raspberry/iOS/Wallet/Sources/Common/Control/Switch/CommonSwitch.swift

//
//  CommonSwitch.swift
//  Wallet
//
//  Created by Igor on 11.02.2021.
//  Copyright © 2021 AM. All rights reserved.
//

import UIKit

class CommonSwitch: CommonControlCustom {
    
    @IBOutlet private weak var actionBtn: UIButton!
    @IBOutlet private weak var backBtn: UIButton!
    @IBOutlet private weak var backPosition: NSLayoutConstraint!
    @IBOutlet private weak var frontBtn: UIButton!
    @IBOutlet private weak var frontPosition: NSLayoutConstraint!
    @IBOutlet private weak var frontHeight: NSLayoutConstraint!
    private var switchWidth: NSLayoutConstraint!
    
    @IBInspectable var cornerRadius: CGFloat = 10 {
        didSet { updateContent() }
    }
    private var _isSelected: Bool = false
    override open var isSelected: Bool {
        get { _isSelected }
        set { set(isSelected: newValue, animated: false) }
    }
    func set(isSelected: Bool, animated: Bool) {
        guard _isSelected != isSelected else { return }
        _isSelected = isSelected
        update(animated: animated)
    }
    @IBInspectable var frontInset: CGFloat = 0 {
        didSet { updateContent() }
    }
    @IBInspectable var isLight: Bool = false {
        didSet { updateContent() }
    }
    @IBInspectable var isActive: Bool = false {
        didSet { updateContent() }
    }
    @IBInspectable var imageBack: UIImage? {
        didSet { updateContent() }
    }
    @IBInspectable var lzTextBack: String? {
        didSet { updateContent() }
    }
    @IBInspectable var imageBackSelected: UIImage? {
        didSet { updateContent() }
    }
    @IBInspectable var lzTextBackSelected: String? {
        didSet { updateContent() }
    }
    @IBInspectable var imageFront: UIImage? {
        didSet { updateContent() }
    }
    @IBInspectable var lzTextFront: String? {
        didSet { updateContent() }
    }
    @IBInspectable var imageFrontSelected: UIImage? {
        didSet { updateContent() }
    }
    @IBInspectable var lzTextFrontSelected: String? {
        didSet { updateContent() }
    }
    
    @IBInspectable var canChange: Bool = true
    
    func toggle(animated: Bool = true) {
        _isSelected = !isSelected
        update(animated: animated)
    }
    
    private func updateContent() {
        if isActive {
            backgroundColor = isLight ? Asset.marble.color : Asset.deepWater.color
        } else {
            backgroundColor = Asset.disabled.color
        }
        layer.cornerRadius = cornerRadius
        
        backBtn.contentEdgeInsets = .init(top: 0, left: 8, bottom: 0, right: 8)
        frontBtn.contentEdgeInsets = .init(top: 0, left: 8, bottom: 0, right: 8)
        
        frontBtn.backgroundColor = isLight ? Asset.deepWater.color : Asset.snow.color
        frontBtn.layer.cornerRadius = cornerRadius - frontInset
        frontBtn.clipsToBounds = true
        frontBtn.contentEdgeInsets = .init(top: 0, left: 4, bottom: 0, right: 4)
        frontHeight.constant = frame.size.height - frontInset*2
        
        self.isUserInteractionEnabled = isActive
        self.isEnabled = isActive
        
        layoutIfNeeded()
        update(animated: false)
    }
    
    private func update(animated: Bool) {
        backPosition.constant = 0
        frontPosition.constant = 0
        if animated {
            UIView.animate(withDuration: Animation.fastest) {
                self.layoutIfNeeded()
            } completion: { _ in
                self.updateComplete(animated: true)
            }
        } else {
            updateComplete(animated: false)
        }
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        if switchWidth != nil, widthConstraint() != nil {
            updateComplete(animated: true)
        }
    }
    
    private func widthConstraint() -> NSLayoutConstraint? {
        constraints.filter({
            NSStringFromClass($0.classForCoder) != "NSAutoresizingMaskLayoutConstraint"
            && $0.firstAttribute == .width
            && $0.priority.rawValue >= (switchWidth?.priority.rawValue ?? 0)
            && $0 != switchWidth
        }).first
    }
    
    private func updateComplete(animated: Bool) {
        let backTextColor = isLight ? Asset.textGranite.color : Asset.textSnow.color
        let frontTextColor = isLight ? Asset.textSnow.color : Asset.textGranite.color
        
        backBtn.setImage(isSelected ? imageBackSelected : imageBack, for: .normal)
        backBtn.setAttributedTitle(
            (isSelected ? lzTextBackSelected : lzTextBack)?.localized.attributed(style: .medium, size: 14, color: backTextColor),
            for: .normal
        )
        if backBtn.image(for: .normal) != nil, backBtn.attributedTitle(for: .normal) != nil {
            backBtn.titleEdgeInsets = .init(top: 0, left: 4, bottom: 0, right: 0)
            backBtn.imageEdgeInsets = .init(top: 0, left: 0, bottom: 0, right: 4)
        } else {
            backBtn.titleEdgeInsets = .zero
            backBtn.imageEdgeInsets = .zero
        }
        frontBtn.setImage(isSelected ? imageFrontSelected : imageFront, for: .normal)
        frontBtn.setAttributedTitle(
            (isSelected ? lzTextFrontSelected : lzTextFront)?.localized.attributed(style: .medium, size: 14, color: frontTextColor),
            for: .normal
        )
        if frontBtn.image(for: .normal) != nil, frontBtn.attributedTitle(for: .normal) != nil {
            frontBtn.titleEdgeInsets = .init(top: 0, left: 4, bottom: 0, right: 0)
            frontBtn.imageEdgeInsets = .init(top: 0, left: 0, bottom: 0, right: 4)
        } else {
            frontBtn.titleEdgeInsets = .zero
            frontBtn.imageEdgeInsets = .zero
        }
        if let constraint = widthConstraint(), switchWidth != nil {
            removeConstraint(switchWidth)
            switchWidth = constraint
        }
        layoutIfNeeded()
        let width = backBtn.frame.width + frontBtn.frame.width + frontInset*2
        if switchWidth == nil {
            switchWidth = widthConstraint() ?? widthAnchor.constraint(equalToConstant: width)
            switchWidth.isActive = true
        }
        switchWidth.constant = width
        backPosition.constant = (isSelected ? -width + backBtn.frame.width : width - backBtn.frame.width)/2
        frontPosition.constant = (isSelected ? width - frontBtn.frame.width - frontInset*2 : -width + frontBtn.frame.width + frontInset*2)/2
        frontHeight.constant = frame.height - frontInset*2
        animated ? UIView.animate(withDuration: Animation.fastest) { self.layoutIfNeeded() } : layoutIfNeeded()
    }
    
    @IBAction func onChangeState(_: AnyObject?) {
        frontBtn.isHighlighted = actionBtn.isHighlighted
    }
    
    @IBAction func onToggle(_: AnyObject?) {
        frontBtn.isHighlighted = actionBtn.isHighlighted
        if canChange { toggle(animated: true) }
        sendActions(for: .valueChanged)
    }
    
}