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

//
//  TextField.swift
//  VDS
//
//  Created by Matt Bruce on 3/13/24.
//

import Foundation
import UIKit
import Combine
import VDSColorTokens

@objc(VDSTextField)
open class TextField: UITextField, ViewProtocol {
    
    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    required public init() {
        super.init(frame: .zero)
        initialSetup()
    }
    
    public override init(frame: CGRect) {
        super.init(frame: frame)
        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

    //--------------------------------------------------
    // MARK: - Properties
    //--------------------------------------------------
    /// Key of whether or not updateView() is called in setNeedsUpdate()
    open var shouldUpdateView: Bool = true
    
    open var surface: Surface = .light { didSet { setNeedsUpdate() } }

    /// Array of LabelAttributeModel objects used in rendering the text.
    open var textAttributes: [any LabelAttributeModel]? { didSet { setNeedsUpdate() } }

    /// TextStyle used on the titleLabel.
    open var textStyle: TextStyle { .defaultStyle }

    /// Will determine if a scaled font should be used for the titleLabel font.
    open var useScaledFont: Bool = false { didSet { setNeedsUpdate() } }

    open override var isEnabled: Bool { didSet { setNeedsUpdate() } }
    
    open override var isSelected: Bool { didSet { setNeedsUpdate() } }

    /// State of animating isHighlight.
    public var isHighlighting = false
    
    /// Whether the Control should handle the isHighlighted state.
    open var shouldHighlight: Bool { isHighlighting == false }
    
    /// Whether the Control is highlighted or not.
    open override var isHighlighted: Bool {
        didSet {
            if shouldHighlight {
                isHighlighting = true
                setNeedsUpdate()
                isHighlighting = false
            }
        }
    }
    
    open var textColorConfiguration: AnyColorable = ViewColorConfiguration().with {
        $0.setSurfaceColors(VDSColor.interactiveDisabledOnlight, VDSColor.interactiveDisabledOndark, forDisabled: true)
        $0.setSurfaceColors(VDSColor.elementsPrimaryOnlight, VDSColor.elementsPrimaryOndark, forDisabled: false)
    }.eraseToAnyColorable(){ didSet { setNeedsUpdate() }}
    
    open override var textColor: UIColor? {
        get { textColorConfiguration.getColor(self) }
        set { }
    }
        
    private enum TextSetMode {
        case text
        case attributedText
    }

    private var textSetMode: TextSetMode = .text

    /// :nodoc:
    open override var text: String! {
        get { super.text }
        set {
            // When text is set, we may need to re-style it as attributedText
            // with the correct paragraph style to achieve the desired line height.
            textSetMode = .text
            styleText(newValue)
        }
    }

    /// :nodoc:
    open override var attributedText: NSAttributedString? {
        get { super.attributedText }
        set {
            // When text is set, we may need to re-style it as attributedText
            // with the correct paragraph style to achieve the desired line height.
            textSetMode = .attributedText
            styleAttributedText(newValue)
        }
    }

    /// :nodoc:
    open override var textAlignment: NSTextAlignment {
        didSet {
            if textAlignment != oldValue {
                // Text alignment can be part of our paragraph style, so we may need to
                // re-style when changed
                restyleText()
            }
        }
    }

    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    open func initialSetup() {
        if !initialSetupPerformed {
            initialSetupPerformed = true
            backgroundColor = .clear
            translatesAutoresizingMaskIntoConstraints = false
            accessibilityCustomActions = []
            setup()
            setNeedsUpdate()
        }
    }
    
    
    open func setup() {
        translatesAutoresizingMaskIntoConstraints = false
    }
    
    open func updateView() {
        restyleText()
    }
    
    open func updateAccessibility() {}

    open func reset() {
        shouldUpdateView = false
        surface = .light
        text = nil
        accessibilityCustomActions = []
        shouldUpdateView = true
        setNeedsUpdate()
    }

    //--------------------------------------------------
    // MARK: - Overrides Methods
    //--------------------------------------------------
    /// :nodoc
    open override func textRect(forBounds bounds: CGRect) -> CGRect {
        super.textRect(forBounds: bounds).inset(by: textStyle.edgeInsets)
    }

    /// :nodoc
    open override func editingRect(forBounds bounds: CGRect) -> CGRect {
        super.editingRect(forBounds: bounds).inset(by: textStyle.edgeInsets)
    }

    /// :nodoc
    open override func clearButtonRect(forBounds bounds: CGRect) -> CGRect {
        super.clearButtonRect(forBounds: bounds).offsetBy(dx: -textStyle.edgeInsets.right, dy: 0)
    }

    /// :nodoc
    open override func leftViewRect(forBounds bounds: CGRect) -> CGRect {
        super.leftViewRect(forBounds: bounds).offsetBy(dx: textStyle.edgeInsets.left, dy: 0)
    }

    /// :nodoc
    open override func rightViewRect(forBounds bounds: CGRect) -> CGRect {
        super.rightViewRect(forBounds: bounds).offsetBy(dx: -textStyle.edgeInsets.right, dy: 0)
    }
    
    //--------------------------------------------------
    // MARK: - Private Methods
    //--------------------------------------------------
    private func restyleText() {
        if textSetMode == .text {
            styleText(text)
        } else {
            styleAttributedText(attributedText)
        }
    }

    private func styleText(_ newValue: String!) {
        defer { invalidateIntrinsicContentSize() }
        guard let newValue else {
            // We don't need to use attributed text
            super.attributedText = nil
            super.text = newValue
            return
        }

        accessibilityCustomActions = []

        //create the primary string
        let mutableText = NSMutableAttributedString.mutableText(for: newValue,
                                                                textStyle: textStyle,
                                                                useScaledFont: useScaledFont,
                                                                textColor: textColorConfiguration.getColor(self),
                                                                alignment: textAlignment,
                                                                lineBreakMode: .byWordWrapping)
        
        applyAttributes(mutableText)
                                
        // Set attributed text to match typography
        super.attributedText = mutableText
        
    }

    private func styleAttributedText(_ newValue: NSAttributedString?) {
        defer { invalidateIntrinsicContentSize() }
        guard let newValue = newValue else {
            // We don't need any additional styling
            super.attributedText = newValue
            return
        }
        
        let mutableText = NSMutableAttributedString(attributedString: newValue)

        applyAttributes(mutableText)
        
        // Modify attributed text to match typography
        super.attributedText = mutableText
    }
    
    private func applyAttributes(_ mutableAttributedString: NSMutableAttributedString) {
        if let textAttributes {
            mutableAttributedString.apply(attributes: textAttributes)
        }
    }
}