magicConstraints.swift

//
//  MagicConstraints+UIView.swift
//  ArctouchQuizChallengeß
//
//  Created by Alcides Junior on 13/01/20.
//  Copyright © 2020 Alcides Junior. All rights reserved.
//

//USAGE EXAMPLE
startButton
            .magicTop(16, scoreLabel.bottomAnchor)
            .magicBottom(16, coverBottomView.bottomAnchor)
            .magicRight(0, safeArea.trailingAnchor)
            .magicLeft(0, safeArea.leadingAnchor)
//

import UIKit

extension UIView{
    
    fileprivate func priorityIsntZero(priority: Float)->Bool{
        if priority >= 100{
            return true
        }
        return false
    }
    
    @discardableResult
    func magicTop(_ padding:CGFloat = 0, _ from:NSLayoutYAxisAnchor? = nil, _ priority: Float = 0) -> Self{
        self.translatesAutoresizingMaskIntoConstraints = false
        if from == nil {
           let topAnchored = topAnchor.constraint(equalTo: topAnchor, constant: padding)
            if priorityIsntZero(priority: priority){
                topAnchored.priority = UILayoutPriority(rawValue: priority)
            }
            topAnchored.isActive = true
        }else{
            if let from = from{
                let topAnchored = topAnchor.constraint(equalTo: from, constant: padding)
                if priorityIsntZero(priority: priority){
                    topAnchored.priority = UILayoutPriority(rawValue: priority)
                }
                topAnchored.isActive = true
            }
        }
        
        return self
    }
    
    
    @discardableResult
    func magicLeft(_ padding:CGFloat = 0, _ from:NSLayoutXAxisAnchor? = nil, _ priority:Float = 100) -> Self{
        self.translatesAutoresizingMaskIntoConstraints = false
        
        if from == nil {
            let leftAnchored = leadingAnchor.constraint(equalTo: leadingAnchor, constant: padding)
            if priorityIsntZero(priority: priority){
                leftAnchored.priority = UILayoutPriority(rawValue: priority)
            }
            leftAnchored.isActive = true
            
        }else{
            if let from = from{
                let leftAnchored = leadingAnchor.constraint(equalTo: from, constant: padding)
                if priorityIsntZero(priority: priority){
                    leftAnchored.priority = UILayoutPriority(rawValue: priority)
                }
                leftAnchored.isActive = true
            }
        }
        
        return self
    }
    
    @discardableResult
    func magicRight(_ padding:CGFloat = 0, _ from:NSLayoutXAxisAnchor? = nil, _ priority:Float = 100) -> Self{
        self.translatesAutoresizingMaskIntoConstraints = false
        
        if from == nil {
            let rightAnchored = trailingAnchor.constraint(equalTo: trailingAnchor, constant: -padding)
            if priorityIsntZero(priority: priority){
                rightAnchored.priority = UILayoutPriority(rawValue: priority)
            }
            rightAnchored.isActive = true
        }else{
            if let from = from{
                let rightAnchored = trailingAnchor.constraint(equalTo: from, constant: -padding)
                if priorityIsntZero(priority: priority){
                    rightAnchored.priority = UILayoutPriority(rawValue: priority)
                }
                rightAnchored.isActive = true
            }
        }
        
        return self
    }
    
    @discardableResult
    func magicBottom(_ padding:CGFloat = 0, _ from:NSLayoutYAxisAnchor? = nil, _ priority:Float = 100) -> Self{
        translatesAutoresizingMaskIntoConstraints = false
        if from == nil {
            let bottomAnchored = bottomAnchor.constraint(equalTo: bottomAnchor, constant: -padding)
            if priorityIsntZero(priority: priority){
                bottomAnchored.priority = UILayoutPriority(rawValue: priority)
            }
            bottomAnchored.isActive = true
        }else{
            if let from = from{
                let bottomAnchored = bottomAnchor.constraint(equalTo: from, constant: -padding)
                if priorityIsntZero(priority: priority){
                    bottomAnchored.priority = UILayoutPriority(rawValue: priority)
                }
                bottomAnchored.isActive = true
            }
        }
        
        return self
    }
    
    @discardableResult
    func magicCenterX(_ padding:CGFloat = 0, _ from:NSLayoutXAxisAnchor? = nil) -> Self{
        translatesAutoresizingMaskIntoConstraints = false
        if from == nil {
            centerXAnchor.constraint(equalTo: centerXAnchor, constant: padding).isActive = true
        }else{
            if let from = from{
                centerXAnchor.constraint(equalTo: from, constant: padding).isActive = true
            }
        }
        
        return self
    }
    
    @discardableResult
    func magicCenterY(_ padding:CGFloat = 0, _ from:NSLayoutYAxisAnchor? = nil) -> Self{
        translatesAutoresizingMaskIntoConstraints = false
        if from == nil {
            centerYAnchor.constraint(equalTo: centerYAnchor, constant: padding).isActive = true
        }else{
            if let from = from{
                centerYAnchor.constraint(equalTo: from, constant: padding).isActive = true
            }
        }
        
        return self
    }
    
    @discardableResult
    func magicWidth(_ width:CGFloat = 0, _ priority: Float = 100) -> Self{
        translatesAutoresizingMaskIntoConstraints = false
        let widthAnchored = widthAnchor.constraint(equalToConstant: width)
        if priorityIsntZero(priority: priority){
            widthAnchored.priority = UILayoutPriority(rawValue: priority)
        }
        widthAnchored.isActive = true
        return self
    }
    
    @discardableResult
    func magicHeight(_ height:CGFloat = 0, _ priority: Float = 100) -> Self{
        translatesAutoresizingMaskIntoConstraints = false
        let heightAnchored = heightAnchor.constraint(equalToConstant: height)
        if priorityIsntZero(priority: priority){
            heightAnchored.priority = UILayoutPriority(rawValue: priority)
        }
        heightAnchored.isActive = true
        return self
    }
}