//
// Swiftfin is subject to the terms of the Mozilla Public
// License, v2.0. If a copy of the MPL was not distributed with this
// file, you can obtain one at https://mozilla.org/MPL/2.0/.
//
// Copyright (c) 2025 Jellyfin & Jellyfin Contributors
//

import Combine
import Engine
import SwiftUI

extension VideoPlayer {
    struct VideoPlayerContainerView<Player: View, PlaybackControls: View>: UIViewControllerRepresentable {

        private let containerState: VideoPlayerContainerState
        private let manager: MediaPlayerManager
        private let player: () -> Player
        private let playbackControls: () -> PlaybackControls

        init(
            containerState: VideoPlayerContainerState,
            manager: MediaPlayerManager,
            @ViewBuilder player: @escaping () -> Player,
            @ViewBuilder playbackControls: @escaping () -> PlaybackControls
        ) {
            self.containerState = containerState
            self.manager = manager
            self.player = player
            self.playbackControls = playbackControls
        }

        func makeUIViewController(context: Context) -> UIVideoPlayerContainerViewController {
            UIVideoPlayerContainerViewController(
                containerState: containerState,
                manager: manager,
                player: player().eraseToAnyView(),
                playbackControls: playbackControls().eraseToAnyView()
            )
        }

        func updateUIViewController(
            _ uiViewController: UIVideoPlayerContainerViewController,
            context: Context
        ) {}
    }

    // MARK: - UIVideoPlayerContainerViewController

    class UIVideoPlayerContainerViewController: UIViewController {

        private struct PlayerContainerView: View {

            @EnvironmentObject
            private var containerState: VideoPlayerContainerState

            let player: AnyView

            var body: some View {
                player
                    .overlay(Color.black.opacity(containerState.isPresentingPlaybackControls ? 0.3 : 0.0))
                    .animation(.linear(duration: 0.2), value: containerState.isPresentingPlaybackControls)
            }
        }

        private lazy var playerViewController: HostingController<AnyView> = {
            let controller = HostingController(
                content: PlayerContainerView(player: player)
                    .environmentObject(containerState)
                    .environmentObject(manager)
                    .eraseToAnyView()
            )
            controller.disablesSafeArea = true
            controller.automaticallyAllowUIKitAnimationsForNextUpdate = true
            controller.view.translatesAutoresizingMaskIntoConstraints = false
            return controller
        }()

        private lazy var playbackControlsViewController: HostingController<AnyView> = {
            let controller = HostingController(
                content: playbackControls
                    .environment(\.onPressEventPublisher, onPressEvent)
                    .environmentObject(containerState)
                    .environmentObject(containerState.scrubbedSeconds)
                    .environmentObject(focusGuide)
                    .environmentObject(manager)
                    .eraseToAnyView()
            )
            controller.disablesSafeArea = true
            controller.automaticallyAllowUIKitAnimationsForNextUpdate = true
            controller.view.translatesAutoresizingMaskIntoConstraints = false
            return controller
        }()

        private lazy var supplementContainerViewController: HostingController<AnyView> = {
            let content = SupplementContainerView()
                .environmentObject(containerState)
                .environmentObject(focusGuide)
                .environmentObject(manager)
                .eraseToAnyView()
            let controller = HostingController(content: content)
            controller.disablesSafeArea = true
            controller.automaticallyAllowUIKitAnimationsForNextUpdate = true
            controller.view.translatesAutoresizingMaskIntoConstraints = false
            return controller
        }()

        private var playerView: UIView { playerViewController.view }
        private var playbackControlsView: UIView { playbackControlsViewController.view }
        private var supplementContainerView: UIView { supplementContainerViewController.view }

        private var supplementRegularConstraints: [NSLayoutConstraint] = []
        private var playerRegularConstraints: [NSLayoutConstraint] = []
        private var playbackControlsConstraints: [NSLayoutConstraint] = []

        private var supplementHeightAnchor: NSLayoutConstraint!
        private var supplementBottomAnchor: NSLayoutConstraint!

        private let manager: MediaPlayerManager
        private let player: AnyView
        private let playbackControls: AnyView
        private let containerState: VideoPlayerContainerState

        let focusGuide = FocusGuide()
        let onPressEvent = OnPressEvent()

        private var cancellables: Set<AnyCancellable> = []

        init(
            containerState: VideoPlayerContainerState,
            manager: MediaPlayerManager,
            player: AnyView,
            playbackControls: AnyView
        ) {
            self.containerState = containerState
            self.manager = manager
            self.player = player
            self.playbackControls = playbackControls

            super.init(nibName: nil, bundle: nil)

            containerState.containerView = self
            containerState.manager = manager
        }

        @available(*, unavailable)
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }

        // MARK: - didPresent

        func presentSupplementContainer(
            _ didPresent: Bool
        ) {
            if didPresent {
                self.supplementBottomAnchor.constant = -(500 + EdgeInsets.edgePadding * 2)
            } else {
                self.supplementBottomAnchor.constant = -(100 + EdgeInsets.edgePadding)
            }

            containerState.isPresentingPlaybackControls = !didPresent
            containerState.supplementOffset = supplementBottomAnchor.constant

            UIView.animate(
                withDuration: 0.75,
                delay: 0,
                usingSpringWithDamping: 0.8,
                initialSpringVelocity: 0.4,
                options: .allowUserInteraction
            ) {
                self.view.layoutIfNeeded()
            }
        }

        override func viewDidLoad() {
            super.viewDidLoad()

            view.backgroundColor = .black

            setupViews()
            setupConstraints()

            let gesture = UITapGestureRecognizer(target: self, action: #selector(ignorePress))
            gesture.allowedPressTypes = [NSNumber(value: UIPress.PressType.menu.rawValue)]
            view.addGestureRecognizer(gesture)
        }

        private func setupViews() {
            addChild(playerViewController)
            view.addSubview(playerView)
            playerViewController.didMove(toParent: self)
            playerView.backgroundColor = .black

            addChild(playbackControlsViewController)
            view.addSubview(playbackControlsView)
            playbackControlsViewController.didMove(toParent: self)
            playbackControlsView.backgroundColor = .clear

            addChild(supplementContainerViewController)
            view.addSubview(supplementContainerView)
            supplementContainerViewController.didMove(toParent: self)
            supplementContainerView.backgroundColor = .clear
        }

        private func setupConstraints() {
            playerRegularConstraints = [
                playerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
                playerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
                playerView.topAnchor.constraint(equalTo: view.topAnchor),
                playerView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            ]

            NSLayoutConstraint.activate(playerRegularConstraints)

            supplementBottomAnchor = supplementContainerView.topAnchor.constraint(
                equalTo: view.bottomAnchor,
                constant: -(100 + EdgeInsets.edgePadding)
            )
            containerState.supplementOffset = supplementBottomAnchor.constant

            let constant = (500 + EdgeInsets.edgePadding * 2)
            supplementHeightAnchor = supplementContainerView.heightAnchor.constraint(equalToConstant: constant)

            supplementRegularConstraints = [
                supplementContainerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
                supplementContainerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
                supplementBottomAnchor,
                supplementHeightAnchor,
            ]

            NSLayoutConstraint.activate(supplementRegularConstraints)

            playbackControlsConstraints = [
                playbackControlsView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
                playbackControlsView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
                playbackControlsView.topAnchor.constraint(equalTo: view.topAnchor),
                playbackControlsView.bottomAnchor.constraint(equalTo: supplementContainerView.topAnchor),
            ]

            NSLayoutConstraint.activate(playbackControlsConstraints)
        }

        @objc
        func ignorePress() {}

        override func pressesBegan(_ presses: Set<UIPress>, with event: UIPressesEvent?) {
            print(presses)
            guard let buttonPress = presses.first else { return }

            onPressEvent.send((type: buttonPress.type, phase: buttonPress.phase))
        }
    }
}

extension VideoPlayer.UIVideoPlayerContainerViewController {

    typealias PressEvent = (type: UIPress.PressType, phase: UIPress.Phase)
    typealias OnPressEvent = LegacyEventPublisher<PressEvent>
}

@propertyWrapper
struct OnPressEvent: DynamicProperty {

    @Environment(\.onPressEventPublisher)
    private var publisher

    var wrappedValue: VideoPlayer.UIVideoPlayerContainerViewController.OnPressEvent {
        publisher
    }
}

extension EnvironmentValues {

    @Entry
    var onPressEventPublisher: VideoPlayer.UIVideoPlayerContainerViewController.OnPressEvent = .init()
}