import UIKit

final class RDEPUBReaderHighlightsViewController: UITableViewController {

    var onSelectHighlight: ((RDEPUBHighlight) -> Void)?

    var onUpdateHighlight: ((RDEPUBHighlight) -> Void)?

    var onDeleteHighlight: ((RDEPUBHighlight) -> Void)?

    private var highlights: [RDEPUBHighlight]

    private let theme: RDEPUBReaderTheme

    private let sectionTitleProvider: (RDEPUBHighlight) -> String?

    private let filterControl = UISegmentedControl(items: ["全部", "批注", "高亮"])

    private var filteredHighlights: [RDEPUBHighlight] {
        switch filterControl.selectedSegmentIndex {
        case 1:
            return highlights.filter(\.hasNote)
        case 2:
            return highlights.filter { $0.style == .highlight }
        default:
            return highlights
        }
    }

    init(
        highlights: [RDEPUBHighlight],
        theme: RDEPUBReaderTheme,
        sectionTitleProvider: @escaping (RDEPUBHighlight) -> String?
    ) {
        self.highlights = highlights.sorted { $0.createdAt > $1.createdAt }
        self.theme = theme
        self.sectionTitleProvider = sectionTitleProvider
        super.init(style: .plain)
        title = "标注"
    }

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

    override func viewDidLoad() {
        super.viewDidLoad()
        view.accessibilityIdentifier = "epub.reader.highlights.panel"
        tableView.accessibilityIdentifier = "epub.reader.highlights.table"
        tableView.tableFooterView = UIView(frame: .zero)
        tableView.separatorInset = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 16)
        configureFilterControl()
        applyTheme()
        updateEmptyState()
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        filteredHighlights.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cellIdentifier = "HighlightCell"
        let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier) ?? UITableViewCell(style: .subtitle, reuseIdentifier: cellIdentifier)
        let highlight = filteredHighlights[indexPath.row]

        cell.backgroundColor = theme.contentBackgroundColor
        cell.textLabel?.textColor = theme.contentTextColor
        cell.textLabel?.font = UIFont.systemFont(ofSize: 15, weight: .medium)
        cell.textLabel?.numberOfLines = 2
        cell.textLabel?.text = titleText(for: highlight)

        cell.detailTextLabel?.textColor = theme.contentTextColor.withAlphaComponent(0.7)
        cell.detailTextLabel?.font = UIFont.systemFont(ofSize: 12)
        cell.detailTextLabel?.numberOfLines = 3
        cell.detailTextLabel?.text = detailText(for: highlight)
        cell.accessoryType = .disclosureIndicator
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        presentActions(for: filteredHighlights[indexPath.row], sourceIndexPath: indexPath)
    }

    private func configureFilterControl() {
        filterControl.selectedSegmentIndex = 0
        filterControl.accessibilityIdentifier = "epub.reader.highlights.filter"
        filterControl.addTarget(self, action: #selector(filterChangedAction), for: .valueChanged)
        navigationItem.titleView = filterControl
    }

    private func applyTheme() {
        tableView.backgroundColor = theme.contentBackgroundColor
        navigationController?.navigationBar.tintColor = theme.toolControlTextColor
        navigationController?.navigationBar.barTintColor = theme.toolBackgroundColor
        navigationController?.navigationBar.titleTextAttributes = [.foregroundColor: theme.toolControlTextColor]
        navigationController?.navigationBar.accessibilityIdentifier = "epub.reader.highlights.navbar"
    }

    private func updateEmptyState() {
        guard filteredHighlights.isEmpty else {
            tableView.backgroundView = nil
            return
        }

        let label = UILabel()
        label.text = emptyStateText()
        label.textAlignment = .center
        label.textColor = theme.contentTextColor.withAlphaComponent(0.7)
        label.numberOfLines = 0
        label.accessibilityIdentifier = "epub.reader.highlights.empty"
        tableView.backgroundView = label
    }

    @objc private func filterChangedAction() {
        tableView.reloadData()
        updateEmptyState()
    }

    private func emptyStateText() -> String {
        switch filterControl.selectedSegmentIndex {
        case 1:
            return "暂无批注"
        case 2:
            return "暂无划线"
        default:
            return "暂无标注"
        }
    }

    private func detailText(for highlight: RDEPUBHighlight) -> String {
        let style = styleDescription(for: highlight)
        let chapter = sectionTitleProvider(highlight)
        let note = normalizedNote(highlight.note)
        let parts = [style, chapter, note].compactMap { $0 }
        if !parts.isEmpty {
            return parts.joined(separator: "\n")
        }
        return highlight.location.href
    }

    private func titleText(for highlight: RDEPUBHighlight) -> String {
        let text = highlight.text.trimmingCharacters(in: .whitespacesAndNewlines)
        if highlight.hasNote {
            return "批注: \(text)"
        }
        return text
    }

    private func styleDescription(for highlight: RDEPUBHighlight) -> String {
        switch highlight.style {
        case .highlight:
            return highlight.hasNote ? "高亮批注" : "高亮"
        case .underline:
            return highlight.hasNote ? "划线批注" : "划线"
        }
    }

    private func presentActions(for highlight: RDEPUBHighlight, sourceIndexPath: IndexPath) {
        let alert = UIAlertController(title: "标注管理", message: nil, preferredStyle: .actionSheet)
        alert.addAction(UIAlertAction(title: "跳转到位置", style: .default) { [weak self] _ in
            self?.onSelectHighlight?(highlight)
        })
        alert.addAction(UIAlertAction(title: "编辑批注", style: .default) { [weak self] _ in
            self?.presentNoteEditor(for: highlight)
        })
        alert.addAction(UIAlertAction(title: "删除标注", style: .destructive) { [weak self] _ in
            self?.deleteHighlight(highlight)
        })
        alert.addAction(UIAlertAction(title: "取消", style: .cancel))

        if let popover = alert.popoverPresentationController,
           let cell = tableView.cellForRow(at: sourceIndexPath) {
            popover.sourceView = cell
            popover.sourceRect = cell.bounds
        }

        present(alert, animated: true)
    }

    private func presentNoteEditor(for highlight: RDEPUBHighlight) {
        let alert = UIAlertController(title: "编辑批注", message: nil, preferredStyle: .alert)
        alert.addTextField { textField in
            textField.placeholder = "输入批注内容"
            textField.text = highlight.note
        }
        alert.addAction(UIAlertAction(title: "取消", style: .cancel))
        alert.addAction(UIAlertAction(title: "保存", style: .default) { [weak self, weak alert] _ in
            guard let self,
                  let note = alert?.textFields?.first?.text,
                  let index = self.highlights.firstIndex(where: { $0.id == highlight.id }) else {
                return
            }

            var updated = highlight
            updated.note = self.normalizedNote(note)
            self.highlights[index] = updated
            self.tableView.reloadData()
            self.onUpdateHighlight?(updated)
            self.updateEmptyState()
        })
        present(alert, animated: true)
    }

    private func deleteHighlight(_ highlight: RDEPUBHighlight) {
        guard let index = highlights.firstIndex(where: { $0.id == highlight.id }) else { return }
        highlights.remove(at: index)
        tableView.reloadData()
        onDeleteHighlight?(highlight)
        updateEmptyState()
    }

    private func normalizedNote(_ note: String?) -> String? {
        let trimmed = note?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
        return trimmed.isEmpty ? nil : trimmed
    }
}

final class RDEPUBReaderBookmarksViewController: UITableViewController {

    var onSelectBookmark: ((RDEPUBBookmark) -> Void)?

    var onDeleteBookmark: ((RDEPUBBookmark) -> Void)?

    private var bookmarks: [RDEPUBBookmark]

    private let theme: RDEPUBReaderTheme

    private let dateFormatter: DateFormatter = {
        let formatter = DateFormatter()
        formatter.dateFormat = "yyyy-MM-dd HH:mm"
        return formatter
    }()

    init(bookmarks: [RDEPUBBookmark], theme: RDEPUBReaderTheme) {
        self.bookmarks = bookmarks.sorted { $0.createdAt > $1.createdAt }
        self.theme = theme
        super.init(style: .plain)
        title = "书签"
    }

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

    override func viewDidLoad() {
        super.viewDidLoad()
        view.accessibilityIdentifier = "epub.reader.bookmarks.panel"
        tableView.accessibilityIdentifier = "epub.reader.bookmarks.table"
        tableView.tableFooterView = UIView(frame: .zero)
        tableView.separatorInset = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 16)
        applyTheme()
        updateEmptyState()
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        bookmarks.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cellIdentifier = "BookmarkCell"
        let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier) ?? UITableViewCell(style: .subtitle, reuseIdentifier: cellIdentifier)
        let bookmark = bookmarks[indexPath.row]

        cell.backgroundColor = theme.contentBackgroundColor
        cell.textLabel?.textColor = theme.contentTextColor
        cell.textLabel?.font = UIFont.systemFont(ofSize: 15, weight: .medium)
        cell.textLabel?.numberOfLines = 2
        cell.textLabel?.text = titleText(for: bookmark)

        cell.detailTextLabel?.textColor = theme.contentTextColor.withAlphaComponent(0.7)
        cell.detailTextLabel?.font = UIFont.systemFont(ofSize: 12)
        cell.detailTextLabel?.numberOfLines = 3
        cell.detailTextLabel?.text = detailText(for: bookmark)
        cell.accessoryType = .disclosureIndicator
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        presentActions(for: bookmarks[indexPath.row], sourceIndexPath: indexPath)
    }

    private func applyTheme() {
        tableView.backgroundColor = theme.contentBackgroundColor
        navigationController?.navigationBar.tintColor = theme.toolControlTextColor
        navigationController?.navigationBar.barTintColor = theme.toolBackgroundColor
        navigationController?.navigationBar.titleTextAttributes = [.foregroundColor: theme.toolControlTextColor]
        navigationController?.navigationBar.accessibilityIdentifier = "epub.reader.bookmarks.navbar"
    }

    private func updateEmptyState() {
        guard bookmarks.isEmpty == false else {
            let label = UILabel()
            label.text = "暂无书签"
            label.textAlignment = .center
            label.textColor = theme.contentTextColor.withAlphaComponent(0.7)
            label.numberOfLines = 0
            label.accessibilityIdentifier = "epub.reader.bookmarks.empty"
            tableView.backgroundView = label
            return
        }
        tableView.backgroundView = nil
    }

    private func titleText(for bookmark: RDEPUBBookmark) -> String {
        if let chapterTitle = bookmark.chapterTitle, !chapterTitle.isEmpty {
            return chapterTitle
        }
        return bookmark.location.href
    }

    private func detailText(for bookmark: RDEPUBBookmark) -> String {
        let parts = [
            dateFormatter.string(from: bookmark.createdAt),
            bookmark.note?.trimmingCharacters(in: .whitespacesAndNewlines),
            bookmark.location.href
        ].compactMap { value -> String? in
            guard let value, !value.isEmpty else { return nil }
            return value
        }
        return parts.joined(separator: "\n")
    }

    private func presentActions(for bookmark: RDEPUBBookmark, sourceIndexPath: IndexPath) {
        let alert = UIAlertController(title: "书签管理", message: nil, preferredStyle: .actionSheet)
        alert.addAction(UIAlertAction(title: "跳转到位置", style: .default) { [weak self] _ in
            self?.onSelectBookmark?(bookmark)
        })
        alert.addAction(UIAlertAction(title: "删除书签", style: .destructive) { [weak self] _ in
            self?.deleteBookmark(bookmark)
        })
        alert.addAction(UIAlertAction(title: "取消", style: .cancel))

        if let popover = alert.popoverPresentationController,
           let cell = tableView.cellForRow(at: sourceIndexPath) {
            popover.sourceView = cell
            popover.sourceRect = cell.bounds
        }

        present(alert, animated: true)
    }

    private func deleteBookmark(_ bookmark: RDEPUBBookmark) {
        guard let index = bookmarks.firstIndex(where: { $0.id == bookmark.id }) else { return }
        bookmarks.remove(at: index)
        tableView.reloadData()
        onDeleteBookmark?(bookmark)
        updateEmptyState()
    }
}