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

namespace AsbCloudInfrastructure.Services
{
    public class UserService :  IUserService
    {
        private readonly CacheTable<User> cacheUsers;
        private readonly CacheTable<RelationUserUserRole> cacheRelationUserToRoles;

        public List<string> Includes { get; }
        public IUserRoleService RoleService { get; }

        public UserService(IAsbCloudDbContext context, CacheDb cacheDb, IUserRoleService roleService)
        {
            var db = (AsbCloudDbContext)context;
            cacheUsers = cacheDb.GetCachedTable<User>(
                db,
                new[] { 
                    nameof(User.RelationUsersUserRoles),
                    nameof(User.Company),
                });
            cacheRelationUserToRoles = cacheDb.GetCachedTable<RelationUserUserRole>(
                db,
                new[] {
                    nameof(RelationUserUserRole.User),
                    nameof(RelationUserUserRole.UserRole),
                });
            RoleService = roleService;
        }

        public async Task<int> InsertAsync(UserExtendedDto dto, CancellationToken token = default)
        {
            var entity = dto.Adapt<User>();
            var updatedEntity = await cacheUsers.InsertAsync(entity, token).ConfigureAwait(false);
            await UpdateRolesCacheForUserAsync((int)updatedEntity.Id, dto.RoleNames, token);
            return updatedEntity?.Id ?? 0;
        }

        public Task<int> InsertRangeAsync(IEnumerable<UserExtendedDto> newItems, CancellationToken token = default)
        {
            throw new NotImplementedException();
        }

        public async Task<IEnumerable<UserExtendedDto>> GetAllAsync(CancellationToken token = default)
        {
            var entities = (await cacheUsers.WhereAsync(token).ConfigureAwait(false))
                .ToList();
            if (entities.Count == 0)
                return null;
            var dtos = entities.Adapt<UserExtendedDto>().ToList();
            for (var i = 0; i < dtos.Count; i++)
                dtos[i].RoleNames = GetRolesNamesByIdUser(dtos[i].Id);

            return dtos;
        }

        public async Task<UserExtendedDto> GetAsync(int id, CancellationToken token = default)
        {
            var entity = await cacheUsers.FirstOrDefaultAsync(u=>u.Id == id, token).ConfigureAwait(false);
            var dto = entity.Adapt<UserExtendedDto>();
            dto.RoleNames = GetRolesNamesByIdUser(dto.Id);
            return dto;
        }

        public async Task<int> UpdateAsync(int id, UserExtendedDto dto, CancellationToken token = default)
        {
            var entity = dto.Adapt<User>();
            await UpdateRolesCacheForUserAsync(id, dto.RoleNames, token);

            var result = await cacheUsers.UpsertAsync(entity, token)
                .ConfigureAwait(false);

            return result;
        }

        public Task<int> DeleteAsync(int id, CancellationToken token = default)
        => cacheUsers.RemoveAsync(r => r.Id == id, token);

        public Task<int> DeleteAsync(IEnumerable<int> ids, CancellationToken token = default)
        => cacheUsers.RemoveAsync(r => ids.Contains(r.Id), token);

        private IEnumerable<string> GetRolesNamesByIdUser(int idUser)
        => GetRolesByIdUser(idUser)
            ?.Select(r => r.Caption)
            .Distinct();

        public IEnumerable<UserRoleDto> GetRolesByIdUser(int idUser)
        {
            var roles = cacheRelationUserToRoles.Where(r => r.IdUser == idUser);
            if (roles?.Any() != true)
                return null;
            return roles.SelectMany(r => RoleService.GetNestedById(r.IdUserRole));
        }

        public IEnumerable<PermissionDto> GetNestedPermissions(int idUser)
        {
            var roles = GetRolesByIdUser(idUser);
            if(roles?.Any() != true)
                return null;
            var permissions = roles
                .Where(r => r.Permissions is not null)
                .SelectMany(r => r.Permissions);

            return permissions;
        }

        private async Task UpdateRolesCacheForUserAsync(int idUser, IEnumerable<string> newRoleNames, CancellationToken token)
        {
            if (newRoleNames?.Any() != true)
                return;

            var relatrions = new List<RelationUserUserRole>(newRoleNames.Count());
            foreach (var roleName in newRoleNames)
            {
                var role = await RoleService.GetByNameAsync(roleName, token)
                    .ConfigureAwait(false);
                if (role != null)
                    relatrions.Add(new()
                    {
                        IdUser = idUser,
                        IdUserRole = role.Id,
                    });
            }
            await cacheRelationUserToRoles.RemoveAsync(r => r.IdUser == idUser, token)
                    .ConfigureAwait(false);
            await cacheRelationUserToRoles.InsertAsync(relatrions, token)
                    .ConfigureAwait(false);
        }

        public bool HasAnyRoleOf(int idUser, IEnumerable<string> roleNames)
        {
            if(!roleNames.Any())
                return true;
            var userRoleNames = GetRolesNamesByIdUser(idUser);
            foreach (var roleName in userRoleNames)
                if (roleNames.Contains(roleName))
                    return true;
                return false;
        }

        public bool HasAnyRoleOf(int idUser, IEnumerable<int> roleIds)
        {
            if (!roleIds.Any())
                return true;
            var userRoles = GetRolesByIdUser(idUser);
            foreach (var role in userRoles)
                if (roleIds.Contains(role.Id))
                    return true;
            return false;
        }

        public bool HasPermission(int idUser, string permissionName)
        {
            var relationsToRoles = cacheRelationUserToRoles.Where(r=>r.IdUser == idUser);
            if (relationsToRoles is null)
                return false;

            return RoleService.HasPermission(relationsToRoles.Select(r => r.IdUserRole),
                                                        permissionName);
        }
    }
}