Core_Be/Models/FacilitySession.cs

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace Fitness_core_BE.Models
{
    /// <summary>One scheduled, bookable occurrence of a Facility (e.g. "Pool, Tue 6-7pm").
    /// Capacity is enforced by counting non-cancelled Bookings against this row, not by a
    /// denormalized counter, to avoid drift between the two.</summary>
    public class FacilitySession
    {
        [Key]
        public Guid FacilitySessionId { get; set; }

        public Guid FKFacilityId { get; set; }
        [ForeignKey(nameof(FKFacilityId))]
        public Facility Facility { get; set; }

        public Guid FKClientId { get; set; }
        [ForeignKey(nameof(FKClientId))]
        public Client Client { get; set; }

        public DateTime StartTime { get; set; }
        public DateTime EndTime { get; set; }

        /// <summary>Overrides Facility.DefaultCapacity when set; null = use the facility default.</summary>
        public int? Capacity { get; set; }

        public bool IsCancelled { get; set; } = false;
        public DateTime CreatedAt { get; set; } = DateTime.UtcNow;

        public virtual ICollection<Booking> Bookings { get; set; }
    }
}