//
//  CustomizableSegmentControl.swift
//  WOKA
//
//  Created by MacBook Pro on 27/05/24.
//

import UIKit

class CustomizableSegmentControl: UISegmentedControl {
    
    private(set) lazy var radius:CGFloat = bounds.height / 2
    
    private let segmentInset: CGFloat = 5
    private let segmentImage: UIImage? = UIImage(color: UIColor.white)
    
    override init(items: [Any]?) {
        super.init(items: items)
        selectedSegmentIndex = 0
    }
    
    required init?(coder: NSCoder) {
//        fatalError("init(coder:) has not been implemented")
        super.init(coder: coder)
    }
    
    
    override func layoutSubviews(){
        super.layoutSubviews()
        
        self.backgroundColor = #colorLiteral(red: 0.01960784314, green: 0, blue: 0.2196078431, alpha: 1)
        
        // selected option color
        self.setTitleTextAttributes([.foregroundColor: UIColor.black, .font : UIFont.systemFont(ofSize: 16, weight: .heavy)], for: .selected)

        // color of other options
        self.setTitleTextAttributes([.foregroundColor: UIColor.white, .font : UIFont.systemFont(ofSize: 16, weight: .heavy)], for: .normal)
        //background
        layer.cornerRadius = radius
        //foreground
        let foregroundIndex = numberOfSegments
        if subviews.indices.contains(foregroundIndex), let foregroundImageView = subviews[foregroundIndex] as? UIImageView{
            foregroundImageView.bounds = foregroundImageView.bounds.insetBy(dx: segmentInset, dy: segmentInset)
            foregroundImageView.image = segmentImage    //substitute with our own colored image
            foregroundImageView.layer.removeAnimation(forKey: "SelectionBounds")    //this removes the weird scaling animation!
            foregroundImageView.layer.masksToBounds = true
            foregroundImageView.layer.cornerRadius = foregroundImageView.bounds.height/2
        }
    }
}

extension UIImage{
    
    //creates a UIImage given a UIColor
    public convenience init?(color: UIColor, size: CGSize = CGSize(width: 1, height: 1)) {
        let rect = CGRect(origin: .zero, size: size)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
        color.setFill()
        UIRectFill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
    
        guard let cgImage = image?.cgImage else { return nil }
        self.init(cgImage: cgImage)
    }
}