//
//  UILabel.swift
//  VDS
//
//  Created by Matt Bruce on 8/4/22.
//

import Foundation
import UIKit

extension UILabel {
    /**
     Provides a text container and layout manager of how the text would appear on screen.
     They are used in tandem to derive low-level TextKit results of the label.
     */
    public func abstractTextContainer() -> (NSTextContainer, NSLayoutManager, NSTextStorage)? {
        
        // Must configure the attributed string to translate what would appear on screen to accurately analyze.
        guard let attributedText = attributedText else { return nil }
        
        let paragraph = NSMutableParagraphStyle()
        paragraph.alignment = textAlignment
        
        let stagedAttributedString = NSMutableAttributedString(attributedString: attributedText)
        stagedAttributedString.addAttributes([NSAttributedString.Key.paragraphStyle: paragraph], range: NSRange(location: 0, length: attributedText.string.count))
        
        let textStorage = NSTextStorage(attributedString: stagedAttributedString)
        let layoutManager = NSLayoutManager()
        let textContainer = NSTextContainer(size: .zero)
        
        layoutManager.addTextContainer(textContainer)
        textStorage.addLayoutManager(layoutManager)
        
        textContainer.lineFragmentPadding = 0.0
        textContainer.lineBreakMode = lineBreakMode
        textContainer.maximumNumberOfLines = numberOfLines
        textContainer.size = bounds.size
        
        return (textContainer, layoutManager, textStorage)
    }
}