//
//  ComposeAttachmentTableViewCell.swift
//  Tusker
//
//  Created by Shadowfacts on 3/13/20.
//  Copyright © 2020 Shadowfacts. All rights reserved.
//

import UIKit
import Photos
import AVFoundation

protocol ComposeAttachmentTableViewCellDelegate: class {
    func removeAttachment(_ cell: ComposeAttachmentTableViewCell)
    func attachmentDescriptionChanged(_ cell: ComposeAttachmentTableViewCell)
}

class ComposeAttachmentTableViewCell: UITableViewCell {
    
    weak var delegate: ComposeAttachmentTableViewCellDelegate?

    @IBOutlet weak var assetImageView: UIImageView!
    @IBOutlet weak var descriptionTextView: UITextView!
    @IBOutlet weak var descriptionPlaceholderLabel: UILabel!
    @IBOutlet weak var removeButton: UIButton!
    
    var attachment: CompositionAttachment!
    
    override func awakeFromNib() {
        super.awakeFromNib()
        
        assetImageView.layer.masksToBounds = true
        assetImageView.layer.cornerRadius = 8
        
        descriptionTextView.delegate = self
    }
    
    func updateUI(for attachment: CompositionAttachment) {
        self.attachment = attachment
        
        descriptionTextView.text = attachment.attachmentDescription
        updateDescriptionPlaceholderLabel()

        assetImageView.contentMode = .scaleAspectFill
        assetImageView.backgroundColor = .secondarySystemBackground
        switch attachment.data {
        case let .image(image):
            assetImageView.image = image
        case let .asset(asset):
            let size = CGSize(width: 80, height: 80)
            PHImageManager.default().requestImage(for: asset, targetSize: size, contentMode: .aspectFill, options: nil) { (image, _) in
                guard self.attachment == attachment else { return }
                self.assetImageView.image = image
            }
        case let .video(url):
            let asset = AVURLAsset(url: url)
            let imageGenerator = AVAssetImageGenerator(asset: asset)
            if let cgImage = try? imageGenerator.copyCGImage(at: .zero, actualTime: nil) {
                assetImageView.image = UIImage(cgImage: cgImage)
            }
        case let .drawing(drawing):
            assetImageView.image = drawing.imageInLightMode(from: drawing.bounds)
            assetImageView.contentMode = .scaleAspectFit
            assetImageView.backgroundColor = .white
        }
    }
    
    func updateDescriptionPlaceholderLabel() {
        descriptionPlaceholderLabel.isHidden = !descriptionTextView.text.isEmpty
    }
    
    func setEnabled(_ enabled: Bool) {
        descriptionTextView.isEditable = enabled
        removeButton.isEnabled = enabled
    }
    
    override func prepareForReuse() {
        super.prepareForReuse()
        assetImageView.image = nil
    }

    @IBAction func removeButtonPressed(_ sender: Any) {
        delegate?.removeAttachment(self)
    }
    
}

extension ComposeAttachmentTableViewCell: UITextViewDelegate {
    func textViewDidChange(_ textView: UITextView) {
        attachment.attachmentDescription = textView.text
        updateDescriptionPlaceholderLabel()
        delegate?.attachmentDescriptionChanged(self)
    }
}