//
//  CloudDriveDetailSheetViewController.swift
//  suixinkan
//

import SnapKit
import UIKit

/// 云盘文件详情底部表单，严格对齐 Android `CloudStorageFileDetailBottomModal`。
final class CloudDriveDetailSheetViewController: UIViewController {
    private let file: CloudFile
    private let onSave: (String) -> Void
    private let dimView = UIView()
    private let panelView = UIView()
    private let scrollView = UIScrollView()
    private let contentView = UIView()
    private let nameField = UITextField()

    /// 初始化云盘文件详情表单。
    init(file: CloudFile, onSave: @escaping (String) -> Void) {
        self.file = file
        self.onSave = onSave
        super.init(nibName: nil, bundle: nil)
        modalPresentationStyle = .overFullScreen
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
        setupConstraints()
        registerKeyboardNotifications()
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        dimView.alpha = 0
        panelView.transform = CGAffineTransform(translationX: 0, y: 620)
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        UIView.animate(withDuration: 0.24, delay: 0, options: [.curveEaseOut]) {
            self.dimView.alpha = 1
            self.panelView.transform = .identity
        }
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    private func setupUI() {
        view.backgroundColor = .clear
        dimView.backgroundColor = UIColor.black.withAlphaComponent(0.35)
        dimView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(cancelTapped)))

        panelView.backgroundColor = .white
        panelView.layer.cornerRadius = 28
        panelView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
        panelView.clipsToBounds = true
        scrollView.alwaysBounceVertical = false
        scrollView.keyboardDismissMode = .interactive

        view.addSubview(dimView)
        view.addSubview(panelView)
        panelView.addSubview(scrollView)
        scrollView.addSubview(contentView)

        let dragHandle = UIView()
        dragHandle.backgroundColor = UIColor(hex: 0x79747E)
        dragHandle.layer.cornerRadius = 2

        let typeIcon = UIImageView(image: fileTypeIcon())
        typeIcon.contentMode = .scaleAspectFit

        let fileNameLabel = UILabel()
        fileNameLabel.text = file.name
        fileNameLabel.font = .systemFont(ofSize: 16)
        fileNameLabel.textColor = UIColor(hex: 0x333333)
        fileNameLabel.numberOfLines = 1
        fileNameLabel.lineBreakMode = .byTruncatingTail

        let metaLabel = UILabel()
        metaLabel.text = "\(file.createdAt) | \(CloudDriveFormatter.fileSize(file.fileSize))"
        metaLabel.font = .systemFont(ofSize: 12)
        metaLabel.textColor = UIColor(hex: 0x999999)
        metaLabel.numberOfLines = 1

        let closeButton = UIButton(type: .system)
        closeButton.setImage(
            UIImage(systemName: "xmark")?.withConfiguration(UIImage.SymbolConfiguration(pointSize: 17, weight: .medium)),
            for: .normal
        )
        closeButton.tintColor = UIColor(hex: 0x333333)
        closeButton.accessibilityLabel = "关闭"
        closeButton.addTarget(self, action: #selector(cancelTapped), for: .touchUpInside)

        let nameTitleLabel = makeFieldTitle("文件名称")
        nameField.text = file.name
        nameField.placeholder = file.name
        nameField.font = .systemFont(ofSize: 16)
        nameField.textColor = UIColor(hex: 0x333333)
        nameField.clearButtonMode = .whileEditing
        nameField.returnKeyType = .done
        nameField.delegate = self
        nameField.backgroundColor = .white
        nameField.layer.cornerRadius = 4
        nameField.layer.borderWidth = 1
        nameField.layer.borderColor = UIColor(hex: 0x9CA3AF).cgColor
        nameField.leftView = UIView(frame: CGRect(x: 0, y: 0, width: 12, height: 1))
        nameField.leftViewMode = .always

        let infoStack = UIStackView()
        infoStack.axis = .vertical
        infoStack.spacing = 0
        infoStack.addArrangedSubview(makeInfoRow(label: "文件类型", value: detailTypeText()))
        if file.isFolder {
            infoStack.addArrangedSubview(makeInfoRow(label: "项目数量", value: String(file.childNum)))
        } else {
            infoStack.addArrangedSubview(makeInfoRow(label: "文件大小", value: CloudDriveFormatter.fileSize(file.fileSize)))
        }
        infoStack.addArrangedSubview(makeInfoRow(label: "创建时间", value: file.createdAt))
        infoStack.addArrangedSubview(makeInfoRow(label: "修改时间", value: file.updatedAt))

        let saveButton = UIButton(type: .system)
        saveButton.setTitle("保存", for: .normal)
        saveButton.setTitleColor(.white, for: .normal)
        saveButton.titleLabel?.font = .systemFont(ofSize: 15, weight: .medium)
        saveButton.backgroundColor = AppColor.primary
        saveButton.layer.cornerRadius = 10
        saveButton.addTarget(self, action: #selector(saveTapped), for: .touchUpInside)

        [dragHandle, typeIcon, fileNameLabel, metaLabel, closeButton, nameTitleLabel, nameField, infoStack, saveButton]
            .forEach(contentView.addSubview)

        dragHandle.snp.makeConstraints { make in
            make.top.equalToSuperview().offset(15)
            make.centerX.equalToSuperview()
            make.width.equalTo(40)
            make.height.equalTo(4)
        }
        typeIcon.snp.makeConstraints { make in
            make.top.equalTo(dragHandle.snp.bottom).offset(24)
            make.leading.equalToSuperview().offset(16)
            make.width.height.equalTo(40)
        }
        closeButton.snp.makeConstraints { make in
            make.centerY.equalTo(typeIcon)
            make.trailing.equalToSuperview().inset(4)
            make.width.height.equalTo(44)
        }
        fileNameLabel.snp.makeConstraints { make in
            make.top.equalTo(typeIcon)
            make.leading.equalTo(typeIcon.snp.trailing).offset(12)
            make.trailing.equalTo(closeButton.snp.leading).offset(-8)
        }
        metaLabel.snp.makeConstraints { make in
            make.top.equalTo(fileNameLabel.snp.bottom).offset(4)
            make.leading.trailing.equalTo(fileNameLabel)
        }
        nameTitleLabel.snp.makeConstraints { make in
            make.top.equalTo(typeIcon.snp.bottom).offset(16)
            make.leading.trailing.equalToSuperview().inset(16)
        }
        nameField.snp.makeConstraints { make in
            make.top.equalTo(nameTitleLabel.snp.bottom).offset(6)
            make.leading.trailing.equalTo(nameTitleLabel)
            make.height.equalTo(52)
        }
        infoStack.snp.makeConstraints { make in
            make.top.equalTo(nameField.snp.bottom).offset(10)
            make.leading.trailing.equalTo(nameField)
        }
        saveButton.snp.makeConstraints { make in
            make.top.equalTo(infoStack.snp.bottom).offset(20)
            make.leading.trailing.equalTo(nameField)
            make.height.equalTo(44)
            make.bottom.equalToSuperview().inset(12)
        }
    }

    private func setupConstraints() {
        dimView.snp.makeConstraints { make in make.edges.equalToSuperview() }
        panelView.snp.makeConstraints { make in
            make.leading.trailing.equalToSuperview()
            make.bottom.equalToSuperview()
            make.top.greaterThanOrEqualTo(view.safeAreaLayoutGuide).offset(16)
            make.height.equalTo(590).priority(.high)
        }
        scrollView.snp.makeConstraints { make in
            make.top.leading.trailing.equalToSuperview()
            make.bottom.equalTo(view.safeAreaLayoutGuide)
        }
        contentView.snp.makeConstraints { make in
            make.edges.equalTo(scrollView.contentLayoutGuide)
            make.width.equalTo(scrollView.frameLayoutGuide)
        }
    }

    private func makeFieldTitle(_ text: String) -> UILabel {
        let label = UILabel()
        label.text = text
        label.font = .systemFont(ofSize: 13)
        label.textColor = UIColor(hex: 0x7B8EAA)
        return label
    }

    private func makeInfoRow(label: String, value: String) -> UIView {
        let container = UIView()
        let labelView = makeFieldTitle(label)
        let valueContainer = UIView()
        valueContainer.backgroundColor = UIColor(hex: 0xF4F4F4)
        valueContainer.layer.cornerRadius = 6
        let valueLabel = UILabel()
        valueLabel.text = value
        valueLabel.font = .systemFont(ofSize: 14)
        valueLabel.textColor = UIColor(hex: 0x333333)
        valueLabel.numberOfLines = 1
        valueLabel.lineBreakMode = .byTruncatingTail

        container.addSubview(labelView)
        container.addSubview(valueContainer)
        valueContainer.addSubview(valueLabel)
        labelView.snp.makeConstraints { make in
            make.top.leading.trailing.equalToSuperview()
        }
        valueContainer.snp.makeConstraints { make in
            make.top.equalTo(labelView.snp.bottom).offset(4)
            make.leading.trailing.equalToSuperview()
            make.height.equalTo(36)
            make.bottom.equalToSuperview().inset(6)
        }
        valueLabel.snp.makeConstraints { make in
            make.leading.trailing.equalToSuperview().inset(12)
            make.centerY.equalToSuperview()
        }
        return container
    }

    private func fileTypeIcon() -> UIImage? {
        if file.isFolder {
            return CloudDriveAsset.image(named: "icon_cloud_storage_file_type_folder", fallbackSystemName: "folder.fill")
        }
        if file.isVideo {
            return CloudDriveAsset.image(named: "icon_cloud_storage_file_type_video", fallbackSystemName: "video.fill")
        }
        return CloudDriveAsset.image(named: "icon_cloud_storage_file_type_photo", fallbackSystemName: "photo.fill")
    }

    private func detailTypeText() -> String {
        if file.isFolder { return "文件夹" }
        let suffix = (file.name as NSString).pathExtension.uppercased()
        return suffix.isEmpty ? "文件" : suffix
    }

    private func registerKeyboardNotifications() {
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(keyboardFrameChanged(_:)),
            name: UIResponder.keyboardWillChangeFrameNotification,
            object: nil
        )
    }

    private func close(completion: (() -> Void)? = nil) {
        view.endEditing(true)
        UIView.animate(withDuration: 0.2, delay: 0, options: [.curveEaseIn]) {
            self.dimView.alpha = 0
            self.panelView.transform = CGAffineTransform(translationX: 0, y: self.panelView.bounds.height + 40)
        } completion: { _ in
            self.dismiss(animated: false, completion: completion)
        }
    }

    @objc private func cancelTapped() {
        close()
    }

    @objc private func saveTapped() {
        let name = (nameField.text ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
        close { [onSave] in onSave(name) }
    }

    @objc private func keyboardFrameChanged(_ notification: Notification) {
        guard let frame = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect else { return }
        let frameInView = view.convert(frame, from: nil)
        let overlap = max(0, view.bounds.maxY - frameInView.minY)
        scrollView.contentInset.bottom = overlap
        scrollView.verticalScrollIndicatorInsets.bottom = overlap
        guard overlap > 0 else { return }
        let fieldFrame = nameField.convert(nameField.bounds, to: scrollView)
        scrollView.scrollRectToVisible(fieldFrame.insetBy(dx: 0, dy: -16), animated: true)
    }
}

extension CloudDriveDetailSheetViewController: UITextFieldDelegate {
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true
    }
}