//
//  SettingsViewControllers.swift
//  suixinkan
//

import SnapKit
import UIKit
import WebKit

// MARK: - Diffable 标识

/// 设置页行标识。
private enum SettingsRowID {
    static let about = "settings:about"
    static let version = "settings:version"
    static let download = "settings:download"
    static let userAgreement = "settings:userAgreement"
    static let privacyPolicy = "settings:privacyPolicy"
}

/// 设置页行操作类型。
private enum SettingsRowAction {
    case agreement(AgreementPage)
    case version
    case download
}

/// 设置中心页面。
final class SettingsViewController: SimpleTableDiffableViewController {

    private var copiedDownloadLink = false

    private let rowActions: [String: SettingsRowAction] = [
        SettingsRowID.about: .agreement(.about),
        SettingsRowID.version: .version,
        SettingsRowID.download: .download,
        SettingsRowID.userAgreement: .agreement(.userAgreement),
        SettingsRowID.privacyPolicy: .agreement(.privacyPolicy)
    ]

    private let rowTitles: [String: String] = [
        SettingsRowID.about: "关于我们",
        SettingsRowID.version: "系统版本",
        SettingsRowID.download: "App下载",
        SettingsRowID.userAgreement: "用户协议",
        SettingsRowID.privacyPolicy: "隐私政策"
    ]

    /// 视图加载完成后的 UI 初始化与数据绑定。
    override func viewDidLoad() {
        super.viewDidLoad()
        title = "设置"
    }

    /// 构建 Diffable snapshot。
    override func buildSnapshot() -> NSDiffableDataSourceSnapshot<SimpleTableSection, SimpleTableRow> {
        var snapshot = NSDiffableDataSourceSnapshot<SimpleTableSection, SimpleTableRow>()
        snapshot.appendSections([0])
        snapshot.appendItems([
            SettingsRowID.about,
            SettingsRowID.version,
            SettingsRowID.download,
            SettingsRowID.userAgreement,
            SettingsRowID.privacyPolicy
        ], toSection: 0)
        return snapshot
    }

    /// section 页脚文案。
    override func sectionFooter(for section: SimpleTableSection) -> String? {
        "Copyright © 2025 All Rights Reserved\n苏ICP备2025157647号"
    }

    /// 配置 Cell 展示内容。
    override func configureCell(_ cell: UITableViewCell, row: SimpleTableRow, at indexPath: IndexPath) {
        cell.textLabel?.text = rowTitles[row]
        cell.textLabel?.textColor = UIColor(hex: 0x4B5563)
        cell.detailTextLabel?.text = nil
        cell.detailTextLabel?.textColor = nil
        cell.accessoryType = .none
        cell.selectionStyle = .default

        guard let action = rowActions[row] else { return }
        switch action {
        case .version:
            cell.detailTextLabel?.text = SettingsDisplayPolicy.versionText()
            cell.selectionStyle = .none
        case .download:
            cell.detailTextLabel?.text = copiedDownloadLink ? "已复制" : "复制链接"
            cell.detailTextLabel?.textColor = AppDesignUIKit.primary
        case .agreement:
            cell.accessoryType = .disclosureIndicator
        }
    }

    /// 处理行选中。
    override func didSelectRow(_ row: SimpleTableRow, at indexPath: IndexPath) {
        guard let action = rowActions[row] else { return }
        switch action {
        case .agreement(let page):
            HomeMenuRouting.pushProfile(.agreement(page), from: self)
        case .download:
            copyDownloadLink()
        case .version:
            break
        }
    }

    private var downloadLink: String {
        APIEnvironment.current.baseURL.appending(path: "/h5/app/download").absoluteString
    }

    /// 复制下载链接并刷新对应行展示。
    private func copyDownloadLink() {
        UIPasteboard.general.string = downloadLink
        copiedDownloadLink = true
        showToast("下载链接已复制")
        var snapshot = tableDataSource.snapshot()
        snapshot.reconfigureItems([SettingsRowID.download])
        tableDataSource.apply(snapshot, animatingDifferences: false)
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) { [weak self] in
            guard let self else { return }
            self.copiedDownloadLink = false
            var snapshot = self.tableDataSource.snapshot()
            snapshot.reconfigureItems([SettingsRowID.download])
            self.tableDataSource.apply(snapshot, animatingDifferences: false)
        }
    }
}

/// 协议 H5 页面。
final class AgreementViewController: UIViewController {

    private let page: AgreementPage
    private let webView = WKWebView(frame: .zero)
    private let loadingIndicator = UIActivityIndicatorView(style: .large)

    /// 初始化实例。
    init(page: AgreementPage) {
        self.page = page
        super.init(nibName: nil, bundle: nil)
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { fatalError() }

    /// 视图加载完成后的 UI 初始化与数据绑定。
    override func viewDidLoad() {
        super.viewDidLoad()
        title = page.title
        view.backgroundColor = AppDesignUIKit.pageBackground
        webView.navigationDelegate = self
        view.addSubview(webView)
        view.addSubview(loadingIndicator)
        webView.snp.makeConstraints { make in make.edges.equalToSuperview() }
        loadingIndicator.snp.makeConstraints { make in make.center.equalToSuperview() }
        loadingIndicator.startAnimating()
        webView.load(URLRequest(url: page.url))
    }
}

extension AgreementViewController: WKNavigationDelegate {
    /// web视图相关逻辑。
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        loadingIndicator.stopAnimating()
    }

    /// web视图相关逻辑。
    func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
        loadingIndicator.stopAnimating()
        showToast(error.localizedDescription)
    }
}