//
//  NotificationsTableViewController.swift
//  Tusker
//
//  Created by Shadowfacts on 9/2/18.
//  Copyright © 2018 Shadowfacts. All rights reserved.
//

import UIKit
import Pachyderm

class NotificationsTableViewController: UITableViewController {
    
    let router: AppRouter
    
    var notifications: [Pachyderm.Notification] = [] {
        didSet {
            DispatchQueue.main.async {
                self.tableView.reloadData()
            }
        }
    }
    
    var newer: RequestRange?
    var older: RequestRange?
    
    init(router: AppRouter) {
        self.router = router
        
        super.init(style: .plain)
        
        self.title = "Notifications"
        self.refreshControl = UIRefreshControl()
        refreshControl!.addTarget(self, action: #selector(refreshNotifications(_:)), for: .valueChanged)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        tableView.rowHeight = UITableView.automaticDimension
        tableView.estimatedRowHeight = 140
        
        tableView.register(UINib(nibName: "StatusTableViewCell", bundle: nil), forCellReuseIdentifier: "statusCell")
        tableView.register(UINib(nibName: "ActionNotificationTableViewCell", bundle: nil), forCellReuseIdentifier: "actionCell")
        tableView.register(UINib(nibName: "FollowNotificationTableViewCell", bundle: nil), forCellReuseIdentifier: "followCell")
        
        let request = MastodonController.client.getNotifications()
        MastodonController.client.run(request) { result in
            guard case let .success(notifications, pagination) = result else { fatalError() }
            self.notifications = notifications
            MastodonCache.addAll(statuses: notifications.compactMap { $0.status })
            MastodonCache.addAll(accounts: notifications.map { $0.account })
            self.newer = pagination?.newer
            self.older = pagination?.older
        }
        
        registerForPreviewing(with: self, sourceView: view)
        
        userActivity = UserActivityManager.checkNotificationsActivity()
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        for cell in tableView.visibleCells {
            if let cell = cell as? PreferencesAdaptive {
                cell.updateUIForPreferences()
            }
        }
    }

    // MARK: - Table view data source

    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

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

    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let notification = notifications[indexPath.row]
        
        switch notification.kind {
        case .mention:
            guard let cell = tableView.dequeueReusableCell(withIdentifier: "statusCell", for: indexPath) as? StatusTableViewCell else { fatalError() }
            let status = notification.status!
            cell.updateUI(for: status.id)
            cell.delegate = self
            return cell
        case .favourite, .reblog:
            guard let cell = tableView.dequeueReusableCell(withIdentifier: "actionCell", for: indexPath) as? ActionNotificationTableViewCell else { fatalError() }
            cell.updateUI(for: notification)
            cell.delegate = self
            return cell
        case .follow:
            guard let cell = tableView.dequeueReusableCell(withIdentifier: "followCell", for: indexPath) as? FollowNotificationTableViewCell else { fatalError() }
            cell.updateUI(for: notification)
            cell.delegate = self
            return cell
        }
    }
 

    override func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
        if indexPath.row == notifications.count - 1 {
            guard let older = older else { return }
            
            let request = MastodonController.client.getNotifications(range: older)
            MastodonController.client.run(request) { result in
                guard case let .success(newNotifications, pagination) = result else { fatalError() }
                self.older = pagination?.older
                self.notifications.append(contentsOf: newNotifications)
            }
        }
    }
    
    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        return tableView.cellForRow(at: indexPath) is TableViewSwipeActionProvider
    }
    
    override func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
        return (tableView.cellForRow(at: indexPath) as? TableViewSwipeActionProvider)?.leadingSwipeActionsConfiguration()
    }
    
    override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
        return (tableView.cellForRow(at: indexPath) as? TableViewSwipeActionProvider)?.trailingSwipeActionsConfiguration()
    }
    
    @objc func refreshNotifications(_ sender: Any) {
        guard let newer = newer else { return }
        
        let request = MastodonController.client.getNotifications(range: newer)
        MastodonController.client.run(request) { result in
            guard case let .success(newNotifications, pagination) = result else { fatalError() }
            self.newer = pagination?.newer
            MastodonCache.addAll(statuses: newNotifications.compactMap { $0.status })
            self.notifications.insert(contentsOf: newNotifications, at: 0)
            DispatchQueue.main.async {
                self.refreshControl?.endRefreshing()
                
                // maintain the current position in the list (don't scroll to top)
                self.tableView.scrollToRow(at: IndexPath(row: newNotifications.count, section: 0), at: .top, animated: false)
            }
        }
    }

}

extension NotificationsTableViewController: StatusTableViewCellDelegate {}