using Data.SeaHavenIndustries.Enums;

namespace SeaHaven.Services.Helpers
{
    public static class WorkOrderBoardMutationRules
    {
        private static readonly HashSet<LifecycleStatus?> ReadOnlyStatuses =
            LifecycleStatusSets.Terminal.Cast<LifecycleStatus?>().ToHashSet();

        public static bool IsReadOnly(LifecycleStatus? status) => ReadOnlyStatuses.Contains(status);

        public static bool IsFullyLocked(LifecycleStatus? status)
            => status == LifecycleStatus.Canceled;

        public static bool IsCoreLocked(LifecycleStatus? status)
            => status == LifecycleStatus.Completed;

        public static bool CanPatchBoardField(LifecycleStatus? status, string field)
        {
            if (IsFullyLocked(status))
                return false;
            if (!IsCoreLocked(status))
                return true;
            return field.Equals(WorkOrderBoardFieldNames.FlagColor, StringComparison.OrdinalIgnoreCase);
        }

        public static bool CanMutateComments(LifecycleStatus? status)
            => !IsFullyLocked(status);

        public static bool CanMutateExtraMedia(LifecycleStatus? status, WorkOrderMediaCategory? category)
        {
            if (IsFullyLocked(status))
                return false;
            if (!IsCoreLocked(status))
                return true;
            return IsExtraDocsFamily(category);
        }

        public static bool IsExtraDocsFamily(WorkOrderMediaCategory? category)
        {
            var resolved = category ?? WorkOrderMediaCategory.Extra;
            return resolved == WorkOrderMediaCategory.Extra || resolved == WorkOrderMediaCategory.Aveta;
        }

        public static bool ShouldBlockStatusChangeWhenPastDue(string field, bool isPastDue)
            => field.Equals(WorkOrderBoardFieldNames.LifecycleStatus, StringComparison.OrdinalIgnoreCase) && isPastDue;

        /// <summary>
        /// Concrete Schedule On: a calendar day is set and the row is not week-only.
        /// </summary>
        public static bool HasConcreteSchedule(DateTime? scheduledDate, bool? scheduleWeekOnly)
            => scheduledDate.HasValue && scheduleWeekOnly != true;

        /// <summary>
        /// Incomplete or Pending + concrete scheduled date → Scheduled. Assignee is not required.
        /// Week-only targets do not auto-schedule (same as <see cref="WorkOrderDerivedFields.ApplyAutoScheduleIfEligible"/>).
        /// </summary>
        public static bool ShouldAutoSchedule(
            LifecycleStatus? status,
            DateTime? scheduledDate,
            string? assignTo,
            bool? scheduleWeekOnly = null)
        {
            _ = assignTo;
            return ShouldPromoteToScheduled(status, scheduledDate, scheduleWeekOnly);
        }

        public static bool ShouldPromoteToScheduled(
            LifecycleStatus? status,
            DateTime? scheduledDate,
            bool? scheduleWeekOnly = null)
            => (status == LifecycleStatus.Incomplete || status == LifecycleStatus.Pending)
               && HasConcreteSchedule(scheduledDate, scheduleWeekOnly);

        /// <summary>
        /// Scheduled without a concrete date (cleared or week-only) → Pending. Later statuses are ignored.
        /// </summary>
        public static bool ShouldDemoteFromScheduled(
            LifecycleStatus? status,
            DateTime? scheduledDate,
            bool? scheduleWeekOnly = null)
            => status == LifecycleStatus.Scheduled
               && !HasConcreteSchedule(scheduledDate, scheduleWeekOnly);

        public static bool IsReschedule(DateTime? previousDate, DateTime? newDate)
            => previousDate.HasValue
               && newDate.HasValue
               && previousDate.Value.Date != newDate.Value.Date;

        public static DateOnly? ComputeOriginalWeek(DateTime? scheduledDate)
            => scheduledDate.HasValue
                ? DateOnly.FromDateTime(GetWeekStartMonday(scheduledDate.Value))
                : null;

        public static DateTime GetWeekStartMonday(DateTime date)
        {
            var diff = (7 + (date.DayOfWeek - DayOfWeek.Monday)) % 7;
            return date.Date.AddDays(-diff);
        }
    }
}