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

namespace Fitness_core_BE.Models
{
    /// <summary>A prepaid time balance on an RFID card, deducted by actual use via a tap-in/
    /// tap-out swipe pattern (a 1-hour visit deducts 60 minutes, a 15-minute visit deducts 15 --
    /// see ActiveSessionStartedAt) — separate from Booking's per-session OTP flow. Can belong to
    /// a member (FKCustomerId set, e.g. an add-on to their plan) or be sold standalone to a
    /// walk-in against just the RFID tag.</summary>
    public class TimeBankCard
    {
        [Key]
        public Guid TimeBankCardId { get; set; }

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

        // Tenant-bucket entity: holds a TenantCustomerLinkId, not the central Customer.CusId
        // directly -- see Models/TenantCustomerLink.cs. Null for a card sold to a walk-in with
        // no membership at all.
        public Guid? FKCustomerId { get; set; }
        [ForeignKey(nameof(FKCustomerId))]
        public TenantCustomerLink? TenantCustomerLink { get; set; }

        [MaxLength(64)]
        public string RfidTagId { get; set; } = string.Empty;

        public int TotalMinutesPurchased { get; set; }
        public int MinutesRemaining { get; set; }

        public decimal AmountPaid { get; set; } = 0m;
        public Guid? FKPaymentTransactionId { get; set; }
        [ForeignKey(nameof(FKPaymentTransactionId))]
        public PaymentTransaction? PaymentTransaction { get; set; }

        public DateTime PurchasedAt { get; set; } = DateTime.UtcNow;

        /// <summary>Null = balance never expires (spend it whenever); business can still set one.</summary>
        public DateTime? ExpiresAt { get; set; }

        public bool IsActive { get; set; } = true;
        public DateTime CreatedAt { get; set; } = DateTime.UtcNow;

        // Tap-in/tap-out state: null = not currently on the floor anywhere. A swipe with this
        // null starts a session (tap-in, no deduction yet); a swipe with this set ends it
        // (tap-out) and deducts the elapsed minutes. One open session per card at a time --
        // a second tap-in without a matching tap-out first is rejected by the service, not
        // silently overwritten, so a lost/forgotten tap-out surfaces instead of losing time.
        public DateTime? ActiveSessionStartedAt { get; set; }
        public Guid? ActiveSessionFacilityId { get; set; }
        [ForeignKey(nameof(ActiveSessionFacilityId))]
        public Facility? ActiveSessionFacility { get; set; }

        public virtual ICollection<TimeBankCardUsageLog> UsageLogs { get; set; }
    }
}