mastodon-app-ufficiale-iphone-ios/Mastodon/Scene/Compose/ComposeViewController.swift

//
//  ComposeViewController.swift
//  Mastodon
//
//  Created by MainasuK Cirno on 2021-3-11.
//

import os.log
import UIKit
import Combine
import TwitterTextEditor
import KeyboardGuide

final class ComposeViewController: UIViewController, NeedsDependency {
    
    weak var context: AppContext! { willSet { precondition(!isViewLoaded) } }
    weak var coordinator: SceneCoordinator! { willSet { precondition(!isViewLoaded) } }
    
    var disposeBag = Set<AnyCancellable>()
    var viewModel: ComposeViewModel!
    
    let composeTootBarButtonItem: UIBarButtonItem = {
        let button = RoundedEdgesButton(type: .custom)
        button.setTitle(L10n.Scene.Compose.composeAction, for: .normal)
        button.titleLabel?.font = .systemFont(ofSize: 14, weight: .bold)
        button.setBackgroundImage(.placeholder(color: Asset.Colors.Button.normal.color), for: .normal)
        button.setBackgroundImage(.placeholder(color: Asset.Colors.Button.normal.color.withAlphaComponent(0.5)), for: .highlighted)
        button.setBackgroundImage(.placeholder(color: Asset.Colors.Button.disabled.color), for: .disabled)
        button.setTitleColor(.white, for: .normal)
        button.contentEdgeInsets = UIEdgeInsets(top: 3, left: 16, bottom: 3, right: 16)
        button.adjustsImageWhenHighlighted = false
        let barButtonItem = UIBarButtonItem(customView: button)
        return barButtonItem
    }()
    
    let tableView: UITableView = {
        let tableView = ControlContainableTableView()
        tableView.register(ComposeRepliedToTootContentTableViewCell.self, forCellReuseIdentifier: String(describing: ComposeRepliedToTootContentTableViewCell.self))
        tableView.register(ComposeTootContentTableViewCell.self, forCellReuseIdentifier: String(describing: ComposeTootContentTableViewCell.self))
        tableView.rowHeight = UITableView.automaticDimension
        tableView.separatorStyle = .none
        return tableView
    }()
    
    let composeToolbarView: ComposeToolbarView = {
        let composeToolbarView = ComposeToolbarView()
        return composeToolbarView
    }()
    var composeToolbarViewBottomLayoutConstraint: NSLayoutConstraint!
    let composeToolbarBackgroundView: UIView = {
        let backgroundView = UIView()
        return backgroundView
    }()
    
}

extension ComposeViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        viewModel.title
            .receive(on: DispatchQueue.main)
            .sink { [weak self] title in
                guard let self = self else { return }
                self.title = title
            }
            .store(in: &disposeBag)
        view.backgroundColor = Asset.Colors.Background.systemBackground.color
        navigationItem.leftBarButtonItem = UIBarButtonItem(title: L10n.Common.Controls.Actions.cancel, style: .plain, target: self, action: #selector(ComposeViewController.cancelBarButtonItemPressed(_:)))
        navigationItem.rightBarButtonItem = composeTootBarButtonItem
        
        tableView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(tableView)
        NSLayoutConstraint.activate([
            tableView.topAnchor.constraint(equalTo: view.topAnchor),
            tableView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            tableView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
        ])
        
        composeToolbarView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(composeToolbarView)
        composeToolbarViewBottomLayoutConstraint = view.bottomAnchor.constraint(equalTo: composeToolbarView.bottomAnchor)
        NSLayoutConstraint.activate([
            composeToolbarView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            composeToolbarView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            composeToolbarViewBottomLayoutConstraint,
            composeToolbarView.heightAnchor.constraint(equalToConstant: ComposeToolbarView.toolbarHeight),
        ])
        composeToolbarView.preservesSuperviewLayoutMargins = true
        composeToolbarView.delegate = self
        
        tableView.delegate = self
        viewModel.setupDiffableDataSource(for: tableView, dependency: self)
        
        // respond scrollView overlap change
        view.layoutIfNeeded()
        // update layout when keyboard show/dismiss
        Publishers.CombineLatest3(
            KeyboardResponderService.shared.isShow.eraseToAnyPublisher(),
            KeyboardResponderService.shared.state.eraseToAnyPublisher(),
            KeyboardResponderService.shared.endFrame.eraseToAnyPublisher()
        )
        .sink(receiveValue: { [weak self] isShow, state, endFrame in
            guard let self = self else { return }
            
            guard isShow, state == .dock else {
                self.tableView.contentInset.bottom = 0.0
                self.tableView.verticalScrollIndicatorInsets.bottom = 0.0
                UIView.animate(withDuration: 0.3) {
                    self.composeToolbarViewBottomLayoutConstraint.constant = 0.0
                    self.view.layoutIfNeeded()
                }
                return
            }

            // isShow AND dock state
            let contentFrame = self.view.convert(self.tableView.frame, to: nil)
            let padding = contentFrame.maxY - endFrame.minY
            guard padding > 0 else {
                self.tableView.contentInset.bottom = 0.0
                self.tableView.verticalScrollIndicatorInsets.bottom = 0.0
                UIView.animate(withDuration: 0.3) {
                    self.composeToolbarViewBottomLayoutConstraint.constant = 0.0
                    self.view.layoutIfNeeded()
                }
                return
            }

            // add 16pt margin
            self.tableView.contentInset.bottom = padding + 16
            self.tableView.verticalScrollIndicatorInsets.bottom = padding + 16
            UIView.animate(withDuration: 0.3) {
                self.composeToolbarViewBottomLayoutConstraint.constant = padding
                self.view.layoutIfNeeded()
            }
        })
        .store(in: &disposeBag)
        
        viewModel.isComposeTootBarButtonItemEnabled
            .receive(on: DispatchQueue.main)
            .assign(to: \.isEnabled, on: composeTootBarButtonItem)
            .store(in: &disposeBag)
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        // Fix AutoLayout conflict issue
        DispatchQueue.main.async { [weak self] in
            guard let self = self else { return }
            self.markTextViewEditorBecomeFirstResponser()
        }
    }
    
}

extension ComposeViewController {
    private func markTextViewEditorBecomeFirstResponser() {
        guard let diffableDataSource = viewModel.diffableDataSource else { return }
        let items = diffableDataSource.snapshot().itemIdentifiers
        for item in items {
            switch item {
            case .toot:
                guard let indexPath = diffableDataSource.indexPath(for: item),
                      let cell = tableView.cellForRow(at: indexPath) as? ComposeTootContentTableViewCell else {
                    continue
                }
                cell.textEditorView.isEditing = true
                return
            default:
                continue
            }
        }
    }
    
    private func showDismissConfirmAlertController() {
        let alertController = UIAlertController(
            title: L10n.Common.Alerts.DiscardComposeContent.title,
            message: L10n.Common.Alerts.DiscardComposeContent.message,
            preferredStyle: .alert
        )
        let discardAction = UIAlertAction(title: L10n.Common.Controls.Actions.discard, style: .destructive) { [weak self] _ in
            guard let self = self else { return }
            self.dismiss(animated: true, completion: nil)
        }
        alertController.addAction(discardAction)
        let cancelAction = UIAlertAction(title: L10n.Common.Controls.Actions.cancel, style: .cancel)
        alertController.addAction(cancelAction)
        present(alertController, animated: true, completion: nil)
    }
}

extension ComposeViewController {

    @objc private func cancelBarButtonItemPressed(_ sender: UIBarButtonItem) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
        guard viewModel.shouldDismiss.value else {
            showDismissConfirmAlertController()
            return
        }
        dismiss(animated: true, completion: nil)
    }
    
}

// MARK: - TextEditorViewTextAttributesDelegate
extension ComposeViewController: TextEditorViewTextAttributesDelegate {
    
    func textEditorView(_ textEditorView: TextEditorView, updateAttributedString attributedString: NSAttributedString, completion: @escaping (NSAttributedString?) -> Void) {
        // TODO:
    }
    
}

// MARK: - ComposeToolbarViewDelegate
extension ComposeViewController: ComposeToolbarViewDelegate {
    
    func composeToolbarView(_ composeToolbarView: ComposeToolbarView, cameraButtonDidPressed sender: UIButton) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
    func composeToolbarView(_ composeToolbarView: ComposeToolbarView, gifButtonDidPressed sender: UIButton) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
    func composeToolbarView(_ composeToolbarView: ComposeToolbarView, atButtonDidPressed sender: UIButton) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
    func composeToolbarView(_ composeToolbarView: ComposeToolbarView, topicButtonDidPressed sender: UIButton) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
    func composeToolbarView(_ composeToolbarView: ComposeToolbarView, locationButtonDidPressed sender: UIButton) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
}

// MARK: - UITableViewDelegate
extension ComposeViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return UITableView.automaticDimension
    }
}

// MARK: - ComposeViewController
extension ComposeViewController: UIAdaptivePresentationControllerDelegate {

    func presentationControllerShouldDismiss(_ presentationController: UIPresentationController) -> Bool {
        return viewModel.shouldDismiss.value
    }
    
    func presentationControllerDidAttemptToDismiss(_ presentationController: UIPresentationController) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
        showDismissConfirmAlertController()

    }
    
    func presentationControllerDidDismiss(_ presentationController: UIPresentationController) {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
}