Tusker/Pachyderm/Utilities/NotificationGroup.swift

//
//  NotificationGroup.swift
//  Pachyderm
//
//  Created by Shadowfacts on 9/5/19.
//  Copyright © 2019 Shadowfacts. All rights reserved.
//

import Foundation

public class NotificationGroup {
    public let notificationIDs: [String]
    public let id: String
    public let kind: Notification.Kind
    public let statusState: StatusState?
    
    init?(notifications: [Notification]) {
        guard !notifications.isEmpty else { return nil }
        self.notificationIDs = notifications.map { $0.id }
        self.id = notifications.first!.id
        self.kind = notifications.first!.kind
        if kind == .mention {
            self.statusState = .unknown
        } else {
            self.statusState = nil
        }
    }

    public static func createGroups(notifications: [Notification], only allowedTypes: [Notification.Kind]) -> [NotificationGroup] {
        return notifications.reduce(into: [[Notification]]()) { (groups, notification) in
            if allowedTypes.contains(notification.kind),
                let lastGroup = groups.last,
                let firstStatus = lastGroup.first,
                firstStatus.kind == notification.kind,
                firstStatus.status?.id == notification.status?.id {
                
                groups[groups.count - 1].append(notification)
            } else {
                groups.append([notification])
            }
        }.map {
            NotificationGroup(notifications: $0)!
        }
    }
    
}

extension NotificationGroup: Identifiable {}