MessageKit/Example/Sources/View Controllers/ChatViewController.swift

/*
MIT License

Copyright (c) 2017-2018 MessageKit

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

import UIKit
import MessageKit
import MessageInputBar

/// A base class for the example controllers
class ChatViewController: MessagesViewController, MessagesDataSource {
    
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }
    
    var messageList: [MockMessage] = []
    
    let refreshControl = UIRefreshControl()
    
    let formatter: DateFormatter = {
        let formatter = DateFormatter()
        formatter.dateStyle = .medium
        return formatter
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        configureMessageCollectionView()
        configureMessageInputBar()
        loadFirstMessages()
        title = "MessageKit"
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        MockSocket.shared.connect(with: [SampleData.shared.steven, SampleData.shared.wu])
            .onNewMessage { [weak self] message in
                self?.insertMessage(message)
        }
    }
    
    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        MockSocket.shared.disconnect()
    }
    
    func loadFirstMessages() {
        DispatchQueue.global(qos: .userInitiated).async {
            let count = UserDefaults.standard.mockMessagesCount()
            SampleData.shared.getMessages(count: count) { messages in
                DispatchQueue.main.async {
                    self.messageList = messages
                    self.messagesCollectionView.reloadData()
                    self.messagesCollectionView.scrollToBottom()
                }
            }
        }
    }
    
    @objc
    func loadMoreMessages() {
        DispatchQueue.global(qos: .userInitiated).asyncAfter(deadline: .now() + 1) {
            SampleData.shared.getMessages(count: 20) { messages in
                DispatchQueue.main.async {
                    self.messageList.insert(contentsOf: messages, at: 0)
                    self.messagesCollectionView.reloadDataAndKeepOffset()
                    self.refreshControl.endRefreshing()
                }
            }
        }
    }
    
    func configureMessageCollectionView() {
        
        messagesCollectionView.messagesDataSource = self
        messagesCollectionView.messageCellDelegate = self
        
        scrollsToBottomOnKeyboardBeginsEditing = true // default false
        maintainPositionOnKeyboardFrameChanged = true // default false
        
        messagesCollectionView.addSubview(refreshControl)
        refreshControl.addTarget(self, action: #selector(loadMoreMessages), for: .valueChanged)
    }
    
    func configureMessageInputBar() {
        messageInputBar.delegate = self
        messageInputBar.inputTextView.tintColor = .primaryColor
        messageInputBar.sendButton.tintColor = .primaryColor
    }
    
    // MARK: - Helpers
    
    func insertMessage(_ message: MockMessage) {
        messageList.append(message)
        // Reload last section to update header/footer labels and insert a new one
        messagesCollectionView.performBatchUpdates({
            messagesCollectionView.insertSections([messageList.count - 1])
            if messageList.count >= 2 {
                messagesCollectionView.reloadSections([messageList.count - 2])
            }
        }, completion: { [weak self] _ in
            if self?.isLastSectionVisible() == true {
                self?.messagesCollectionView.scrollToBottom(animated: true)
            }
        })
    }
    
    func isLastSectionVisible() -> Bool {
        
        guard !messageList.isEmpty else { return false }
        
        let lastIndexPath = IndexPath(item: 0, section: messageList.count - 1)
        
        return messagesCollectionView.indexPathsForVisibleItems.contains(lastIndexPath)
    }
    
    // MARK: - MessagesDataSource
    
    func currentSender() -> SenderType {
        return SampleData.shared.currentSender
    }
    
    func numberOfSections(in messagesCollectionView: MessagesCollectionView) -> Int {
        return messageList.count
    }
    
    func messageForItem(at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> MessageType {
        return messageList[indexPath.section]
    }
    
    func cellTopLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString? {
        if indexPath.section % 3 == 0 {
            return NSAttributedString(string: MessageKitDateFormatter.shared.string(from: message.sentDate), attributes: [NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 10), NSAttributedString.Key.foregroundColor: UIColor.darkGray])
        }
        return nil
    }
    
    func messageTopLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString? {
        let name = message.sender.displayName
        return NSAttributedString(string: name, attributes: [NSAttributedString.Key.font: UIFont.preferredFont(forTextStyle: .caption1)])
    }
    
    func messageBottomLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString? {
        
        let dateString = formatter.string(from: message.sentDate)
        return NSAttributedString(string: dateString, attributes: [NSAttributedString.Key.font: UIFont.preferredFont(forTextStyle: .caption2)])
    }
    
}

// MARK: - MessageCellDelegate

extension ChatViewController: MessageCellDelegate {
    
    func didTapAvatar(in cell: MessageCollectionViewCell) {
        print("Avatar tapped")
    }
    
    func didTapMessage(in cell: MessageCollectionViewCell) {
        print("Message tapped")
    }
    
    func didTapCellTopLabel(in cell: MessageCollectionViewCell) {
        print("Top cell label tapped")
    }
    
    func didTapMessageTopLabel(in cell: MessageCollectionViewCell) {
        print("Top message label tapped")
    }
    
    func didTapMessageBottomLabel(in cell: MessageCollectionViewCell) {
        print("Bottom label tapped")
    }
    
    func didTapAccessoryView(in cell: MessageCollectionViewCell) {
        print("Accessory view tapped")
    }
    
}

// MARK: - MessageLabelDelegate

extension ChatViewController: MessageLabelDelegate {
    
    func didSelectAddress(_ addressComponents: [String: String]) {
        print("Address Selected: \(addressComponents)")
    }
    
    func didSelectDate(_ date: Date) {
        print("Date Selected: \(date)")
    }
    
    func didSelectPhoneNumber(_ phoneNumber: String) {
        print("Phone Number Selected: \(phoneNumber)")
    }
    
    func didSelectURL(_ url: URL) {
        print("URL Selected: \(url)")
    }
    
    func didSelectTransitInformation(_ transitInformation: [String: String]) {
        print("TransitInformation Selected: \(transitInformation)")
    }
    
}

// MARK: - MessageInputBarDelegate

extension ChatViewController: MessageInputBarDelegate {
    
    func messageInputBar(_ inputBar: MessageInputBar, didPressSendButtonWith text: String) {
          
        for component in inputBar.inputTextView.components {

            let user = SampleData.shared.currentSender
            if let str = component as? String {
                let message = MockMessage(text: str, user: user, messageId: UUID().uuidString, date: Date())
                insertMessage(message)
            } else if let img = component as? UIImage {
                let message = MockMessage(image: img, user: user, messageId: UUID().uuidString, date: Date())
                insertMessage(message)
            }
            
        }
        inputBar.inputTextView.text = String()
        messagesCollectionView.scrollToBottom(animated: true)
    }
    
}