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

import UIKit
import Pachyderm

protocol StatusTableViewCellDelegate {
    
    func selected(account: Account)
    
    func selected(mention: Mention)
    
    func selected(tag: Hashtag)
    
    func selected(url: URL)
    
    func selected(status statusID: String)
    
    func reply(to statusID: String)
    
    func showLargeImage(_ image: UIImage, description: String?, animatingFrom originView: UIView)
    
    func showMoreOptions(status statusID: String)
    
}

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!
    @IBOutlet weak var favoriteButton: UIButton!
    @IBOutlet weak var reblogButton: UIButton!
    
    var statusID: String!
    var account: Account!
    var reblogger: Account?
    
    var favorited: Bool = false {
        didSet {
            favoriteButton.tintColor = favorited ? UIColor(displayP3Red: 1, green: 0.8, blue: 0, alpha: 1) : tintColor
        }
    }
    var reblogged: Bool = false {
        didSet {
            reblogButton.tintColor = reblogged ? UIColor(displayP3Red: 1, green: 0.8, blue: 0, alpha: 1) : tintColor
        }
    }
    
    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
        contentLabel.delegate = self
    }
    
    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 statusID: String) {
        self.statusID = statusID
        guard let status = StatusCache.get(id: statusID) else { fatalError("Missing cached status \(statusID)") }
        
        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
        avatarURL = account.avatar
        AvatarCache.shared.get(account.avatar) { image in
            DispatchQueue.main.async {
                self.avatarImageView.image = image
                self.avatarURL = nil
            }
        }
        updateTimestamp()
        
        let attachments = status.attachments.filter({ $0.kind == .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
            
        }
        
        let realStatus = status.reblog ?? status
        favorited = realStatus.favourited ?? false
        reblogged = realStatus.reblogged ?? false
        
        contentLabel.statusID = statusID
    }
    
    func updateTimestamp() {
        guard let status = StatusCache.get(id: 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
        }
    }
    
    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()
            view.removeFromSuperview()
        }
    }

    override func setSelected(_ selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
        
        if selected {
            delegate?.selected(status: statusID)
        }
    }
    
    @IBAction func replyPressed(_ sender: Any) {
        delegate?.reply(to: statusID)
    }
    
    @objc func accountPressed() {
        delegate?.selected(account: account)
    }
    
    @objc func reblogLabelPressed() {
        guard let reblogger = reblogger else { return }
        delegate?.selected(account: reblogger)
    }
    
    @IBAction func favoritePressed(_ sender: Any) {
        guard let status = StatusCache.get(id: statusID) else { fatalError("Missing cached status \(statusID!)") }
        
        let oldValue = favorited
        favorited = !favorited
        
        let realStatus: Status = status.reblog ?? status
        let request = (favorited ? Status.favourite : Status.unfavourite)(realStatus)
        MastodonController.shared.client.run(request) { response in
            DispatchQueue.main.async {
                self.favorited = realStatus.favourited ?? false
                if case .success = response {
                    self.favorited = realStatus.favourited ?? false
                    UIImpactFeedbackGenerator(style: .light).impactOccurred()
                } else {
                    self.favorited = oldValue
                    print("Couldn't favorite status \(realStatus.id)")
                    // todo: display error message
                    UINotificationFeedbackGenerator().notificationOccurred(.error)
                    return
                }
            }
        }
    }
    
    @IBAction func reblogPressed(_ sender: Any) {
        guard let status = StatusCache.get(id: statusID) else { fatalError("Missing cached status \(statusID!)") }
        
        let oldValue = reblogged
        reblogged = !reblogged
        
        let realStatus: Status = status.reblog ?? status
        let request = (reblogged ? Status.reblog : Status.unreblog)(realStatus)
        MastodonController.shared.client.run(request) { response in
            self.reblogged = realStatus.reblogged ?? false
            DispatchQueue.main.async {
                if case .success = response {
                    self.reblogged = realStatus.reblogged ?? false
                    UIImpactFeedbackGenerator(style: .light).impactOccurred()
                } else {
                    self.reblogged = oldValue
                    print("Couldn't reblog status \(realStatus.id)")
                    // todo: display error message
                    UINotificationFeedbackGenerator().notificationOccurred(.error)
                }
            }
        }
    }
    
    @IBAction func morePressed(_ sender: Any) {
        delegate?.showMoreOptions(status: statusID)
    }
    
}

extension StatusTableViewCell: TableViewSwipeActionProvider {
    
    static var favoriteActionImage: UIImage = UIGraphicsImageRenderer(size: CGSize(width: 30 * 137/131, height: 30)).image { _ in
        UIImage(named: "Favorite")!.draw(in: CGRect(x: 0, y: 0, width: 30 * 137/131, height: 30))
    }
    static var reblogActionImage: UIImage = UIGraphicsImageRenderer(size: CGSize(width: 30 * 927/558, height: 30)).image { _ in
        UIImage(named: "Reblog")!.draw(in: CGRect(x: 0, y: 0, width: 30 * 927/558, height: 30))
    }
    static var replyActionImage: UIImage = UIGraphicsImageRenderer(size: CGSize(width: 30 * 205/151, height: 30)).image { _ in
        UIImage(named: "Reply")!.draw(in: CGRect(x: 0, y: 0, width: 30 * 205/151, height: 30))
    }
    static var moreActionImage: UIImage = UIGraphicsImageRenderer(size: CGSize(width: 30 * 2/1, height: 30)).image { _ in
        UIImage(named: "More")!.draw(in: CGRect(x: 0, y: 0, width: 30 * 2/1, height: 30))
    }
    
    func leadingSwipeActionsConfiguration() -> UISwipeActionsConfiguration? {
        guard let status = StatusCache.get(id: statusID) else { fatalError("Missing cached status \(statusID!)") }
        
        let favoriteTitle: String
        let favoriteRequest: Request<Status>
        let favoriteColor: UIColor
        if status.favourited ?? false {
            favoriteTitle = "Unfavorite"
            favoriteRequest = Status.unfavourite(status)
            favoriteColor = UIColor(displayP3Red: 235/255, green: 77/255, blue: 62/255, alpha: 1)
            
        } else {
            favoriteTitle = "Favorite"
            favoriteRequest = Status.favourite(status)
            favoriteColor = UIColor(displayP3Red: 1, green: 204/255, blue: 0, alpha: 1)
        }
        let favorite = UIContextualAction(style: .normal, title: favoriteTitle) { (action, view, completion) in
            MastodonController.shared.client.run(favoriteRequest, completion: { response in
                DispatchQueue.main.async {
                    guard case let .success(status, _) = response else {
                        completion(false)
                        return
                    }
                    completion(true)
                    StatusCache.add(status)
                    self.updateUI(for: self.statusID)
                }
            })
        }
        favorite.image = StatusTableViewCell.favoriteActionImage
        favorite.backgroundColor = favoriteColor
        
        let reblogTitle: String
        let reblogRequest: Request<Status>
        let reblogColor: UIColor
        if status.reblogged ?? false {
            reblogTitle = "Unreblog"
            reblogRequest = Status.unreblog(status)
            reblogColor = UIColor(displayP3Red: 235/255, green: 77/255, blue: 62/255, alpha: 1)
        } else {
            reblogTitle = "Reblog"
            reblogRequest = Status.reblog(status)
            reblogColor = tintColor
        }
        let reblog = UIContextualAction(style: .normal, title: reblogTitle) { (action, view, completion) in
            MastodonController.shared.client.run(reblogRequest, completion: { response in
                DispatchQueue.main.async {
                    guard case let .success(status, _) = response else {
                        completion(false)
                        return
                    }
                    completion(true)
                    StatusCache.add(status)
                    self.updateUI(for: self.statusID)
                }
            })
        }
        reblog.image = StatusTableViewCell.reblogActionImage
        reblog.backgroundColor = reblogColor
        
        return UISwipeActionsConfiguration(actions: [favorite, reblog])
    }
    
    func trailingSwipeActionsConfiguration() -> UISwipeActionsConfiguration? {
        let reply = UIContextualAction(style: .normal, title: "Reply") { (action, view, completion) in
            completion(true)
            self.delegate?.reply(to: self.statusID)
        }
        reply.image = StatusTableViewCell.replyActionImage
        reply.backgroundColor = tintColor
        let more = UIContextualAction(style: .normal, title: "More") { (action, view, completion) in
            completion(true)
            self.delegate?.showMoreOptions(status: self.statusID)
        }
        more.image = StatusTableViewCell.moreActionImage
        more.backgroundColor = .gray
        return UISwipeActionsConfiguration(actions: [reply, more])
    }
    
    
}

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

extension StatusTableViewCell: AttachmentViewDelegate {
    func showLargeAttachment(for attachmentView: AttachmentView) {
        delegate?.showLargeImage(attachmentView.image!, description: attachmentView.attachment.description, animatingFrom: attachmentView)
    }
}