/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    This file contains the SwitchCell class, which is a UITableViewCell sub-class for a cell that contains a UISwitch.

*/

import UIKit

/// A custom table cell object that contains a switch

class SwitchCell: UITableViewCell {

    // MARK: Properties

    /// The switch contained in the cell.

    @IBOutlet weak var toggle: UISwitch!

    /// The table view controller of the table view that contains this cell. Used when inserting and removing cells that are conditionally displayed by the switch.

    @IBOutlet weak var tableViewController: UITableViewController!

    /// A list of cells that are inserted/removed from the table based on the value of the switch.

    var dependentCells = [UITableViewCell]()

    /// A block to call to get the index path of this cell int its containing table.

    var getIndexPath: ((Void) -> IndexPath?)?

    /// A block to call when the value of the switch changes.

    var valueChanged: ((Void) -> Void)?

    /// A boolean that toggles the switch.

    var isOn: Bool {

        get {

            return toggle.isOn

        }

        set (newValue) {

            let changed = toggle.isOn != newValue

            toggle.isOn = newValue

            if changed {

                handleValueChanged()

            }

        }

    }

    // MARK: Interface

    /// Handle the user toggling the switch.

    @IBAction func toggled(_ sender: AnyObject) {

        handleValueChanged()

    }

    /// Handle changes in the switch's value.

    func handleValueChanged() {

        valueChanged?()

        guard let switchIndexPath = getIndexPath?() else { return }

        guard dependentCells.count > 0 else { return }

        var indexPaths = [IndexPath]()

        // Create index paths for the dependent cells based on the index path of this cell.

        for row in 1...dependentCells.count {

            indexPaths.append(IndexPath(row: (switchIndexPath as NSIndexPath).row + row, section: (switchIndexPath as NSIndexPath).section))

        }

        guard !indexPaths.isEmpty else { return }

        if toggle.isOn {

            tableViewController.tableView.insertRows(at: indexPaths, with: .bottom)

        } else {

            tableViewController.tableView.deleteRows(at: indexPaths, with: .bottom)

        }

    }

}