import UIKit

struct RDEPUBReaderSearchSection: Equatable {

    struct Item: Equatable {

        let matchIndex: Int

        let previewText: String

        let isCurrent: Bool
    }

    let title: String

    let items: [Item]
}

final class RDEPUBReaderSearchBarView: RDEPUBReaderToolView {

    var onSearchSubmit: ((String) -> Void)?

    var onSearchTextChanged: ((String) -> Void)?

    var onSearchPrevious: (() -> Void)?

    var onSearchNext: (() -> Void)?

    var onSelectMatch: ((Int) -> Void)?

    var onClose: (() -> Void)?

    let textField: UITextField = {
        let field = UITextField()
        field.placeholder = "搜索"
        field.font = UIFont.systemFont(ofSize: 18, weight: .medium)
        field.returnKeyType = .search
        field.autocorrectionType = .no
        field.autocapitalizationType = .none
        field.clearButtonMode = .whileEditing
        field.isAccessibilityElement = true
        if #available(iOS 13.0, *) {
            field.accessibilityTraits = .searchField
        }
        return field
    }()

    private let backgroundButton = UIButton(type: .custom)

    let panelView = UIView()

    private let grabberView = UIView()

    private let searchRowView = UIView()

    private let searchFieldContainer = UIView()

    private let searchIcon = UIImageView()

    private let searchFieldDivider = UIView()

    private let cancelButton = UIButton(type: .system)

    private let tableView = UITableView(frame: .zero, style: .plain)

    private let emptyStateLabel = UILabel()

    private let previousButton = RDEPUBReaderTintButton(type: .system)

    private let nextButton = RDEPUBReaderTintButton(type: .system)

    private let countLabel = UILabel()

    private var searchSections: [RDEPUBReaderSearchSection] = []

    private var keyword = ""

    private var currentMatchIndex: Int?

    override init(frame: CGRect) {
        super.init(frame: frame)
        accessibilityIdentifier = "epub.reader.search.bar"
        shouldGroupAccessibilityChildren = false
        isAccessibilityElement = false
        setupSubviews()
        setupConstraints()
        setupActions()
        updateLegacyNavigationEnabled(false)
        showInitialState()
    }

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

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        // Only claim touches that fall within the panelView or the
        // accessibility-only navigation buttons. Taps on the dimmed scrim
        // area pass through to the reader content below, allowing chrome
        // toggle taps to work.
        let panelPoint = convert(point, to: panelView)
        if panelView.point(inside: panelPoint, with: event) {
            return super.hitTest(point, with: event)
        }
        // Also claim touches on the accessibility-only navigation buttons
        if previousButton.frame.contains(point)
            || nextButton.frame.contains(point)
            || countLabel.frame.contains(point) {
            return super.hitTest(point, with: event)
        }
        return nil
    }

    override func lineFrame(in bounds: CGRect) -> CGRect {
        .zero
    }

    override func apply(theme: RDEPUBReaderTheme) {
        super.apply(theme: theme)
        let isDarkBackground = theme.contentBackgroundColor.rd_isDarkBackground

        let overlayColor = isDarkBackground
            ? UIColor(white: 0.12, alpha: 0.92)
            : UIColor(white: 0.08, alpha: 0.82)
        let panelColor = isDarkBackground
            ? UIColor(red: 0.18, green: 0.18, blue: 0.19, alpha: 1)
            : UIColor(red: 0.15, green: 0.15, blue: 0.16, alpha: 1)
        let rowColor = isDarkBackground
            ? UIColor(white: 0.18, alpha: 1)
            : UIColor(white: 0.14, alpha: 0.96)
        let cardColor = isDarkBackground
            ? UIColor(white: 0.12, alpha: 1)
            : UIColor(white: 0.10, alpha: 0.98)
        let activeCardColor = UIColor(red: 0.17, green: 0.28, blue: 0.38, alpha: 1)
        let textColor = UIColor(white: 0.96, alpha: 1)
        let secondaryTextColor = UIColor(white: 0.72, alpha: 1)

        backgroundColor = .clear
        backgroundButton.backgroundColor = overlayColor
        panelView.backgroundColor = panelColor
        grabberView.backgroundColor = UIColor(white: 0.75, alpha: 0.7)
        searchRowView.backgroundColor = rowColor
        searchFieldContainer.backgroundColor = .clear
        searchFieldDivider.backgroundColor = UIColor(white: 1, alpha: 0.12)
        searchIcon.tintColor = secondaryTextColor
        cancelButton.tintColor = textColor
        cancelButton.setTitleColor(textColor, for: .normal)
        textField.textColor = textColor
        textField.tintColor = UIColor.systemBlue
        textField.keyboardAppearance = isDarkBackground ? .dark : .default
        textField.attributedPlaceholder = NSAttributedString(
            string: "搜索",
            attributes: [.foregroundColor: secondaryTextColor]
        )

        emptyStateLabel.textColor = secondaryTextColor
        tableView.backgroundColor = .clear
        tableView.separatorStyle = .none

        previousButton.tintColor = textColor
        nextButton.tintColor = textColor
        countLabel.textColor = textColor
        countLabel.backgroundColor = .clear

        RDEPUBReaderSearchResultCell.cardBackgroundColor = cardColor
        RDEPUBReaderSearchResultCell.activeCardBackgroundColor = activeCardColor
        RDEPUBReaderSearchResultCell.primaryTextColor = textColor
        RDEPUBReaderSearchResultCell.highlightTextColor = UIColor.systemBlue
        RDEPUBReaderSearchResultCell.activeHighlightTextColor = UIColor(red: 0.40, green: 0.77, blue: 1, alpha: 1)

        tableView.reloadData()
    }

    var presentedView: UIView {
        panelView
    }

    func updateMatchCount(current: Int, total: Int) {
        countLabel.text = "\(current)/\(total)"
        textField.accessibilityValue = "\(current)/\(total)"
        updateLegacyNavigationEnabled(total > 0)
    }

    func showNoResults() {
        currentMatchIndex = nil
        updateMatchCount(current: 0, total: 0)
        tableView.isHidden = true
        emptyStateLabel.isHidden = false
        emptyStateLabel.text = keyword.isEmpty ? "输入关键词开始搜索" : "未找到相关内容"
    }

    func showSearching() {
        updateMatchCount(current: 0, total: 0)
        tableView.isHidden = true
        emptyStateLabel.isHidden = false
        emptyStateLabel.text = "搜索中..."
    }

    func restoreKeyword(_ keyword: String) {
        textField.text = keyword
        self.keyword = keyword
    }

    func updateResults(
        sections: [RDEPUBReaderSearchSection],
        keyword: String,
        currentMatchIndex: Int?
    ) {
        self.keyword = keyword
        self.searchSections = sections
        self.currentMatchIndex = currentMatchIndex

        let total = sections.reduce(0) { $0 + $1.items.count }
        if let currentMatchIndex, total > 0 {
            updateMatchCount(current: currentMatchIndex + 1, total: total)
        } else {
            updateMatchCount(current: 0, total: total)
        }

        if total == 0 {
            showNoResults()
            return
        }

        emptyStateLabel.isHidden = true
        tableView.isHidden = false
        tableView.reloadData()
        scrollToCurrentMatchIfNeeded()
    }

    private func setupSubviews() {
        backgroundButton.translatesAutoresizingMaskIntoConstraints = false
        panelView.translatesAutoresizingMaskIntoConstraints = false
        grabberView.translatesAutoresizingMaskIntoConstraints = false
        searchRowView.translatesAutoresizingMaskIntoConstraints = false
        searchFieldContainer.translatesAutoresizingMaskIntoConstraints = false
        searchIcon.translatesAutoresizingMaskIntoConstraints = false
        textField.translatesAutoresizingMaskIntoConstraints = false
        searchFieldDivider.translatesAutoresizingMaskIntoConstraints = false
        cancelButton.translatesAutoresizingMaskIntoConstraints = false
        tableView.translatesAutoresizingMaskIntoConstraints = false
        emptyStateLabel.translatesAutoresizingMaskIntoConstraints = false
        previousButton.translatesAutoresizingMaskIntoConstraints = false
        nextButton.translatesAutoresizingMaskIntoConstraints = false
        countLabel.translatesAutoresizingMaskIntoConstraints = false

        addSubview(backgroundButton)
        addSubview(panelView)

        panelView.addSubview(grabberView)
        panelView.addSubview(searchRowView)
        panelView.addSubview(tableView)
        panelView.addSubview(emptyStateLabel)

        searchRowView.addSubview(searchFieldContainer)
        searchRowView.addSubview(searchFieldDivider)
        searchRowView.addSubview(cancelButton)
        searchFieldContainer.addSubview(searchIcon)
        searchFieldContainer.addSubview(textField)

        addSubview(previousButton)
        addSubview(nextButton)
        addSubview(countLabel)

        if #available(iOS 13.0, *) {
            searchIcon.image = UIImage(systemName: "magnifyingglass")
            previousButton.setImage(UIImage(systemName: "chevron.up"), for: .normal)
            nextButton.setImage(UIImage(systemName: "chevron.down"), for: .normal)
        } else {
            previousButton.setTitle("▲", for: .normal)
            nextButton.setTitle("▼", for: .normal)
        }

        searchIcon.contentMode = .scaleAspectFit
        searchIcon.preferredSymbolConfiguration = UIImage.SymbolConfiguration(pointSize: 22, weight: .regular)

        panelView.layer.cornerRadius = 28
        panelView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
        panelView.clipsToBounds = true

        grabberView.layer.cornerRadius = 3
        searchRowView.layer.cornerRadius = 22
        searchFieldContainer.layer.cornerRadius = 22
        searchRowView.clipsToBounds = true

        cancelButton.setTitle("取消", for: .normal)
        cancelButton.titleLabel?.font = UIFont.systemFont(ofSize: 18, weight: .medium)
        cancelButton.accessibilityIdentifier = "epub.reader.search.close"

        emptyStateLabel.font = UIFont.systemFont(ofSize: 17, weight: .medium)
        emptyStateLabel.textAlignment = .center
        emptyStateLabel.numberOfLines = 0

        previousButton.accessibilityIdentifier = "epub.reader.search.previous"
        nextButton.accessibilityIdentifier = "epub.reader.search.next"
        countLabel.accessibilityIdentifier = "epub.reader.search.count"
        textField.accessibilityIdentifier = "epub.reader.search.field"
        // 0.02 而非 0.01：CALayer.opacity 为 Float32，0.01 落盘后略小于
        // 0.01，会被 UIKit 命中测试按「透明视图」剔除，导致按钮永远点不中。
        previousButton.alpha = 0.02
        nextButton.alpha = 0.02
        countLabel.alpha = 0.02

        tableView.register(RDEPUBReaderSearchResultCell.self, forCellReuseIdentifier: RDEPUBReaderSearchResultCell.reuseIdentifier)
        tableView.dataSource = self
        tableView.delegate = self
        tableView.showsVerticalScrollIndicator = false
        tableView.contentInset = UIEdgeInsets(top: 4, left: 0, bottom: 16, right: 0)
    }

    private func setupConstraints() {
        NSLayoutConstraint.activate([
            backgroundButton.leadingAnchor.constraint(equalTo: leadingAnchor),
            backgroundButton.trailingAnchor.constraint(equalTo: trailingAnchor),
            backgroundButton.topAnchor.constraint(equalTo: topAnchor),
            backgroundButton.bottomAnchor.constraint(equalTo: bottomAnchor),

            panelView.leadingAnchor.constraint(equalTo: leadingAnchor),
            panelView.trailingAnchor.constraint(equalTo: trailingAnchor),
            panelView.topAnchor.constraint(equalTo: safeAreaLayoutGuide.topAnchor, constant: 8),
            panelView.bottomAnchor.constraint(equalTo: bottomAnchor),

            grabberView.topAnchor.constraint(equalTo: panelView.topAnchor, constant: 10),
            grabberView.centerXAnchor.constraint(equalTo: panelView.centerXAnchor),
            grabberView.widthAnchor.constraint(equalToConstant: 92),
            grabberView.heightAnchor.constraint(equalToConstant: 6),

            searchRowView.leadingAnchor.constraint(equalTo: panelView.leadingAnchor, constant: 20),
            searchRowView.trailingAnchor.constraint(equalTo: panelView.trailingAnchor, constant: -20),
            searchRowView.topAnchor.constraint(equalTo: grabberView.bottomAnchor, constant: 18),
            searchRowView.heightAnchor.constraint(equalToConstant: 52),

            searchFieldContainer.leadingAnchor.constraint(equalTo: searchRowView.leadingAnchor, constant: 12),
            searchFieldContainer.topAnchor.constraint(equalTo: searchRowView.topAnchor),
            searchFieldContainer.bottomAnchor.constraint(equalTo: searchRowView.bottomAnchor),

            searchIcon.leadingAnchor.constraint(equalTo: searchFieldContainer.leadingAnchor, constant: 10),
            searchIcon.centerYAnchor.constraint(equalTo: searchFieldContainer.centerYAnchor),
            searchIcon.widthAnchor.constraint(equalToConstant: 24),
            searchIcon.heightAnchor.constraint(equalToConstant: 24),

            textField.leadingAnchor.constraint(equalTo: searchIcon.trailingAnchor, constant: 10),
            textField.trailingAnchor.constraint(equalTo: searchFieldContainer.trailingAnchor, constant: -10),
            textField.topAnchor.constraint(equalTo: searchFieldContainer.topAnchor),
            textField.bottomAnchor.constraint(equalTo: searchFieldContainer.bottomAnchor),

            searchFieldDivider.leadingAnchor.constraint(equalTo: searchFieldContainer.trailingAnchor, constant: 12),
            searchFieldDivider.centerYAnchor.constraint(equalTo: searchRowView.centerYAnchor),
            searchFieldDivider.widthAnchor.constraint(equalToConstant: 1),
            searchFieldDivider.heightAnchor.constraint(equalToConstant: 28),

            cancelButton.leadingAnchor.constraint(equalTo: searchFieldDivider.trailingAnchor, constant: 18),
            cancelButton.trailingAnchor.constraint(equalTo: searchRowView.trailingAnchor, constant: -18),
            cancelButton.centerYAnchor.constraint(equalTo: searchRowView.centerYAnchor),

            tableView.leadingAnchor.constraint(equalTo: panelView.leadingAnchor, constant: 0),
            tableView.trailingAnchor.constraint(equalTo: panelView.trailingAnchor, constant: 0),
            tableView.topAnchor.constraint(equalTo: searchRowView.bottomAnchor, constant: 18),
            tableView.bottomAnchor.constraint(equalTo: panelView.safeAreaLayoutGuide.bottomAnchor),

            emptyStateLabel.leadingAnchor.constraint(equalTo: panelView.leadingAnchor, constant: 32),
            emptyStateLabel.trailingAnchor.constraint(equalTo: panelView.trailingAnchor, constant: -32),
            emptyStateLabel.topAnchor.constraint(equalTo: searchRowView.bottomAnchor, constant: 56),

            // 无障碍/UI 测试专用的隐形控件：必须放在 panel 顶部而非视图
            // 左上角——视图左上角落在系统状态栏区域内，合成点击会被状态栏
            // 窗口拦截，永远到不了这些按钮。
            previousButton.topAnchor.constraint(equalTo: panelView.topAnchor),
            previousButton.leadingAnchor.constraint(equalTo: leadingAnchor),
            previousButton.widthAnchor.constraint(equalToConstant: 1),
            previousButton.heightAnchor.constraint(equalToConstant: 1),

            nextButton.topAnchor.constraint(equalTo: panelView.topAnchor),
            nextButton.leadingAnchor.constraint(equalTo: previousButton.trailingAnchor),
            nextButton.widthAnchor.constraint(equalToConstant: 1),
            nextButton.heightAnchor.constraint(equalToConstant: 1),

            countLabel.topAnchor.constraint(equalTo: panelView.topAnchor),
            countLabel.leadingAnchor.constraint(equalTo: nextButton.trailingAnchor),
            countLabel.widthAnchor.constraint(equalToConstant: 1),
            countLabel.heightAnchor.constraint(equalToConstant: 1)
        ])
    }

    private func setupActions() {
        textField.delegate = self
        textField.addTarget(self, action: #selector(textFieldDidReturn), for: .editingDidEndOnExit)
        textField.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)
        previousButton.addTarget(self, action: #selector(previousAction), for: .touchUpInside)
        nextButton.addTarget(self, action: #selector(nextAction), for: .touchUpInside)
        cancelButton.addTarget(self, action: #selector(closeAction), for: .touchUpInside)
        backgroundButton.addTarget(self, action: #selector(closeAction), for: .touchUpInside)
    }

    private func updateLegacyNavigationEnabled(_ enabled: Bool) {
        previousButton.isEnabled = enabled
        nextButton.isEnabled = enabled
    }

    private func showInitialState() {
        tableView.isHidden = true
        emptyStateLabel.isHidden = false
        emptyStateLabel.text = "输入关键词开始搜索"
    }

    private func scrollToCurrentMatchIfNeeded() {
        guard let currentMatchIndex else { return }
        for (sectionIndex, section) in searchSections.enumerated() {
            if let rowIndex = section.items.firstIndex(where: { $0.matchIndex == currentMatchIndex }) {
                let indexPath = IndexPath(row: rowIndex, section: sectionIndex)
                DispatchQueue.main.async { [weak self] in
                    self?.tableView.scrollToRow(at: indexPath, at: .middle, animated: false)
                }
                return
            }
        }
    }

    private func item(at indexPath: IndexPath) -> RDEPUBReaderSearchSection.Item {
        searchSections[indexPath.section].items[indexPath.row]
    }

    @objc private func textFieldDidReturn() {
        let keyword = textField.text?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
        guard !keyword.isEmpty else { return }
        onSearchSubmit?(keyword)
        textField.resignFirstResponder()
    }

    @objc private func textFieldDidChange() {
        guard textField.markedTextRange == nil else { return }
        onSearchTextChanged?(textField.text ?? "")
    }

    @objc private func previousAction() {
        onSearchPrevious?()
    }

    @objc private func nextAction() {
        onSearchNext?()
    }

    @objc private func closeAction() {
        onClose?()
    }
}

extension RDEPUBReaderSearchBarView: UITableViewDataSource, UITableViewDelegate {

    func numberOfSections(in tableView: UITableView) -> Int {
        searchSections.count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        searchSections[section].items.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(
            withIdentifier: RDEPUBReaderSearchResultCell.reuseIdentifier,
            for: indexPath
        )

        guard let cell = cell as? RDEPUBReaderSearchResultCell else {
            return cell
        }

        let item = item(at: indexPath)
        cell.configure(
            previewText: item.previewText,
            keyword: keyword,
            isCurrent: item.isCurrent
        )
        cell.accessibilityIdentifier = "epub.reader.search.result.\(item.matchIndex)"
        return cell
    }

    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        let container = UIView()
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.font = UIFont.systemFont(ofSize: 19, weight: .bold)
        label.textColor = UIColor(white: 0.96, alpha: 1)
        label.text = searchSections[section].title
        label.numberOfLines = 2
        container.addSubview(label)

        NSLayoutConstraint.activate([
            label.leadingAnchor.constraint(equalTo: container.leadingAnchor, constant: 20),
            label.trailingAnchor.constraint(equalTo: container.trailingAnchor, constant: -20),
            label.topAnchor.constraint(equalTo: container.topAnchor, constant: 4),
            label.bottomAnchor.constraint(equalTo: container.bottomAnchor, constant: -4)
        ])
        return container
    }

    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        40
    }

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        UITableView.automaticDimension
    }

    func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
        116
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        onSelectMatch?(item(at: indexPath).matchIndex)
    }
}

extension RDEPUBReaderSearchBarView: UITextFieldDelegate {

    func textFieldShouldClear(_ textField: UITextField) -> Bool {
        DispatchQueue.main.async { [weak self] in
            self?.onSearchTextChanged?("")
        }
        return true
    }
}

private final class RDEPUBReaderSearchResultCell: UITableViewCell {

    static let reuseIdentifier = "RDEPUBReaderSearchResultCell"

    static var cardBackgroundColor = UIColor(white: 0.12, alpha: 1)

    static var activeCardBackgroundColor = UIColor(red: 0.17, green: 0.28, blue: 0.38, alpha: 1)

    static var primaryTextColor = UIColor(white: 0.96, alpha: 1)

    static var highlightTextColor = UIColor.systemBlue

    static var activeHighlightTextColor = UIColor(red: 0.40, green: 0.77, blue: 1, alpha: 1)

    private let cardView = UIView()

    private let previewLabel = UILabel()

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        setupSubviews()
        setupConstraints()
    }

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

    override func prepareForReuse() {
        super.prepareForReuse()
        previewLabel.attributedText = nil
    }

    func configure(previewText: String, keyword: String, isCurrent: Bool) {
        selectionStyle = .none
        backgroundColor = .clear
        contentView.backgroundColor = .clear
        cardView.backgroundColor = isCurrent ? Self.activeCardBackgroundColor : Self.cardBackgroundColor
        previewLabel.attributedText = attributedPreviewText(
            previewText,
            keyword: keyword,
            isCurrent: isCurrent
        )
    }

    private func setupSubviews() {
        cardView.translatesAutoresizingMaskIntoConstraints = false
        previewLabel.translatesAutoresizingMaskIntoConstraints = false

        contentView.addSubview(cardView)
        cardView.addSubview(previewLabel)

        cardView.layer.cornerRadius = 16
        cardView.clipsToBounds = true

        previewLabel.numberOfLines = 0
        previewLabel.font = UIFont.systemFont(ofSize: 18, weight: .regular)
    }

    private func setupConstraints() {
        NSLayoutConstraint.activate([
            cardView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 20),
            cardView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -20),
            cardView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 10),
            cardView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -10),

            previewLabel.leadingAnchor.constraint(equalTo: cardView.leadingAnchor, constant: 16),
            previewLabel.trailingAnchor.constraint(equalTo: cardView.trailingAnchor, constant: -16),
            previewLabel.topAnchor.constraint(equalTo: cardView.topAnchor, constant: 16),
            previewLabel.bottomAnchor.constraint(equalTo: cardView.bottomAnchor, constant: -16)
        ])
    }

    private func attributedPreviewText(_ previewText: String, keyword: String, isCurrent: Bool) -> NSAttributedString {
        let normalizedText = previewText
            .replacingOccurrences(of: "\n", with: " ")
            .replacingOccurrences(of: "\\s+", with: " ", options: .regularExpression)
            .trimmingCharacters(in: .whitespacesAndNewlines)

        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = 8

        let attributed = NSMutableAttributedString(
            string: normalizedText,
            attributes: [
                .font: UIFont.systemFont(ofSize: 18, weight: .regular),
                .foregroundColor: Self.primaryTextColor,
                .paragraphStyle: paragraphStyle
            ]
        )

        let searchKeyword = keyword.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !searchKeyword.isEmpty else { return attributed }

        let nsText = normalizedText as NSString
        var searchRange = NSRange(location: 0, length: nsText.length)
        let highlightColor = isCurrent ? Self.activeHighlightTextColor : Self.highlightTextColor

        while searchRange.length > 0 {
            let foundRange = nsText.range(of: searchKeyword, options: [.caseInsensitive], range: searchRange)
            guard foundRange.location != NSNotFound else { break }
            attributed.addAttribute(.foregroundColor, value: highlightColor, range: foundRange)
            let nextLocation = foundRange.location + max(foundRange.length, 1)
            guard nextLocation < nsText.length else { break }
            searchRange = NSRange(location: nextLocation, length: nsText.length - nextLocation)
        }

        return attributed
    }
}