Tusker/Tusker/Views/Notifications/ActionNotificationTableViewCell.swift

//
//  ActionNotificationTableViewCell.swift
//  Tusker
//
//  Created by Shadowfacts on 9/2/18.
//  Copyright © 2018 Shadowfacts. All rights reserved.
//

import UIKit
import Pachyderm

class ActionNotificationTableViewCell: UITableViewCell {
    
    var delegate: StatusTableViewCellDelegate? {
        didSet {
            contentLabel.navigationDelegate = delegate
        }
    }
    
    @IBOutlet weak var displayNameLabel: UILabel!
    @IBOutlet weak var usernameLabel: UILabel!
    @IBOutlet weak var contentLabel: StatusContentLabel!
    @IBOutlet weak var avatarContainerView: UIView!
    @IBOutlet weak var opAvatarImageView: UIImageView!
    @IBOutlet weak var actionAvatarImageView: UIImageView!
    @IBOutlet weak var actionLabel: UILabel!
    @IBOutlet weak var timestampLabel: UILabel!
    @IBOutlet weak var attachmentsView: UIStackView!
    
    var notification: Pachyderm.Notification!
    var statusID: String!
    
    var opAvatarURL: URL?
    var actionAvatarURL: URL?
    var updateTimestampWorkItem: DispatchWorkItem?
    
    override func awakeFromNib() {
        displayNameLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
        displayNameLabel.isUserInteractionEnabled = true
        usernameLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
        usernameLabel.isUserInteractionEnabled = true
        opAvatarImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
        opAvatarImageView.isUserInteractionEnabled = true
        opAvatarImageView.layer.masksToBounds = true
        actionAvatarImageView.layer.masksToBounds = true
        actionLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(actionPressed)))
        actionLabel.isUserInteractionEnabled = true
        
        NotificationCenter.default.addObserver(self, selector: #selector(updateUIForPreferences), name: .preferencesChanged, object: nil)
    }
    
    @objc func updateUIForPreferences() {
        guard let status = MastodonCache.status(for: statusID) else { fatalError("Missing cached status \(statusID!)") }
        
        opAvatarImageView.layer.cornerRadius = Preferences.shared.avatarStyle.cornerRadius(for: opAvatarImageView)
        actionAvatarImageView.layer.cornerRadius = Preferences.shared.avatarStyle.cornerRadius(for: actionAvatarImageView)
        displayNameLabel.text = status.account.realDisplayName
        
        let verb: String
        switch notification.kind {
        case .favourite:
            verb = "Liked"
        case .reblog:
            verb = "Reblogged"
        default:
            fatalError("Invalid notification type \(notification.kind) for ActionNotificationTableViewCell")
        }
        actionLabel.text = "\(verb) by \(notification.account.realDisplayName)"
    }
    
    func updateUI(for notification: Pachyderm.Notification) {
        guard notification.kind == .favourite || notification.kind == .reblog else {
            fatalError("Invalid notification type \(notification.kind) for ActionNotificationTableViewCell")
        }
        self.notification = notification
        let status = notification.status!
        self.statusID = status.id
        
        updateUIForPreferences()
        
        usernameLabel.text = "@\(status.account.acct)"
        opAvatarImageView.image = nil
        opAvatarURL = status.account.avatar
        ImageCache.avatars.get(status.account.avatar) { (data) in
            guard let data = data else { return }
            DispatchQueue.main.async {
                self.opAvatarImageView.image = UIImage(data: data)
                self.opAvatarURL = nil
            }
        }
        actionAvatarImageView.image = nil
        actionAvatarURL = notification.account.avatar
        ImageCache.avatars.get(notification.account.avatar) { (data) in
            guard let data = data else { return }
            DispatchQueue.main.async {
                self.actionAvatarImageView.image = UIImage(data: data)
                self.actionAvatarURL = nil
            }
        }
        updateTimestamp()
        let attachments = status.attachments.filter({ $0.kind == .image })
        if attachments.count > 0 {
            attachmentsView.isHidden = false
            for attachment in attachments {
                let url = attachment.textURL ?? attachment.url
                let label = UILabel()
                label.textColor = .secondaryLabel
                
                let textAttachment = InlineTextAttachment()
                textAttachment.image = UIImage(named: "Link")!
                textAttachment.bounds = CGRect(x: 0, y: 0, width: label.font.pointSize, height: label.font.pointSize)
                textAttachment.fontDescender = label.font.descender
                let attachmentStr = NSAttributedString(attachment: textAttachment)
                let text = NSMutableAttributedString(string: " ")
                text.append(attachmentStr)
                text.append(NSAttributedString(string: " "))
                
                text.append(NSAttributedString(string: "\(url.lastPathComponent)"))
                text.addAttribute(.foregroundColor, value: UIColor.systemBlue, range: NSRange(location: 0, length: 2))
                
                label.attributedText = text
                attachmentsView.addArrangedSubview(label)
            }
        } else {
            attachmentsView.isHidden = true
        }
        
        contentLabel.setTextFromHtml(status.content)
    }
    
    func updateTimestamp() {
        guard let status = MastodonCache.status(for: statusID) else { fatalError("Missing cached status \(statusID!)") }
        
        timestampLabel.text = status.createdAt.timeAgoString()
        let delay: DispatchTimeInterval?
        switch status.createdAt.timeAgo().1 {
        case .second:
            delay = .seconds(10)
        case .minute:
            delay = .seconds(60)
        default:
            delay = nil
        }
        if let delay = delay {
            updateTimestampWorkItem = DispatchWorkItem {
                self.updateTimestamp()
            }
            DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: updateTimestampWorkItem!)
        } else {
            updateTimestampWorkItem = nil
        }
    }
    
    override func prepareForReuse() {
        if let url = opAvatarURL {
            ImageCache.avatars.cancel(url)
        }
        if let url = actionAvatarURL {
            ImageCache.avatars.cancel(url)
        }
        updateTimestampWorkItem?.cancel()
        updateTimestampWorkItem = nil
        attachmentsView.subviews.forEach { $0.removeFromSuperview() }
    }
    
    override func setSelected(_ selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
        
        if selected {
            delegate?.selected(status: statusID)
        }
    }
    
    @objc func accountPressed() {
        delegate?.selected(account: notification.status!.account.id)
    }
    
    @objc func actionPressed() {
        delegate?.selected(account: notification.account.id)
    }
    
}

extension ActionNotificationTableViewCell: MenuPreviewProvider {
    func getPreviewProviders(for location: CGPoint, sourceViewController: UIViewController) -> PreviewProviders? {
        if avatarContainerView.frame.contains(location) {
            let accountID = notification.account.id
            return (content: { ProfileTableViewController(accountID: accountID) }, actions: { self.actionsForProfile(accountID: accountID) })
        } else if contentLabel.frame.contains(location),
            let link = contentLabel.getLink(atPoint: contentLabel.convert(location, from: self)) {
            return (
                content: { self.contentLabel.getViewController(forLink: link.url, inRange: link.range) },
                actions: {
                    let text = (self.contentLabel.text! as NSString).substring(with: link.range)
                    if let mention = self.contentLabel.getMention(for: link.url, text: text) {
                        return self.actionsForProfile(accountID: mention.id)
                    } else if let hashtag = self.contentLabel.getHashtag(for: link.url, text: text) {
                        return self.actionsForHashtag(hashtag)
                    } else {
                        return self.actionsForURL(link.url)
                    }
                }
            )
        }
        return (content: { ConversationTableViewController(for: self.statusID) }, actions: { self.actionsForStatus(statusID: self.statusID) })
    }
}