/*

    Copyright (C) 2017 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A BaseViewController subclass that displays a list of groups from 

                which you can you select a group.

                Destination view controller for the performAddContactToGroup segue.

                Executes the addContactToGroup segue when tapping any group in its UI.

*/

import UIKit

import Contacts

class PlainViewController: BaseViewController {

    // MARK: - Properties

    /// Group selected by the user.

    fileprivate var selectedGroup: CNGroup?

    // MARK: - UITableViewDelegate

    override func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {

        let model = data[indexPath.section]

        let group = data[indexPath.section].content[indexPath.row] as! CNGroup

        cell.textLabel!.text = group.name

        if model.segue!.main == MGCAppConfiguration.MainStoryboard.SegueIdentifiers.Groups.performAddContactToGroup {

            cell.accessoryType = .disclosureIndicator

            cell.isUserInteractionEnabled = true

        }

    }

    // MARK: - Navigation

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

        let selectedIndex = tableView.indexPathForSelectedRow!

        let model = data[selectedIndex.section]

        if segue.identifier == MGCAppConfiguration.MainStoryboard.SegueIdentifiers.Groups.addContactToGroup {

            let groups = model.content as! [CNGroup]

            // Fetch the current selected group.

            selectedGroup = groups[selectedIndex.row]

            let addContactToGroupViewController = segue.destination as! AddContactToGroupViewController

            /* Groups and contacts must belong to the same container. For 

               instance, you cannot add Exchange contacts to an iCloud group. 

               Fetch the container associated with the selected group. 

            */

            MGCContactStore.sharedInstance.fetchContainerOfGroup(with: selectedGroup!.identifier, completion: ({(container: CNContainer?) in

                if let container = container {

                    let containerID = container.identifier

                    // Fetch and display contacts associated with the above container.

                    MGCContactStore.sharedInstance.fetchContactsInContainer(with: containerID, completion: ({(contacts: [CNContact]) in

                        let withContacts = [MGCModel(tab: MGCAppConfiguration.Content.groups,

                                                category: MGCAppConfiguration.MainStoryboard.TableHeaderSection.Groups.selectAllContacts,

                                                   segue: model.segue!),

                                            MGCModel(tab: MGCAppConfiguration.Content.groups,

                                                 content: contacts,

                                                category: MGCAppConfiguration.Content.contacts,

                                                   segue: model.segue!)]

                        let noContacts = [MGCModel(tab: MGCAppConfiguration.Content.groups,

                                               content: [MGCAppConfiguration.Content.NoItems.contacts.rawValue as AnyObject],

                                              category: MGCAppConfiguration.Content.NoItems.contacts.rawValue)]

                        addContactToGroupViewController.data = (contacts.count > 0) ? withContacts : noContacts

                        addContactToGroupViewController.title = self.selectedGroup!.name

                        /* Enable the Save button in the navigation bar if we

                           have some contacts. Disable it, otherwise.

                        */

                        addContactToGroupViewController.enableSaveButton = (contacts.count > 0) ? true : false

                    }))

                }

            }))

        }

    }

    // MARK: - Actions

    /// Attempt to add one or more contacts to a group.

    @IBAction func saveContactToGroup(_ sender: UIStoryboardSegue) {

        if let addContactToGroupViewController = sender.source as? AddContactToGroupViewController, let group = selectedGroup {

            // Attempt to add the selected contacts to group.

            if addContactToGroupViewController.selectedContacts.count > 0 {

                MGCContactStore.sharedInstance.save(addContactToGroupViewController.selectedContacts, to: group)

            }

        }

    }

}