//
//  ServerPanelPresenter.swift
//  PrivadoVPN
//
//  Created by Juraldinio on 1/31/21.
//  Copyright © 2021 Privado LLC. All rights reserved.
//

import Foundation

enum ServerPanelState {
    case undefined
    case selected(country: String, city: String, flag: String)
    case overqoute(country: String, city: String, flag: String)
}

protocol ServerPanelOutput: AnyObject {
    var updateEmitter: Emitter<Void> { get }
    
    func update(for panel: ServerPanelInput)
    func selectRequired(from panel: ServerPanelInput)
}

protocol ServerPanelInput: AnyObject {
    func update(state: ServerPanelState)
}

final class ServerPanelPresenter {
    
    private weak var output: ServerPanelOutput?
    
    weak var viewInput: ServerPanelViewInput?
    
    // MARK: - Init
    
    init(output: ServerPanelOutput?) {
        self.output = output
        output?.updateEmitter.addReaction { [weak self] in
            guard let self = self else { return false }
            self.output?.update(for: self)
            return true
        }
        
        guard let session = try? Session.instance() else { return }
        
        session.vpnConnectionStateEmitter.addReaction { [weak self, weak session] state, _ in
            guard let session = session else {
                self?.viewInput?.countryCircle(isHighlited: false)
                return self.isExist
            }
            
            self?.viewInput?.countryCircle(isHighlited: state == .connected)
//            self?.viewInput?.selection(enabled: state == .disconnected && session.currentRecord.isExist)
            
            return self.isExist
        }
    }
}

// MARK: - ServerPanelInput

extension ServerPanelPresenter: ServerPanelInput {
    
    func update(state: ServerPanelState) {
        switch state {
        case .undefined:
            self.viewInput?.hide()
        case let .selected(country: countryCode, city: city, flag: flag):
            self.viewInput?.useHandCursor(enable: true)
            self.viewInput?.show(country: CountryResolver.name(from: countryCode), city: city, flag: flag)
        case let .overqoute(country: countryCode, city: city, flag: flag):
            self.viewInput?.useHandCursor(enable: true)
            self.viewInput?.show(country: CountryResolver.name(from: countryCode), city: city, flag: flag)
        }
    }
}

// MARK: - ServerPanelViewOutput

extension ServerPanelPresenter: ServerPanelViewOutput {
    
    func viewIsReady() {
        self.output?.update(for: self)
    }
    
    func viewWillDisappear() {
        
    }
    
    func serverSelectRequired() {
        self.output?.selectRequired(from: self)
    }
}