//
//  SideMenuPresenter.swift
//  PrivadoVPN
//
//  Created by Murad Shabanov on 17.03.2022.
//  Copyright © 2022 Privado LLC. All rights reserved.
//

import Foundation

protocol SideMenuModuleOutput {
    func closeSideMenu()
    var hasUnreadEmitter: Emitter<Bool>? { get }
}

final class SideMenuPresenter: SideMenuControllerOutput {
    
    enum Constants {
        
        enum Image {
            static let dock = "sidemenu-dock"
            static let undock = "sidemenu-undock"
            static let notifications = "sidemenu-notification"
            static let preferences = "sidemenu-preferences"
        }
    }
    
    weak var input: SideMenuControllerInput?
    private var output: SideMenuModuleOutput
    private var hasUnreadNotifications: Bool = false
    
    init(output: SideMenuModuleOutput) {
        self.output = output
        
        UserSettings.shared.isDockedEmitter.addReaction { [weak self] _ in
            self?.input?.reloadBottomItems()
            return self.isExist
        }
        
        self.output.hasUnreadEmitter?.addReaction({ [weak self] value in
            self?.hasUnreadNotifications = value
            self?.input?.reloadBottomItems()
            return self.isExist
        })
        
        guard let session = try? Session.instance() else { return }
        
        session.sessionEmitter.addReaction { [weak self] record -> ShouldContinueReceiveNotifications in
             
            guard record.isExist else {
                self?.output.closeSideMenu()
                return self.isExist
            }
            
            return self.isExist
        }
    }
    
    func itemSelectedAt(index: Int) {
        guard index != -1 else { return }
        let item = sideMenuItems[index].type
        
        var route: Route?
        switch item {
        case .preferences:
            route = .preference(tab: nil)
        case .dock:
            route = UserSettings.shared.isDocked ? .undock : .dock
        case .notification:
            route = .notification
        }
        
        route >>- { openApplicationRoute($0) }
    }
    
    private var sideMenuItems: [SideMenuItem] {
        let dockImage = UserSettings.shared.isDocked ? Constants.Image.undock : Constants.Image.dock
        
        return [
            SideMenuItem(image: dockImage, type: .dock),
            SideMenuItem(image: Constants.Image.notifications, type: .notification(unread: self.hasUnreadNotifications)),
            SideMenuItem(image: Constants.Image.preferences, type: .preferences)
        ]
    }
    
    func sideMenuBottomItem(at index: Int) -> SideMenuItem {
        return self.sideMenuItems[index]
    }
    
    func bottomItemscount() -> Int {
        return self.sideMenuItems.count
    }
    
}