RootViewController.swift

//
//  RootViewController.swift
//  Filters
//
//  Created by Haldun Bayhantopcu on 03/03/16.
//  Copyright © 2016 Haldun Bayhantopcu. All rights reserved.
//

import UIKit

struct Filter {
  let key: String
  let value: String?
}

extension Filter: Equatable {}

func ==(lhs: Filter, rhs: Filter) -> Bool {
  return lhs.key == rhs.key
}

final class RootViewController: UITableViewController {

  var filters = [
    Filter(key: "filter 1", value: nil),
    Filter(key: "filter 2", value: "hehehehe"),
  ]

  override func viewDidLoad() {
    super.viewDidLoad()
  }

  override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return filters.count
  }

  override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
    let filter = filters[indexPath.row]
    cell.textLabel?.text = filter.key
    cell.detailTextLabel?.text = filter.value
    return cell
  }

  override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    let filter = filters[indexPath.row]
    let filterViewController = FilterViewController(filter: filter)
    filterViewController.delegate = self
    showViewController(filterViewController, sender: self)
  }
}

extension RootViewController: FilterViewControllerDelegate {
  func filterChanged(filter: Filter) {
    navigationController?.popViewControllerAnimated(true)
    print("filter changed: \(filter)")

    if let index = filters.indexOf(filter) {
      filters[index] = filter
      tableView.reloadRowsAtIndexPaths([NSIndexPath(forRow: index, inSection: 0)], withRowAnimation: .Automatic)
    }
  }
}

protocol FilterViewControllerDelegate: class {
  func filterChanged(filter: Filter)
}

class FilterViewController: UIViewController {

  let filter: Filter

  weak var delegate: FilterViewControllerDelegate?

  init(filter: Filter) {
    self.filter = filter
    super.init(nibName: nil, bundle: nil)
  }

  required init?(coder aDecoder: NSCoder) {
      fatalError("init(coder:) has not been implemented")
  }

  override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = UIColor.whiteColor()
    view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "tapped:"))
  }

  func tapped(sender: AnyObject?) {
    delegate?.filterChanged(Filter(key: filter.key, value: "new value!"))
  }
}