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

import Foundation
import UIKit

extension UITapGestureRecognizer {
    
    /// Determines if the touch event has a action attribute within the range given
    /// - Parameters:
    ///   - label: UILabel in question
    ///   - targetRange: Range to look within
    /// - Returns: Wether the range in the label has an action
    public func didTapActionInLabel(_ label: Label, inRange targetRange: NSRange) -> Bool {
        guard let abstractContainer = label.abstractTextContainer() else { return false }
        let location = location(in: label)
        
        let textContainer = abstractContainer.textContainer
        let layoutManager = abstractContainer.layoutManager
        
        let indexOfGlyph = layoutManager.glyphIndex(for: location, in: textContainer)
        let intrinsicWidth = label.intrinsicContentSize.width
        
        // Assert that tapped occured within acceptable bounds based on alignment.
        switch label.textAlignment {
        case .right:
            if location.x < label.bounds.width - intrinsicWidth {
                return false
            }
        case .center:
            let halfBounds = label.bounds.width / 2
            let halfIntrinsicWidth = intrinsicWidth / 2
            
            if location.x > halfBounds + halfIntrinsicWidth {
                return false
            } else if location.x < halfBounds - halfIntrinsicWidth {
                return false
            }
        default: // Left align
            if location.x > intrinsicWidth {
                return false
            }
        }
        
        // Affirms that the tap occured in the desired rect of provided by the target range.
        return layoutManager.boundingRect(forGlyphRange: targetRange, in: textContainer).contains(location)
        && NSLocationInRange(indexOfGlyph, targetRange)
    }
}