SearchFilterSequence.swift

//
//  SearchFilterSequence.swift
//  Khan Academy
//
//  Created by Mike Parker on 12/2/15.
//  Copyright © 2015 Khan Academy. All rights reserved.
//

import Foundation

public struct SearchFilterSequence {
	public let values: [SearchFilter]

	/// Returns the SearchFilter instances that are selected.
	public var selectedFilters: [SearchFilter] {
		return values.filter { $0.selected }
	}

	/// Returns whether the filter for offline content is selected.
	public var isAvailableOfflineSelected: Bool {
		return values.any { filter in
			switch filter.predicate {
			case .AvailableOfflinePredicate:
				return filter.selected
			default:
				return false
			}
		}
	}

	/// Returns the domain names for the selected topic filters.
	public var selectedTopicDomainNames: [String] {
		return selectedFilters.flatMap { filter in
			switch filter.predicate {
			case .TopicPredicate:
				return filter.localizedName
			default:
				return nil
			}
		}
	}
}