//
//  EmojiCollectionViewCell.swift
//  Tusker
//
//  Created by Shadowfacts on 10/12/20.
//  Copyright © 2020 Shadowfacts. All rights reserved.
//

import UIKit
import Pachyderm
import WebURLFoundationExtras

class EmojiCollectionViewCell: UICollectionViewCell {

    private var emojiImageView: UIImageView!
    private var emojiNameLabel: UILabel!
    
    private var currentEmojiShortcode: String?
    private var imageRequest: ImageCache.Request?
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        
        commonInit()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        
        commonInit()
    }
    
    private func commonInit() {
        emojiImageView = UIImageView()
        emojiImageView.translatesAutoresizingMaskIntoConstraints = false
        emojiImageView.contentMode = .scaleAspectFit
        addSubview(emojiImageView)
        NSLayoutConstraint.activate([
            emojiImageView.leadingAnchor.constraint(equalTo: leadingAnchor),
            emojiImageView.trailingAnchor.constraint(equalTo: trailingAnchor),
            emojiImageView.topAnchor.constraint(equalTo: topAnchor),
            emojiImageView.bottomAnchor.constraint(equalTo: bottomAnchor),
        ])
    }
    
    func updateUI(emoji: Emoji) {
        currentEmojiShortcode = emoji.shortcode
        
        imageRequest = ImageCache.emojis.get(URL(emoji.url)!) { [weak self] (_, image) in
            guard let image = image else { return }
            DispatchQueue.main.async { [weak self] in
                guard let self = self, self.currentEmojiShortcode == emoji.shortcode else { return }
                self.emojiImageView.image = image
            }
        }
    }
    
    override func prepareForReuse() {
        super.prepareForReuse()
        
        imageRequest?.cancel()
    }

}