VideoPlayerViewController.swift

//
//  VideoPlayerViewController.swift
//  Tattoo Store
//
//  Created by Eugenio Baglieri on 13/07/18.
//  Copyright © 2018 Eugenio Baglieri. All rights reserved.
//

import UIKit
import YoutubeKit

class VideoPlayerViewController: UIViewController {
    
    private enum Constants {
        static let playerSizeRatio: CGFloat = 4/3
        static let animationDuration: TimeInterval = 0.3
    }
    
    let video: Video
    private var trimView: UIView!
    private var player: YTSwiftyPlayer!
    private var isShowingTrimView: Bool = false
    
    // MARK: - Inits
    
    init(video: Video) {
        self.video = video
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - Lifecycle
    
    override func loadView() {
        super.loadView()
        view.backgroundColor = .black
        player = createAndSetupPlayer()
        trimView = createAndSetupTrimView()
        view.addSubview(player)
        view.addSubview(trimView)
        
        view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(VideoPlayerViewController.showTrimView)))
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        player.loadPlayer()
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        let viewWidth = view.bounds.size.width
        let viewHeight = view.bounds.size.height
        let viewBounds = view.bounds
        let viewSafeInsets = view.safeAreaInsets
        
        let safeBounds = CGRect(x: viewBounds.origin.x + viewSafeInsets.left,
                                y: viewBounds.origin.y + viewSafeInsets.top,
                                width: viewBounds.width - viewSafeInsets.left - viewSafeInsets.right,
                                height: viewBounds.height - viewSafeInsets.top - viewSafeInsets.bottom)
        
        if viewWidth > viewHeight {
            // Landscape mode
            player.frame = safeBounds
        } else {
            // Portrait mode
            let playerWidth = safeBounds.width
            let playerHeight = ceil(playerWidth / Constants.playerSizeRatio)
            let playerFrame = CGRect(x: safeBounds.origin.x,
                                     y: (viewHeight - playerHeight) / 2,
                                     width: playerWidth,
                                     height: playerHeight)
            player.frame = playerFrame
        }
        trimView.frame = safeBounds
    }
    
    // MARK: - Private methods
    
    private func createAndSetupPlayer() -> YTSwiftyPlayer {
        let setup: [VideoEmbedParameter] = [.videoID(video.id), .playsInline(true), .loopVideo(false), .showModestbranding(true), .showRelatedVideo(false), .alwaysShowCaption(false), .loopVideo(true), .autoplay(true)]
        return YTSwiftyPlayer(frame: CGRect(x: 0, y: 0, width: 640, height: 480), playerVars: setup)
    }
    
    private func createAndSetupTrimView() -> UIView {
        let trim = UIView()
        trim.isOpaque = false
        trim.backgroundColor = UIColor(white: 0, alpha: 0.5)
        trim.alpha = 0.0
        
        let closeButton = UIButton(type: .system)
        trim.addSubview(closeButton)
        
        let closeImage = UIImage(named: "close-icon")
        closeButton.setImage(closeImage, for: .normal)
        closeButton.tintColor = .white
        closeButton.translatesAutoresizingMaskIntoConstraints = false
        closeButton.widthAnchor.constraint(equalToConstant: 26).isActive = true
        closeButton.heightAnchor.constraint(equalToConstant: 26).isActive = true
        closeButton.topAnchor.constraint(equalTo: trim.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
        closeButton.leftAnchor.constraint(equalTo: trim.safeAreaLayoutGuide.leftAnchor, constant: 16).isActive = true
        
        closeButton.addTarget(self, action: #selector(VideoPlayerViewController.didTapCloseButton(_:)), for: .touchUpInside)
        
        trim.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(VideoPlayerViewController.hideTrimView)))
        
        return trim
    }
    
    @objc
    private func hideTrimView() {
        isShowingTrimView = false
        UIView.animate(withDuration: Constants.animationDuration) { [unowned self] in
            self.trimView.alpha = 0.0
        }
    }
    
    @objc
    private func showTrimView() {
        isShowingTrimView = true
        UIView.animate(withDuration: Constants.animationDuration) { [unowned self] in
            self.trimView.alpha = 1
        }
    }
    
    @objc
    private func didTapCloseButton(_ sender: UIButton) {
        self.presentingViewController?.dismiss(animated: true, completion: nil)
    }
}