//
//  ToolbarViewController.swift
//  SBrowser
//
//  Created by James Magahern on 7/23/20.
//

import UIKit

class ToolbarButtonView: UIView
{
    private var buttonPadding = CGFloat(24.0)
    private var buttonViews: [UIView] = []
    
    func addButtonView(_ button: UIView) {
        buttonViews.append(button)
        addSubview(button)
        setNeedsLayout()
    }
    
    override func sizeThatFits(_ size: CGSize) -> CGSize {
        let width: CGFloat = buttonViews.reduce(0.0) { (result, button) -> CGFloat in
            return result + button.sizeThatFits(size).width + buttonPadding
        }
        
        return CGSize(width: width, height: size.height)
    }
    
    override func layoutSubviews() {
        var buttonRect = CGRect(origin: .zero, size: CGSize(width: 0, height: bounds.height))
        buttonRect.origin.x = layoutMargins.left
        
        for button in buttonViews {
            let buttonSize = button.sizeThatFits(bounds.size)
            buttonRect.size = CGSize(width: buttonSize.width, height: bounds.height)
            button.frame = buttonRect
            
            buttonRect.origin.x += buttonRect.width + buttonPadding
        }
    }
}

class ToolbarView: UIView
{
    var urlBar: URLBar? { didSet { containerView.addSubview(urlBar!) } }
    
    var cancelButtonVisible: Bool = false { didSet { layoutSubviews() } }
    
    let containerView = UIView(frame: .zero)
    let backgroundView = UIVisualEffectView(effect: UIBlurEffect(style: .systemThickMaterial))
    let buttonsView = ToolbarButtonView(frame: .zero)
    let cancelButton = UIButton(type: .system)
    
    convenience init()
    {
        self.init(frame: .zero)
        addSubview(backgroundView)
        addSubview(containerView)
        
        containerView.addSubview(buttonsView)
        
        cancelButton.setTitle("Cancel", for: .normal)
        containerView.addSubview(cancelButton)
    }
    
    override func sizeThatFits(_ size: CGSize) -> CGSize
    {
        return CGSize(width: size.width, height: 44.0)
    }
    
    override func layoutSubviews()
    {
        super.layoutSubviews()

        backgroundView.frame = bounds
        
        var containerBounds = bounds
        containerBounds.size.height -= safeAreaInsets.bottom
        containerView.frame = containerBounds
        containerView.frame = containerView.frame.insetBy(dx: 8.0, dy: 4.0)
        
        // Cancel button
        let urlBarPadding: CGFloat = 8.0
        let cancelButtonSize = cancelButton.sizeThatFits(containerView.bounds.size)
        cancelButton.frame = CGRect(origin: CGPoint(x: (urlBar?.frame.maxX ?? 0) + urlBarPadding, y: 0),
                                    size: CGSize(width: cancelButtonSize.width, height: containerView.bounds.height))
        
        // Toolbar buttons
        let toolbarSize = buttonsView.sizeThatFits(containerView.bounds.size)
        buttonsView.frame = CGRect(origin: CGPoint(x: (urlBar?.frame.maxX ?? 0) + urlBarPadding, y: 0), size: toolbarSize)
        
        var avoidingSize: CGSize = .zero
        if cancelButtonVisible {
            cancelButton.alpha = 1.0
            buttonsView.alpha = 0.0
            
            avoidingSize = cancelButtonSize
        } else {
            cancelButton.alpha = 0.0
            buttonsView.alpha = 1.0
            
            avoidingSize = toolbarSize
        }
        
        if let urlBar = urlBar {
            urlBar.frame = CGRect(origin: .zero, size: CGSize(width: containerView.bounds.width - avoidingSize.width - urlBarPadding, height: containerView.bounds.height))
        }
    }
}

class ToolbarViewController: UIViewController
{
    let urlBar = URLBar()
    let toolbarView = ToolbarView()
    let scriptControllerIconView = ScriptControllerIconView()
    let shareButton = UIButton(frame: .zero)
    let darkModeButton = UIButton(frame: .zero)
    
    init() {
        super.init(nibName: nil, bundle: nil)
        
        toolbarView.urlBar = urlBar
        
        darkModeButton.setImage(UIImage(systemName: "moon.circle"), for: .normal)
        toolbarView.buttonsView.addButtonView(darkModeButton)
        
        shareButton.setImage(UIImage(systemName: "square.and.arrow.up"), for: .normal)
        toolbarView.buttonsView.addButtonView(shareButton)
        toolbarView.buttonsView.addButtonView(scriptControllerIconView)
        
        let toolbarAnimationDuration: TimeInterval = 0.3
        urlBar.textField.addAction(.init(handler: { _ in
            UIView.animate(withDuration: toolbarAnimationDuration) {
                self.toolbarView.cancelButtonVisible = self.urlBar.textField.isFirstResponder
            }
        }), for: [ .editingDidBegin, .editingDidEnd ])
        
        toolbarView.cancelButton.addAction(.init(handler: { action in
            self.urlBar.textField.resignFirstResponder()
        }), for: .touchUpInside)
    }
    
    override func loadView() {
        self.view = toolbarView
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}