using gehGassi.Core.Interfaces;
using gehGassi.Domain.Walks;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using gehGassi.Domain.Common;
using gehGassi.Domain.Dogs;
using gehGassi.Domain.Ratings;
using Microsoft.EntityFrameworkCore.Metadata.Internal;
using Microsoft.EntityFrameworkCore;
using gehGassi.Common.Extensions;

namespace gehGassi.Core.Services
{
    /// <summary>
    /// Service der die Verwaltung von Ratings ermöglicht
    /// </summary>
    public class RatingService : ServiceBase<Rating>, IRatingService
    {
        private readonly IRepository<RatingWithNames> _namesRepository;
        private readonly IRepository<RatingWithNamesEx> _namesExRepository;
        private readonly IRepository<Dog> _dogsRepository;
        private readonly IRepository<AppUser> _appUserRepository;
        private readonly IRepository<Walk> _walksRepository;

        /// <summary>
        /// Erstellt eine Instanz
        /// </summary>
        /// <param name="unitOfWork">Instanz eines IUnitOfWork</param>
        public RatingService(IUnitOfWork unitOfWork) : base(unitOfWork)
        {
            _namesRepository = unitOfWork.GetRepository<RatingWithNames>();
            _namesExRepository = unitOfWork.GetRepository<RatingWithNamesEx>();
            _dogsRepository = unitOfWork.GetRepository<Dog>();
            _appUserRepository = unitOfWork.GetRepository<AppUser>();
            _walksRepository = unitOfWork.GetRepository<Walk>();
        }

        /// <summary>
        /// Erstellen eines Ratings
        /// </summary>
        /// <returns>Rating</returns>
        public Rating Create()
        {
            var rating = new Rating()
            {
                Id = Guid.NewGuid().ToString("N"),
                Created = DateTimeOffset.UtcNow
            };
            return rating;
        }

        /// <summary>
        /// Erstellen eines Ratings
        /// </summary>
        /// <param name="fromId">Id der Rating Quelle</param>
        /// <param name="fromType">Typ der Rating Quelle</param>
        /// <param name="targetId">Id des Ziels des Ratings</param>
        /// <param name="targetType">Typ des Rating Ziels</param>
        /// <param name="points">Vergebene Punkte</param>
        /// <param name="info">Zusatzinfo zum Rating</param>
        /// <returns>Rating</returns>
        public Rating Create(string fromId, AppUserType fromType, string targetId, RatingTarget targetType, decimal points, string info)
        {
            var rating = new Rating()
            {
                Id = Guid.NewGuid().ToString("N"),
                FromId = fromId,
                FromType = fromType,
                TargetId = targetId,
                TargetType = targetType,
                Points = points,
                Info = info,
                Created = DateTimeOffset.UtcNow
            };
            return rating;
        }

        /// <summary>
        /// Gibt eine Liste der Ratings eines Benutzers zurück. Kann Owner und Walker sein
        /// </summary>
        /// <param name="appUserId">Id des AppUsers</param>
        /// <param name="lastUpdate">Letztes Update</param>
        /// <returns>Liste der öffentlichen Anfragen</returns>
        public async Task<List<Rating>> GetForSyncAppAsync(string appUserId, DateTimeOffset? lastUpdate)
        {
            var query = Repository.Query(c => c.FromId == appUserId);

            if (lastUpdate.HasValue)
                query = query.Where(c => c.UpdatedAt > lastUpdate);

            return await query.ToListAsync().ConfigureAwait(false);
        }

        /// <summary>
        /// Gibt ein Rating basierend auf Abfragekriterien zurück
        /// </summary>
        /// <param name="fromId">Id der Rating Quelle</param>
        /// <param name="fromType">Typ der Rating Quelle</param>
        /// <param name="targetId">Id des Ziels des Ratings</param>
        /// <param name="targetType">Typ des Rating Ziels</param>
        /// <returns>Rating wenn gefunden, null sonst</returns>
        public async Task<Rating> GetRatingExAsync(string fromId, AppUserType fromType, string targetId, RatingTarget targetType)
        {
            var rating = await Repository.FirstOrDefaultAsync(c => c.FromId == fromId && c.FromType == fromType && c.TargetId == targetId && c.TargetType == targetType).ConfigureAwait(false);
            return rating;
        }

        /// <summary>
        /// Neu berechnen der Ratings-Statistics für ein Ziel
        /// </summary>
        /// <param name="targetId">Id des Ziels des Ratings</param>
        /// <param name="targetType">Typ des Rating Ziels</param>
        /// <returns>true wenn erfolgreich, false sonst</returns>
        public async Task<bool> UpdateRatingStatisticsAsync(string targetId, RatingTarget targetType)
        {
            if (targetType == RatingTarget.Dog || targetType == RatingTarget.Owner || targetType == RatingTarget.Walker)
            {
                var totalRatings = await Repository.CountAsync(c => c.TargetId == targetId && c.Deleted == false).ConfigureAwait(false);
                var totalPoints = (await Repository.FindAsync(c => c.TargetId == targetId && c.Deleted == false).ConfigureAwait(false)).Sum(c => c.Points);
                var averageRating = 0m;
                if (totalRatings > 0)
                    averageRating = totalPoints / totalRatings;

                if (targetType == RatingTarget.Dog)
                {
                    var dog = await _dogsRepository.FirstOrDefaultAsync(c => c.Id == targetId);
                    if (dog != null)
                    {
                        dog.RatingStatistics.TotalRatings = totalRatings;
                        dog.RatingStatistics.TotalPoints = totalPoints;
                        dog.RatingStatistics.AverageRating = averageRating;
                        dog.UpdatedAt = DateTimeOffset.UtcNow;

                        return true;
                    }
                }

                if (targetType == RatingTarget.Owner)
                {
                    var appUser = await _appUserRepository.FirstOrDefaultAsync(c => c.Id == targetId);
                    if (appUser != null)
                    {
                        appUser.RatingStatistics.TotalRatings = totalRatings;
                        appUser.RatingStatistics.TotalPoints = totalPoints;
                        appUser.RatingStatistics.AverageRating = averageRating;
                        appUser.UpdatedAt = DateTimeOffset.UtcNow;

                        return true;
                    }
                }

                if (targetType == RatingTarget.Walker)
                {
                    var appUser = await _appUserRepository.FirstOrDefaultAsync(c => c.Id == targetId);
                    if (appUser != null)
                    {
                        appUser.RatingStatisticsWalker.TotalRatings = totalRatings;
                        appUser.RatingStatisticsWalker.TotalPoints = totalPoints;
                        appUser.RatingStatisticsWalker.AverageRating = averageRating;
                        appUser.UpdatedAt = DateTimeOffset.UtcNow;

                        return true;
                    }
                }
            }

            return false;
        }

        /// <summary>
        /// Gibt an ob ein Bewerter ein Ziel bereits bewertet hat
        /// </summary>
        /// <param name="fromId">Id der Rating Quelle</param>
        /// <param name="fromType">Typ der Rating Quelle</param>
        /// <param name="targetId">Id des Ziels des Ratings</param>
        /// <param name="targetType">Typ des Rating Ziels</param>
        /// <returns>true wenn bereits bewertet, false sonst</returns>
        public async Task<bool> HasRatedAsync(string fromId, AppUserType fromType, string targetId, RatingTarget targetType)
        {
            var rating = await Repository.FirstOrDefaultAsync(c => c.FromId == fromId && c.FromType == fromType && c.TargetId == targetId && c.TargetType == targetType).ConfigureAwait(false);
            return rating != null;
        }

        /// <summary>
        /// Gibt zurück ob ein Bewerter ein Ziel bewerten darf.
        /// z.B. ein Walker darf einen hund nur bewerten, wenn mindestens ein Walk mit dem hund stattgefunden hat.
        /// Ein Owner darf einen Walker nur bewerten, wenn dieser mindestens einen Walk für den Owen gemacht hat usw.
        /// </summary>
        /// <param name="fromId">Id der Rating Quelle</param>
        /// <param name="fromType">Typ der Rating Quelle</param>
        /// <param name="targetId">Id des Ziels des Ratings</param>
        /// <param name="targetType">Typ des Rating Ziels</param>
        /// <returns>true wenn eine Bewertung stattfinden darf, false sonst</returns>
        public async Task<bool> CanRateAsync(string fromId, AppUserType fromType, string targetId, RatingTarget targetType)
        {
            if (targetType == RatingTarget.Dog || targetType == RatingTarget.Owner || targetType == RatingTarget.Walker)
            {
                //1. Darf ein Walker einen Hund bewerten?
                if ((fromType == AppUserType.DogWalker || fromType == AppUserType.Both) && targetType == RatingTarget.Dog)
                {
                    var existingWalk = await _walksRepository.FirstOrDefaultAsync(c => c.DogsJson.Contains(targetId) && c.DogWalkerId == fromId && c.Completed.HasValue).ConfigureAwait(false);
                    return existingWalk != null;
                }

                //2. Darf ein Owner einen Walker bewerten?
                if ((fromType == AppUserType.DogOwner || fromType == AppUserType.Both) && targetType == RatingTarget.Walker)
                {
                    var existingWalk = await _walksRepository.FirstOrDefaultAsync(c => c.DogOwnerId == fromId && c.DogWalkerId == targetId && c.Completed.HasValue).ConfigureAwait(false);
                    return existingWalk != null;
                }

                //2. Darf ein Walker einen Owner bewerten?
                if ((fromType == AppUserType.DogWalker || fromType == AppUserType.Both) && targetType == RatingTarget.Owner)
                {
                    var existingWalk = await _walksRepository.FirstOrDefaultAsync(c => c.DogOwnerId == targetId && c.DogWalkerId == fromId && c.Completed.HasValue).ConfigureAwait(false);
                    return existingWalk != null;
                }
            }
            
            return false;
        }

        /// <summary>
        /// Alle Ratings eines AppUsers und für einen AppUser löschen
        /// </summary>
        /// <param name="appUserId">Id des AppUsers</param>
        /// <returns>Anzahl gelöscht</returns>
        public async Task<List<Tuple<string, RatingTarget>>> DeleteAllForAppUserAsync(string appUserId)
        {
            var targetsToUpdate = new List<Tuple<string, RatingTarget>>();

	        //Zuerst werden alle Ratings gelöscht, die an den AppUser gestellt wurden
            var ratings = await Repository.FindAsync(c => c.TargetId == appUserId).ConfigureAwait(false);
            foreach (var rating in ratings)
            {
				Repository.Remove(rating);
			}
            //Nun alle suchen die von dem Benutzer kommen und diese löschen.
            //Achutung: bei den Zielbenutzern muss dann die Statistik aktualisiert werden!
            var ratingsFromUser = await Repository.FindAsync(c => c.FromId == appUserId).ConfigureAwait(false);
            foreach (var rating in ratingsFromUser)
            {
                if (rating.TargetType == RatingTarget.Dog || rating.TargetType == RatingTarget.Owner || rating.TargetType == RatingTarget.Walker)
                {
                    targetsToUpdate.Add(new Tuple<string, RatingTarget>(rating.TargetId, rating.TargetType));
                }

                Repository.Remove(rating);
			}

            return targetsToUpdate;
        }

        /// <summary>
        /// Gibt eine Liste von Ratings mit Namen aufgelöst zurück
        /// </summary>
        /// <param name="fromId">Id der Rating Quelle</param>
        /// <param name="fromType">Typ der Rating Quelle</param>
        /// <param name="targetId">Id des Ziels des Ratings</param>
        /// <param name="targetType">Typ des Rating Ziels</param>
        /// <param name="sortList">Optional: Liste der sortierung</param>
        /// <param name="skip">Datensätze auslassen</param>
        /// <param name="take">Datensätze nehmen</param>
        /// <returns>Liste gefudene Walks</returns>
        public async Task<(int total, List<RatingWithNames> list)> GetWithNamesAsync(string fromId, AppUserType? fromType, string targetId, RatingTarget? targetType, List<DynamicSortOrder> sortList, int skip, int take)
        {
            var baseQuery = _namesRepository.QueryStoredProcedure("SELECT * FROM vw_RatingsWithNames", c => c.Deleted == false);

            if (!string.IsNullOrWhiteSpace(fromId))
                baseQuery = baseQuery.Where(c => c.FromId == fromId);
            if (fromType.HasValue)
                baseQuery = baseQuery.Where(c => c.FromType == fromType);
            if (!string.IsNullOrWhiteSpace(targetId))
                baseQuery = baseQuery.Where(c => c.TargetId == targetId);
            if (targetType.HasValue)
                baseQuery = baseQuery.Where(c => c.TargetType == targetType);

            var total = await baseQuery.CountAsync().ConfigureAwait(false);

            if (sortList.Any())
            {
                var isFirst = true;
                var orderedBaseQuery = baseQuery.SpecialOrderBy(sortList.First().Property, sortList.First().SortDirection); ;
                foreach (var sortOrder in sortList)
                {
                    if (isFirst)
                    {
                        isFirst = false;
                        continue;
                    }
                    else
                    {
                        orderedBaseQuery = orderedBaseQuery.SpecialThenBy(sortOrder.Property, sortOrder.SortDirection);
                    }
                }
                var list = await orderedBaseQuery.Skip(skip).Take(take).ToListAsync().ConfigureAwait(false);
                return (total, list);
            }
            else
            {
                var list = await baseQuery.OrderByDescending(c => c.UpdatedAt).Skip(skip).Take(take).ToListAsync().ConfigureAwait(false);
                return (total, list);
            }
        }

        /// <summary>
        /// Gibt eine Liste von Ratings mit Namen aufgelöst und mit lock und block Info zurück
        /// </summary>
        /// <param name="blockingAppUserId">Id des Benutzers der abfrägt und für den Blocking geprüft wird</param>
        /// <param name="fromId">Id der Rating Quelle</param>
        /// <param name="fromType">Typ der Rating Quelle</param>
        /// <param name="targetId">Id des Ziels des Ratings</param>
        /// <param name="targetType">Typ des Rating Ziels</param>
        /// <param name="sortList">Optional: Liste der sortierung</param>
        /// <param name="skip">Datensätze auslassen</param>
        /// <param name="take">Datensätze nehmen</param>
        /// <returns>Liste gefudene Walks</returns>
        public async Task<(int total, List<RatingWithNamesEx> list)> GetWithNamesExAsync(string blockingAppUserId, string fromId, AppUserType? fromType, string targetId, RatingTarget? targetType, List<DynamicSortOrder> sortList, int skip, int take)
        {
            var baseQuery = _namesExRepository.QueryStoredProcedure("SELECT * FROM tv_RatingsWithNamesEx({0})", c => c.Deleted == false, blockingAppUserId);

            if (!string.IsNullOrWhiteSpace(fromId))
                baseQuery = baseQuery.Where(c => c.FromId == fromId);
            if (fromType.HasValue)
                baseQuery = baseQuery.Where(c => c.FromType == fromType);
            if (!string.IsNullOrWhiteSpace(targetId))
                baseQuery = baseQuery.Where(c => c.TargetId == targetId);
            if (targetType.HasValue)
                baseQuery = baseQuery.Where(c => c.TargetType == targetType);

            var total = await baseQuery.CountAsync().ConfigureAwait(false);

            if (sortList.Any())
            {
                var isFirst = true;
                var orderedBaseQuery = baseQuery.SpecialOrderBy(sortList.First().Property, sortList.First().SortDirection); ;
                foreach (var sortOrder in sortList)
                {
                    if (isFirst)
                    {
                        isFirst = false;
                        continue;
                    }
                    else
                    {
                        orderedBaseQuery = orderedBaseQuery.SpecialThenBy(sortOrder.Property, sortOrder.SortDirection);
                    }
                }
                var list = await orderedBaseQuery.Skip(skip).Take(take).ToListAsync().ConfigureAwait(false);
                return (total, list);
            }
            else
            {
                var list = await baseQuery.OrderByDescending(c => c.UpdatedAt).Skip(skip).Take(take).ToListAsync().ConfigureAwait(false);
                return (total, list);
            }
        }

        /// <summary>
        /// Gibt ein Rating mit Namen aufgelöst zurück
        /// </summary>
        /// <param name="ratingId">Id des Ratings</param>
        /// <returns>Rating oder null, wenn nicht gefunden</returns>
        public async Task<RatingWithNames> GetWithNamesAsync(string ratingId)
        {
            return await _namesRepository.FirstOrDefaultAsync(c => c.Id == ratingId).ConfigureAwait(false);
        }
    }
}