//
//  MastodonConfirmEmailViewController.swift
//  Mastodon
//
//  Created by sxiaojian on 2021/2/23.
//

import Combine
import MastodonSDK
import os.log
import ThirdPartyMailer
import UIKit
import MastodonAsset
import MastodonLocalization

final class MastodonConfirmEmailViewController: UIViewController, NeedsDependency {
    
    var disposeBag = Set<AnyCancellable>()

    weak var context: AppContext! { willSet { precondition(!isViewLoaded) } }
    weak var coordinator: SceneCoordinator! { willSet { precondition(!isViewLoaded) } }

    var viewModel: MastodonConfirmEmailViewModel!

    let stackView = UIStackView()

    let largeTitleLabel: UILabel = {
        let label = UILabel()
        label.font = UIFontMetrics(forTextStyle: .largeTitle).scaledFont(for: UIFont.systemFont(ofSize: 34, weight: .bold))
        label.textColor = .label
        label.text = L10n.Scene.ConfirmEmail.title
        return label
    }()

    private(set) lazy var subtitleLabel: UILabel = {
        let label = UILabel()
        label.font = UIFontMetrics(forTextStyle: .title1).scaledFont(for: UIFont.systemFont(ofSize: 20))
        label.textColor = .secondaryLabel
        label.text = L10n.Scene.ConfirmEmail.subtitle
        label.numberOfLines = 0
        return label
    }()
    
    let emailImageView: UIImageView = {
        let imageView = UIImageView()
        imageView.image = Asset.Asset.email.image
        imageView.backgroundColor = .clear
        imageView.contentMode = .scaleAspectFit
        return imageView
    }()
    
    let navigationActionView: NavigationActionView = {
        let navigationActionView = NavigationActionView()
        navigationActionView.backgroundColor = Asset.Scene.Onboarding.onboardingBackground.color
        return navigationActionView
    }()
    
    deinit {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
}

extension MastodonConfirmEmailViewController {

    override func viewDidLoad() {

        navigationItem.leftBarButtonItem = UIBarButtonItem()

        setupOnboardingAppearance()
        configureTitleLabel()
        configureMargin()

        // stackView
        stackView.axis = .vertical
        stackView.distribution = .fill
        stackView.spacing = 10
        stackView.layoutMargins = UIEdgeInsets(top: 10, left: 0, bottom: 23, right: 0)
        stackView.isLayoutMarginsRelativeArrangement = true
        stackView.addArrangedSubview(largeTitleLabel)
        stackView.addArrangedSubview(subtitleLabel)
        stackView.addArrangedSubview(emailImageView)
        emailImageView.setContentHuggingPriority(.defaultLow, for: .vertical)
        emailImageView.setContentCompressionResistancePriority(.defaultLow, for: .vertical)
        stackView.addArrangedSubview(navigationActionView)

        view.addSubview(stackView)
        stackView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            stackView.topAnchor.constraint(equalTo: view.readableContentGuide.topAnchor),
            stackView.leadingAnchor.constraint(equalTo: view.layoutMarginsGuide.leadingAnchor),
            stackView.trailingAnchor.constraint(equalTo: view.layoutMarginsGuide.trailingAnchor),
            stackView.bottomAnchor.constraint(equalTo: view.readableContentGuide.bottomAnchor),
        ])
        
        self.viewModel.timestampUpdatePublisher
            .sink { [weak self] _ in
                guard let self = self else { return }
                AuthenticationViewModel.verifyAndSaveAuthentication(context: self.context, info: self.viewModel.authenticateInfo, userToken: self.viewModel.userToken)
                    .receive(on: DispatchQueue.main)
                    .sink { completion in
                        switch completion {
                        case .failure(let error):
                            os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: swap user access token swap fail: %s", (#file as NSString).lastPathComponent, #line, #function, error.localizedDescription)
                        case .finished:
                            // upload avatar and set display name in the background
                            Just(self.viewModel.userToken.accessToken)
                                .asyncMap { token in
                                    try await self.context.apiService.accountUpdateCredentials(
                                        domain: self.viewModel.authenticateInfo.domain,
                                        query: self.viewModel.updateCredentialQuery,
                                        authorization: Mastodon.API.OAuth.Authorization(accessToken: token)
                                    )
                                }
                                .retry(3)
                                .sink { completion in
                                    switch completion {
                                    case .failure(let error):
                                        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: setup avatar & display name fail: %s", ((#file as NSString).lastPathComponent), #line, #function, error.localizedDescription)
                                    case .finished:
                                        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: setup avatar & display name success", ((#file as NSString).lastPathComponent), #line, #function)
                                    }
                                } receiveValue: { _ in
                                    // do nothing
                                }
                                .store(in: &self.context.disposeBag)    // execute in the background
                        }   // end switch
                    } receiveValue: { response in
                        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: user %s's email confirmed", ((#file as NSString).lastPathComponent), #line, #function, response.value.username)
                        self.coordinator.setup()
                        // self.dismiss(animated: true, completion: nil)
                    }
                    .store(in: &self.disposeBag)
            }
            .store(in: &self.disposeBag)
        
        
        navigationActionView.backButton.setTitle(L10n.Scene.ConfirmEmail.Button.resend, for: .normal)
        navigationActionView.backButton.addTarget(self, action: #selector(MastodonConfirmEmailViewController.resendButtonPressed(_:)), for: .touchUpInside)
        
        navigationActionView.nextButton.setTitle(L10n.Scene.ConfirmEmail.Button.openEmailApp, for: .normal)
        navigationActionView.nextButton.addTarget(self, action: #selector(MastodonConfirmEmailViewController.openEmailButtonPressed(_:)), for: .touchUpInside)
    }
    
    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        super.traitCollectionDidChange(previousTraitCollection)
        
        configureTitleLabel()
        configureMargin()
    }
    
}

extension MastodonConfirmEmailViewController {
    private func configureTitleLabel() {
        switch traitCollection.horizontalSizeClass {
        case .regular:
            navigationItem.largeTitleDisplayMode = .always
            navigationItem.title = L10n.Scene.ConfirmEmail.title.replacingOccurrences(of: "\n", with: " ")
            largeTitleLabel.isHidden = true
        default:
            navigationItem.largeTitleDisplayMode = .never
            navigationItem.title = nil
            largeTitleLabel.isHidden = false
        }
    }
    
    private func configureMargin() {
        switch traitCollection.horizontalSizeClass {
        case .regular:
            let margin = MastodonConfirmEmailViewController.viewEdgeMargin
            stackView.layoutMargins = UIEdgeInsets(top: 18, left: margin, bottom: 23, right: margin)
        default:
            stackView.layoutMargins = UIEdgeInsets(top: 10, left: 0, bottom: 23, right: 0)
        }
    }
}

extension MastodonConfirmEmailViewController {
    @objc private func openEmailButtonPressed(_ sender: UIButton) {
        let alertController = UIAlertController(title: L10n.Scene.ConfirmEmail.OpenEmailApp.title, message: L10n.Scene.ConfirmEmail.OpenEmailApp.description, preferredStyle: .alert)
        let openEmailAction = UIAlertAction(title: L10n.Scene.ConfirmEmail.Button.openEmailApp, style: .default) { [weak self] _ in
            guard let self = self else { return }
            self.showEmailAppAlert()
        }
        let cancelAction = UIAlertAction(title: L10n.Common.Controls.Actions.cancel, style: .cancel, handler: nil)
        alertController.addAction(openEmailAction)
        alertController.addAction(cancelAction)
        alertController.preferredAction = openEmailAction
        self.coordinator.present(scene: .alertController(alertController: alertController), from: self, transition: .alertController(animated: true, completion: nil))
    }

    @objc private func resendButtonPressed(_ sender: UIButton) {
        let alertController = UIAlertController(title: L10n.Scene.ConfirmEmail.DontReceiveEmail.title, message: L10n.Scene.ConfirmEmail.DontReceiveEmail.description, preferredStyle: .alert)
        let resendAction = UIAlertAction(title: L10n.Scene.ConfirmEmail.DontReceiveEmail.resendEmail, style: .default) { _ in
            let url = Mastodon.API.resendEmailURL(domain: self.viewModel.authenticateInfo.domain)
            let viewModel = MastodonResendEmailViewModel(resendEmailURL: url, email: self.viewModel.email)
            self.coordinator.present(scene: .mastodonResendEmail(viewModel: viewModel), from: self, transition: .modal(animated: true, completion: nil))
        }
        let okAction = UIAlertAction(title: L10n.Common.Controls.Actions.ok, style: .default) { _ in
        }
        alertController.addAction(resendAction)
        alertController.addAction(okAction)
        self.coordinator.present(scene: .alertController(alertController: alertController), from: self, transition: .alertController(animated: true, completion: nil))
    }

    func showEmailAppAlert() {
        let clients = ThirdPartyMailClient.clients()
        let application = UIApplication.shared
        let availableClients = clients.filter { client -> Bool in
            ThirdPartyMailer.application(application, isMailClientAvailable: client)
        }
        let alertController = UIAlertController(title: L10n.Scene.ConfirmEmail.OpenEmailApp.openEmailClient, message: nil, preferredStyle: .alert)

        let alertAction = UIAlertAction(title: L10n.Scene.ConfirmEmail.OpenEmailApp.mail, style: .default) { _ in
            UIApplication.shared.open(URL(string: "message://")!, options: [:], completionHandler: nil)
        }
        alertController.addAction(alertAction)
        _ = availableClients.compactMap { client -> UIAlertAction in
            let alertAction = UIAlertAction(title: client.name, style: .default) { _ in
                _ = ThirdPartyMailer.application(application, openMailClient: client)
            }
            alertController.addAction(alertAction)
            return alertAction
        }
        let cancelAction = UIAlertAction(title: L10n.Common.Controls.Actions.cancel, style: .cancel, handler: nil)
        alertController.addAction(cancelAction)
        self.coordinator.present(scene: .alertController(alertController: alertController), from: self, transition: .alertController(animated: true, completion: nil))
    }
}

// MARK: - OnboardingViewControllerAppearance
extension MastodonConfirmEmailViewController: OnboardingViewControllerAppearance { }

#if canImport(SwiftUI) && DEBUG
import SwiftUI

struct MastodonConfirmEmailViewController_Previews: PreviewProvider {
    
    static var controls: some View {
        UIViewControllerPreview {
            let viewController = MastodonConfirmEmailViewController()
            return viewController
        }
        .previewLayout(.fixed(width: 375, height: 800))
    }
    
    static var previews: some View {
            Group {
                controls.colorScheme(.light)
                controls.colorScheme(.dark)
            }
    }
    
}

#endif