/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    The master view controller.

*/

import UIKit

class MasterViewController: UITableViewController {

    // MARK: Types 

    /// A simple data structure to populate the table view.

    struct PreviewDetail {

        let title: String

        let preferredHeight: Double

    }

    // MARK: Properties

    let sampleData = [

        PreviewDetail(title: "Small", preferredHeight: 160.0),

        PreviewDetail(title: "Medium", preferredHeight: 320.0),

        PreviewDetail(title: "Large", preferredHeight: 0.0) // 0.0 to get the default height.

    ]

    /// An alert controller used to notify the user if 3D touch is not available.

    var alertController: UIAlertController?

    // MARK: View Life Cycle

    override func viewDidLoad() {

        super.viewDidLoad()

        // Check for force touch feature, and add force touch/previewing capability.

        if traitCollection.forceTouchCapability == .available {

            /*  

                Register for `UIViewControllerPreviewingDelegate` to enable

                "Peek" and "Pop".

                (see: MasterViewController+UIViewControllerPreviewing.swift)

                The view controller will be automatically unregistered when it is

                deallocated.

            */

            registerForPreviewing(with: self, sourceView: view)

        }

        else {

            // Create an alert to display to the user.

            alertController = UIAlertController(title: "3D Touch Not Available", message: "Unsupported device.", preferredStyle: .alert)

        }

    }

    override func viewWillAppear(_ animated: Bool) {

        // Clear the selection if the split view is only showing one view controller.

        clearsSelectionOnViewWillAppear = splitViewController!.isCollapsed

        super.viewWillAppear(animated)

    }

    override func viewDidAppear(_ animated: Bool) {

        super.viewDidAppear(animated)

        // Present the alert if necessary.

        if let alertController = alertController {

            alertController.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))

            present(alertController, animated: true, completion: nil)

            // Clear the `alertController` to ensure it's not presented multiple times.

            self.alertController = nil

        }

    }

    // MARK: UIStoryboardSegue Handling

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

        super.prepare(for: segue, sender: sender)

        if segue.identifier == "showDetail", let indexPath = tableView.indexPathForSelectedRow {

            let previewDetail = sampleData[(indexPath as NSIndexPath).row]

            let detailViewController = (segue.destination as! UINavigationController).topViewController as! DetailViewController

            // Pass the `title` to the `detailViewController`.

            detailViewController.sampleTitle = previewDetail.title

        }

    }

    // MARK: Table View

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

        // Return the number of items in the sample data structure.

        return sampleData.count

    }

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

        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)

        let previewDetail = sampleData[(indexPath as NSIndexPath).row]

        cell.textLabel!.text = previewDetail.title

        return cell

    }

}