using GB5Shared.DTO.Framework.Login;
using GoodBooks.PAY.PAYDAL.DTO.Loyalty;

namespace GoodBooks.PAY.PAYBLL.Loyalty
{
    public interface ILoyaltyEarnCfgBLL
    {
        Task<IEnumerable<LoyaltyEarnCfgDTO>> GetEarnCfgsByProgram(int programId, LoginDTO login, CancellationToken ct);

        /// <summary>
        /// Resolves the highest-priority active earn rule for a given transaction context.
        /// Priority order (highest wins): ByProduct (5) > ByCategory (4) > ByGateway (3) > ByTier (2) > Global (1).
        /// Returns null when no eligible rule exists.
        /// Pure in-memory operation — no async.
        /// </summary>
        LoyaltyEarnCfgDTO? ResolveEarnRule(
            IEnumerable<LoyaltyEarnCfgDTO> rules,
            int? productId,
            int? categoryId,
            int? gatewayId,
            int? tierId);

        /// <summary>
        /// Calculates the earn points for a given net payable amount.
        /// Result is floored to a whole number.
        /// tierMultiplier defaults to 1.0 when the program has no tiering.
        /// </summary>
        decimal CalculateEarnPoints(decimal netPayableAmt, LoyaltyEarnCfgDTO earnRule, LoyaltyTierDTO? tier);
    }
}