//
//  ReportSupplementaryViewController.swift
//  Mastodon
//
//  Created by MainasuK on 2022-2-7.
//

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

final class ReportSupplementaryViewController: UIViewController, NeedsDependency, ReportViewControllerAppearance {
    
    let logger = Logger(subsystem: "ReportSupplementaryViewController", category: "ViewController")
    
    var disposeBag = Set<AnyCancellable>()
    private var observations = Set<NSKeyValueObservation>()

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

    
    // MAKK: - UI
    lazy var cancelBarButtonItem = UIBarButtonItem(
        barButtonSystemItem: .cancel,
        target: self,
        action: #selector(ReportSupplementaryViewController.cancelBarButtonItemDidPressed(_:))
    )
    
    let activityIndicatorBarButtonItem: UIBarButtonItem = {
        let activityIndicatorView = UIActivityIndicatorView(style: .medium)
        activityIndicatorView.startAnimating()
        let barButtonItem = UIBarButtonItem(customView: activityIndicatorView)
        return barButtonItem
    }()
    
    let tableView: UITableView = {
        let tableView = ControlContainableTableView()
        tableView.backgroundColor = Asset.Scene.Report.background.color
        tableView.rowHeight = UITableView.automaticDimension
        tableView.separatorStyle = .none
        tableView.backgroundColor = .clear
        tableView.keyboardDismissMode = .onDrag
        if #available(iOS 15.0, *) {
            tableView.sectionHeaderTopPadding = .leastNonzeroMagnitude
        } else {
            // Fallback on earlier versions
        }
        return tableView
    }()
    
    let navigationActionView: NavigationActionView = {
        let navigationActionView = NavigationActionView()
        navigationActionView.backgroundColor = Asset.Scene.Onboarding.background.color
        navigationActionView.backButton.setTitle(L10n.Common.Controls.Actions.skip, for: .normal)
        return navigationActionView
    }()
    
    deinit {
        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
    }
    
}

extension ReportSupplementaryViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        setupAppearance()
        defer { setupNavigationBarBackgroundView() }
        
        navigationItem.rightBarButtonItem = cancelBarButtonItem
        
        viewModel.$isReporting
            .receive(on: DispatchQueue.main)
            .sink { [weak self] isReporting in
                guard let self = self else { return }
                self.navigationActionView.isUserInteractionEnabled = !isReporting
            }
            .store(in: &disposeBag)
        
        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),
        ])
        
        tableView.delegate = self
        viewModel.setupDiffableDataSource(
            tableView: tableView
        )
        
        navigationActionView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(navigationActionView)
        defer {
            view.bringSubviewToFront(navigationActionView)
        }
        NSLayoutConstraint.activate([
            navigationActionView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            navigationActionView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            view.bottomAnchor.constraint(equalTo: navigationActionView.bottomAnchor),
        ])
        
        navigationActionView
            .observe(\.bounds, options: [.initial, .new]) { [weak self] navigationActionView, _ in
                guard let self = self else { return }
                let inset = navigationActionView.frame.height
                self.tableView.contentInset.bottom = inset
                self.tableView.verticalScrollIndicatorInsets.bottom = inset
            }
            .store(in: &observations)
        
        viewModel.$isNextButtonEnabled
            .receive(on: DispatchQueue.main)
            .assign(to: \.isEnabled, on: navigationActionView.nextButton)
            .store(in: &disposeBag)
        
        navigationActionView.backButton.addTarget(self, action: #selector(ReportSupplementaryViewController.skipButtonDidPressed(_:)), for: .touchUpInside)
        navigationActionView.nextButton.addTarget(self, action: #selector(ReportSupplementaryViewController.nextButtonDidPressed(_:)), for: .touchUpInside)
    }
    
}

extension ReportSupplementaryViewController {
    private func report(withComment: Bool) {
        Task {
            do {
                let _ = try await viewModel.report(withComment: withComment)
                logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): report success")
                
                let reportResultViewModel = ReportResultViewModel(
                    context: context,
                    user: viewModel.user
                )
                
                coordinator.present(
                    scene: .reportResult(viewModel: reportResultViewModel),
                    from: self,
                    transition: .show
                )
                
            } catch {
                let alertController = UIAlertController(for: error, title: nil, preferredStyle: .alert)
                let okAction = UIAlertAction(title: L10n.Common.Controls.Actions.ok, style: .default, handler: nil)
                alertController.addAction(okAction)
                self.coordinator.present(
                    scene: .alertController(alertController: alertController),
                    from: nil,
                    transition: .alertController(animated: true, completion: nil)
                )
            }
        }   // end Task
    }
}

extension ReportSupplementaryViewController {

    @objc private func cancelBarButtonItemDidPressed(_ sender: UIBarButtonItem) {
        dismiss(animated: true, completion: nil)
    }

    @objc func skipButtonDidPressed(_ sender: UIButton) {
        report(withComment: false)
    }

    @objc func nextButtonDidPressed(_ sender: UIButton) {
        report(withComment: true)
    }

}

// MARK: - UITableViewDelegate
extension ReportSupplementaryViewController: UITableViewDelegate { }