//
//  ProfileHeaderTableViewCell.swift
//  Tusker
//
//  Created by Shadowfacts on 8/27/18.
//  Copyright © 2018 Shadowfacts. All rights reserved.
//

import UIKit
import Pachyderm
import Combine

protocol ProfileHeaderTableViewCellDelegate: TuskerNavigationDelegate {
    func showMoreOptions(cell: ProfileHeaderTableViewCell)
}

class ProfileHeaderTableViewCell: UITableViewCell {
    
    weak var delegate: ProfileHeaderTableViewCellDelegate?
    var mastodonController: MastodonController! { delegate?.apiController }

    @IBOutlet weak var headerImageView: UIImageView!
    @IBOutlet weak var avatarContainerView: UIView!
    @IBOutlet weak var avatarImageView: UIImageView!
    @IBOutlet weak var displayNameLabel: EmojiLabel!
    @IBOutlet weak var usernameLabel: UILabel!
    @IBOutlet weak var followsYouLabel: UILabel!
    @IBOutlet weak var noteTextView: StatusContentTextView!
    @IBOutlet weak var fieldsStackView: UIStackView!
    @IBOutlet weak var fieldNamesStackView: UIStackView!
    @IBOutlet weak var fieldValuesStack: UIStackView!
    @IBOutlet weak var moreButtonVisualEffectView: UIVisualEffectView!
    
    var accountID: String!
    
    var avatarRequest: ImageCache.Request?
    var headerRequest: ImageCache.Request?
    
    private var accountUpdater: Cancellable?

    override func awakeFromNib() {
        avatarContainerView.layer.masksToBounds = true
        avatarImageView.layer.masksToBounds = true
        avatarImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(avatarPressed)))
        avatarImageView.isUserInteractionEnabled = true
        headerImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(headerPressed)))
        headerImageView.isUserInteractionEnabled = true
        moreButtonVisualEffectView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(morePressed)))
        
        let maskLayer = CAShapeLayer()
        maskLayer.frame = moreButtonVisualEffectView.bounds
        maskLayer.path = CGPath(ellipseIn: moreButtonVisualEffectView.bounds, transform: nil)
        moreButtonVisualEffectView.layer.mask = maskLayer
        
        NotificationCenter.default.addObserver(self, selector: #selector(updateUIForPreferences), name: .preferencesChanged, object: nil)
    }
    
    func updateUI(for accountID: String) {
        guard accountID != self.accountID else { return }
        self.accountID = accountID
        
        guard let account = mastodonController.cache.account(for: accountID) else { fatalError("Missing cached account \(accountID)") }
        
        updateUIForPreferences()
        
        usernameLabel.text = "@\(account.acct)"
        
        avatarRequest = ImageCache.avatars.get(account.avatar) { [weak self] (data) in
            guard let self = self, let data = data, self.accountID == accountID else { return }
            self.avatarRequest = nil
            DispatchQueue.main.async {
                self.avatarImageView.image = UIImage(data: data)
            }
        }
        headerRequest = ImageCache.headers.get(account.header) { [weak self] (data) in
            guard let self = self, let data = data, self.accountID == accountID else { return }
            self.headerRequest = nil
            DispatchQueue.main.async {
                self.headerImageView.image = UIImage(data: data)
            }
        }
        
        noteTextView.navigationDelegate = delegate
        noteTextView.setTextFromHtml(account.note)
        noteTextView.setEmojis(account.emojis)
        
        if accountID != mastodonController.account.id {
            // don't show relationship label for the user's own account
            if let relationship = mastodonController.cache.relationship(for: accountID) {
                followsYouLabel.isHidden = !relationship.followedBy
            } else {
                mastodonController.cache.relationship(for: accountID) { relationship in
                    DispatchQueue.main.async {
                        self.followsYouLabel.isHidden = !(relationship?.followedBy ?? false)
                    }
                }
            }
        }
        
        if let fields = account.fields, !fields.isEmpty {
            fieldsStackView.isHidden = false
            
            fieldsStackView.arrangedSubviews.forEach { $0.removeFromSuperview() }
            for field in fields {
                let nameLabel = UILabel()
                nameLabel.text = field.name
                nameLabel.font = .boldSystemFont(ofSize: 17)
                nameLabel.textAlignment = .right
                nameLabel.numberOfLines = 0
                fieldNamesStackView.addArrangedSubview(nameLabel)
                
                let valueTextView = ContentTextView()
                valueTextView.isSelectable = false
                valueTextView.font = .systemFont(ofSize: 17)
                valueTextView.setTextFromHtml(field.value)
                valueTextView.setEmojis(account.emojis)
                valueTextView.textAlignment = .left
                valueTextView.awakeFromNib()
                valueTextView.navigationDelegate = delegate
                fieldValuesStack.addArrangedSubview(valueTextView)
            }
        } else {
            fieldsStackView.isHidden = true
        }
        
        if accountUpdater == nil {
            accountUpdater = mastodonController.cache.accountSubject
                .filter { [unowned self] in $0.id == self.accountID }
                .receive(on: DispatchQueue.main)
                .sink { [unowned self] in self.updateUI(for: $0.id) }
        }
    }

    @objc func updateUIForPreferences() {
        guard let account = mastodonController.cache.account(for: accountID) else { fatalError("Missing cached account \(accountID!)") }
        
        avatarContainerView.layer.cornerRadius = Preferences.shared.avatarStyle.cornerRadius(for: avatarContainerView)
        avatarImageView.layer.cornerRadius = Preferences.shared.avatarStyle.cornerRadius(for: avatarImageView)
        displayNameLabel.updateForAccountDisplayName(account: account)
    }
    
    override func prepareForReuse() {
        avatarRequest?.cancel()
        headerRequest?.cancel()
    }
    
    @objc func morePressed() {
        delegate?.showMoreOptions(cell: self)
    }
    
    @objc func avatarPressed() {
        delegate?.showLargeImage(avatarImageView.image!, description: nil, animatingFrom: avatarImageView)
    }
    
    @objc func headerPressed() {
        delegate?.showLargeImage(headerImageView.image!, description: nil, animatingFrom: headerImageView)
    }
    
}