//
//  SearchResultViewController.swift
//  Mastodon
//
//  Created by MainasuK Cirno on 2021-7-14.
//

import UIKit
import Combine
import AVKit

final class SearchResultViewController: UIViewController, NeedsDependency, MediaPreviewableViewController {

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

    let mediaPreviewTransitionController = MediaPreviewTransitionController()

    var viewModel: SearchResultViewModel!
    var disposeBag = Set<AnyCancellable>()

    let tableView: UITableView = {
        let tableView = UITableView()
        tableView.register(SearchResultTableViewCell.self, forCellReuseIdentifier: String(describing: SearchResultTableViewCell.self))
        tableView.register(StatusTableViewCell.self, forCellReuseIdentifier: String(describing: StatusTableViewCell.self))
        tableView.register(TimelineBottomLoaderTableViewCell.self, forCellReuseIdentifier: String(describing: TimelineBottomLoaderTableViewCell.self))
        return tableView
    }()

}

extension SearchResultViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        setupBackgroundColor(theme: ThemeService.shared.currentTheme.value)
        ThemeService.shared.currentTheme
            .receive(on: RunLoop.main)
            .sink { [weak self] theme in
                guard let self = self else { return }
                self.setupBackgroundColor(theme: theme)
            }
            .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),
        ])

        viewModel.setupDiffableDataSource(
            tableView: tableView,
            dependency: self,
            statusTableViewCellDelegate: self
        )

        // listen keyboard events and set content inset
        let keyboardEventPublishers = Publishers.CombineLatest3(
            KeyboardResponderService.shared.isShow,
            KeyboardResponderService.shared.state,
            KeyboardResponderService.shared.endFrame
        )
        Publishers.CombineLatest(
            keyboardEventPublishers,
            viewModel.viewDidAppear
        )
        .sink(receiveValue: { [weak self] keyboardEvents, _ in
            guard let self = self else { return }
            let (isShow, state, endFrame) = keyboardEvents

            // update keyboard background color
            guard isShow, state == .dock else {
                self.tableView.contentInset.bottom = 0
                self.tableView.verticalScrollIndicatorInsets.bottom = 0
                return
            }
            // isShow AND dock state

            // adjust inset for tableView
            let contentFrame = self.view.convert(self.tableView.frame, to: nil)
            let padding = contentFrame.maxY - endFrame.minY
            guard padding > 0 else {
                self.tableView.contentInset.bottom = self.view.safeAreaInsets.bottom
                self.tableView.verticalScrollIndicatorInsets.bottom = self.view.safeAreaInsets.bottom
                return
            }

            self.tableView.contentInset.bottom = padding - self.view.safeAreaInsets.bottom
            self.tableView.verticalScrollIndicatorInsets.bottom = padding - self.view.safeAreaInsets.bottom
        })
        .store(in: &disposeBag)
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        viewModel.viewDidAppear.value = true
    }

}

extension SearchResultViewController {
    private func setupBackgroundColor(theme: Theme) {
        view.backgroundColor = theme.systemGroupedBackgroundColor
        tableView.backgroundColor = theme.systemBackgroundColor
//        searchHeader.backgroundColor = theme.systemGroupedBackgroundColor
    }

}

// MARK: - AVPlayerViewControllerDelegate
extension SearchResultViewController: AVPlayerViewControllerDelegate {

    func playerViewController(_ playerViewController: AVPlayerViewController, willBeginFullScreenPresentationWithAnimationCoordinator coordinator: UIViewControllerTransitionCoordinator) {
        handlePlayerViewController(playerViewController, willBeginFullScreenPresentationWithAnimationCoordinator: coordinator)
    }

    func playerViewController(_ playerViewController: AVPlayerViewController, willEndFullScreenPresentationWithAnimationCoordinator coordinator: UIViewControllerTransitionCoordinator) {
        handlePlayerViewController(playerViewController, willEndFullScreenPresentationWithAnimationCoordinator: coordinator)
    }

}

// MARK: - StatusTableViewCellDelegate
extension SearchResultViewController: StatusTableViewCellDelegate {
    weak var playerViewControllerDelegate: AVPlayerViewControllerDelegate? { return self }
    func parent() -> UIViewController { return self }
}

//extension SearchResultViewController: LoadMoreConfigurableTableViewContainer {
//    typealias BottomLoaderTableViewCell = TimelineBottomLoaderTableViewCell
//    typealias LoadingState = SearchViewModel.LoadOldestState.Loading
//    var loadMoreConfigurableTableView: UITableView { searchingTableView }
//    var loadMoreConfigurableStateMachine: GKStateMachine { viewModel.loadoldestStateMachine }
//}