using System.Data.Common;
using System.Threading.Tasks;
using GB5Shared.DTO.Framework.Login;
using GoodBooks.PAY.PAYDAL.DTO.Loyalty;

namespace GoodBooks.PAY.PAYDAL.CustomCode.Loyalty
{
    /// <summary>
    /// Data-access contract for MLOYALTYPROGRAM.
    /// Methods that write data accept an optional DbTransaction so they can participate
    /// in multi-step BLL transactions (header + tiers + earn configs in one commit).
    /// </summary>
    public interface ILoyaltyProgramDAL
    {
        /// <summary>
        /// Fetches a single loyalty program with embedded tier and earn-config child arrays.
        /// Returns serialised JSON string.
        /// </summary>
        Task<string> GetLoyaltyProgram(int programId, LoginDTO login);

        /// <summary>
        /// Returns a paged JSON list of active loyalty programs for the tenant.
        /// </summary>
        Task<string> GetLoyaltyProgramList(int pageOffset, int pageSize, LoginDTO login);

        /// <summary>
        /// Inserts the program header row. Returns rows affected.
        /// Caller is responsible for inserting child tiers and earn configs in the same transaction.
        /// </summary>
        Task<int> InsertLoyaltyProgram(LoyaltyProgramDTO dto, LoginDTO login, DbTransaction? tx);

        /// <summary>
        /// Updates the program header row. Returns rows affected.
        /// Caller must delete and re-insert tiers in the same transaction.
        /// </summary>
        Task<int> UpdateLoyaltyProgram(LoyaltyProgramDTO dto, LoginDTO login, DbTransaction? tx);

        /// <summary>
        /// Deletes all tier rows for the given program (used before re-inserting updated tiers).
        /// Must run in the same transaction as the subsequent tier inserts.
        /// Returns rows affected.
        /// </summary>
        Task<int> DeleteLoyaltyTiersByProgram(int programId, LoginDTO login, DbTransaction? tx);
    }
}