ReadViewSDK/Sources/RDEpubReaderView/EPUBUI/RDEPUBReaderTopToolView.swift

import UIKit
import SnapKit

open class RDEPUBReaderTopToolView: RDEPUBReaderToolView, RDEPUBReaderTopToolViewProtocol {

    public var onBack: (() -> Void)?

    public var onToggleBookmark: (() -> Void)?

    public var onSearch: (() -> Void)?

    /// 宿主可配置的登录 / 购买等业务入口。未设置标题时不占用工具栏空间。
    public var onAuthorization: (() -> Void)?

    private let backButton = RDEPUBReaderTintButton(type: .system)
    private let searchButton = RDEPUBReaderTintButton(type: .system)
    private let bookmarkButton = RDEPUBReaderTintButton(type: .system)
    private let authorizationButton = RDEPUBReaderTintButton(type: .system)
    private var authorizationButtonWidthConstraint: Constraint!
    private let titleLabel: UILabel = {
        let label = UILabel()
        label.textAlignment = .center
        label.font = UIFont.systemFont(ofSize: 16, weight: .semibold)
        label.numberOfLines = 1
        return label
    }()
    private var isBookmarked = false

    public override init(frame: CGRect) {
        super.init(frame: frame)
        accessibilityIdentifier = "epub.reader.topToolbar"
        self.backgroundColor = .white
        addSubview(backButton)
        addSubview(searchButton)
        addSubview(bookmarkButton)
        addSubview(authorizationButton)
        addSubview(titleLabel)

        backButton.addTarget(self, action: #selector(backAction), for: .touchUpInside)
        searchButton.addTarget(self, action: #selector(searchAction), for: .touchUpInside)
        bookmarkButton.addTarget(self, action: #selector(bookmarkAction), for: .touchUpInside)
        authorizationButton.addTarget(self, action: #selector(authorizationAction), for: .touchUpInside)

        backButton.snp.makeConstraints { make in
            make.leading.equalToSuperview().offset(8)
            make.top.equalTo(safeAreaLayoutGuide).offset(4)
            make.bottom.equalToSuperview().inset(4)
            make.size.equalTo(44)
        }
        authorizationButton.snp.makeConstraints { make in
            make.trailing.equalToSuperview().inset(8)
            make.top.equalTo(safeAreaLayoutGuide).offset(4)
            make.bottom.equalToSuperview().inset(4)
            make.height.equalTo(44)
            authorizationButtonWidthConstraint = make.width.equalTo(0).constraint
        }
        bookmarkButton.snp.makeConstraints { make in
            make.trailing.equalTo(authorizationButton.snp.leading).offset(-4)
            make.top.equalTo(safeAreaLayoutGuide).offset(4)
            make.bottom.equalToSuperview().inset(4)
            make.size.equalTo(44)
        }
        searchButton.snp.makeConstraints { make in
            make.trailing.equalTo(bookmarkButton.snp.leading).offset(-4)
            make.top.equalTo(safeAreaLayoutGuide).offset(4)
            make.bottom.equalToSuperview().inset(4)
            make.size.equalTo(44)
        }
        titleLabel.snp.makeConstraints { make in
            make.leading.equalTo(backButton.snp.trailing).offset(8)
            make.trailing.equalTo(searchButton.snp.leading).offset(-8)
            make.centerY.equalTo(backButton)
        }

        if #available(iOS 13.0, *) {
            backButton.setImage(UIImage(systemName: "chevron.left")?.withRenderingMode(.alwaysTemplate), for: .normal)
            searchButton.setImage(UIImage(systemName: "magnifyingglass")?.withRenderingMode(.alwaysTemplate), for: .normal)
        } else {
            backButton.setTitle("返回", for: .normal)
            searchButton.setTitle("搜索", for: .normal)
        }
        backButton.accessibilityIdentifier = "epub.reader.back"
        searchButton.accessibilityIdentifier = "epub.reader.search"
        bookmarkButton.accessibilityIdentifier = "epub.reader.bookmark"
        authorizationButton.accessibilityIdentifier = "epub.reader.authorization"
        titleLabel.accessibilityIdentifier = "epub.reader.title"
        updateBookmarkButtonAppearance()
    }

    public required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override public func lineFrame(in bounds: CGRect) -> CGRect {
        CGRect(x: 0, y: bounds.height - 0.5, width: bounds.width, height: 0.5)
    }

    override public func apply(theme: RDEPUBReaderTheme) {
        super.apply(theme: theme)
        titleLabel.textColor = theme.toolControlTextColor
        backButton.tintColor = theme.toolControlTextColor
        searchButton.tintColor = theme.toolControlTextColor
        bookmarkButton.tintColor = theme.toolControlTextColor
        authorizationButton.tintColor = theme.toolControlTextColor
        if #unavailable(iOS 13.0) {
            backButton.setTitleColor(theme.toolControlTextColor, for: .normal)
            searchButton.setTitleColor(theme.toolControlTextColor, for: .normal)
            bookmarkButton.setTitleColor(theme.toolControlTextColor, for: .normal)
            authorizationButton.setTitleColor(theme.toolControlTextColor, for: .normal)
        }
        updateBookmarkButtonAppearance()
    }

    public func setTitle(_ title: String?) {
        titleLabel.text = title
    }

    public func setBookmarkSelected(_ isSelected: Bool) {
        isBookmarked = isSelected
        updateBookmarkButtonAppearance()
    }

    public func setBookmarkEnabled(_ isEnabled: Bool) {
        bookmarkButton.isEnabled = isEnabled
        bookmarkButton.alpha = isEnabled ? 1 : 0.45
    }

    /// 设置右上角业务按钮。传 `nil` 或空字符串时隐藏按钮并恢复原工具栏布局。
    public func setAuthorizationButton(title: String?) {
        let resolvedTitle = title?.trimmingCharacters(in: .whitespacesAndNewlines)
        let isVisible = resolvedTitle?.isEmpty == false
        authorizationButton.setTitle(resolvedTitle, for: .normal)
        authorizationButton.isHidden = !isVisible
        authorizationButton.isEnabled = isVisible
        authorizationButtonWidthConstraint.update(offset: isVisible ? 56 : 0)
        authorizationButton.accessibilityLabel = resolvedTitle
    }

    @objc private func backAction() {
        onBack?()
    }

    @objc private func searchAction() {
        onSearch?()
    }

    @objc private func bookmarkAction() {
        onToggleBookmark?()
    }

    @objc private func authorizationAction() {
        onAuthorization?()
    }

    private func updateBookmarkButtonAppearance() {
        if #available(iOS 13.0, *) {
            let imageName = isBookmarked ? "bookmark.fill" : "bookmark"
            bookmarkButton.setImage(UIImage(systemName: imageName)?.withRenderingMode(.alwaysTemplate), for: .normal)
        } else {
            bookmarkButton.setTitle(isBookmarked ? "已签" : "书签", for: .normal)
        }
        bookmarkButton.accessibilityValue = isBookmarked ? "selected" : "unselected"
    }
}