UIView+Style.swift

//
//  UIView+Style.swift
//  Created / Copyright © : Mike Johnson, 2020
//

import Foundation
import UIKit

// MARK: - App Size Values

public struct AppSizing {
    static let margin: CGFloat = 20
    static let cornerRadius: CGFloat = 8
}

// MARK: - App Font Values

extension UIFont {
    static let AppBody : UIFont = UIFont.systemFont( ofSize: 24, weight: UIFont.Weight.regular )
}

// MARK: - App Color Values

public struct AppColor {
    private struct Palette {
        static let primaryBlue = UIColor.blue
        static let bodyText = UIColor.black
        static let titleText = UIColor.darkGray
    }

    static let primaryText = Palette.bodyText
    static let secondaryText = Palette.primaryBlue
    static let titleText = Palette.titleText
}

// MARK: - Unused?

protocol Viewable {}
extension Viewable where Self: UIView {
    /// MARK: - Convenience Initializers
    init( background: UIColor, height: CGFloat ) {
        self.init()
        self.backgroundColor = background
        self.height = height
    }
    init( background: UIColor, frame: CGRect ) {
        self.init()
        self.backgroundColor = background
        self.frame = frame
    }
    init( background: UIColor, size : CGSize = CGSize( width: 200, height: 200 ) ) {
        self.init( background: background, frame: CGRect( x: 0, y: 0, width: size.width, height: size.height ) )
    }
    
    func debugStyle() {
        self.backgroundColor = .secondarySystemFill
    }
}
extension UIView: Viewable {}

// MARK: - UIView Extensions

extension UIView {
    enum ViewStyle {
        case normal
        case rounded
    }
    convenience init(style: ViewStyle ) {
        self.init()
        self.style( style )
    }
    @discardableResult func style(_ style: ViewStyle) -> UIView {
        switch style {
        case .normal:
            self.backgroundColor = .white
        case .rounded:
            self.layer.cornerRadius = 8
            self.layer.borderWidth = 0
        }
        
        return self
    }
    @discardableResult func rounded( cornerRadius: CGFloat = AppSizing.cornerRadius ) -> UIView {
        self.layer.cornerRadius = 8
        return self
    }
    @discardableResult func bordered( color: UIColor, width: CGFloat = 1 ) -> UIView {
        self.layer.borderColor = color.cgColor
        self.layer.borderWidth = width
        return self
    }
}


// MARK: - UILabel Extensions

extension UILabel {
    enum Style {
        case body
        case title
    }
    
    convenience init(style: Style) {
        self.init()
        self.style( style )
    }
    
    @discardableResult func style(_ style: Style) -> UILabel {
        switch style {
        case .body:
            self.font = UIFont.systemFont(ofSize: 14, weight: .regular)
        case .title:
            self.font = UIFont.systemFont(ofSize: 24, weight: .bold)
            self.textColor = AppColor.titleText
            self.textAlignment = .center
        }
        
        //self.setContentCompressionResistancePriority(.required, for: .vertical)
        
        // set defaults for sizing
        self.width = superview?.width ?? 300
        self.height = font.pointSize * 1.3
        
        return self
    }
    
}

// MARK: - UIButton Extensions

extension UIButton {
    enum Style {
        case standard
    }
    
    convenience init(style: Style) {
        self.init()
        self.style( style )
    }
    @discardableResult func style(_ style: Style) -> UIButton {
        self.layer.cornerRadius = AppSizing.cornerRadius
        self.titleLabel?.font = UIFont.systemFont(ofSize: 18, weight: .semibold)
        self.setTitleColor( .white, for: .normal )
        self.backgroundColor = .darkGray
        self.size = CGSize( width: 200, height: 44 )
        
        return self
    }
}

// MARK: - UIImageView Extensions

extension UIImageView {
    enum Style {
        case fill
        case fit
    }
    
    convenience init( style: Style ) {
        self.init()
        self.clipsToBounds = true
        if style == .fill {
            self.contentMode = UIView.ContentMode.scaleAspectFill
        } else {
            self.contentMode = UIView.ContentMode.scaleAspectFit
        }
        backgroundColor = UIColor.secondarySystemFill
    }
    convenience init( imageName: String ) {
        if let img = UIImage( named: imageName ) {
            self.init( image: img )
            self.size = img.size
            self.contentMode = UIView.ContentMode.scaleAspectFill
        }
        else {
            self.init()
        }
    }
}

// MARK: - UICollectionView Extensions

extension UICollectionView {
    enum Style {
        case horizontal
        case vertical
    }
    convenience init( style: Style ) {
        let mylayout = UICollectionViewFlowLayout()
        //mylayout.itemSize = itemSize
        mylayout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        mylayout.minimumLineSpacing = 0
        mylayout.minimumInteritemSpacing = 0
        mylayout.scrollDirection = ( style == .horizontal ) ? .horizontal : .vertical
        
        self.init( frame: CGRect.zero, collectionViewLayout: mylayout )
        self.alwaysBounceVertical = ( style == .vertical )
        self.alwaysBounceHorizontal = ( style == .horizontal )
    }
}