/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A table view controller that allows you to search contacts by 

                name (first name, last name, and organization name).

 */

import Contacts

import UIKit

class SearchViewController: UITableViewController, UISearchResultsUpdating {

    // MARK: - Types

    fileprivate struct MainStoryboard {

        struct TableViewCellIdentifiers {

            static let cellIdentifier = "cellID"

            static let cellSubtitleIdentifier = "cellSubtitleID"

        }

    }

    // MARK: - Properties

    /// Stores all contacts available in the contact store.

    fileprivate var allContacts = [CNContact]()

    // Stores contacts matching the search string.

    fileprivate var filteredContacts = [CNContact]()

    fileprivate var searchController: UISearchController!

    /**

        - returns: Boolean value that determines whether to show a subtitle cell.\

                   true if the contact is a person and the matching name was found 

                   in its associated organization name rather than in its name. 

                   Also true if the contact is an organization and the matching 

                   name was found in its associated formatted name. false, 

                   otherwise.

    */

    fileprivate var shouldShowSubtitleCell: Bool = false

    var data: [CNContact] = [CNContact]() {

        didSet {

            filteredContacts = data

            allContacts = data

            tableView.reloadData()

        }

    }

    // MARK: - View Life Cycle

    override func viewDidLoad() {

        super.viewDidLoad()

        // Create the search controller.

        searchController = UISearchController(searchResultsController: nil)

        searchController.searchResultsUpdater = self

        // Make sure the that the search bar is visible within the navigation bar.

        searchController.searchBar.sizeToFit()

        // Include the search controller's search bar in the table header view.

        tableView.tableHeaderView = searchController.searchBar

        searchController.dimsBackgroundDuringPresentation = false

        definesPresentationContext = true

    }

    // MARK: - UITableViewDataSource

    override func numberOfSections(in tableView: UITableView) -> Int {

        return 1

    }

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

        return filteredContacts.count

    }

    // MARK: - UITableViewDelegate    

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

        var cell: UITableViewCell

        let contact = filteredContacts[indexPath.row]

        var name = String()

        if let searchString = searchController.searchBar.text, !(searchString.isEmpty) {

            /* CNContact's predicateForContactsMatchingName looks thru the first 

               name, last name, and organization name fields of a contact. In 

               some cases, Contacts may find the searched name in the organization 

               name of a contact, which is a person or in the first name and

               last name of a contact, which is an organization.

               Display a subtitle cell if the contact is a person and its first 

               name and last name do not contain the search string.

            */

            if contact.isPerson && !(contact.formattedName.localizedCaseInsensitiveContains(searchString)) {

                name = contact.organizationName

                shouldShowSubtitleCell = true

            }

            // Display a subtitle cell if the contact is an organization and its name does not contain the searchString

            else if !contact.isPerson && !(contact.organizationName.localizedCaseInsensitiveContains(searchString)) {

                name = (contact.familyName.localizedCaseInsensitiveContains(searchString)) ? contact.familyName : contact.givenName

                shouldShowSubtitleCell = true

            }

        }

        if shouldShowSubtitleCell {

            cell = tableView.dequeueReusableCell(withIdentifier: MainStoryboard.TableViewCellIdentifiers.cellSubtitleIdentifier, for: indexPath)

            // Display the name of the contact.

            cell.textLabel!.text = (contact.isPerson) ? contact.formattedName : contact.organizationName

            // Display the contact's associated field containing the search string.

            cell.detailTextLabel!.text = name

        }

        else {

            cell = tableView.dequeueReusableCell(withIdentifier: MainStoryboard.TableViewCellIdentifiers.cellIdentifier, for: indexPath)

            cell.textLabel!.text = (contact.isPerson) ? contact.formattedName : contact.organizationName

       }

       return cell

    }

    // MARK: -  UISearchResultsUpdating

    func updateSearchResults(for searchController: UISearchController) {

        let searchString = searchController.searchBar.text

        /*

            Show all contacts if the user did not enter anything. Show the 

            contacts matching the search string otherwise.

        */

        if searchString!.isEmpty {

            filteredContacts = allContacts

            tableView.reloadData()

        }

        else {

            MGCContactStore.sharedInstance.fetchContacts(with: searchString!, completion: ({(contacts: [CNContact]) in

                self.filteredContacts = contacts

                self.tableView.reloadData()

            }))

        }

    }

    // MARK: - Memory Management

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

    }

}