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

namespace AsbCloudInfrastructure.Services
{
    public class MessageService : IMessageService
    {
        private readonly IAsbCloudDbContext db;
        private readonly ITelemetryService telemetryService;
        private readonly IMapper mapper;
        private readonly CacheTable<Event> cacheEvents;
        private readonly CacheTable<TelemetryUser> cacheTUsers;

        public MessageService(IAsbCloudDbContext db, CacheDb cacheDb, ITelemetryService telemetryService, MapperConfiguration mapperConfiguration)
        {
            this.db = db;
            this.telemetryService = telemetryService;
            mapper = mapperConfiguration.CreateMapper();
            cacheEvents = cacheDb.GetCachedTable<Event>((AsbCloudDbContext)db);
            cacheTUsers = cacheDb.GetCachedTable<TelemetryUser>((AsbCloudDbContext)db);
        }

        public PaginationContainer<MessageDto> GetMessages(int wellId, IEnumerable<int> categoryids = default, DateTime begin = default, DateTime end = default, int skip = 0, int take = 32)
        {
            var telemetry = telemetryService.GetTelemetryByWellId(wellId);
            if (telemetry is null)
                return null;

            var events = cacheEvents.Select(e => e.IdTelemetry == telemetry.Id);

            if (!events.Any())
                return null;

            var messages = from m in db.Messages
                           where m.IdTelemetry == telemetry.Id
                           select m;

            if ((categoryids != default) && (categoryids.Any()))
            {
                var eventIds = from e in events
                               where categoryids.ToList().Contains(e.IdCategory)
                               select e.IdEvent;

                if (!eventIds.Any())
                    return null;

                messages = messages.Where(m => eventIds.Contains(m.IdEvent));
            }

            var result = new PaginationContainer<MessageDto>() { Skip = skip, Take = take };

            messages = messages.OrderByDescending(m => m.Date);

            if (begin != default)
                messages = messages.Where(m => m.Date >= begin);

            if (end != default)
                messages = messages.Where(m => m.Date <= end);

            result.Count = messages.Count();

            if (skip > 0)
                messages = messages.Skip(skip);

            var messagesList = messages.Take(take).ToList();

            if (messagesList.Count == 0)
                return result;

            var users = cacheTUsers.Select(u => u.IdTelemetry == telemetry.Id);

            foreach (var message in messagesList)
            {
                var messageDto = new MessageDto
                {
                    Date = message.Date,
                    Id = message.Id,
                    User = users.FirstOrDefault(u => u.IdUser == message.IdTelemetryUser).MakeDisplayName(),
                };

                var e = events.FirstOrDefault(e => e.IdEvent == message.IdEvent);
                if (e != null)
                {
                    messageDto.CategoryId = e.IdCategory;
                    messageDto.Message = e.MakeMessageText(message);
                }

                result.Items.Add(messageDto);
            }

            return result;
        }

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

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

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

        public void Insert(string uid, IEnumerable<TelemetryMessageDto> dtos)
        {
            if (!dtos.Any())
                return;

            var telemetryId = telemetryService.GetOrCreateTemetryIdByUid(uid);

            foreach (var dto in dtos)
            {
                var entity = mapper.Map<Message>(dto);
                entity.Id = 0;
                entity.IdTelemetry = telemetryId;
                db.Messages.Add(entity);
            }

            db.SaveChanges();
        }
    }
}