Core_Be/Models/SubscriptionInstallment.cs

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

namespace Fitness_core_BE.Models
{
    /// <summary>
    /// One scheduled part of a subscription's price (mostly-equal split, e.g. a
    /// Rs. 6000 six-month plan → 6 monthly rows of Rs. 1000; the last row absorbs
    /// rounding). Payments are allocated to installments in InstallmentNo order.
    /// InstallmentCount = 1 plans get a single row due at onboarding.
    /// </summary>
    public class SubscriptionInstallment
    {
        [Key]
        public Guid SubscriptionInstallmentId { get; set; }

        public Guid FKSubscriptionId { get; set; }
        [ForeignKey("FKSubscriptionId")]
        public virtual CustomerSubscription Subscription { get; set; }

        /// <summary>1-based position in the schedule.</summary>
        public int InstallmentNo { get; set; }

        public DateTime DueDate { get; set; }
        public decimal Amount { get; set; }
        public decimal PaidAmount { get; set; } = 0m;

        /// <summary>"Pending" | "Partial" | "Paid".</summary>
        public string Status { get; set; } = "Pending";

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