import UIKit

@objc public protocol RDReaderDataSource: NSObjectProtocol {

    func pageCountOfReaderView(readerView: RDReaderView) -> Int

    func pageContentView(readerView: RDReaderView, pageNum: Int, containerView: UIView?) -> UIView

    func pageIdentifier(readerView: RDReaderView, pageNum: Int) -> String?

    @objc optional func topToolView(readerView: RDReaderView) -> UIView?

    @objc optional func bottomToolView(readerView: RDReaderView) -> UIView?
}

@objc public protocol RDReaderPageProvider: NSObjectProtocol {

    func numberOfPages(in readerView: RDReaderView) -> Int

    func readerView(_ readerView: RDReaderView, viewForPageAt index: Int, reusableView: UIView?) -> UIView

    @objc optional func pageIdentifier(in readerView: RDReaderView, index: Int) -> String?

    @objc optional func readerViewTopChrome(_ readerView: RDReaderView) -> UIView?

    @objc optional func readerViewBottomChrome(_ readerView: RDReaderView) -> UIView?
}

@objc public protocol RDReaderDelegate: NSObjectProtocol {

    func pageNum(readerView: RDReaderView, pageNum: Int)

    @objc optional func readerViewOrientationWillChange(readerView: RDReaderView, isLandscape: Bool)
}

public protocol RDReaderPageNavigating: AnyObject {

    var currentPage: Int { get }

    func reloadPages()

    func transition(to page: Int, animated: Bool)
}

extension RDReaderView {

    public enum DisplayType {

        case pageCurl

        case horizontalScroll

        case verticalScroll
    }

    public enum PageDirection {

        case leftToRight

        case rightToLeft
    }
}

final class RDReaderLegacyDataSourceAdapter: NSObject, RDReaderPageProvider {

    weak var dataSource: RDReaderDataSource?

    func numberOfPages(in readerView: RDReaderView) -> Int {
        dataSource?.pageCountOfReaderView(readerView: readerView) ?? 0
    }

    func readerView(_ readerView: RDReaderView, viewForPageAt index: Int, reusableView: UIView?) -> UIView {
        dataSource?.pageContentView(readerView: readerView, pageNum: index, containerView: reusableView) ?? UIView()
    }

    func pageIdentifier(in readerView: RDReaderView, index: Int) -> String? {
        dataSource?.pageIdentifier(readerView: readerView, pageNum: index)
    }

    func readerViewTopChrome(_ readerView: RDReaderView) -> UIView? {
        dataSource?.topToolView?(readerView: readerView)
    }

    func readerViewBottomChrome(_ readerView: RDReaderView) -> UIView? {
        dataSource?.bottomToolView?(readerView: readerView)
    }
}