//
// 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 SwiftUI
import UIKit

class UICinematicBackgroundView: UIView {

	private var currentImageView: UIView?

	private var selectDelayTimer: Timer?

	init(initialImageView: UIImageView) {
		super.init(frame: .zero)

		initialImageView.translatesAutoresizingMaskIntoConstraints = false
		initialImageView.alpha = 0

		addSubview(initialImageView)
		NSLayoutConstraint.activate([
			initialImageView.topAnchor.constraint(equalTo: topAnchor),
			initialImageView.bottomAnchor.constraint(equalTo: bottomAnchor),
			initialImageView.leftAnchor.constraint(equalTo: leftAnchor),
			initialImageView.rightAnchor.constraint(equalTo: rightAnchor),
		])

		self.currentImageView = initialImageView
	}

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

	func update(imageView: UIImageView) {

		selectDelayTimer?.invalidate()

		selectDelayTimer = Timer.scheduledTimer(timeInterval: 0.5, target: self, selector: #selector(delayTimerTimed), userInfo: imageView,
		                                        repeats: false)
	}

	@objc
	private func delayTimerTimed(timer: Timer) {
		let newImageView = timer.userInfo as! UIImageView

		newImageView.translatesAutoresizingMaskIntoConstraints = false
		newImageView.alpha = 0

		addSubview(newImageView)
		NSLayoutConstraint.activate([
			newImageView.topAnchor.constraint(equalTo: topAnchor),
			newImageView.bottomAnchor.constraint(equalTo: bottomAnchor),
			newImageView.leftAnchor.constraint(equalTo: leftAnchor),
			newImageView.rightAnchor.constraint(equalTo: rightAnchor),
		])

		UIView.animate(withDuration: 0.2) {
			newImageView.alpha = 1
			self.currentImageView?.alpha = 0
		} completion: { _ in
			self.currentImageView?.removeFromSuperview()
			self.currentImageView = newImageView
		}
	}
}