import UIKit

@available(*, deprecated, message: "Use RDEpubReaderPageProvider instead.")
@objc public protocol RDEpubReaderDataSource: NSObjectProtocol {

    func pageCountOfReaderView(readerView: RDEpubReaderView) -> Int

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

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

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

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

@objc public protocol RDEpubReaderPageProvider: NSObjectProtocol {

    func numberOfPages(in readerView: RDEpubReaderView) -> Int

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

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

    /// 指定页面是否允许进入阅读器预加载。默认允许。
    /// 包含不可复制宿主 View 的页面应返回 false，避免预加载抢占可见页面内容。
    @objc optional func readerView(_ readerView: RDEpubReaderView, shouldPreloadPageAt index: Int) -> Bool

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

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

@objc public protocol RDEpubReaderDelegate: NSObjectProtocol {

    func pageNum(readerView: RDEpubReaderView, pageNum: Int)

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

public protocol RDEpubReaderPageNavigating: AnyObject {

    var currentPage: Int { get }

    func reloadPages()

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

extension RDEpubReaderView {

    public enum DisplayType {

        case pageCurl

        case horizontalScroll

        case verticalScroll
    }

    public enum PageDirection {

        case leftToRight

        case rightToLeft
    }
}

final class RDEpubReaderLegacyDataSourceAdapter: NSObject, RDEpubReaderPageProvider {

    weak var dataSource: RDEpubReaderDataSource?

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

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

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

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

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