using AsbCloudApp.Data;
using AsbCloudApp.Services;
using AsbCloudDb.Model;
using AsbCloudInfrastructure.Services.Cache;
using AutoMapper;
using System;
using System.Collections.Generic;
using System.Linq;

namespace AsbCloudInfrastructure.Services
{
    public class DataService : IDataService
    {
        private readonly IAsbCloudDbContext db;
        private readonly ITelemetryService telemetryService;
        private readonly IMapper mapper;
        private readonly CacheTable<Telemetry> cacheTelemetry;
        private readonly CacheTable<Well> cacheWells;

        public DataService(IAsbCloudDbContext db, ITelemetryService telemetryService, CacheDb cacheDb, MapperConfiguration mapperConfiguration)
        {
            this.db = db;
            this.telemetryService = telemetryService;
            mapper = mapperConfiguration.CreateMapper();
            cacheTelemetry = cacheDb.GetCachedTable<Telemetry>((AsbCloudDbContext)db);
            cacheWells = cacheDb.GetCachedTable<Well>((AsbCloudDbContext)db);
        }

        public IEnumerable<DataSaubBaseDto> Get(int wellId, DateTime dateBegin = default, double intervalSec = 600d, int approxPointsCount = 1024)
        {
            var well = cacheWells.FirstOrDefault(w => w.Id == wellId);
            if (well is null)
                return default;

            var telemetry = cacheTelemetry.FirstOrDefault(t => t.Id == well.IdTelemetry);
            if (telemetry is null)
                return default;

            if (dateBegin == default)
                dateBegin = DateTime.Now.AddSeconds(-intervalSec);

            var datEnd = dateBegin.AddSeconds(intervalSec);

            var fullData = from data in db.DataSaubBases
                           where data.IdTelemetry == telemetry.Id
                           && data.Date >= dateBegin && data.Date < datEnd
                           select data;

            var fullDataCount = fullData.Count();

            if (fullDataCount == 0)
                return default;

            if (fullDataCount > 1.2 * approxPointsCount)
            {
                var m = approxPointsCount / fullDataCount;
                fullData = fullData.Where(d => d.Id % m == 0);
            }

            var dbData = fullData.ToList();
            var result = new List<DataSaubBaseDto>(dbData.Count);

            foreach (var item in dbData)
                result.Add(mapper.Map<DataSaubBaseDto>(item));

            return result;
        }

        public void UpdateData(string uid, IEnumerable<DataSaubBaseDto> dtos)
        {
            if (dtos == default || !dtos.Any())
                return;

            var telemetryId = telemetryService.GetOrCreateTemetryIdByUid(uid);
            var dtoMinDate = dtos.Min(d => d.Date);
            var dtoMaxDate = dtos.Max(d => d.Date);

            var oldDataSaubBase = (from d in db.DataSaubBases
                                    where d.IdTelemetry == telemetryId 
                                        && d.Date > dtoMinDate
                                        && d.Date < dtoMaxDate
                                    select d).ToList();

            if (oldDataSaubBase.Any())
            {
                db.DataSaubBases.RemoveRange(oldDataSaubBase);
            }

            foreach (var item in dtos)
            {
                var dataSaub = mapper.Map<DataSaubBase>(item);
                dataSaub.IdTelemetry = telemetryId;
                db.DataSaubBases.Add(dataSaub);
            }

            db.SaveChanges();
        }

        public DatesRangeDto GetDataDatesRange(int wellId)
        {
            var telemetry = telemetryService.GetTelemetryByWellId(wellId);
            if (telemetry is null)
                return null;

            var (From, To) = db.GetDatesRange<DataSaubBase>(telemetry.Id);

            return new DatesRangeDto { From = From, To = To};
        }
    }
}