//
//  BusListViewController.swift
//  QLead
//
//  Created by Raed Fayad on 2018-08-26.
//  Copyright © 2018 kirkbyo. All rights reserved.
//

import UIKit
import Foundation

struct Model {
    var title: String
    var bus: String
}

let dataArray = [
    [Model(title: "Name1", bus: "Bus 1"), Model(title: "Name2", bus: "Bus 1"), Model(title:              "Name3", bus: "Bus 1"),Model(title: "Name4", bus: "Bus 1"), Model(title: "Name5", bus: "Bus 1"), Model(title: "Name6", bus: "Bus 1"), Model(title: "Name7", bus: "Bus 1"), Model(title: "Name8", bus: "Bus 1")] ,
    [Model(title: "Name9", bus: "Bus 2"), Model(title: "Name10", bus: "Bus 2"), Model(title: "Name11", bus: "Bus 2"), Model(title: "Name12", bus: "Bus 2"), Model(title: "Name13", bus: "Bus 2")],
    [Model(title: "Name14", bus: "Bus 3"), Model(title: "Name15", bus: "Bus 3"), Model(title: "Name16", bus: "Bus 3")]]

class ViewModelItem {
    private var item: Model
    var isSelected = false
    var title: String {
        return item.title
    }
    init(item: Model) {
        self.item = item
    }
}

class ViewModel: NSObject {
    var items = [ViewModelItem]()

    var didToggleSelection: ((_ hasSelection: Bool) -> ())? {
        didSet {
            didToggleSelection?(!selectedItems.isEmpty)
        }
    }

    var selectedItems: [ViewModelItem] {
        return items.filter { return $0.isSelected }
    }

    override init() {
        super.init()
        let temp = dataArray.flatMap { $0 }
        items = temp.map { ViewModelItem(item: $0) }
    }
}

extension ViewModel: UITableViewDataSource {

    func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return dataArray.count
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return dataArray[section].count
    }
    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return dataArray[section][0].bus

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

        if let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as? BusListTableViewCell {

            cell.titleLabel.text = dataArray[indexPath.section][indexPath.row].title

            // select/deselect the cell
            if items[indexPath.row].isSelected {
                if !cell.isSelected {
                    tableView.selectRow(at: indexPath, animated: false, scrollPosition: .none)
                }
            } else {
                if cell.isSelected {
                    tableView.deselectRow(at: indexPath, animated: false)
                }
            }

            return cell
        }
        return UITableViewCell()
    }
}

extension ViewModel: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

        // update ViewModel item
        items[indexPath.row].isSelected = true

        didToggleSelection?(!selectedItems.isEmpty)
    }

    func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {

        // update ViewModel item
        items[indexPath.row].isSelected = false

        didToggleSelection?(!selectedItems.isEmpty)
    }

    func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath?{
        return indexPath
    }
}


class BusListViewController: UIViewController {

    var viewModel = ViewModel()

    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var nextButton: UIButton!
    @IBAction func buttonPressed(_ sender: Any) {

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        tableView?.estimatedRowHeight = 100
        tableView?.rowHeight = UITableViewAutomaticDimension
        tableView?.allowsMultipleSelection = true
        tableView?.dataSource = viewModel
        tableView?.delegate = viewModel
        tableView?.separatorStyle = .none

        viewModel.didToggleSelection = { [weak self] hasSelection in
            self?.nextButton.isEnabled = hasSelection
        }
    }

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