using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using UserService.DatabaseLayer.DataModels;

namespace UserService.DatabaseLayer.Repository
{
    public class OrganizationUnitsRepository : BaseRepository<OrganizationUnit>, IOrganizationUnitsRepository
    {
        public OrganizationUnitsRepository() : base(x => x.OrganizationUnits)
        {
        }

        /// <inheritdoc />
        public override async Task<IReadOnlyList<OrganizationUnit>> GetAllAsync(CancellationToken token = default)
        {


            await using var db = new UserServiceDbContext();
            var result = new List<OrganizationUnit>();
            var rootOus = await _context(db)
                .Include(x => x.Parent)
                .ToListAsync(token);

            IEnumerable<OrganizationUnit> Rec(Node node)
            {
                if (!(node is OrganizationUnit organizationUnit)) yield break;
                yield return organizationUnit;
                foreach (var ouChild in rootOus.Where(x=>x.ParentId != null && x.ParentId == organizationUnit.Id))
                {
                    foreach (var unit in Rec(ouChild))
                    {
                        yield return unit;
                    }
                }
            }
            foreach (var ou in rootOus.Where(x=> x.ParentId is null))
            {
                result.AddRange(Rec(ou));
            }
            return result;
        }
    }

    public class SecurityGroupsRepository : BaseRepository<SecurityGroup>, ISecurityGroupsRepository
    {
        public SecurityGroupsRepository() : base(x=> x.SecurityGroups)
        {
        }
    }


    public class UsersRepository : BaseRepository<User>, IUsersRepository
    {
        public UsersRepository() : base(x => x.Users)
        {
        }
    }

    public class NodesRepository : INodesRepository
    {
        public NodesRepository()
        {
        }

        public static async IAsyncEnumerable<Node> GetNodesAsync([EnumeratorCancellation] CancellationToken token = default)
        {
            await using var db = new UserServiceDbContext();
            await foreach (var note in db.OrganizationUnits.AsAsyncEnumerable().WithCancellation(token))
            {
                yield return note;
            }
            await foreach (var node in db.SecurityGroups.AsAsyncEnumerable().WithCancellation(token))
            {
                yield return node;
            }

            await foreach (var node in db.Users.AsAsyncEnumerable().WithCancellation(token))
            {
                yield return node;
            }
        }

        public async Task<IReadOnlyList<Node>> GetAllAsync(CancellationToken token = default)
        {
            
            var list = new List<Node>();
            await foreach (var node in GetNodesAsync(token))
            {
                list.Add(node);
            }

            return list;
        }

        public Task<Node?> GetAsync(Expression<Func<Node, bool>> predicate, CancellationToken token = default)
        {
            throw new NotImplementedException();
        }

        public Task AddAsync(Node entity, CancellationToken token = default)
        {
            throw new NotImplementedException();
        }

        public Task UpdateAsync(Node entity, CancellationToken token = default)
        {
            throw new NotImplementedException();
        }

        public Task DeleteAsync(Node entity, CancellationToken token = default)
        {
            throw new NotImplementedException();
        }
    }
}