//
//  ClipEditViewController.swift
//  Note
//
//  Created by Kimi Code CLI on 2026/7/15.
//

import UIKit

class ClipEditViewController: UIViewController {

    private var textView: UITextView!
    private var floatingDoneButton: UIButton!
    private var floatingDoneButtonBottomConstraint: NSLayoutConstraint!
    private var clip: Clip

    init(clip: Clip) {
        self.clip = clip
        super.init(nibName: nil, bundle: nil)
    }

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

    override func viewDidLoad() {
        super.viewDidLoad()
        title = "编辑文案"
        navigationItem.largeTitleDisplayMode = .never
        view.backgroundColor = .systemGroupedBackground

        setupNavigationBar()
        setupTextView()
        setupKeyboardObservers()
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    private func setupKeyboardObservers() {
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: UIResponder.keyboardWillHideNotification, object: nil)
    }

    @objc private func keyboardWillShow(_ notification: Notification) {
        guard let keyboardFrame = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect else { return }
        let keyboardFrameInView = view.convert(keyboardFrame, from: nil)
        let intersection = keyboardFrameInView.intersection(view.bounds)
        let keyboardHeight = intersection.height

        let duration = notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? TimeInterval ?? 0.25

        UIView.animate(withDuration: duration, delay: 0, options: .beginFromCurrentState) {
            self.textView.contentInset.bottom = keyboardHeight
            self.textView.verticalScrollIndicatorInsets.bottom = keyboardHeight
            self.floatingDoneButtonBottomConstraint.constant = -(keyboardHeight + 16)
            self.floatingDoneButton.alpha = 1
            self.view.layoutIfNeeded()
        }
    }

    @objc private func keyboardWillHide(_ notification: Notification) {
        let duration = notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? TimeInterval ?? 0.25

        UIView.animate(withDuration: duration, delay: 0, options: .beginFromCurrentState) {
            self.textView.contentInset.bottom = 0
            self.textView.verticalScrollIndicatorInsets.bottom = 0
            self.floatingDoneButtonBottomConstraint.constant = -16
            self.floatingDoneButton.alpha = 0
            self.view.layoutIfNeeded()
        }
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        textView.becomeFirstResponder()
    }

    private func setupNavigationBar() {
        let saveButton = UIBarButtonItem(
            title: "保存",
            style: .prominent,
            target: self,
            action: #selector(didTapSaveButton)
        )
        navigationItem.rightBarButtonItem = saveButton
    }

    private func setupTextView() {
        textView = UITextView()
        textView.translatesAutoresizingMaskIntoConstraints = false
        textView.backgroundColor = UIColor { traitCollection in
            traitCollection.userInterfaceStyle == .dark ? .secondarySystemBackground : .white
        }
        textView.layer.cornerRadius = 12
        textView.layer.borderWidth = 0.5
        textView.layer.borderColor = UIColor.separator.cgColor
        textView.layer.masksToBounds = true
        textView.font = UIFont.preferredFont(forTextStyle: .body)
        textView.textContainerInset = UIEdgeInsets(top: 12, left: 12, bottom: 12, right: 12)
        textView.text = clip.text
        view.addSubview(textView)

        var doneConfig = UIButton.Configuration.glass()
        doneConfig.title = "完成"
        doneConfig.titleTextAttributesTransformer = UIConfigurationTextAttributesTransformer { incoming in
            var outgoing = incoming
            outgoing.font = UIFont.systemFont(ofSize: 17, weight: .semibold)
            return outgoing
        }
        doneConfig.baseForegroundColor = .label
        doneConfig.cornerStyle = .capsule
        doneConfig.contentInsets = NSDirectionalEdgeInsets(top: 15, leading: 22, bottom: 15, trailing: 22)
        floatingDoneButton = UIButton(configuration: doneConfig)
        floatingDoneButton.translatesAutoresizingMaskIntoConstraints = false
        floatingDoneButton.alpha = 0
        floatingDoneButton.addTarget(self, action: #selector(didTapFloatingDoneButton), for: .touchUpInside)
        view.addSubview(floatingDoneButton)

        let safeArea = view.safeAreaLayoutGuide
        floatingDoneButtonBottomConstraint = floatingDoneButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -16)

        NSLayoutConstraint.activate([
            textView.topAnchor.constraint(equalTo: safeArea.topAnchor, constant: 16),
            textView.leadingAnchor.constraint(equalTo: safeArea.leadingAnchor, constant: 16),
            textView.trailingAnchor.constraint(equalTo: safeArea.trailingAnchor, constant: -16),
            textView.bottomAnchor.constraint(equalTo: safeArea.bottomAnchor, constant: -16),

            floatingDoneButton.trailingAnchor.constraint(equalTo: safeArea.trailingAnchor, constant: -16),
            floatingDoneButtonBottomConstraint
        ])
    }

    @objc private func didTapFloatingDoneButton() {
        textView.resignFirstResponder()
    }

    @objc private func didTapSaveButton() {
        let updatedText = textView.text ?? ""
        guard !updatedText.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else {
            let alert = UIAlertController(title: "提示", message: "文案不能为空。", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "确定", style: .default))
            present(alert, animated: true)
            return
        }

        var updatedClip = clip
        updatedClip.text = updatedText

        Task {
            do {
                try await ClipStore.shared.update(updatedClip)
                _ = await MainActor.run {
                    self.navigationController?.popViewController(animated: true)
                    return ()
                }
            } catch {
                await MainActor.run {
                    let alert = UIAlertController(title: "提示", message: "保存失败: \(error.localizedDescription)", preferredStyle: .alert)
                    alert.addAction(UIAlertAction(title: "确定", style: .default))
                    self.present(alert, animated: true)
                }
            }
        }
    }
}