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

namespace Fitness_core_BE.Models
{
    public class CustomerPlan
    {
        [Key]
        public Guid CustomerPlanId { get; set; }
        public Guid FKClientId { get; set; }
        [ForeignKey("FKClientId")]
        public virtual Client Client { get; set; }
        public string? PlanName { get; set; }
        public string? PlanDescription { get; set; }
        public decimal PlanPrice { get; set; }

        /// <summary>Whether this plan charges a one-time fee when a new subscription starts.</summary>
        public bool HasOnboardingFee { get; set; } = false;

        /// <summary>One-time amount added to the first invoice/installment.</summary>
        public decimal OnboardingFeeAmount { get; set; } = 0m;

        /// <summary>Used when DurationMode == "Rolling"; 0 for FixedRange plans.</summary>
        public int DurationInDays { get; set; }

        /// <summary>"Individual" | "Group" (couple/family — one subscription covers MemberLimit members).</summary>
        public string PlanScope { get; set; } = "Individual";

        /// <summary>1 for Individual; >= 2 for Group (couple = 2).</summary>
        public int MemberLimit { get; set; } = 1;

        /// <summary>"Rolling" (DurationInDays from join date) | "FixedRange" (ValidFrom–ValidTo).</summary>
        public string DurationMode { get; set; } = "Rolling";

        public DateTime? ValidFrom { get; set; }
        public DateTime? ValidTo { get; set; }

        /// <summary>Owner decides: when true the price splits into InstallmentCount scheduled parts.</summary>
        public bool AllowSplitPayments { get; set; } = false;

        /// <summary>Number of mostly-equal installments (1 = full payment upfront).</summary>
        public int InstallmentCount { get; set; } = 1;

        /// <summary>Null = unlimited-access plan (existing gym behavior). A number = this plan
        /// grants that many bookable Facility sessions per billing cycle (e.g. "4 pool sessions
        /// a month") — enforced by the booking flow, not by this model.</summary>
        public int? SessionsPerCycle { get; set; }

        /// <summary>"NoRollover" (unused sessions are forfeited when the cycle renews) |
        /// "GracePeriod" (unused sessions stay usable for RolloverGraceDays after renewal).
        /// Set per package at creation time, per owner's requirement.</summary>
        public string SessionRolloverPolicy { get; set; } = "NoRollover";

        /// <summary>Days into the new cycle that last cycle's unused sessions remain usable.
        /// Only meaningful when SessionRolloverPolicy == "GracePeriod".</summary>
        public int RolloverGraceDays { get; set; } = 0;

        /// <summary>"Prepaid" (pay before the cycle starts, existing behavior) | "Postpaid"
        /// (use first, invoice at cycle end — reuses Client.LockAfterDaysOverdue /
        /// OverdueLockJob to suspend access if that invoice goes unpaid past due). Asked once,
        /// per package, at creation time per owner's requirement.</summary>
        public string BillingTiming { get; set; } = "Prepaid";

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

        /// <summary>Meaningful only for a plan linked to one or more classes (via
        /// CustomerPlanClass) -- never consulted for an ordinary plan with no class links,
        /// which always grants gym access regardless of this flag's stored value. Lets a class
        /// plan optionally also grant general gym-floor access ("class + gym" as one product)
        /// instead of class-only. Migration default true (so every pre-existing plan, which has
        /// no class links, keeps behaving exactly as before); new class plans default this to
        /// false in the UI.</summary>
        public bool GrantsGymAccess { get; set; } = true;
    }
}