//

import UIKit

class AutoSizingStringDrawer: UIView {
	@NSCopying var attributedText = NSAttributedString() {
		didSet {
			self.setNeedsDisplay()
			self.invalidateIntrinsicContentSize()
		}
	}
	
	override func draw(_ rect: CGRect) {
		self.attributedText.draw(with: rect, options: [.truncatesLastVisibleLine, .usesLineFragmentOrigin], context: nil)
	}
	
	override var intrinsicContentSize: CGSize {
		let measuredSize = self.attributedText.boundingRect(
			with: CGSize(width:self.bounds.width, height:10000),
			options: [.truncatesLastVisibleLine, .usesLineFragmentOrigin],
			context: nil).size
		print("Drawer intrinsicContentSize:", measuredSize, "bounds:", bounds.size)
		return CGSize(width: UIView.noIntrinsicMetric, height: measuredSize.height.rounded(.up) + 5)
	}
	
	var currentWidth: CGFloat = 0.0
	override func layoutSubviews() {
		super.layoutSubviews()
		if currentWidth != bounds.width {
			currentWidth = bounds.width
			self.invalidateIntrinsicContentSize()
		}
		print("Drawer layoutSubviews bounds.size", bounds.size)
	}
	
}

class MyLabel: UILabel {
	
	override var intrinsicContentSize: CGSize {
		let sz = super.intrinsicContentSize
		print("MyLabel intrinsicContentSize:", sz, "bounds:", bounds.size)
		return sz
	}
	
	override func layoutSubviews() {
		super.layoutSubviews()
		print("MyLabel layoutSubviews bounds.size:", bounds.size)
	}

}

class StringDrawer: UIView {
	@NSCopying var attributedText = NSAttributedString() {
		didSet {
			self.setNeedsDisplay()
			self.invalidateIntrinsicContentSize()
		}
	}
	
	override func draw(_ rect: CGRect) {
		self.attributedText.draw(with: rect, options: [.truncatesLastVisibleLine, .usesLineFragmentOrigin], context: nil)
	}
	
	override var intrinsicContentSize: CGSize {
		let measuredSize = self.attributedText.boundingRect(
			with: CGSize(width:self.bounds.width, height:10000),
			options: [.truncatesLastVisibleLine, .usesLineFragmentOrigin],
			context: nil).size
		print("Drawer intrinsicContentSize:", measuredSize, "bounds:", bounds.size)
		return CGSize(width: UIView.noIntrinsicMetric, height: measuredSize.height.rounded(.up) + 5)
	}
	
	override func layoutSubviews() {
		super.layoutSubviews()
		print("Drawer layoutSubviews bounds.size", bounds.size)
	}
	
}

class TestViewController: UIViewController {
	
	let testDrawer: StringDrawer = StringDrawer()
	let testLabel: MyLabel = MyLabel()
	
	let testString = "enough text to cause word wrapping to test the intrinsic content size issue."
	
	override func viewDidLoad() {
		super.viewDidLoad()
		
		view.backgroundColor = .yellow
		
		[testDrawer, testLabel].forEach { v in
			v.translatesAutoresizingMaskIntoConstraints = false
			view.addSubview(v)
		}
		
		let g = view.safeAreaLayoutGuide
		
		NSLayoutConstraint.activate([
			testDrawer.topAnchor.constraint(equalTo: g.topAnchor, constant: 100.0),
			testDrawer.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
			testDrawer.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
			
			testLabel.topAnchor.constraint(equalTo: g.topAnchor, constant: 200.0),
			testLabel.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
			testLabel.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
		])
		
		testDrawer.backgroundColor = .cyan
		
		testLabel.backgroundColor = .green
		testLabel.numberOfLines = 0
		
		let drawerString = NSAttributedString(string: "Drawer: " + testString, attributes: [
			.foregroundColor : UIColor.darkText,
			.font : UIFont(name: "Helvetica", size: 14)!
		])
		
		let labelString = NSAttributedString(string: "Label: " + testString, attributes: [
			.foregroundColor : UIColor.darkText,
			.font : UIFont(name: "Helvetica", size: 14)!
		])
		
		testDrawer.attributedText = drawerString
		testLabel.attributedText = labelString
		
	}
	
}

/*
Console output with iPhone 8 / 14.0 / Simulator

Drawer intrinsicContentSize: (513.59765625, 16.1) bounds: (0.0, 0.0)
MyLabel intrinsicContentSize: (65536.0, 16.5) bounds: (0.0, 0.0)
MyLabel intrinsicContentSize: (65536.0, 16.5) bounds: (0.0, 0.0)
MyLabel intrinsicContentSize: (335.0, 32.5) bounds: (0.0, 0.0)
MyLabel intrinsicContentSize: (65536.0, 16.5) bounds: (0.0, 0.0)
MyLabel intrinsicContentSize: (335.0, 32.5) bounds: (0.0, 0.0)
MyLabel layoutSubviews bounds.size: (335.0, 32.5)
MyLabel layoutSubviews bounds.size: (335.0, 32.5)
Drawer layoutSubviews bounds.size (335.0, 22.0)

*/