CTDLRecipeEditorViewController.swift

//
//  BLOGMainViewController.swift
//  BlogApp
//
//  Created by Steven Troughton-Smith on 30/12/2021.
//  
//

import UIKit


class CTDLTokenAttachmentView: UIView {
	let label = UILabel()
	let contentView = UIView()
	
	init() {
		super.init(frame: .zero)
		
		addSubview(contentView)
		contentView.addSubview(label)
		
		label.font = UIFont.systemFont(ofSize: UIFloat(14))
		
		label.textColor = .white
		contentView.backgroundColor = .systemBlue
		
		contentView.layer.cornerRadius = UIFloat(8)
		contentView.layer.cornerCurve = .continuous
		contentView.layer.masksToBounds = true
		
		isUserInteractionEnabled = false
		
	}
	
	required init?(coder: NSCoder) {
		fatalError("init(coder:) has not been implemented")
	}
	
	// MARK: -
	
	override func layoutSubviews() {
		
		let padding = UIFloat(4)
		var newFrame = bounds
		
		newFrame.origin.y = UIFloat(8)

		contentView.frame = newFrame
		
		label.frame = contentView.bounds.insetBy(dx: padding, dy: padding)
	}
	
	var suggestedBounds: CGRect {
		let padding = UIFloat(4)
		var f = label.frame
		
		f.size.width += padding * 2
		f.size.height += padding * 2

		return f
	}
}

class CTDLTokenAttachmentProvider: NSTextAttachmentViewProvider {
	
	override init(textAttachment: NSTextAttachment, parentView: UIView?, textLayoutManager: NSTextLayoutManager?, location: NSTextLocation) {
		super.init(textAttachment: textAttachment, parentView: parentView, textLayoutManager: textLayoutManager, location: location)
		
		let tv = CTDLTokenAttachmentView()
		
		if let data = textAttachment.contents {
			tv.label.text = String(data: data, encoding: .utf8)
		}
		
		tv.label.sizeToFit()
		textAttachment.bounds = tv.suggestedBounds
		
		view = tv
	}
}

final class CTDLRecipeEditorViewController: UIViewController, UITextViewDelegate, UIPopoverPresentationControllerDelegate {
	
	let textView = UITextView()
	
	let sampleText = """

"""
	
	init() {
		super.init(nibName: nil, bundle: nil)
		
		textView.delegate = self
		textView.font = UIFont.systemFont(ofSize: UIFloat(16))
		
		NSTextAttachment.registerViewProviderClass(CTDLTokenAttachmentProvider.self, forFileType: "public.text")
		
		let attributedString = NSMutableAttributedString(string:sampleText)
		attributedString.setAttributes([.foregroundColor:UIColor.label, .font:textView.font!], range: NSRange(location: 0, length: attributedString.length))
		
		textView.attributedText = attributedString
		
		view.addSubview(textView)
	
	}
	
	// MARK: -
	
	override func viewDidLayoutSubviews() {
		textView.frame = view.bounds
		textView.contentInsetAdjustmentBehavior = .always
	}
	
	func insertToken(string:String) {
		let attachment = NSTextAttachment()
		attachment.fileType = "public.text"
		attachment.contents = string.data(using: .utf8)

		let attachmentString = NSAttributedString(attachment: attachment)
		
		let mutableContents = NSMutableAttributedString(attributedString: self.textView.attributedText)
		
		var selectedRange = textView.selectedRange

		if selectedRange.location + 1 <= textView.attributedText.string.count {
			selectedRange.length = 1
			mutableContents.insert(attachmentString, at: selectedRange.location)
		}
		else {
			mutableContents.append(attachmentString)
		}
		
		textView.attributedText = mutableContents
		
		selectedRange.length = 0
		selectedRange.location += 1
		textView.selectedRange = selectedRange

		textView.layoutManager.invalidateLayout(forCharacterRange: NSRange(location: 0, length: textView.attributedText.length), actualCharacterRange: nil)
		
		textView.becomeFirstResponder()
	}
	
	
}