import UIKit

final class RDEPUBReaderChapterListController: UITableViewController {

    var onSelectItem: ((RDEPUBReaderTableOfContentsItem) -> Void)?

    private let items: [RDEPUBReaderTableOfContentsItem]

    private let currentItem: RDEPUBReaderTableOfContentsItem?

    private let theme: RDEPUBReaderTheme

    init(
        items: [RDEPUBReaderTableOfContentsItem],
        currentItem: RDEPUBReaderTableOfContentsItem?,
        theme: RDEPUBReaderTheme
    ) {
        self.items = items
        self.currentItem = currentItem
        self.theme = theme
        super.init(style: .plain)
        title = "目录"
    }

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

    override func viewDidLoad() {
        super.viewDidLoad()
        view.accessibilityIdentifier = "epub.reader.toc.panel"
        tableView.accessibilityIdentifier = "epub.reader.toc.table"
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
        tableView.tableFooterView = UIView(frame: .zero)
        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.toc.navbar"
    }

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

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let item = items[indexPath.row]
        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
        cell.backgroundColor = theme.contentBackgroundColor
        cell.textLabel?.numberOfLines = 2
        cell.textLabel?.text = item.title
        if isCurrentItem(item) {
            cell.textLabel?.textColor = .systemBlue
        } else if item.isReadable {
            cell.textLabel?.textColor = theme.contentTextColor
        } else {
            cell.textLabel?.textColor = .systemGray
        }
        cell.selectionStyle = item.isReadable ? .default : .none
        cell.isUserInteractionEnabled = item.isReadable
        cell.indentationLevel = item.depth
        cell.indentationWidth = 18
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let item = items[indexPath.row]
        guard item.isReadable else { return }
        onSelectItem?(item)
    }

    private func isCurrentItem(_ item: RDEPUBReaderTableOfContentsItem) -> Bool {
        guard let currentItem else { return false }
        return currentItem.href == item.href
    }
}