// RDEPUBReaderController+RuntimeBridge.swift
// EPUB 阅读器运行时桥接层
// 将阅读器控制器的公开行为委托给 runtime 对象执行，涵盖配置应用、
// 出版物加载与分页、阅读位置恢复、加载状态管理、错误处理等生命周期操作。

import UIKit

/// RDEPUBReaderController 运行时桥接扩展
///
/// 本文件将阅读器控制器的公开行为委托给 runtime 对象执行，涵盖配置应用、
/// 出版物加载与分页、阅读位置恢复、加载状态管理、错误处理等生命周期操作。

extension RDEPUBReaderController {
    /// 应用阅读器视图配置，处理显示类型/翻页方向/横屏双页等变更并恢复位置
    func applyReaderViewConfiguration() {
        let resolvedDirection = resolvedPageDirection()
        let presentationDidChange = readerView.currentDisplayType != configuration.displayType
            || readerView.landscapeDualPageEnabled != configuration.landscapeDualPageEnabled
            || readerView.pageDirection != resolvedDirection
        let preservedLocation = presentationDidChange
            ? (runtime.viewportMonitor.consumePendingPresentationRestoreLocation() ?? currentVisibleLocation() ?? persistenceLocation())
            : nil
        view.backgroundColor = configuration.theme.contentBackgroundColor
        readerView.landscapeDualPageEnabled = configuration.landscapeDualPageEnabled
        readerView.pageDirection = resolvedDirection
        updateReaderChrome()
        if presentationDidChange {
            readerView.switchReaderDisplayType(configuration.displayType)
            if let preservedLocation {
                _ = restoreReadingLocation(preservedLocation)
            }
        }
    }

    /// 启动初始加载流程（如果尚未加载）
    func startInitialLoadIfNeeded() {
        runtime.startInitialLoadIfNeeded()
    }

    /// 加载 EPUB 出版物
    func loadPublication() {
        runtime.loadPublication()
    }

    /// 应用已解析的出版物数据（解析器、出版物模型、书签、高亮等）
    func applyParsedPublication(
        parser: RDEPUBParser,
        publication: RDEPUBPublication,
        bookIdentifier: String,
        restoreLocation: RDEPUBLocation?,
        bookmarks: [RDEPUBBookmark],
        highlights: [RDEPUBHighlight]
    ) {
        runtime.applyParsedPublication(
            parser: parser,
            publication: publication,
            bookIdentifier: bookIdentifier,
            restoreLocation: restoreLocation,
            bookmarks: bookmarks,
            highlights: highlights
        )
    }

    /// 对出版物执行分页计算
    func paginatePublication(restoreLocation: RDEPUBLocation?) {
        runtime.paginatePublication(restoreLocation: restoreLocation)
    }

    /// 应用文本书籍数据并恢复阅读位置
    func applyTextBook(_ textBook: RDEPUBTextBook, restoreLocation: RDEPUBLocation?) {
        runtime.applyTextBook(textBook, restoreLocation: restoreLocation)
    }

    /// 应用分页快照（页面列表与章节信息）
    func applyPaginationSnapshot(
        _ snapshot: (pages: [EPUBPage], chapters: [EPUBChapterInfo]),
        restoreLocation: RDEPUBLocation?
    ) {
        runtime.applyPaginationSnapshot(snapshot, restoreLocation: restoreLocation)
    }

    /// 完成分页流程并恢复阅读位置
    func finishPagination(restoreLocation: RDEPUBLocation?) {
        runtime.finishPagination(restoreLocation: restoreLocation)
    }

    /// 保留当前位置重新执行分页
    func repaginatePreservingCurrentLocation() {
        runtime.repaginatePreservingCurrentLocation()
    }

    /// 恢复到指定阅读位置，返回是否成功
    @discardableResult
    func restoreReadingLocation(_ location: RDEPUBLocation, animated: Bool = false) -> Bool {
        runtime.restoreReadingLocation(location, animated: animated)
    }

    /// 获取当前可见页面的位置
    func currentVisibleLocation() -> RDEPUBLocation? {
        runtime.currentVisibleLocation()
    }

    /// 获取持久化存储的阅读位置
    func persistenceLocation() -> RDEPUBLocation? {
        readerContext.persistenceLocation()
    }

    /// 持久化当前阅读位置
    func persist(location: RDEPUBLocation) {
        readerContext.persist(location: location)
    }

    /// 更新当前文本选区状态
    func updateCurrentSelection(_ selection: RDEPUBSelection?) {
        runtime.annotationCoordinator.updateCurrentSelection(selection)
    }

    /// 将选区限定到指定 spine 范围内
    func scopedSelection(
        _ selection: RDEPUBSelection,
        relativeToSpineIndex spineIndex: Int?
    ) -> RDEPUBSelection? {
        runtime.annotationCoordinator.scopedSelection(selection, relativeToSpineIndex: spineIndex)
    }

    /// 刷新可见内容并保留当前位置
    func refreshVisibleContentPreservingLocation() {
        runtime.refreshVisibleContentPreservingLocation()
    }

    /// 重建外部文本书籍
    func rebuildExternalTextBook() {
        runtime.rebuildExternalTextBook()
    }

    /// 更新阅读器 UI 装饰层（导航栏、工具栏等）
    func updateReaderChrome() {
        runtime.updateReaderChrome()
    }

    /// 展示书签管理界面
    func presentBookmarksManager() {
        runtime.presentBookmarksManager()
    }

    /// 展示高亮标注管理界面
    func presentHighlightsManager() {
        runtime.presentHighlightsManager()
    }

    /// 展示标注创建界面
    func presentAnnotationCreation() {
        runtime.presentAnnotationCreation()
    }

    /// 处理选区菜单操作（复制、标注、分享等）
    func handleSelectionMenuAction(_ action: RDEPUBAnnotationMenuAction, selection: RDEPUBSelection?) {
        runtime.handleSelectionMenuAction(action, selection: selection)
    }

    /// 展示阅读设置界面
    func presentSettings() {
        runtime.presentSettings()
    }

    /// 使用闭包更新阅读器配置
    func updateConfiguration(_ update: (inout RDEPUBReaderConfiguration) -> Void) {
        var nextConfiguration = configuration
        update(&nextConfiguration)
        configuration = nextConfiguration
    }

    /// 设置屏幕亮度并持久化
    func setScreenBrightness(_ brightness: CGFloat) {
        currentBrightness = max(0, min(1, brightness))
        persistReaderSettingsIfNeeded()
    }

    /// 持久化阅读器设置（亮度、配置等）
    func persistReaderSettingsIfNeeded() {
        let settings = RDEPUBReaderSettings.capture(
            configuration: configuration,
            brightness: currentBrightness
        )
        persistence?.saveReaderSettings(settings)
    }

    /// 判断配置变更是否需要重新分页
    func requiresRepagination(
        from oldConfiguration: RDEPUBReaderConfiguration,
        to newConfiguration: RDEPUBReaderConfiguration
    ) -> Bool {
        oldConfiguration.fontSize != newConfiguration.fontSize ||
        oldConfiguration.fontChoice != newConfiguration.fontChoice ||
        oldConfiguration.lineHeightMultiple != newConfiguration.lineHeightMultiple ||
        oldConfiguration.numberOfColumns != newConfiguration.numberOfColumns ||
        oldConfiguration.columnGap != newConfiguration.columnGap ||
        oldConfiguration.reflowableContentInsets != newConfiguration.reflowableContentInsets ||
        oldConfiguration.fixedContentInset != newConfiguration.fixedContentInset ||
        oldConfiguration.fixedLayoutFit != newConfiguration.fixedLayoutFit ||
        oldConfiguration.fixedLayoutSpreadMode != newConfiguration.fixedLayoutSpreadMode ||
        oldConfiguration.textRenderingEngine != newConfiguration.textRenderingEngine
    }

    /// 判断配置变更是否需要刷新可见内容
    func requiresVisibleRefresh(
        from oldConfiguration: RDEPUBReaderConfiguration,
        to newConfiguration: RDEPUBReaderConfiguration
    ) -> Bool {
        oldConfiguration.theme != newConfiguration.theme ||
        oldConfiguration.darkImageAdjustmentEnabled != newConfiguration.darkImageAdjustmentEnabled ||
        oldConfiguration.darkImageBlendRatio != newConfiguration.darkImageBlendRatio
    }

    /// 展示目录界面
    func presentTableOfContents() {
        runtime.presentTableOfContents()
    }

    /// 处理返回操作
    func handleBackAction() {
        runtime.handleBackAction()
    }

    /// 处理错误：停止分页、隐藏加载指示器、显示错误信息并通知代理
    func handle(error: Error) {
        isRepaginating = false
        hideLoading()
        readerContext.clearActiveSnapshot()
        textBook = nil
        readerContext.bookPageMap = nil
        readerView.reloadData()
        errorLabel.text = error.localizedDescription
        errorLabel.isHidden = false
        delegate?.epubReader(self, didFailWithError: error)
    }

    /// 显示加载指示器
    func showLoading() {
        errorLabel.isHidden = true
        loadingIndicator.startAnimating()
    }

    /// 隐藏加载指示器
    func hideLoading() {
        loadingIndicator.stopAnimating()
    }

    /// 获取当前视口签名（用于检测视口变化）
    func currentViewportSignature() -> RDEPUBViewportSignature? {
        runtime.currentViewportSignature()
    }

    /// 检测并处理视口变化（旋转、尺寸变化等）
    func handleViewportChangeIfNeeded(
        reason: RDEPUBViewportChangeReason,
        viewportSignature: RDEPUBViewportSignature? = nil
    ) {
        runtime.handleViewportChangeIfNeeded(reason: reason, viewportSignature: viewportSignature)
    }

    /// 获取指定页面的搜索结果展示状态
    func searchPresentation(for page: EPUBPage) -> RDEPUBSearchPresentation? {
        runtime.searchPresentation(for: page)
    }

    /// 根据出版物阅读方向解析页面翻页方向
    private func resolvedPageDirection() -> RDReaderView.PageDirection {
        publication?.readingProgression == .rtl ? .rightToLeft : .leftToRight
    }
}

// MARK: - 手势识别器代理

extension RDEPUBReaderController: UIGestureRecognizerDelegate {
    /// 手势识别器代理，始终返回 true 允许手势触发
    public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        true
    }
}