using Fitness_core_BE.Models;

namespace Fitness_core_BE.Interfaces
{
    public interface IFacilityClassRepository
    {
        Task<FacilityClass> CreateFacilityClass(FacilityClass facilityClass);
        Task<List<FacilityClass>> GetFacilityClasses(Guid clientId, bool includeInactive = false);
        Task<FacilityClass?> GetFacilityClassById(Guid facilityClassId);
        Task<FacilityClass> UpdateFacilityClass(FacilityClass facilityClass);

        /// <summary>Active, non-Custom classes whose OccurrencesGeneratedThrough hasn't reached
        /// the horizon yet -- Custom classes are never generated, their occurrences are always
        /// written explicitly.</summary>
        Task<List<FacilityClass>> GetClassesNeedingGenerationAsync(Guid clientId, DateTime horizon);

        /// <summary>Existing occurrence start times for this class in [from, to) -- for
        /// pre-generation dedup. The unique (FKFacilityClassId, StartTime) index is the actual
        /// race-safety net; this just avoids the common sequential case needlessly retrying.</summary>
        Task<HashSet<DateTime>> GetExistingOccurrenceStartTimesAsync(Guid facilityClassId, DateTime from, DateTime to);

        Task AddOccurrencesAsync(IEnumerable<FacilitySession> occurrences);

        Task<List<FacilitySession>> GetOccurrencesForClassAsync(Guid facilityClassId, bool includeCancelled);

        /// <summary>Deletes occurrences that are both in the future and have zero Booking rows
        /// of ANY status (a Cancelled booking still holds the FK, so it would fail the delete) --
        /// the safe-to-regenerate set when a class's recurrence rule changes. Returns the count
        /// deleted.</summary>
        Task<int> DeleteFutureUnbookedOccurrencesAsync(Guid facilityClassId, DateTime nowUtc);

        /// <summary>Confirmed, non-cancelled ad-hoc bookings whose window overlaps an active
        /// (non-cancelled) class occurrence on the same facility -- surfaced to staff as a
        /// conflict to resolve via the existing Reschedule flow, not auto-resolved.</summary>
        Task<List<Booking>> GetSchedulingConflictsAsync(Guid clientId);

        /// <summary>Links a newly-created CustomerPlan to the class it's sold against -- the
        /// "Manage Plan" action's whole reason for being a class-scoped entry point rather than
        /// the general Plans tab.</summary>
        Task LinkPlanToClassAsync(Guid customerPlanId, Guid facilityClassId);
    }
}