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

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

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

        public async Task<PaginationContainer<MessageDto>> GetMessagesAsync(
            int idWell,
            IEnumerable<int> categoryids = default,
            DateTime begin = default,
            DateTime end = default,
            string searchString = default,
            int skip = 0,
            int take = 32,
            CancellationToken token = default)
        {
            var telemetryId = telemetryService.GetIdTelemetryByIdWell(idWell);
            if (telemetryId is null)
                return null;

            var events = cacheEvents.Where(e => e.IdTelemetry == telemetryId);

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

            var query = db.TelemetryMessages.Where(m => m.IdTelemetry == telemetryId)
                .AsNoTracking();

            if ((categoryids?.Any() == true) || !string.IsNullOrEmpty(searchString))
            {
                if (!string.IsNullOrEmpty(searchString))
                    events = events.Where(e => e.MessageTemplate.Contains(searchString, StringComparison.OrdinalIgnoreCase));

                if (categoryids?.Any() == true)
                    events = events.Where(e => categoryids.ToList().Contains(e.IdCategory));

                var eventIds = events.Select(e => e.IdEvent);

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

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

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

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

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

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

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

            var messagesList = await query.Take(take).AsNoTracking()
                .ToListAsync(token).ConfigureAwait(false);

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

            var users = cacheTUsers.Where(u => u.IdTelemetry == telemetryId);

            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 async Task<DatesRangeDto> GetMessagesDatesRangeAsync(int idWell,
            CancellationToken token = default)
        {
            var telemetryId = telemetryService.GetIdTelemetryByIdWell(idWell);
            if (telemetryId is null)
                return null;

            var (From, To) = await db.GetDatesRangeAsync<TelemetryMessage>((int)telemetryId, token)
                .ConfigureAwait(false);

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

        public Task InsertAsync(string uid, IEnumerable<TelemetryMessageDto> dtos,
            CancellationToken token = default)
        {
            if (!dtos.Any())
                return null;

            var telemetryId = telemetryService.GetOrCreateTemetryIdByUid(uid);

            foreach (var dto in dtos)
            {
                var entity = dto.Adapt<TelemetryMessage>();
                entity.Id = 0;
                entity.IdTelemetry = telemetryId;
                db.TelemetryMessages.Add(entity);
            }

            return db.SaveChangesAsync(token);
        }
    }
}