Privado-macOS/macOS/Privado/Sources/Flows/PreferenceFlow/Submodules/Header/View/PreferencesHeaderController.swift

//
//  PreferencesHeaderController.swift
//  PrivadoVPN
//
//  Created by Murad Shabanov on 08.02.2022.
//  Copyright © 2022 Privado LLC. All rights reserved.
//

import Foundation

enum PrefHeaderLeftIcon {
    case none
    case back
}

protocol PreferencesHeaderControllerOutput: AnyObject {
    func leftIconAction()
    var title: String { get }
}

final class PreferencesHeaderController: NSViewController {
    
    private enum Constants {
        
        enum Geometry {
            
            static let leading: CGFloat = 100
            static let trailing: CGFloat = 10
            
            static let bellWidthMultiplyer: CGFloat = 0.5
            static let bellHeightMultiplyer: CGFloat = 0.8
        }
        
        enum Color {
            static let background = NSColor(calibratedRed: 25.0 / 255, green: 33.0 / 255, blue: 70.0 / 255, alpha: 1.0)
        }
        
        enum Images {
            static let navigationBack = "navigation.left"
        }
        
    }
    
    private let output: PreferencesHeaderControllerOutput?
    private let icon: PrefHeaderLeftIcon
    
    // UI
    private var imageBackView: View?
    private var leftImageView: ImageView?
    private var titleText: NSTextField?
    
    // MARK: - Init
    
    init(icon: PrefHeaderLeftIcon, output: PreferencesHeaderControllerOutput?) {
        self.output = output
        self.icon = icon
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - Lyfecycle
    
    override func loadView() {
        let view = TopView(frame: .zero)
        view.autoresizesSubviews = true
        view.translatesAutoresizingMaskIntoConstraints = false
        view.wantsLayer = true
        view.viewBackgroundColor = NSColor.clear
        self.view = view
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        
        self.configureUI()
        self.activateLayoutUI()
    }
    
    override func viewDidAppear() {
        super.viewDidAppear()
        
        if let superview = self.view.superview {
            NSLayoutConstraint.activate([
                self.view.topAnchor.constraint(equalTo: superview.topAnchor),
                self.view.leadingAnchor.constraint(equalTo: superview.leadingAnchor),
                self.view.trailingAnchor.constraint(equalTo: superview.trailingAnchor),
                self.view.bottomAnchor.constraint(equalTo: superview.bottomAnchor)
            ])
        }
    }
    
    // MARK: - UI
    
    private func configureUI() {
        
        if self.icon == .back {
            if let image = NSImage(named: Constants.Images.navigationBack) {
                let leftImageView = ImageView(image: image)
                leftImageView.useHandCursor = true
                leftImageView.increaseHitArea = true
                leftImageView.target = self
                leftImageView.action = #selector(self.onBackAction)
                
                let backgroundView = ImageBackgroundView(frame: .zero)
                backgroundView.translatesAutoresizingMaskIntoConstraints = false
                backgroundView.isHoverEnabled = true
                backgroundView.hoverColor = NSColor(red: 29, green: 36, blue: 89)
                self.view.addSubview(backgroundView)
                backgroundView.addSubview(leftImageView)
                self.view.addSubview(leftImageView)
                
                self.leftImageView = leftImageView
                self.imageBackView = backgroundView
            }
        }
        
        if let output = self.output {
            let titleText = NSTextField(frame: .zero)
            titleText.translatesAutoresizingMaskIntoConstraints = false
            titleText.stringValue = output.title
            titleText.backgroundColor = .clear
            titleText.isBezeled = false
            titleText.isEditable = false
            titleText.sizeToFit()
            titleText.textColor = .white
            titleText.font = NSFont(name: PrivadoConstants.Font.semiBold, size: 13.5)
            self.view.addSubview(titleText)
            self.titleText = titleText
        }
    }
    
    private func activateLayoutUI() {
        
        var constraints = [NSLayoutConstraint]()
        
        if let leftImageView = self.leftImageView, let imageBackView = self.imageBackView {
            
            constraints.append(contentsOf: [
                
                imageBackView.widthAnchor.constraint(equalToConstant: 25),
                imageBackView.heightAnchor.constraint(equalToConstant: 25),
                imageBackView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: Constants.Geometry.leading),
                imageBackView.centerYAnchor.constraint(equalTo: self.view.centerYAnchor),
                
                leftImageView.centerXAnchor.constraint(equalTo: imageBackView.centerXAnchor),
                leftImageView.centerYAnchor.constraint(equalTo: imageBackView.centerYAnchor),
                leftImageView.heightAnchor.constraint(equalToConstant: 12),
                leftImageView.widthAnchor.constraint(equalToConstant: 7)
            ])
        }
        
        if let titleText = self.titleText {
            constraints.append(contentsOf: [
                titleText.centerYAnchor.constraint(equalTo: self.view.centerYAnchor),
                titleText.centerXAnchor.constraint(equalTo: self.view.centerXAnchor)
            ])
        }
        
        
        NSLayoutConstraint.activate(constraints)
    }
    
    // MARK: - On Handlers
    
    @objc
    private func onBackAction() {
        self.output?.leftIconAction()
    }
}