/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 The main table view controller for the app, which displays a list of received chats from other users.

 */

import UIKit

class ChatTableViewController: UITableViewController {

    private let chatItemManager = ChatItemManager.sharedInstance

    private var newChatDelegate: NewChatDelegate?

    override func viewDidLoad() {

        super.viewDidLoad()

        navigationItem.rightBarButtonItem?.isEnabled = NewChatDelegate.isCameraAvailable()

        registerForPreviewing(with: self, sourceView: tableView)

    }

    override func viewWillAppear(_ animated: Bool) {

        super.viewWillAppear(animated)

        if let selectedIndexPaths = tableView.indexPathsForSelectedRows {

            for selectedIndexPath in selectedIndexPaths {

                tableView.deselectRow(at: selectedIndexPath, animated: true)

            }

        }

    }

    func chatItem(at indexPath: IndexPath) -> ChatItem {

        return chatItemManager.receivedChatItems[indexPath.row]

    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        return chatItemManager.receivedChatItems.count

    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: ChatTableViewCell.identifier, for: indexPath)

        if let chatTableCell = cell as? ChatTableViewCell {

            let chatItem = self.chatItem(at: indexPath)

            chatTableCell.configure(with: chatItem)

        }

        return cell

    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        if let chatDetailViewController = segue.destination as? ChatDetailViewController, let selectedIndexPath = tableView.indexPathForSelectedRow {

            chatDetailViewController.chatItem = chatItem(at: selectedIndexPath)

        }

    }

    @IBAction func createNewChat(_ sender: AnyObject?) {

        presentNewChatController()

    }

    func presentNewChatController(for friend: Friend? = nil, animated: Bool = true, completion: (() -> Void)? = nil) {

        assert(NewChatDelegate.isCameraAvailable(), "The device must have a camera to create a new chat.")

        guard newChatDelegate == nil else {

            completion?()

            return

        }

        newChatDelegate = NewChatDelegate(presentingViewController: self, recipient: friend) {[unowned self] (chatImage: UIImage?) in

            self.newChatDelegate = nil

        }

        let imagePickerController = UIImagePickerController()

        imagePickerController.delegate = newChatDelegate

        imagePickerController.sourceType = .camera

        present(imagePickerController, animated: animated, completion: completion)

    }

}

extension ChatTableViewController: UIViewControllerPreviewingDelegate {

    func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {

        guard let indexPath = tableView.indexPathForRow(at: location) else { return nil }

        let storyboard = UIStoryboard(name: "Main", bundle: nil)

        let viewController = storyboard.instantiateViewController(withIdentifier: ChatDetailViewController.identifier)

        guard let chatDetailViewController = viewController as? ChatDetailViewController else { return nil }

        chatDetailViewController.chatItem = chatItem(at: indexPath)

        let cellRect = tableView.rectForRow(at: indexPath)

        previewingContext.sourceRect = previewingContext.sourceView.convert(cellRect, from: tableView)

        chatDetailViewController.isReplyButtonHidden = true

        return chatDetailViewController

    }

    func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {

        if let chatDetailViewController = viewControllerToCommit as? ChatDetailViewController {

            chatDetailViewController.isReplyButtonHidden = false

        }

        show(viewControllerToCommit, sender: self)

    }

}