kiwix-apple/App/CompactViewController.swift

//
//  CompactViewController.swift
//  Kiwix
//
//  Created by Chris Li on 9/4/23.
//  Copyright © 2023 Chris Li. All rights reserved.
//

#if os(iOS)
import Combine
import SwiftUI
import UIKit

final class CompactViewController: UIHostingController<AnyView>, UISearchControllerDelegate, UISearchResultsUpdating {
    private let searchViewModel: SearchViewModel
    private let searchController: UISearchController
    private var searchTextObserver: AnyCancellable?
    private var openURLObserver: NSObjectProtocol?
    
    init() {
        searchViewModel = SearchViewModel()
        let searchResult = SearchResults().environmentObject(searchViewModel)
        searchController = UISearchController(searchResultsController: UIHostingController(rootView: searchResult))
        super.init(rootView: AnyView(CompactView()))
        searchController.searchResultsUpdater = self
    }
    
    @MainActor required dynamic init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        definesPresentationContext = true
        navigationController?.isToolbarHidden = false
        navigationController?.toolbar.scrollEdgeAppearance = {
            let apperance = UIToolbarAppearance()
            apperance.configureWithDefaultBackground()
            return apperance
        }()
        navigationItem.scrollEdgeAppearance = {
            let apperance = UINavigationBarAppearance()
            apperance.configureWithDefaultBackground()
            return apperance
        }()
        searchController.searchBar.autocorrectionType = .no
        navigationItem.titleView = searchController.searchBar
        searchController.automaticallyShowsCancelButton = false
        searchController.delegate = self
        searchController.hidesNavigationBarDuringPresentation = false
        searchController.showsSearchResultsController = true
        searchController.searchBar.searchTextField.placeholder = "common.search".localized

        searchTextObserver = searchViewModel.$searchText.sink { [weak self] searchText in
            guard self?.searchController.searchBar.text != searchText else { return }
            self?.searchController.searchBar.text = searchText
        }
        openURLObserver = NotificationCenter.default.addObserver(
            forName: .openURL, object: nil, queue: nil
        ) { [weak self] _ in
            self?.searchController.isActive = false
            self?.navigationItem.setRightBarButton(nil, animated: true)
        }
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    func willPresentSearchController(_ searchController: UISearchController) {
        navigationController?.setToolbarHidden(true, animated: true)
        navigationItem.setRightBarButton(
            UIBarButtonItem(
                title: "common.button.cancel".localized,
                style: .done,
                target: self,
                action: #selector(onSearchCancelled)
            ),
            animated: true
        )
    }
    @objc func onSearchCancelled() {
        searchController.isActive = false
        navigationItem.setRightBarButton(nil, animated: true)
    }

    func willDismissSearchController(_ searchController: UISearchController) {
        navigationController?.setToolbarHidden(false, animated: true)
        searchViewModel.searchText = ""
    }
    
    func updateSearchResults(for searchController: UISearchController) {
        searchViewModel.searchText = searchController.searchBar.text ?? ""
    }
}

private struct CompactView: View {
    @EnvironmentObject private var navigation: NavigationViewModel
    
    var body: some View {
        if case let .tab(tabID) = navigation.currentItem {
            Content().id(tabID).toolbar {
                ToolbarItemGroup(placement: .bottomBar) {
                    HStack {
                        NavigationButtons()
                        Spacer()
                        OutlineButton()
                        Spacer()
                        BookmarkButton()
                        Spacer()
                        ArticleShortcutButtons(displayMode: .randomArticle)
                        Spacer()
                        TabsManagerButton()
                    }
                }
            }
            .environmentObject(BrowserViewModel.getCached(tabID: tabID))
        }
    }
}

private struct Content: View {
    @EnvironmentObject private var browser: BrowserViewModel
    
    var body: some View {
        Group {
            if browser.url == nil {
                Welcome()
            } else {
                WebView().ignoresSafeArea()
            }
        }
        .focusedSceneValue(\.browserViewModel, browser)
        .focusedSceneValue(\.canGoBack, browser.canGoBack)
        .focusedSceneValue(\.canGoForward, browser.canGoForward)
        .modifier(ExternalLinkHandler(externalURL: $browser.externalURL))
        .onAppear {
            browser.updateLastOpened()
        }
        .onDisappear {
            browser.persistState()
        }
    }
}
#endif