//
//  ViewController.swift
//  demo
//
//  Created by azun on 6/8/25.
//

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var navBar: UINavigationBar!
    
    private let actionButton: UIButton = {
        let button = UIButton(type: .custom)
        button.configuration = .clearGlass()
        button.setTitle("UIButton", for: .normal)
        button.setTitleColor(.red, for: .normal)
        button.titleLabel?.font = UIFont.systemFont(ofSize: 18, weight: .semibold)
        button.translatesAutoresizingMaskIntoConstraints = false
        return button
    }()
    
    private let toggleButton: UIButton = {
        let button = UIButton(type: .custom)
        button.configuration = .clearGlass()
        button.setTitle("Disable some buttons", for: .normal)
        button.setTitleColor(.blue, for: .normal)
        button.titleLabel?.font = UIFont.systemFont(ofSize: 20, weight: .semibold)
        button.translatesAutoresizingMaskIntoConstraints = false
        return button
    }()
    
    private let pencilButton = UIBarButtonItem(image: UIImage(systemName: "pencil.tip.crop.circle"),
                                               style: .plain,
                                               target: nil,
                                               action: #selector(buttonTapped))
    
    private lazy var pencilLabel: UILabel = makeLabel(for: pencilButton)
    private lazy var eraserLabel: UILabel = makeLabel(for: eraserButton)
    private lazy var trashLabel: UILabel = makeLabel(for: trashButton)
    
    private let eraserButton: UIBarButtonItem = {
        let button = UIBarButtonItem(image: UIImage(systemName: "eraser.fill"),
                                     style: .prominent,
                                     target: nil,
                                     action: #selector(buttonTapped))
        button.tintColor = .red
        return button
    }()
    
    private let trashButton: UIBarButtonItem = {
        let button = UIBarButtonItem(image: UIImage(systemName: "trash.fill"),
                                     style: .prominent,
                                     target: nil,
                                     action: #selector(buttonTapped))
        button.tintColor = .red
        return button
    }()
    
    private lazy var toolbar1 = makeToolbarWith(barButton: pencilButton)
    private lazy var toolbar2 = makeToolbarWith(barButton: eraserButton)
    private lazy var toolbar3 = makeToolbarWith(barButton: trashButton)
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
        setupGradientBackground()
    }
    
    private func setupUI() {
        view.addSubview(toolbar1)
        view.addSubview(toolbar2)
        view.addSubview(toolbar3)
        view.addSubview(pencilLabel)
        view.addSubview(eraserLabel)
        view.addSubview(trashLabel)
        
        view.addSubview(actionButton)
        actionButton.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
        
        view.addSubview(toggleButton)
        toggleButton.addTarget(self, action: #selector(toggleButtonTapped), for: .touchUpInside)
        
        // Center the button using Auto Layout
        NSLayoutConstraint.activate([
            toolbar1.topAnchor.constraint(equalTo: navBar.bottomAnchor, constant: 44),
            toolbar1.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10),
            toolbar1.widthAnchor.constraint(equalToConstant: 100),
            
            pencilLabel.leadingAnchor.constraint(equalTo: toolbar1.trailingAnchor, constant: 10),
            pencilLabel.centerYAnchor.constraint(equalTo: toolbar1.centerYAnchor),
            pencilLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10),
            
            toolbar2.topAnchor.constraint(equalTo: toolbar1.bottomAnchor, constant: 44),
            toolbar2.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10),
            toolbar2.widthAnchor.constraint(equalToConstant: 100),
            
            eraserLabel.leadingAnchor.constraint(equalTo: toolbar2.trailingAnchor, constant: 10),
            eraserLabel.centerYAnchor.constraint(equalTo: toolbar2.centerYAnchor),
            eraserLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10),
            
            toolbar3.topAnchor.constraint(equalTo: toolbar2.bottomAnchor, constant: 44),
            toolbar3.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10),
            toolbar3.widthAnchor.constraint(equalToConstant: 100),
            
            trashLabel.leadingAnchor.constraint(equalTo: toolbar3.trailingAnchor, constant: 10),
            trashLabel.centerYAnchor.constraint(equalTo: toolbar3.centerYAnchor),
            trashLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10),
            
            actionButton.topAnchor.constraint(equalTo: toolbar3.bottomAnchor, constant: 44),
            actionButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            actionButton.heightAnchor.constraint(equalToConstant: 44),
            
            toggleButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            toggleButton.topAnchor.constraint(equalTo: actionButton.bottomAnchor, constant: 44),
            toggleButton.heightAnchor.constraint(equalToConstant: 44),
        ])
    }
    
    @objc private func buttonTapped(sender: Any) {
        toggleButtonTapped()
    }
    
    @objc private func toggleButtonTapped() {
        actionButton.isEnabled.toggle()
        
        pencilButton.isEnabled.toggle()
        pencilButton.hidesSharedBackground = false
        pencilLabel.text = Self.genText(for: pencilButton)
        
        eraserButton.isEnabled.toggle()
        eraserButton.hidesSharedBackground = false
        eraserLabel.text = Self.genText(for: eraserButton)
        
        trashButton.isEnabled.toggle()
        trashButton.hidesSharedBackground = !trashButton.isEnabled
        trashLabel.text = Self.genText(for: trashButton)
        
        toggleButton.setTitle(actionButton.isEnabled ? "Disable some buttons" : "Enable them", for: .normal)
    }
}

private extension ViewController {
    func makeToolbarWith(barButton: UIBarButtonItem) -> UIToolbar {
        let toolbar = UIToolbar()
        toolbar.barStyle = .default
        toolbar.layer.cornerRadius = 22
        toolbar.backgroundColor = .systemCyan.withAlphaComponent(0.3)
        toolbar.translatesAutoresizingMaskIntoConstraints = false
        toolbar.items = [
            UIBarButtonItem.flexibleSpace(),
            barButton,
            UIBarButtonItem.flexibleSpace()
        ]
        return toolbar
    }
    
    func makeLabel(for barButton: UIBarButtonItem) -> UILabel {
        let label = UILabel()
        label.numberOfLines = 0
        label.translatesAutoresizingMaskIntoConstraints = false
        label.text = Self.genText(for: barButton)
        label.font = UIFont.systemFont(ofSize: 18, weight: .regular)
        label.textAlignment = .left
        label.textColor = .white
        return label
    }
    
    static func genText(for button: UIBarButtonItem) -> String {
        " style:\(button.style.name) \n isEnabled:\(button.isEnabled) \n hidesSharedBackground:\(button.hidesSharedBackground)"
    }
    func setupGradientBackground() {
        // Create gradient layer
        let gradientLayer = CAGradientLayer()
        
        // Set gradient frame to match view bounds
        gradientLayer.frame = view.bounds
        
        // Define gradient colors
        let startColor = UIColor(red: 0.2, green: 0.4, blue: 0.3, alpha: 1.0).cgColor
        let endColor = UIColor(red: 0.5, green: 0.2, blue: 0.1, alpha: 1.0).cgColor
        gradientLayer.colors = [startColor, endColor]
        
        // Set gradient direction (top-left to bottom-right)
        gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.0)
        gradientLayer.endPoint = CGPoint(x: 1.0, y: 1.0)
        
        // Insert gradient layer at the bottom of the view's layer stack
        view.layer.insertSublayer(gradientLayer, at: 0)
    }
}

extension UIBarButtonItem.Style {
    var name: String {
        switch self {
        case .plain: return "plain"
        case .done: return "done"
        case .prominent: return "prominent"
        case .bordered: return "bordered"
        @unknown default:
            return "unknown"
        }
    }
}