vds_ios/VDS/Components/TextFields/InputField/TextField.swift

//
//  TextField.swift
//  VDS
//
//  Created by Matt Bruce on 5/1/24.
//

import Foundation
import UIKit
import Combine

@objc(VDSTextField)
open class TextField: UITextField, ViewProtocol, Errorable {
        
    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    required public init() {
        super.init(frame: .zero)
        initialSetup()
    }
    
    public override init(frame: CGRect) {
        super.init(frame: .zero)
        initialSetup()
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
        initialSetup()
    }
    
    //--------------------------------------------------
    // MARK: - Combine Properties
    //--------------------------------------------------
    /// Set of Subscribers for any Publishers for this Control.
    open var subscribers = Set<AnyCancellable>()

    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    private var initialSetupPerformed = false

    private var horizontalPadding: CGFloat = 0

    //--------------------------------------------------
    // MARK: - Properties
    //--------------------------------------------------
    /// Key of whether or not updateView() is called in setNeedsUpdate()
    open var shouldUpdateView: Bool = true
    
    open var surface: Surface = .light { didSet { setNeedsUpdate() } }
    
    open var showError: Bool = false { didSet { setNeedsUpdate() } }
    
    open var errorText: String? { didSet { setNeedsUpdate() } }
    
    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    open func initialSetup() {
        if !initialSetupPerformed {
            initialSetupPerformed = true
            backgroundColor = .clear
            translatesAutoresizingMaskIntoConstraints = false
            setup()
            setNeedsUpdate()
        }
    }
    
    open func setup() {
        let accessView = UIView(frame: .init(origin: .zero, size: .init(width: UIScreen.main.bounds.width, height: 44)))
        accessView.backgroundColor = .white
        accessView.addBorder(side: .top, width: 1, color: .lightGray)
        let done = UIButton(type: .system)
        done.setTitle("Done", for: .normal)
        done.translatesAutoresizingMaskIntoConstraints = false
        done.addTarget(self, action: #selector(doneButtonAction), for: .touchUpInside)
        accessView.addSubview(done)
        done.pinCenterY()
            .pinTrailing(16)
        inputAccessoryView = accessView
    }
    
    @objc func doneButtonAction() {
        // Resigns the first responder status when 'Done' is tapped
        resignFirstResponder()
    }

    open func updateView() {}

    open func updateAccessibility() {
        if let errorText, showError {
            accessibilityLabel = "error, \(errorText)"
        } else {
            accessibilityLabel = nil
        }
    }
    
    open func reset() {
        shouldUpdateView = false
        surface = .light
        text = nil
        shouldUpdateView = true
        setNeedsUpdate()
    }
    
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    open override func textRect(forBounds bounds: CGRect) -> CGRect {
        let rect = super.textRect(forBounds: bounds)
        return rect.insetBy(dx: -horizontalPadding, dy: 0)
    }
    
    open override func editingRect(forBounds bounds: CGRect) -> CGRect {
        let rect = super.editingRect(forBounds: bounds)
        return rect.insetBy(dx: -horizontalPadding, dy: 0)
    }
    
    open override func placeholderRect(forBounds bounds: CGRect) -> CGRect {
        let rect = super.placeholderRect(forBounds: bounds)
        return rect.insetBy(dx: -horizontalPadding, dy: 0)
    }
    
    open override var isSecureTextEntry: Bool {
        didSet {
            if isFirstResponder {
                _ = becomeFirstResponder()
            }
        }
    }
    
    open override func becomeFirstResponder() -> Bool {
        let success = super.becomeFirstResponder()
        if isSecureTextEntry, let text {
            self.text?.removeAll()
            insertText(text)
        }
        return success
    }
}

extension UITextField {
    public func cursorPosition(range: NSRange, replacementString string: String, rawNumber: String, formattedNumber: String) -> UITextPosition? {
        let start = range.location
        let length = string.count
       
        let newCursorLocation = start + length
       
        // Adjust the cursor position to skip over formatting characters
        var formattedCharacterCount = 0
        for (index, character) in formattedNumber.enumerated() {
            if index >= newCursorLocation + formattedCharacterCount {
                break
            }
            if !character.isNumber {
                formattedCharacterCount += 1
            }
        }
       
        let finalCursorLocation = min(newCursorLocation + formattedCharacterCount, formattedNumber.count)
        return position(from: beginningOfDocument, offset: finalCursorLocation)
    }
}