetry,
                    DateTime = recordItems.Date.ToUtcDateTimeOffset(timezoneHours),
                    IdRecord = recordItems.Id,
                    IdItem = dtoItems.Key,
                    Value = System.Text.Json.JsonSerializer.Deserialize<T>(dtoItems.Value.ToString())
                };
                entities.Add(entityItems);
            }            
            return entities;
        }

        private static WitsRecordDto GetDto(IEnumerable<WitsItemBase<T>> entities, int idTelemetry, double timezoneHours)
        {
            var entity = entities.First();
            var dto = new WitsRecordDto
            {
                Id = entity.IdRecord,
                Date = entity.DateTime.ToRemoteDateTime(timezoneHours),
                IdTelemetry = idTelemetry
            };

            foreach (var entityItems in entities)
            {
                var valueItem = new JsonValue(entityItems.Value!);                
                dto.Items.Add(entityItems.IdItem, valueItem);
            }
            return dto;
        }
    }
#nullable disable
}