//
//  MainController.swift
//  PrivadoVPN
//
//  Created by Juraldinio on 1/27/21.
//  Copyright © 2021 Privado LLC. All rights reserved.
//

import Foundation
import AppKit

protocol MainControllerOutput: AnyObject {
    func viewIsReady()
}

protocol MainControllerInput: AnyObject {
    func loading(progress: Bool)
    func activate(components: [MainControllerComponent])
}

enum MainControllerComponent: CaseIterable {
    case notification
    case connection
    case servers
    case killswitch
    case remaining
}

final class MainController: NSViewController {
    
    typealias HeaderCreationClosure = () -> NSViewController
    typealias ComponentCreationClosure = (MainControllerComponent) -> NSView
    
    private enum Constants {
        
        enum Geometry {
            // static let logoHeight: CGFloat = 87
            static let progressSize = CGSize(width: 120, height: 120)
            static let textHeight: CGFloat = 20
            static let textTopSpace: CGFloat = 5
        }
        
        enum Color {
            static let background = NSColor(red: 81, green: 88, blue: 193)
            static let activityTitle = NSColor(red: 122, green: 134, blue: 190)
        }
        
        enum Font {
            
            // swiftlint:disable nesting
            enum Name {
                static let activityTitle = PrivadoConstants.Font.light
            }
            
            enum Size {
                static let activityTitle: CGFloat = 14
            }
            // swiftlint:enable nesting
        }
        
        enum Image {
            static let background = "map.background"
        }
    }
    
    private let output: MainControllerOutput
    private var headerCreationClosure: HeaderCreationClosure
    private var componentCreationClosure: ComponentCreationClosure
    
    private lazy var activityIndicator: ITProgressIndicator = {
        let indicator = ITProgressIndicator(frame: CGRect(x: 0, y: 0, width: 50, height: 50))
        indicator.color = .white
        indicator.hideWhenStopped = true
        indicator.lengthOfLine = 13
        indicator.widthOfLine = 5
        indicator.numberOfLines = 9
        indicator.innerMargin = 8
        indicator.translatesAutoresizingMaskIntoConstraints = false
        return indicator
    }()
    
    private lazy var loader = PrivadoLoader(frame: .zero, isButton: false)
    private var header: NSViewController?
    private var firstLoading = true
    private var backgroundImageView: ImageView
    
    // MARK: - JSNavigationBarViewControllerProvider
    
    var navigationController: JSNavigationController?
    
    // MARK: - Init
    
    init(output: MainControllerOutput, headerCreation: @escaping HeaderCreationClosure, componentCreation: @escaping ComponentCreationClosure) {
        self.output = output
        self.headerCreationClosure = headerCreation
        self.componentCreationClosure = componentCreation
        self.backgroundImageView = ImageView()
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - Lyfecycle
    
    override func loadView() {
        
        let view = NSView(frame: .zero)
        view.autoresizesSubviews = true
        view.translatesAutoresizingMaskIntoConstraints = false
        view.wantsLayer = true
        view.layer?.backgroundColor = Constants.Color.background.cgColor
        self.view = view
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.output.viewIsReady()
    }
    
    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)
            ])
        }
        
        self.view.makeKey()
    }
    
    // MARK: - UI
    
    private func configureBackground() {
        if let image = NSImage(named: Constants.Image.background) {
            let coloredImage = image.imageWithTintColor(tintColor: NSColor.black)
            self.backgroundImageView.image = coloredImage
        }
        
        self.backgroundImageView.imageScaling = .scaleNone
        self.view.addSubview(self.backgroundImageView)
        NSLayoutConstraint.activate([
            self.backgroundImageView.topAnchor.constraint(equalTo: self.view.topAnchor, constant: -50),
            self.backgroundImageView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
            self.backgroundImageView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
            self.backgroundImageView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor)
        ])
    }
}

// MARK: - MainControllerInput

extension MainController: MainControllerInput {
    
    func loading(progress: Bool) {
        
        if self.firstLoading {
            
            guard progress else { return }

            self.loader.translatesAutoresizingMaskIntoConstraints = false
            self.loader.arcColor = NSColor(red: 132, green: 138, blue: 217)
            self.loader.keyholeColor = NSColor.white
            self.loader.arcWidth = 5

            self.view.addSubview(self.loader)

            NSLayoutConstraint.activate([
                self.loader.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
                self.loader.centerYAnchor.constraint(equalTo: self.view.centerYAnchor),
                self.loader.heightAnchor.constraint(equalToConstant: Constants.Geometry.progressSize.height),
                self.loader.widthAnchor.constraint(equalToConstant: Constants.Geometry.progressSize.height)
            ])
            
            self.loader.startAnimation(clockwise: false)
            
            self.firstLoading = false
            
        } else {
            
            if !progress {
                self.loader.removeFromSuperview()
            }
        }

    }
    
    func delay(_ delay: Double, closure: @escaping () -> Void) {
        DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: closure)
    }
    
    func activate(components: [MainControllerComponent]) {

        self.loader.removeFromSuperview()
        self.configureBackground()

        let wholeComponents = MainControllerComponent.allCases.count == components.count

        let views = components.map { self.componentCreationClosure($0) }
        views.forEach { self.view.addSubview($0) }
        views.enumerated().forEach { index, view in

            let constraints: [NSLayoutConstraint]

            if index == 0 {

                constraints = [
                    view.topAnchor.constraint(equalTo: self.view.topAnchor),
                    view.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
                    view.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
                ]

            } else if index == views.count - 1, wholeComponents {

                constraints = [
                    view.topAnchor.constraint(equalTo: views[index - 1].bottomAnchor),
                    view.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
                    view.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
                    view.bottomAnchor.constraint(equalTo: self.view.bottomAnchor)
                ]
            } else {
                constraints = [
                    view.topAnchor.constraint(equalTo: views[index - 1].bottomAnchor),
                    view.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
                    view.trailingAnchor.constraint(equalTo: self.view.trailingAnchor)
                ]
            }

            NSLayoutConstraint.activate(constraints)
        }
    }
}

extension MainController: JSNavigationBarViewControllerProvider {

    func navigationBarViewController() -> NSViewController {
        
        if let header = self.header { return header }
        
        let header = self.headerCreationClosure()
        self.header = header
        return header
    }
}