Privado-iOS/iOS/Privado/Sources/Flows/ServersFlow/Submodules/Upgrade/View/UpgradeView.swift

//
//  UpgradeView.swift
//  PrivadoVPN
//
//  Created by Zhandos Bolatbekov on 29.01.2021.
//  Copyright © 2021 Privado LLC. All rights reserved.
//

import Foundation
import UIKit

final class UpgradeView: UIViewController, UpgradeViewInput {
    
    private enum Constants {
        
        enum Color {
            static let background = UIColor(rgb: 0x03072a).withAlphaComponent(0.9)
            static let titleText = UIColor.white
            static let bodyText = UIColor(rgb: 0x7a85be)
            static let actionButtonBackground = UIColor(rgb: 0xff8f00)
            static let actionButtonText = UIColor.white
        }
        
        enum Font {
            static let title = UIFont(name: "SFProText-Light", size: 30)
            static let body = UIFont(name: "SFProText-Regular", size: 21.3)
            static let actionButtonText = UIFont(name: "Roboto-Black", size: 21.3)
        }
        
        enum Geometry {
            static let bodyHorizontalOffset: CGFloat = 24
            static let titleBottom: CGFloat = 17
            static let titleHorizontalOffset: CGFloat = 24
            static let actionButtonCornerRadius: CGFloat = 33.3
            static let actionButtonHeight: CGFloat = 60.7
            static let actionButtonHorizontalOffset: CGFloat = 31.7
            static let actionButtonTop: CGFloat = 35.7
        }
        
        enum LocalizedString {
            static let actionButtonText = "upgrade.actionButton.title"
        }
    }
    
    private let output: UpgradeViewOutput
    private var titleLabel: UILabel?
    private var bodyLabel: UILabel?
    private var actionButton: UIButton?
    
    // MARK: - Init
    
    init(output: UpgradeViewOutput) {
        self.output = output
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - Lifecycle
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.output.viewIsReady()
        self.configureUI()
    }
    
    override func loadView() {
        let view = UIView(frame: .zero)
        view.autoresizesSubviews = true
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = Constants.Color.background
        self.view = view
    }
    
    // MARK: - UpgradeViewInput
    
    func set(title: String?, body: String?) {
        self.titleLabel?.text = title
        self.bodyLabel?.text = body
        self.view.isHidden = false
        self.parent?.view.bringSubviewToFront(self.view)
    }
    
    func hide() {
        self.view.isHidden = true
    }
    
    func showLoader(_ show: Bool) {
        if show {
            LoaderView.shared.startAnimation()
        } else {
            LoaderView.shared.stopAnimation()
        }
        self.actionButton?.isEnabled = !show
    }
    
    // MARK: - Private
    
    private func configureUI() {
        
        let bodyLabel = self.initializeBodyLabel()
        self.bodyLabel = bodyLabel
        NSLayoutConstraint.activate([
            bodyLabel.centerYAnchor.constraint(equalTo: self.view.centerYAnchor),
            bodyLabel.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: Constants.Geometry.bodyHorizontalOffset),
            bodyLabel.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: -Constants.Geometry.bodyHorizontalOffset)
        ])
        
        let titleLabel = self.initializeTitleLabel()
        self.titleLabel = titleLabel
        NSLayoutConstraint.activate([
            titleLabel.bottomAnchor.constraint(equalTo: bodyLabel.topAnchor, constant: -Constants.Geometry.titleBottom),
            titleLabel.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: Constants.Geometry.titleHorizontalOffset),
            titleLabel.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: -Constants.Geometry.titleHorizontalOffset)
        ])
        
        let actionButton = self.initializeActionButton()
        NSLayoutConstraint.activate([
            actionButton.topAnchor.constraint(equalTo: bodyLabel.bottomAnchor, constant: Constants.Geometry.actionButtonTop),
            actionButton.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: Constants.Geometry.actionButtonHorizontalOffset),
            actionButton.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: -Constants.Geometry.actionButtonHorizontalOffset),
            actionButton.heightAnchor.constraint(equalToConstant: Constants.Geometry.actionButtonHeight)
        ])
    }
    
    private func initializeTitleLabel() -> UILabel {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.numberOfLines = 0
        label.textColor = Constants.Color.titleText
        label.font = Constants.Font.title
        label.textAlignment = .center
        self.view.addSubview(label)
        return label
    }

    private func initializeBodyLabel() -> UILabel {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.numberOfLines = 0
        label.textColor = Constants.Color.bodyText
        label.font = Constants.Font.body
        label.textAlignment = .center
        self.view.addSubview(label)
        return label
    }

    private func initializeActionButton() -> UIButton {
        let actionButton = UIButton(frame: .zero)
        actionButton.translatesAutoresizingMaskIntoConstraints = false
        
        actionButton.layer.cornerRadius = Constants.Geometry.actionButtonCornerRadius
        actionButton.clipsToBounds = true
        
        actionButton.backgroundColor = Constants.Color.actionButtonBackground
        actionButton.setTitleColor(Constants.Color.actionButtonText, for: .normal)
        actionButton.titleLabel?.font = Constants.Font.actionButtonText
        actionButton.setTitle(NSLocalizedString(Constants.LocalizedString.actionButtonText, comment: "OK"), for: .normal)
        actionButton.addTarget(self, action: #selector(self.onActionButtonTouch), for: .touchUpInside)
        self.view.addSubview(actionButton)
        self.actionButton = actionButton
        return actionButton
    }
    
    @objc
    private func onActionButtonTouch() {
        self.output.didTapActionButton()
    }
}