#nullable enable
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using UserService.DatabaseLayer.DataModels;
using UserService.Infrastructure.DataModels;

namespace UserService.DatabaseLayer.Repository
{
    public class BaseRepository<T> where T : Node
    {
        protected Func<UserServiceDbContext, DbSet<T>> Context { get; }

        protected BaseRepository(Func<UserServiceDbContext, DbSet<T>> context)
        {
            Context = context;
        }

        public virtual async Task<IReadOnlyList<T>> GetAllAsync(Expression<Func<T, bool>>? predicate = null, CancellationToken token = default)
        {
            await using var db = new UserServiceDbContext();
            return await Context(db).Include(x => x.Parent).WhereOrDefault(predicate).ToListAsync(token).ConfigureAwait(false);
        }

        public async Task<T?> GetAsync(Expression<Func<T, bool>> predicate, CancellationToken token = default)
        {
            await using var db = new UserServiceDbContext();
            return await Context(db).FirstOrDefaultAsync(predicate, token).ConfigureAwait(false);
        }

        public async Task AddAsync(T entity, CancellationToken token = default)
        {
            await using var db = new UserServiceDbContext();
            await Context(db).AddAsync(@entity, token).ConfigureAwait(false);
            await db.SaveChangesAsync(token).ConfigureAwait(false);
        }

        public async Task<bool> UpdateAsync(T entity, CancellationToken token = default)
        {
            await using var db = new UserServiceDbContext();
            Context(db).Update(entity);
            var items= await db.SaveChangesAsync(token).ConfigureAwait(false);
            return items > 0;
        }

        public async Task DeleteAsync(T entity, CancellationToken token = default)
        {
            await using var db = new UserServiceDbContext();
            Context(db).Remove(entity);
            await db.SaveChangesAsync(token).ConfigureAwait(false);
        }
    }
}