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

namespace AsbCloudInfrastructure.Services.Subsystems
{
    internal class SubsystemOperationTimeService : ISubsystemOperationTimeService
    {

        private readonly IAsbCloudDbContext db;
        private readonly IWellService wellService;
        private readonly SubsystemService subsystemService;

        public SubsystemOperationTimeService(IAsbCloudDbContext db, IWellService wellService, SubsystemService subsystemService)
        {
            this.db = db;
            this.wellService = wellService;
            this.subsystemService = subsystemService;
        }

        public async Task <IEnumerable<SubsystemDto>> GetSubsystemAsync(int idWell, CancellationToken token)
        {            
                var well = await wellService.GetOrDefaultAsync(idWell, token);                
                if (well?.IdTelemetry is null || well.Timezone is null)
                    return null;
                var wellSubsystem = db.SubsystemOperationTimes
                    .Include(e=>e.Subsystem)
                    .AsNoTracking()
                    .Where(o => o.IdTelemetry == well.IdTelemetry)
                    .DistinctBy(o => o.IdSubsystem)
                    .Select(d => new SubsystemDto
                    {
                        Id = d.Subsystem.Id,
                        Name = d.Subsystem.Name,
                        Description = d.Subsystem.Description,

                    });                
                return wellSubsystem;
        }
        

        public async Task<int> DeleteAsync(SubsystemOperationTimeRequest request, CancellationToken token)
        {
            var well = await wellService.GetOrDefaultAsync(request.IdWell, token);
            if (well?.IdTelemetry is null || well.Timezone is null)
                return 0;
            var query = BuildQuery(request);
            db.SubsystemOperationTimes.RemoveRange(query);
            return await db.SaveChangesAsync(token);
        }

        public async Task<IEnumerable<SubsystemOperationTimeDto>> GetOperationTimeAsync(SubsystemOperationTimeRequest request, CancellationToken token)
        {           

            var query = BuildQuery(request)
                .AsNoTracking();
            if (query is null)
                return null;
            var data = await query.ToListAsync(token);            
            var dtos = data.Select(o => Convert(o));
            
            return dtos;
        }

       

        public async Task<IEnumerable<SubsystemStatisticsDto>?> GetStatAsync(SubsystemOperationTimeRequest request, CancellationToken token)
        {            
            var query = BuildQuery(request)
                ?.AsNoTracking();
            if (query is null)
                return null;
            var groupedData = await query
                .GroupBy(o => o.IdSubsystem)
                .ToListAsync(token);
            var statList = CalcStat(groupedData,request);
            return statList;
        }

       

        private IEnumerable<SubsystemStatisticsDto> CalcStat(List<IGrouping<int, SubsystemOperationTime>> groupedData, SubsystemOperationTimeRequest request)
        {
            var result = new List<SubsystemStatisticsDto>();
            var periodGroupTotal = groupedData.Sum(g => g.Sum(o=> o.DateEnd.ToUnixTimeSeconds()-o.DateStart.ToUnixTimeSeconds()));            
            foreach (IEnumerable<SubsystemOperationTime> item in groupedData)
            {
                var periodGroup = item.Sum(g => g.DateEnd.ToUnixTimeSeconds() - g.DateStart.ToUnixTimeSeconds());
                var periodRequest = item.Where(o => o.DateStart==request.GtDate & o.DateEnd == request.LtDate)
                    .Sum(o =>  o.DateEnd.ToUnixTimeSeconds() - o.DateStart.ToUnixTimeSeconds());
                int idSubsystem = item.First().IdSubsystem; 
                var subsystemStat = new SubsystemStatisticsDto()
                {
                    IdSubsystem = idSubsystem,
                    Subsystem = subsystemService.GetOrDefault(idSubsystem)?.Name ?? "unknown",
                    UsedTime = ConvertToTimeSpan(periodGroup),
                    KUsage = ConvertToTimeSpan(periodGroup / periodRequest),
                    K2 = ConvertToTimeSpan(periodGroup / periodGroupTotal),
                };
                result.Add(subsystemStat);
            }
            return result;
        }

        private TimeSpan ConvertToTimeSpan(long sec)
        {
            TimeSpan ts = TimeSpan.FromSeconds(sec);
            return ts;
        }

        private IQueryable<SubsystemOperationTime>? BuildQuery(SubsystemOperationTimeRequest request)
        {
            var idTelemetry = wellService.GetOrDefault(request.IdWell)?.IdTelemetry;
            if (idTelemetry is null)
                return null;

            var query = db.SubsystemOperationTimes
            .Include(o => o.Subsystem)
            .Where(o => o.IdTelemetry == idTelemetry);
            
            if(request.IdsSubsystems?.Any() == true)
                query = query.Where(o => request.IdsSubsystems.Contains(o.IdSubsystem));

            switch(request.SelectMode)
            {
                case 0:
                case 2:
                    if (request.GtDate is not null)
                        query = query.Where(o => o.DateStart >= request.GtDate.Value||o.DateEnd >= request.GtDate.Value);

                    if (request.LtDate is not null)
                        query = query.Where(o => o.DateEnd <= request.LtDate.Value||o.DateStart <= request.LtDate.Value);
                    break;
                    
                case 1:
                    if (request.GtDate is not null)
                        query = query.Where(o => o.DateStart >= request.GtDate.Value);

                    if (request.LtDate is not null)
                        query = query.Where(o => o.DateEnd <= request.LtDate.Value);
                    break;              

            }
            
            if (request.GtDepth is not null)
                query = query.Where(o => o.DepthStart >= request.GtDepth.Value);

            if (request.LtDepth is not null)
                query = query.Where(o => o.DepthEnd <= request.LtDepth.Value);                
            

            if (request?.SortFields?.Any() == true)
            {
                query = query.SortBy(request.SortFields);
            }
            else
                query = query
                    .OrderBy(o => o.DateStart)
                    .ThenBy(o => o.DepthStart);

            if (request?.Skip > 0)
                query = query.Skip((int)request.Skip);

            if (request?.Take > 0)
                query = query.Take((int)request.Take);
            else
                query = query.Take(3000);

            return query;
        }

        private SubsystemOperationTimeDto Convert(SubsystemOperationTime operationTime)
        {
            var dto = operationTime.Adapt<SubsystemOperationTimeDto>();           
            return dto;
        }



    }
}