Tusker/Tusker/Views/StatusTableViewCell.swift

//
//  StatusTableViewCell.swift
//  Tusker
//
//  Created by Shadowfacts on 8/16/18.
//  Copyright © 2018 Shadowfacts. All rights reserved.
//

import UIKit
import MastodonKit

protocol StatusTableViewCellDelegate {
    
    func selected(account: Account)
    
    func selected(mention: Mention)
    
    func selected(tag: MastodonKit.Tag)
    
    func selected(url: URL)
    
    func selected(status: Status)
    
    func reply(to status: Status)
    
    func showLargeAttachment(for attachmentView: AttachmentView)
    
}

class StatusTableViewCell: UITableViewCell, PreferencesAdaptive {

    var delegate: StatusTableViewCellDelegate?
    
    @IBOutlet weak var displayNameLabel: UILabel!
    @IBOutlet weak var usernameLabel: UILabel!
    @IBOutlet weak var contentLabel: StatusContentLabel!
    @IBOutlet weak var avatarImageView: UIImageView!
    @IBOutlet weak var reblogLabel: UILabel!
    @IBOutlet weak var timestampLabel: UILabel!
    @IBOutlet weak var attachmentsView: UIView!
    
    var status: Status!
    var account: Account!
    var reblogger: Account?
    
    var avatarURL: URL?
    
    var updateTimestampWorkItem: DispatchWorkItem?
    
    var attachmentDataTasks: [URLSessionDataTask] = []
    
    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
        reblogLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(reblogLabelPressed)))
        reblogLabel.isUserInteractionEnabled = true
        avatarImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
        avatarImageView.isUserInteractionEnabled = true
        avatarImageView.layer.masksToBounds = true
        attachmentsView.layer.cornerRadius = 5
        attachmentsView.layer.masksToBounds = true
    }
    
    func updateUIForPreferences() {
        avatarImageView.layer.cornerRadius = Preferences.shared.avatarStyle.cornerRadius(for: avatarImageView)
        if let reblogger = reblogger {
            reblogLabel.text = "Reblogged by \(reblogger.realDisplayName)"
        }
        displayNameLabel.text = account.realDisplayName
    }
    
    func updateUI(for status: Status) {
        self.status = status
        
        let account: Account
        if let reblog = status.reblog {
            account = reblog.account
            reblogger = status.account
            reblogLabel.isHidden = false
        } else {
            account = status.account
            reblogLabel.isHidden = true
            reblogger = nil
        }
        self.account = account
        
        
        updateUIForPreferences()
        
        usernameLabel.text = "@\(account.acct)"
        avatarImageView.image = nil
        if let url = URL(string: account.avatar) {
            avatarURL = url
            AvatarCache.shared.get(url) { image in
                DispatchQueue.main.async {
                    self.avatarImageView.image = image
                    self.avatarURL = nil
                }
            }
        }
        updateTimestamp()
        
        attachmentsView.subviews.forEach { $0.removeFromSuperview() }
        let attachments = status.mediaAttachments.filter({ $0.type == .image })
        if attachments.count > 0 {
            attachmentsView.isHidden = false
            let width = attachmentsView.bounds.width
            let height: CGFloat = 200
            switch attachments.count {
            case 1:
                addAttachmentView(frame: CGRect(x: 0, y: 0, width: width, height: height), attachment: attachments[0])
            case 2:
                addAttachmentView(frame: CGRect(x: 0, y: 0, width: width / 2 - 4, height: height), attachment: attachments[0])
                addAttachmentView(frame: CGRect(x: width / 2 + 4, y: 0, width: width / 2 - 4, height: height), attachment: attachments[1])
            case 3:
                addAttachmentView(frame: CGRect(x: 0, y: 0, width: width / 2 - 4, height: height), attachment: attachments[0])
                addAttachmentView(frame: CGRect(x: width / 2 + 4, y: 0, width: width / 2 - 4, height: height / 2 - 4), attachment: attachments[1])
                addAttachmentView(frame: CGRect(x: width / 2 + 4, y: height / 2 + 4, width: width / 2 - 4, height: height / 2 - 4), attachment: attachments[2])
            case 4:
                addAttachmentView(frame: CGRect(x: 0, y: 0, width: width / 2 - 4, height: height / 2 - 4), attachment: attachments[0])
                addAttachmentView(frame: CGRect(x: 0, y: height / 2 + 4, width: width / 2 - 4, height: height / 2 - 4), attachment: attachments[1])
                addAttachmentView(frame: CGRect(x: width / 2 + 4, y: 0, width: width / 2 - 4, height: height / 2 - 4), attachment: attachments[2])
                addAttachmentView(frame: CGRect(x: width / 2 + 4, y: height / 2 + 4, width: width / 2 - 4, height: height / 2 - 4), attachment: attachments[3])
            default:
                fatalError("Too many attachments")
            }
        } else {
            attachmentsView.isHidden = true
            
        }
        
        contentLabel.status = status
        contentLabel.delegate = self
    }
    
    func updateTimestamp() {
        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
        }
    }
    
    func addAttachmentView(frame: CGRect, attachment: Attachment) {
        let attachmentView = AttachmentView(frame: frame, attachment: attachment)
        attachmentView.delegate = self
        attachmentsView.addSubview(attachmentView)
    }
    
    override func prepareForReuse() {
        if let url = avatarURL {
            AvatarCache.shared.cancel(url)
        }
        updateTimestampWorkItem?.cancel()
        updateTimestampWorkItem = nil
        attachmentsView.subviews.forEach { view in
            (view as? AttachmentView)?.task?.cancel()
        }
    }

    @IBAction func replyPressed(_ sender: Any) {
        delegate?.reply(to: status)
    }
    
    @objc func accountPressed() {
        delegate?.selected(account: account)
    }
    
    @objc func reblogLabelPressed() {
        guard let reblogger = reblogger else { return }
        delegate?.selected(account: reblogger)
    }
    
    func didSelect() {
        delegate?.selected(status: status)
    }
    
}

extension StatusTableViewCell: HTMLContentLabelDelegate {
    
    func selected(mention: Mention) {
        delegate?.selected(mention: mention)
    }
    
    func selected(tag: MastodonKit.Tag) {
        delegate?.selected(tag: tag)
    }
    
    func selected(url: URL) {
        delegate?.selected(url: url)
    }
    
}

extension StatusTableViewCell: AttachmentViewDelegate {
    func showLargeAttachment(for attachmentView: AttachmentView) {
        delegate?.showLargeAttachment(for: attachmentView)
    }
}