/*
 * KeyboardTableController.swift
 * FirstVoices app
 * 
 * License: MIT
 *
 * Copyright © 2022 FirstVoices.
 *
 * Created by Shawn Schantz on 2022-01-13.
 * 
 * The main screen of the app containing the list (UITableView) of FirstVoices keyboards.
 * From here, users can tap on a keyboard which will cause it to transition to a detail page for that keyboard, or
 * they can tap on the info icon for a keyboard which will load the help web page for the keyboard in the browser.
 *
 */

import UIKit

let keymanHelpSite: String = "https://help.keyman.com/keyboard/"

/*
 * define protocol so that KeyboardDetailController can send message to update state of checkmark in keyboard list
 */
protocol RefreshKeyboardCheckmark {
  func refreshCheckmark()
}

class KeyboardTableController: UIViewController, RefreshKeyboardCheckmark {
  var settingsRepo = KeyboardSettingsRepository.shared

/*
 * mark the row to be reloaded after return segue -- it can be reloaded immediately
 * when the state changes because it is outside the view hierachy until the user
 * navigates back
 */
 func refreshCheckmark() {
    self.rowToReload = self.selectedKeyboardIndex
  }
 
  @IBOutlet weak var tableView: UITableView!

  var selectedKeyboardIndex: IndexPath = IndexPath(row: 0, section: 0)
    
  private var _keyboardList: FVRegionList!
  private var keyboardList: FVRegionList {
    get {
      if _keyboardList == nil {
        _keyboardList = FVRegionStorage.load()
      }
      return _keyboardList!
    }
  }
  private var rowToReload: IndexPath? = nil

  override func viewDidLoad() {
    super.viewDidLoad()

    tableView.delegate = self
    tableView.dataSource = self
  }
  
  override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    self.navigationController!.isNavigationBarHidden = false
    navigationController?.setToolbarHidden(true, animated: false)
  }

  /*
   * Needed to override to add the checkmark to the keyboard that has just been made active. Cannot call reloadRows before the view appears because it causes layout.
   */
  override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    
    if(rowToReload != nil) {
      let rows: [IndexPath] = [rowToReload!]
      self.tableView.reloadRows(at: rows, with: UITableView.RowAnimation.none)
      self.rowToReload = nil;
    }

  }
  /*
   * Segue to keyboard details screen.
   * Before the segue, call the details view controller and pass the state of the keyboard and
   * a reference to self to be called back to update the row if the state changes.
   */
  override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "keyboardDetails" {
      let detailsController = segue.destination as! KeyboardDetailController

      let indexPath = self.tableView.indexPathForSelectedRow
      let keyboards = (self.keyboardList[indexPath!.section]).keyboards
      let keyboard = keyboards[indexPath!.row]
      
      if let keyboardState: KeyboardState = settingsRepo.loadKeyboardState(keyboardId: keyboard.id) {
        detailsController.configure(delegate: self, keyboard: keyboardState)
      } else {
        print("Could not find keyboard \(keyboard.id) in available keyboards list.")
      }
    }
  }

  // TODO: stop using deprecated openURL method when we upgrade to iOS 10 or later
  func tableView(_ tableView: UITableView, accessoryButtonTappedForRowWith indexPath: IndexPath) {
    let keyboards: FVKeyboardList = (self.keyboardList[indexPath.section]).keyboards
    let keyboard: FVKeyboard = keyboards[indexPath.row]
    let helpUrl: URL = URL.init(string: "\(keymanHelpSite)\(keyboard.id)")!
    UIApplication.shared.openURL(helpUrl)
  }
  
  func reportFatalError(message: String) {
    let alertController = UIAlertController(title: title, message: message,
      preferredStyle: UIAlertController.Style.alert)
    alertController.addAction(UIAlertAction(title: "OK",
                                            style: UIAlertAction.Style.cancel,
                                            handler: nil))

    self.present(alertController, animated: true, completion: nil)
    print(message)
    // TODO: send the error message + call stack through to us
    // some reporting mechanism
  }
}

extension KeyboardTableController: UITableViewDataSource, UITableViewDelegate {

  func numberOfSections(in tableView: UITableView) -> Int {
    return self.keyboardList.count
  }

  func tableView(_ tableView: UITableView,
                 titleForHeaderInSection section: Int) -> String? {
    return self.keyboardList[section].name
  }

  func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    self.selectedKeyboardIndex = indexPath
  }
  
  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.keyboardList[section].keyboards.count
  }
  
  func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let keyboards = (self.keyboardList[indexPath.section]).keyboards
    let keyboard = keyboards[indexPath.row]
    let keyboardState = settingsRepo.loadKeyboardState(keyboardId: keyboard.id)
    
    let cell = tableView.dequeueReusableCell(withIdentifier: "KeyboardCell")
    cell!.textLabel!.text = keyboardState?.name

    cell!.imageView?.isHidden = !keyboardState!.isActive
        
    return cell!
  }
}