Extensions for manually adding UIView constraints

extension UIView {
    func addConstraintsWithFormat(_ format: String, views: UIView...) {
        var viewsDictionary = [String: UIView]()

        for (index, view) in views.enumerated() {
            let key = "v\(index)"
            view.translatesAutoresizingMaskIntoConstraints = false
            viewsDictionary[key] = view
        }
        addConstraints(NSLayoutConstraint.constraints(withVisualFormat: format, options: NSLayoutFormatOptions(), metrics: nil, views: viewsDictionary))
    }

    func centerHorizontallyWithOffset(_ subview: UIView, offset: CGFloat) {
        addConstraint(NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerX, multiplier: 1.0, constant: offset))
    }

    // center subview horizontally in view
    func centerHorizontally(_ subview: UIView) {
        addConstraint(NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerX, multiplier: 1.0, constant: 0))
    }
    // combine with centerhorizontally and simply add an optional parameter
    func centerVerticallyWithOffset(_ subview: UIView, offset: CGFloat) {
        addConstraint(NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerY, multiplier: 1.0, constant: offset))
    }

    // center subview vertically in view
    func centerVertically(_ subview: UIView, multiplier: CGFloat = 1.0, offset: CGFloat = 0.0) {
        // from https://autolayoutconstraints.com/
        addConstraint(NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerY, multiplier: multiplier, constant: offset))
    }

    func unCenterVertically(_ subview: UIView) {
        removeConstraint(NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerY, multiplier: 1.0, constant: 0.0))
    }

    // add constraint for width to equal height
    func makeSquare(_ subview: UIView) {
        addConstraint(NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: subview, attribute: NSLayoutAttribute.width, multiplier: 1.0, constant: 0.0))
    }

    // make a subview a percentage from the top of the superview (this)
    func percentFromTop(_ subview: UIView, percent: CGFloat, constant: CGFloat = 0) {
        addConstraint(NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal,
            toItem: self, attribute: NSLayoutAttribute.bottom, multiplier: percent, constant: constant))
    }

    // constrain a child view to its sibling based on the distance between the top of the child to the bottom of the sibling
    func percentFromSibling(_ child: UIView, sibling: UIView, percent: CGFloat, constant: CGFloat = 0) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal,
            toItem: sibling, attribute: NSLayoutAttribute.bottom, multiplier: percent, constant: constant))
    }

    func widthPercentOfParent(_ child: UIView, percent: CGFloat) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.width, multiplier: percent, constant: 0.0))
    }

    func heightPercentOfParent(_ child: UIView, percent: CGFloat) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.height, multiplier: percent, constant: 0.0))
    }

    func widthPercentOfSibling(_ child: UIView, sibling: UIView, percent: CGFloat, offset: CGFloat = 0) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: sibling, attribute: NSLayoutAttribute.width, multiplier: percent, constant: offset))
    }

    func heightPercentOfSibling(_ child: UIView, sibling: UIView, percent: CGFloat, offset: CGFloat = 0) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: sibling, attribute: NSLayoutAttribute.height, multiplier: percent, constant: offset))
    }

    func centerChildVerticallyToSibling(_ child: UIView, sibling: UIView, offset: CGFloat = 0) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: sibling, attribute: NSLayoutAttribute.centerY, multiplier: 1.0, constant: offset))
    }

    func centerChildHorizontallyToSibling(_ child: UIView, sibling: UIView, offset: CGFloat = 0) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: sibling, attribute: NSLayoutAttribute.centerY, multiplier: 1.0, constant: offset))
    }

    func centerChildToSibling(_ child: UIView, sibling: UIView) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: sibling, attribute: NSLayoutAttribute.centerX, multiplier: 1.0, constant: 0.0))
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: sibling, attribute: NSLayoutAttribute.centerY, multiplier: 1.0, constant: 0.0))
    }

    func spaceVerticallyFromSibling(_ child: UIView, sibling: UIView, constant: CGFloat = 20, percent: CGFloat = 1) {
        addConstraint(NSLayoutConstraint(item: child, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: sibling, attribute: NSLayoutAttribute.bottom, multiplier: percent, constant: constant))
    }

    func fillAndCenter(_ child: UIView) {
        addConstraintsWithFormat("V:|[v0]|", views: child)
        addConstraintsWithFormat("H:|[v0]|", views: child)
    }

    func makeRound() {
        layer.cornerRadius = frame.width / 2
        clipsToBounds = true
        //layer.masksToBounds = true
    }

    // add multiple subviews at once
    func addSubviews(_ views: UIView...) {
        for (_, view) in views.enumerated() {
            addSubview(view)
        }
    }
}