namespace SeaHaven.Services.DTOs
{
    /// <summary>
    /// Feed reasons in their fixed tie-break order. Every reason the Notification Center
    /// can show is listed here so a new producer only adds items, never a contract change.
    /// </summary>
    public static class NotificationReasons
    {
        public const string SeverityCritical = "severity-critical";
        public const string Sla = "sla";
        public const string Mentions = "mentions";
        public const string Unassigned = "unassigned";
        public const string DueSoon = "due-soon";
        public const string NoVendor = "no-vendor";
        public const string AvetaMissing = "aveta-missing";
        public const string Activity = "activity";
        public const string VendorConflict = "vendor-conflict";

        public static readonly IReadOnlyList<string> Order = new[]
        {
            SeverityCritical, Sla, Mentions, Unassigned, DueSoon, NoVendor, AvetaMissing, Activity, VendorConflict
        };

        public static readonly IReadOnlyDictionary<string, string> Labels = new Dictionary<string, string>
        {
            [SeverityCritical] = "Critical severity",
            [Sla] = "SLA at Risk",
            [Mentions] = "Mentions",
            [Unassigned] = "Unassigned",
            [DueSoon] = "Due Soon",
            [NoVendor] = "No Vendor",
            [AvetaMissing] = "Aveta Missing",
            [Activity] = "Recent activity",
            [VendorConflict] = "Vendor Conflict"
        };
    }

    public static class NotificationSeverities
    {
        public const string Critical = "Critical";
        public const string High = "High";
        public const string Medium = "Medium";
        public const string Low = "Low";

        public static int Rank(string severity) => severity switch
        {
            Critical => 3,
            High => 2,
            Medium => 1,
            _ => 0
        };
    }

    /// <summary>
    /// How a row leaves the feed. <see cref="Dismissable"/> rows are hidden client-side for the
    /// session; <see cref="Acknowledge"/> rows (a missed response deadline) are excluded from
    /// dismiss and dismiss-all and leave only through their own acknowledge action.
    /// </summary>
    public static class NotificationRowTypes
    {
        public const string Dismissable = "dismissable";
        public const string Acknowledge = "acknowledge";
    }

    public static class NotificationTargetKinds
    {
        public const string WorkOrder = "workOrder";
        public const string Queue = "queue";
    }

    /// <summary>Named work-order queues a grouped item opens.</summary>
    public static class NotificationQueues
    {
        public const string Unassigned = "unassigned";
        /// <summary>The signed-in user's own open work orders.</summary>
        public const string AssignedToMe = "assigned-to-me";
    }

    /// <summary>Work-order detail tabs a single-work-order item can open on.</summary>
    public static class NotificationWorkOrderTabs
    {
        public const string Info = "info";
        public const string Comments = "comments";
        public const string Extras = "extras";
        public const string Uplifts = "uplifts";
    }

    public sealed class NotificationTargetDto
    {
        public string Kind { get; init; } = NotificationTargetKinds.WorkOrder;
        public int? WorkOrderId { get; init; }
        public string? Tab { get; init; }
        public string? Queue { get; init; }
    }

    public sealed class NotificationWorkOrderRefDto
    {
        public int Id { get; init; }
        public string? Number { get; init; }
    }

    public sealed class NotificationItemDto
    {
        /// <summary>Stable across reads while the condition holds; the client dismisses by it.</summary>
        public string Id { get; init; } = "";
        public string Reason { get; init; } = "";
        public string Severity { get; init; } = NotificationSeverities.Low;
        public string RowType { get; init; } = NotificationRowTypes.Dismissable;
        public string Title { get; init; } = "";
        /// <summary>Work orders this item represents.</summary>
        public int Count { get; init; }
        /// <summary>When the condition started; drives recency ordering.</summary>
        public DateTime TriggeredAt { get; init; }
        public NotificationTargetDto Target { get; init; } = new();
        public IReadOnlyList<NotificationWorkOrderRefDto> WorkOrders { get; init; } = Array.Empty<NotificationWorkOrderRefDto>();
    }

    public sealed class NotificationSectionDto
    {
        public string Reason { get; init; } = "";
        public string Label { get; init; } = "";
        /// <summary>Highest item severity in the section.</summary>
        public string Severity { get; init; } = NotificationSeverities.Low;
        /// <summary>Work orders the whole section represents, including items beyond the returned slice.</summary>
        public int Count { get; init; }
        public IReadOnlyList<NotificationItemDto> Items { get; init; } = Array.Empty<NotificationItemDto>();
    }

    /// <summary>
    /// A work order past half of its SEV response window and not yet past the whole window, with the
    /// server-computed clock. Drives the top-of-app banner and the one-time 50% toast.
    /// </summary>
    public sealed class NotificationSlaWorkOrderDto
    {
        public int Id { get; init; }
        public string? Number { get; init; }
        public int Severity { get; init; }
        /// <summary>The work order's creation time; the response clock never starts at the scheduled date.</summary>
        public DateTime StartedAt { get; init; }
        public DateTime DeadlineAt { get; init; }
        public int PercentElapsed { get; init; }
    }

    public sealed class NotificationFeedDto
    {
        public DateTime GeneratedAt { get; init; }
        public IReadOnlyList<NotificationSectionDto> Sections { get; init; } = Array.Empty<NotificationSectionDto>();
        /// <summary>Every at-risk work order in the feed's scope, oldest first; not capped like section items.</summary>
        public IReadOnlyList<NotificationSlaWorkOrderDto> SlaAtRisk { get; init; } = Array.Empty<NotificationSlaWorkOrderDto>();
    }
}