using AsbCloudApp.Data.GTR;
using AsbCloudApp.Repositories;
using AsbCloudApp.Services;
using AsbCloudDb.Model;
using AsbCloudDb.Model.GTR;
using Mapster;
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 : IGtrRepository
    {
        private readonly IAsbCloudDbContext db;
        private readonly ITelemetryService telemetryService;

        public GtrWitsRepository(
            IAsbCloudDbContext db,
            ITelemetryService telemetryService)
        {
            
            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 dateEnd = dateBeginUtc.AddSeconds(intervalSec);

            var queryWitsInt = db.Set<WitsItemInt>()
                .Where(d => d.IdTelemetry == telemetry.Id
                    && d.DateTime >= dateBeginUtc);
            var queryWitsString = db.Set<WitsItemString>()
                .Where(d => d.IdTelemetry == telemetry.Id
                    && d.DateTime >= dateBeginUtc);
            var queryWitsFloat = db.Set<WitsItemFloat>()
                .Where(d => d.IdTelemetry == telemetry.Id
                    && d.DateTime >= dateBeginUtc);

            var recordAllInt = await GetItemsOrDefaultAsync(queryWitsInt, dateEnd, filterByDateEnd, approxPointsCount, timezone.Hours, token);
            var recordAllFloat = await GetItemsOrDefaultAsync(queryWitsFloat, dateEnd, filterByDateEnd, approxPointsCount,timezone.Hours, token);
            var recordAllString = await GetItemsOrDefaultAsync(queryWitsString, dateEnd, filterByDateEnd, approxPointsCount, timezone.Hours, token);
            var groupRecordDate = (recordAllFloat.Union(recordAllInt)).Union(recordAllString)
                .GroupBy(g => new
                {
                    g.IdRecord,
                    g.Date
                }).ToList();
            var dtos = groupRecordDate.Select(g => new WitsRecordDto
            {
                Id = g.Key.IdRecord,
                Date = g.Key.Date,
                IdTelemetry = g.First().IdTelemetry,
                Items = g.Select(r => new { 
                 Key = r.IdItem,
                 Value = r.Item
                }).ToList().ToDictionary(x => x.Key, x => x.Value)                
            });           
            return dtos;
        }

        public async Task SaveDataAsync(int idTelemetry, WitsRecordDto dto, CancellationToken token)
        {
            if (dto is null)
                return;
            var timezoneHours = telemetryService.GetTimezone(idTelemetry).Hours;
            foreach (var item in dto.Items)
            {                
                var jsonValue = item.Value;       
                if(jsonValue.Value is string valueString)
                {
                    var entity = ConvertToEntity(dto, valueString, item.Key, timezoneHours);
                    db.WitsItemString.Add(entity.Adapt<WitsItemString>());
                }
                if (jsonValue.Value is float valueFloat)
                {
                    var entity = ConvertToEntity(dto, valueFloat, item.Key, timezoneHours);
                    db.WitsItemFloat.Add(entity.Adapt<WitsItemFloat>());
                }
                if (jsonValue.Value is int valueInt)
                {
                    var entity = ConvertToEntity(dto, valueInt, item.Key, timezoneHours);
                    db.WitsItemInt.Add(entity.Adapt<WitsItemInt>());
                }                
            }            
            await db.SaveChangesAsync(token);
        }

        private static async Task<IEnumerable<ItemRecord>> GetItemsOrDefaultAsync<T>(IQueryable<WitsItemBase<T>> query,
            DateTimeOffset dateEnd, bool filterByDateEnd, int approxPointsCount, double timezoneHours
            , CancellationToken token)
        {
            if (filterByDateEnd)
                query = query.Where(d => d.DateTime <= dateEnd);

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

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

            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 items = entities.Select(e => new ItemRecord
            {
                IdRecord = e.IdRecord,
                IdTelemetry = e.IdTelemetry,
                Date = e.DateTime.ToRemoteDateTime(timezoneHours),
                IdItem = e.IdItem,
                Item = new JsonValue(e.Value)
            });
            return items;
        }
        private static WitsItemBase<Tvalue> ConvertToEntity<Tvalue>(WitsRecordDto record, Tvalue value, int idItems, double timezoneHours)
        {
            var entity = new WitsItemBase<Tvalue>
            {
                IdTelemetry = record.IdTelemetry,
                DateTime = record.Date.ToUtcDateTimeOffset(timezoneHours),
                IdRecord = record.Id,
                IdItem = idItems,
                Value = value,
            };
            return entity;
        }

        internal class ItemRecord
        {
            public int IdRecord { get; set; }            
            public int IdTelemetry { get; set; }
            public DateTime Date { get; set; }
            public int IdItem { get; set; }
            public JsonValue Item { get; set; }
        }            
    }
#nullable disable
}