//
//  DropDownButton.swift
//  PrivadoVPN
//
//  Created by Zhandos Bolatbekov on 25.05.2021.
//  Copyright © 2021 Privado LLC. All rights reserved.
//

final class DropDownButton: NSButton {
    
    // swiftlint:disable nesting
    enum Constants {
        enum Font {
            enum Name {
                static let title = PrivadoConstants.Font.semiBold
            }
            enum Size {
                static let title: CGFloat = 10
            }
        }
        enum Color {
            static let text = NSColor(red: 122, green: 134, blue: 190)
            static let activeText = NSColor.white
            static let background = NSColor(red: 45, green: 51, blue: 82)
        }
        enum Geometry {
            static let height: CGFloat = 37
            static let iconSize = CGSize(width: 8, height: 5)
        }
        enum Image {
            static let arrowUp = "countryArrowUp"
            static let arrowDown = "countryArrowDown"
        }
    }
    // swiftlint:enable nesting
    
    private let text: String
    private var isActive: Bool
    private var arrowUp: Bool
    
    // MARK: - Init
    
    init(title: String, isActive: Bool = false, arrowUp: Bool = true) {
        self.text = title
        self.isActive = isActive
        self.arrowUp = arrowUp
        
        super.init(frame: .zero)
        
        self.configureUI()
    }
    
    required init?(coder: NSCoder) { nil }
    
    // MARK: - Interface
    
    func set(isActive: Bool) {
        self.isActive = isActive
        self.updateUI()
    }
    
    func set(arrowUp: Bool) {
        self.arrowUp = arrowUp
        self.updateUI()
    }
    
    // MARK: - Private
    
    private func configureUI() {
        self.translatesAutoresizingMaskIntoConstraints = false
        self.isBordered = false
        self.wantsLayer = true
        self.layer?.backgroundColor = .clear
        self.updateUI()
    }
    
    private func updateUI() {
        let icon = NSImage(imageLiteralResourceName: self.arrowUp ? Constants.Image.arrowUp : Constants.Image.arrowDown)
        let font = NSFont(name: Constants.Font.Name.title, size: Constants.Font.Size.title)
            ?? .systemFont(ofSize: Constants.Font.Size.title)
        let attributedTitle = NSMutableAttributedString(
            string: self.text,
            attributes: [.font: font,
                         .foregroundColor: self.isActive ? Constants.Color.activeText : Constants.Color.text]
        )
        
        let textAttachment = NSTextAttachment()
        textAttachment.bounds = CGRect(x: 0,
                                       y: (font.capHeight - Constants.Geometry.iconSize.height).rounded() / 2,
                                       width: Constants.Geometry.iconSize.width,
                                       height: Constants.Geometry.iconSize.height)
        textAttachment.image = icon
        
        attributedTitle.append(NSAttributedString(string: " "))
        attributedTitle.append(NSAttributedString(attachment: textAttachment))
        
        self.attributedTitle = attributedTitle
    }
}