//
//  CloudDriveTransferViewController.swift
//  suixinkan
//

import SnapKit
import UIKit

/// 云盘传输管理页，对齐 Android `CloudStorageTransitScreen`。
final class CloudDriveTransferViewController: BaseViewController {
    private enum Tab: Int {
        case upload
        case download
    }

    private let manager: CloudTransferManager
    private let segmentedControl = UISegmentedControl(items: ["上传", "下载"])
    private let tableView = UITableView(frame: .zero, style: .plain)
    private var selectedTab: Tab = .upload

    /// 初始化传输管理页。
    init(manager: CloudTransferManager = .shared) {
        self.manager = manager
        super.init(nibName: nil, bundle: nil)
    }

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

    override func setupNavigationBar() {
        title = "传输管理"
    }

    override func setupUI() {
        view.backgroundColor = AppColor.pageBackground
        segmentedControl.selectedSegmentIndex = selectedTab.rawValue
        tableView.backgroundColor = AppColor.pageBackground
        tableView.separatorStyle = .none
        tableView.dataSource = self
        tableView.delegate = self
        tableView.register(CloudTransferCell.self, forCellReuseIdentifier: CloudTransferCell.reuseIdentifier)

        view.addSubview(segmentedControl)
        view.addSubview(tableView)
    }

    override func setupConstraints() {
        segmentedControl.snp.makeConstraints { make in
            make.top.equalTo(view.safeAreaLayoutGuide).offset(AppSpacing.sm)
            make.leading.trailing.equalToSuperview().inset(AppSpacing.md)
            make.height.equalTo(36)
        }
        tableView.snp.makeConstraints { make in
            make.top.equalTo(segmentedControl.snp.bottom).offset(AppSpacing.sm)
            make.leading.trailing.bottom.equalToSuperview()
        }
    }

    override func bindActions() {
        segmentedControl.addTarget(self, action: #selector(tabChanged), for: .valueChanged)
        manager.onTasksChange = { [weak self] in
            Task { @MainActor in self?.tableView.reloadData() }
        }
    }

    private var visibleTasks: [CloudTransferTask] {
        selectedTab == .upload ? manager.uploadTasks : manager.downloadTasks
    }

    @objc private func tabChanged() {
        selectedTab = Tab(rawValue: segmentedControl.selectedSegmentIndex) ?? .upload
        tableView.reloadData()
    }
}

extension CloudDriveTransferViewController: UITableViewDataSource, UITableViewDelegate {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        visibleTasks.count
    }

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        112
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: CloudTransferCell.reuseIdentifier, for: indexPath) as! CloudTransferCell
        let task = visibleTasks[indexPath.row]
        cell.apply(task: task)
        cell.onPrimaryAction = { [weak self] in
            guard let self else { return }
            if task.kind == .upload {
                task.status == .uploading ? self.manager.pauseUpload(id: task.id) : self.manager.resumeUpload(id: task.id)
            } else {
                task.status == .downloading ? self.manager.pauseDownload(id: task.id) : self.manager.resumeDownload(id: task.id)
            }
        }
        cell.onCancel = { [weak self] in
            guard let self else { return }
            task.kind == .upload ? self.manager.cancelUpload(id: task.id) : self.manager.cancelDownload(id: task.id)
        }
        return cell
    }
}

/// 云盘传输任务 Cell。
private final class CloudTransferCell: UITableViewCell {
    static let reuseIdentifier = "CloudTransferCell"

    var onPrimaryAction: (() -> Void)?
    var onCancel: (() -> Void)?

    private let cardView = UIView()
    private let iconView = UIImageView()
    private let titleLabel = UILabel()
    private let statusLabel = UILabel()
    private let primaryButton = UIButton(type: .system)
    private let cancelButton = UIButton(type: .system)
    private let progressView = UIProgressView(progressViewStyle: .default)
    private let percentLabel = UILabel()

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        setupUI()
        setupConstraints()
    }

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

    override func prepareForReuse() {
        super.prepareForReuse()
        onPrimaryAction = nil
        onCancel = nil
    }

    func apply(task: CloudTransferTask) {
        iconView.image = CloudDriveAsset.image(
            named: task.fileType == 1 ? "icon_cloud_storage_file_type_video" : "icon_cloud_storage_file_type_photo",
            fallbackSystemName: task.fileType == 1 ? "video.fill" : "photo.fill"
        )
        titleLabel.text = task.fileName
        statusLabel.text = "\(task.status.title) \(CloudDriveFormatter.fileSize(task.fileSize))"
        progressView.progress = Float(task.progress) / 100
        percentLabel.text = "\(task.progress)%"
        let isRunning = task.status == .uploading || task.status == .downloading
        primaryButton.setImage(UIImage(systemName: isRunning ? "pause.fill" : "play.fill"), for: .normal)
        primaryButton.isHidden = task.status == .completed
    }

    private func setupUI() {
        backgroundColor = .clear
        selectionStyle = .none
        cardView.backgroundColor = .white
        cardView.layer.cornerRadius = AppRadius.sm
        cardView.clipsToBounds = true

        iconView.tintColor = AppColor.primary
        iconView.contentMode = .scaleAspectFit
        titleLabel.font = .app(.body)
        titleLabel.textColor = AppColor.textPrimary
        titleLabel.lineBreakMode = .byTruncatingMiddle
        statusLabel.font = .app(.caption)
        statusLabel.textColor = AppColor.textTertiary
        progressView.progressTintColor = AppColor.primary
        percentLabel.font = .app(.caption)
        percentLabel.textColor = AppColor.textSecondary
        percentLabel.textAlignment = .right

        primaryButton.tintColor = AppColor.primary
        cancelButton.tintColor = AppColor.textSecondary
        cancelButton.setImage(UIImage(systemName: "xmark"), for: .normal)
        primaryButton.addTarget(self, action: #selector(primaryTapped), for: .touchUpInside)
        cancelButton.addTarget(self, action: #selector(cancelTapped), for: .touchUpInside)

        contentView.addSubview(cardView)
        cardView.addSubview(iconView)
        cardView.addSubview(titleLabel)
        cardView.addSubview(statusLabel)
        cardView.addSubview(primaryButton)
        cardView.addSubview(cancelButton)
        cardView.addSubview(progressView)
        cardView.addSubview(percentLabel)
    }

    private func setupConstraints() {
        cardView.snp.makeConstraints { make in
            make.top.bottom.equalToSuperview().inset(AppSpacing.xs)
            make.leading.trailing.equalToSuperview().inset(AppSpacing.md)
        }
        iconView.snp.makeConstraints { make in
            make.leading.top.equalToSuperview().offset(AppSpacing.sm)
            make.width.height.equalTo(48)
        }
        cancelButton.snp.makeConstraints { make in
            make.trailing.top.equalToSuperview().inset(AppSpacing.xs)
            make.width.height.equalTo(36)
        }
        primaryButton.snp.makeConstraints { make in
            make.trailing.equalTo(cancelButton.snp.leading)
            make.centerY.equalTo(cancelButton)
            make.width.height.equalTo(36)
        }
        titleLabel.snp.makeConstraints { make in
            make.leading.equalTo(iconView.snp.trailing).offset(AppSpacing.sm)
            make.top.equalTo(iconView)
            make.trailing.equalTo(primaryButton.snp.leading).offset(-AppSpacing.xs)
        }
        statusLabel.snp.makeConstraints { make in
            make.leading.trailing.equalTo(titleLabel)
            make.top.equalTo(titleLabel.snp.bottom).offset(AppSpacing.xxs)
        }
        progressView.snp.makeConstraints { make in
            make.leading.equalTo(iconView)
            make.trailing.equalToSuperview().inset(AppSpacing.sm)
            make.top.equalTo(iconView.snp.bottom).offset(AppSpacing.sm)
        }
        percentLabel.snp.makeConstraints { make in
            make.top.equalTo(progressView.snp.bottom).offset(AppSpacing.xxs)
            make.trailing.equalTo(progressView)
        }
    }

    @objc private func primaryTapped() {
        onPrimaryAction?()
    }

    @objc private func cancelTapped() {
        onCancel?()
    }
}