djid_sirani_ios/Sirani/View/News/Index/NewsVC.swift

//
//  NewsVC.swift
//  Sirani
//
//  Created by Anhar Solehudin on 06/04/19.
//  Copyright © 2019 Anhar Solehudin. All rights reserved.
//

import UIKit

class NewsVC: UIViewController {
    
    // Outlets
    @IBOutlet weak var newsTV: UITableView!
    @IBOutlet weak var layoutNoData: UIView!
    @IBOutlet weak var progressLoading: UIView!
    
    // Segue
    private let unwindToHomeId = "unwindNewsToHomeSegueId"
    private let detailSegueId = "newsDetailSegueId"
    private let searchSegueId = "searchNewsSegueId"
    
    // View Id
    private let newsCellId = "NewsListCellId"
    
    // Constant Values
    private let alertNoConnectionTitle = "Informasi"
    private let alertNoConnectionMsg = "Sepertinya Anda sedang tidak tersambung pada koneksi internet"
    private let alertNoConnectionActionYes = "OK"
    
    // Initialize
    private var presenter: NewsPresenter!
    private var dataList = [News]()
    
    // Request Params
    private var jenis: String = ""
    private var columns: String = ""
    private var keyword: String = ""
    private var cursor: Int = 0
    private var prev: Int = 1
    
    // Others
    private var loading = false
    private var lastDataLoadedEmpty = false
    private var selectedNewsId = 0
    private var loadMore = false
    
    // View Lifecycles
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        newsTV.delegate = self
        newsTV.dataSource = self
        let footer = UIView()
        footer.backgroundColor = #colorLiteral(red: 0.9814968705, green: 0.9760531783, blue: 1, alpha: 1)
        newsTV.tableFooterView = footer
        
        presenter = NewsPresenter(siraniApiServices: SiraniApiServices())
        presenter.attachView(view: self)
        loadData()
    }
    
    override func viewWillAppear(_ animated: Bool) {
        presenter.attachView(view: self)
    }
    
    override func viewDidDisappear(_ animated: Bool) {
        presenter.detachView()
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let detailsVC = segue.destination as? NewsDetailVC {
            detailsVC.newsId = selectedNewsId
            detailsVC.segueId = detailsVC.SEGUE_NEWS_LIST_ID
        }
        
        if let searchVC = segue.destination as? SearchNewsVC {
            searchVC.delegate = self
        }
    }
    
    // private functions
    private func loadData() {
        if !loading && !lastDataLoadedEmpty {
            if ConnectionHelper.isConnectedToNetwork() {
                presenter.loadData(cursor: cursor, prev: prev, jenis: jenis, columns: columns, keyword: keyword)
            } else {
                showNoConnection()
            }
        }
    }

    // Actions
    @IBAction func onBtnBackTap(_ sender: Any) {
        performSegue(withIdentifier: unwindToHomeId, sender: self)
    }
    
    @IBAction func onBtnSearchTap(_ sender: Any) {
        performSegue(withIdentifier: searchSegueId, sender: self)
    }
    
    @IBAction func unwindToNewsList(segue: UIStoryboardSegue) {}
}

// News View Delegate
extension NewsVC: NewsViewDelegate {
    func showNoConnection() {
        let alertNoConnection = UIAlertController(
            title: alertNoConnectionTitle,
            message: alertNoConnectionMsg,
            preferredStyle: .alert
        )
        alertNoConnection.addAction(
            UIAlertAction(title: alertNoConnectionActionYes, style: .default, handler: nil)
        )
        self.present(alertNoConnection, animated: true, completion: nil)
    }
    
    func showLoading() {
        loading = true
        progressLoading.show()
    }
    
    func hideLoading() {
        loading = false
        progressLoading.hide()
    }
    
    func showNoDataLayout() {
        if cursor == 0 {
            layoutNoData.show()
        }
    }
    
    func hideNoDataLayout() {
        layoutNoData.hide()
    }
    
    func setDataList(dataList: [News]) {
        if cursor == 0 {
            layoutNoData.hide()
        }
        
        if dataList.count > 0 {
            
            for data in dataList {
                self.dataList.append(data)
                newsTV.beginUpdates()
                newsTV.insertRows(
                    at: [IndexPath(row: self.dataList.count-1, section: 0)],
                    with: .none
                )
                newsTV.endUpdates()
            }
            
            let totalData = dataList.count
            cursor += totalData
            loadMore = true
        } else {
            lastDataLoadedEmpty = true
            loadMore = false
        }
    }
}

// Table View Delegate
extension NewsVC: UITableViewDelegate, UITableViewDataSource, UIScrollViewDelegate {
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return dataList.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if tableView == newsTV {
            if let cell = tableView.dequeueReusableCell(withIdentifier: newsCellId, for: indexPath) as? NewsCell {
                
                let news = dataList[indexPath.row]
                cell.updateViews(news: news)
                
                return cell
            } else {
                return NewsCell()
            }
        } else {
            return NewsCell()
        }
    }
    
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        print("KUY")
        let selectedNews = dataList[indexPath.row]
        selectedNewsId = selectedNews.id
        performSegue(withIdentifier: detailSegueId, sender: self)
    }
    
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        let threshold = -5
        let contentOffset = scrollView.contentOffset.y
        let maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height;
        
        if loadMore && !loading && (Int(maximumOffset - contentOffset) <= threshold) {
            loadData()
        }
    }
}

// Search Delegate Protocols
extension NewsVC: SearchNewsDelegate {
    func onSearch(search: String, parameter: String, jenis: String) {
        presenter.attachView(view: self)
        
        loadMore = false
        loading = false
        lastDataLoadedEmpty = false
        
        self.cursor = 0
        self.prev = 1
        self.keyword = search
        self.jenis = jenis
        self.columns = parameter
        
        dataList.removeAll()
        newsTV.reloadData()
        
        loadData()
    }
}