//
// 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) 2022 Jellyfin & Jellyfin Contributors
//

import AVKit
import Combine
import JellyfinAPI
import UIKit

class NativePlayerViewController: AVPlayerViewController {

	let viewModel: VideoPlayerViewModel

	var timeObserverToken: Any?

	var lastProgressTicks: Int64 = 0

	private var cancellables = Set<AnyCancellable>()

	init(viewModel: VideoPlayerViewModel) {

		self.viewModel = viewModel

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

		let player: AVPlayer

		if let transcodedStreamURL = viewModel.transcodedStreamURL {
			player = AVPlayer(url: transcodedStreamURL)
		} else {
			player = AVPlayer(url: viewModel.hlsStreamURL)
		}

		player.appliesMediaSelectionCriteriaAutomatically = false

		let timeScale = CMTimeScale(NSEC_PER_SEC)
		let time = CMTime(seconds: 5, preferredTimescale: timeScale)

		timeObserverToken = player.addPeriodicTimeObserver(forInterval: time, queue: .main) { [weak self] time in
			if time.seconds != 0 {
				self?.sendProgressReport(seconds: time.seconds)
			}
		}

		self.player = player

		self.allowsPictureInPicturePlayback = true
		self.player?.allowsExternalPlayback = true
	}

	private func createMetadataItem(for identifier: AVMetadataIdentifier,
	                                value: Any) -> AVMetadataItem
	{
		let item = AVMutableMetadataItem()
		item.identifier = identifier
		item.value = value as? NSCopying & NSObjectProtocol
		// Specify "und" to indicate an undefined language.
		item.extendedLanguageTag = "und"
		return item.copy() as! AVMetadataItem
	}

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

	override func viewDidLoad() {
		super.viewDidLoad()
	}

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

		stop()
		removePeriodicTimeObserver()
	}

	func removePeriodicTimeObserver() {
		if let timeObserverToken = timeObserverToken {
			player?.removeTimeObserver(timeObserverToken)
			self.timeObserverToken = nil
		}
	}

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

		player?.seek(to: CMTimeMake(value: viewModel.currentSecondTicks, timescale: 10_000_000),
		             toleranceBefore: CMTimeMake(value: 1, timescale: 1), toleranceAfter: CMTimeMake(value: 1, timescale: 1),
		             completionHandler: { _ in
		             	self.play()
		             })
	}

	private func play() {
		player?.play()

		viewModel.sendPlayReport()
	}

	private func sendProgressReport(seconds: Double) {
		viewModel.setSeconds(Int64(seconds))
		viewModel.sendProgressReport()
	}

	private func stop() {
		self.player?.pause()
		viewModel.sendStopReport()
	}
}