PIbd-23_Firsov_KA_SUBD/Hotel/HotelDatabase/Implement/ReservationImplement.cs

using HotelAbstractions.Logic;
using HotelAbstractions.Models;
using Npgsql;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace HotelDatabase.Implement
{
    public class ReservationImplement : IReservationLogic
    {
        public Reservation? Create(Reservation reservation)
        {
            using var con = SqlConnection.GetConnection();
            con.Open();
            using var cmd = new NpgsqlCommand(
                "INSERT INTO reservation (fk_room_id, fk_guest_id, arrival_date, departure_date, price)" +
                             " VALUES (@FKRoom_id, @FKGuest_id, @Arrival_date, @Departure_date, @Price)",
                con
                );
            cmd.Parameters.AddWithValue("@FKRoom_id", reservation.RoomId == 0 ? DBNull.Value : reservation.RoomId);
            cmd.Parameters.AddWithValue("@FKGuest_id", reservation.GuestId == 0 ? DBNull.Value : reservation.GuestId);
            cmd.Parameters.AddWithValue("@Arrival_date", reservation.ArrivalDate);
            cmd.Parameters.AddWithValue("@Departure_date", reservation.DepartureDate);
            cmd.Parameters.AddWithValue("@Price", reservation.Price);
            cmd.ExecuteNonQuery();
            return reservation;
        }

        public Reservation? Delete(int id)
        {
            var element = Get(id);
            using var con = SqlConnection.GetConnection();
            con.Open();
            using var cmd = new NpgsqlCommand($"DELETE FROM reservation WHERE reservation_id = {id}", con);
            cmd.ExecuteNonQuery();
            return element;
        }

        public Reservation? Get(int id)
        {
            using var con = SqlConnection.GetConnection();
            con.Open();
            using var cmd = new NpgsqlCommand($"SELECT * FROM reservation WHERE reservation_id = {id}", con);
            using var reader = cmd.ExecuteReader();
            if (reader.Read())
            {
                return new Reservation
                {
                    Id = reader.GetInt32(0),
                    RoomId = !reader.IsDBNull(1) ? reader.GetInt32(1) : 0,
                    GuestId = !reader.IsDBNull(2) ? reader.GetInt32(2) : 0,
                    ArrivalDate = ToDateOnly(reader.GetDateTime(3)),
                    DepartureDate = ToDateOnly(reader.GetDateTime(4)),
                    Price = reader.GetDouble(5),
                };
            }
            return null;
        }

        public List<Reservation> GetAll()
        {
            var reservations = new List<Reservation>();
            using var con = SqlConnection.GetConnection();
            con.Open();
            using var cmd = new NpgsqlCommand("SELECT * FROM reservation order by reservation_id", con);
            using var reader = cmd.ExecuteReader();
            while (reader.Read())
            {
                reservations.Add(new Reservation
                {
                    Id = reader.GetInt32(0),
                    RoomId = !reader.IsDBNull(1) ? reader.GetInt32(1) : 0,
                    GuestId = !reader.IsDBNull(2) ? reader.GetInt32(2) : 0,
                    ArrivalDate = ToDateOnly(reader.GetDateTime(3)),
                    DepartureDate = ToDateOnly(reader.GetDateTime(4)),
                    Price = reader.GetDouble(5),
                });
            }
            return reservations;
        }

        public Reservation? Update(Reservation reservation)
        {
            using var con = SqlConnection.GetConnection();
            con.Open();
            using var cmd = new NpgsqlCommand($"UPDATE reservation SET " +
                $"fk_room_id = @FKHotel_Id, " +
                $"fk_guest_id = @FKGuest_Id, " +
                $"arrival_date = '{reservation.ArrivalDate}', " +
                $"departure_date = '{reservation.DepartureDate}', " +
                $"price = '{reservation.Price}'  " +
                $"WHERE reservation_id = {reservation.Id}", con);
            cmd.Parameters.AddWithValue("@FKRoom_Id", reservation.RoomId == 0 ? DBNull.Value : reservation.RoomId);
            cmd.Parameters.AddWithValue("@FKGuest_Id", reservation.GuestId == 0 ? DBNull.Value : reservation.GuestId);
            cmd.ExecuteNonQuery();
            var element = Get(reservation.Id);
            return element;
        }

        public DateOnly ToDateOnly(DateTime dateTime)
        {
            var DateTime = dateTime;
            var Date = new DateOnly(DateTime.Year, DateTime.Month, DateTime.Day);
            return Date;
        }
    }
}