import UIKit
import SnapKit

final class RDEPUBAnnotationEditorViewController: UIViewController, UITextViewDelegate {

    private let quote: String
    private let initialNote: String?
    private let theme: RDEPUBReaderTheme
    private let onSave: (String?) -> Void
    private let textView = UITextView()
    private let countLabel = UILabel()

    init(
        quote: String,
        initialNote: String?,
        theme: RDEPUBReaderTheme,
        onSave: @escaping (String?) -> Void
    ) {
        self.quote = quote
        self.initialNote = initialNote
        self.theme = theme
        self.onSave = onSave
        super.init(nibName: nil, bundle: nil)
        title = "写注释"
    }

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

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = theme.toolBackgroundColor
        configureNavigation()
        configureContent()
        updateCount()
        DispatchQueue.main.async { [weak self] in self?.textView.becomeFirstResponder() }
    }

    private func configureNavigation() {
        navigationItem.leftBarButtonItem = UIBarButtonItem(
            title: "取消", style: .plain, target: self, action: #selector(cancelAction)
        )
        navigationItem.rightBarButtonItem = UIBarButtonItem(
            title: "保存", style: .done, target: self, action: #selector(saveAction)
        )
        navigationController?.navigationBar.tintColor = .systemBlue
        navigationController?.navigationBar.titleTextAttributes = [
            .foregroundColor: theme.toolControlTextColor,
            .font: UIFont.systemFont(ofSize: 17, weight: .semibold)
        ]
    }

    private func configureContent() {
        let quoteCard = UIView()
        let rail = UIView()
        let quoteLabel = UILabel()
        let inputCard = UIView()

        view.addSubview(quoteCard)
        quoteCard.addSubview(rail)
        quoteCard.addSubview(quoteLabel)
        view.addSubview(inputCard)
        inputCard.addSubview(textView)
        inputCard.addSubview(countLabel)

        quoteCard.backgroundColor = theme.contentBackgroundColor.withAlphaComponent(0.78)
        quoteCard.layer.cornerRadius = 16
        rail.backgroundColor = UIColor(red: 0.94, green: 0.63, blue: 0.18, alpha: 1)
        rail.layer.cornerRadius = 2
        quoteLabel.text = quote
        quoteLabel.numberOfLines = 5
        quoteLabel.font = UIFont.systemFont(ofSize: 16)
        quoteLabel.textColor = theme.contentTextColor.withAlphaComponent(0.85)

        inputCard.backgroundColor = theme.contentBackgroundColor
        inputCard.layer.cornerRadius = 18
        inputCard.layer.shadowColor = UIColor.black.cgColor
        inputCard.layer.shadowOpacity = 0.06
        inputCard.layer.shadowRadius = 18
        inputCard.layer.shadowOffset = CGSize(width: 0, height: 6)
        textView.text = initialNote
        textView.delegate = self
        textView.font = UIFont.systemFont(ofSize: 17)
        textView.textColor = theme.contentTextColor
        textView.backgroundColor = .clear
        textView.accessibilityIdentifier = "epub.reader.annotation.editor"
        countLabel.font = UIFont.monospacedDigitSystemFont(ofSize: 12, weight: .regular)
        countLabel.textColor = .secondaryLabel
        countLabel.textAlignment = .right

        quoteCard.snp.makeConstraints { make in
            make.top.equalTo(view.safeAreaLayoutGuide).offset(20)
            make.horizontalEdges.equalToSuperview().inset(20)
        }
        rail.snp.makeConstraints { make in
            make.leading.equalToSuperview().offset(16)
            make.verticalEdges.equalToSuperview().inset(16)
            make.width.equalTo(4)
        }
        quoteLabel.snp.makeConstraints { make in
            make.leading.equalTo(rail.snp.trailing).offset(14)
            make.trailing.equalToSuperview().inset(18)
            make.verticalEdges.equalToSuperview().inset(16)
        }
        inputCard.snp.makeConstraints { make in
            make.top.equalTo(quoteCard.snp.bottom).offset(18)
            make.horizontalEdges.equalToSuperview().inset(20)
            make.bottom.equalTo(view.keyboardLayoutGuide.snp.top).offset(-16)
            make.height.greaterThanOrEqualTo(210)
        }
        textView.snp.makeConstraints { make in
            make.top.horizontalEdges.equalToSuperview().inset(14)
            make.bottom.equalTo(countLabel.snp.top).offset(-8)
        }
        countLabel.snp.makeConstraints { make in
            make.horizontalEdges.equalToSuperview().inset(16)
            make.bottom.equalToSuperview().inset(12)
        }
    }

    func textViewDidChange(_ textView: UITextView) {
        if textView.text.count > 1000 {
            textView.text = String(textView.text.prefix(1000))
        }
        updateCount()
    }

    private func updateCount() {
        countLabel.text = "\(textView.text.count)/1000"
    }

    @objc private func cancelAction() {
        dismiss(animated: true)
    }

    @objc private func saveAction() {
        let note = textView.text.trimmingCharacters(in: .whitespacesAndNewlines)
        onSave(note.isEmpty ? nil : note)
        dismiss(animated: true)
    }
}