//
//  TextEntryField.swift
//  VDS
//
//  Created by Matt Bruce on 10/3/22.
//

import Foundation
import UIKit
import VDSTokens
import Combine

/// An input field is an input wherein a customer enters information. They typically appear in forms.
/// Specialized input fields capture credit card numbers, inline actions, passwords, phone numbers,
/// dates and security codes in their correct formats.
@objc(VDSInputField)
open class InputField: EntryFieldBase {
    
    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    required public init() {
        super.init(frame: .zero)
    }
    
    public override init(frame: CGRect) {
        super.init(frame: .zero)
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
    }
    
    //--------------------------------------------------
    // MARK: - Enums
    //--------------------------------------------------
    /// Enum used to describe the input type.
    public enum FieldType: String, CaseIterable {
        case text, number, inlineAction, password, creditCard, tel, date, securityCode
    }
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    internal var inputFieldStackView: UIStackView = {
        return UIStackView().with {
            $0.translatesAutoresizingMaskIntoConstraints = false
            $0.axis = .horizontal
            $0.distribution = .fill
            $0.spacing = 12
        }
    }()
    
    internal var minWidthConstraint: NSLayoutConstraint?
    
    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    /// Label to render the successText.
    open var successLabel = Label().with {
        $0.setContentCompressionResistancePriority(.required, for: .vertical)
        $0.textStyle = .bodySmall
    }
    
    /// UITextField shown in the InputField.
    open var textField = TextField().with {
        $0.translatesAutoresizingMaskIntoConstraints = false
        $0.font = TextStyle.bodyLarge.font
    }
    
    /// Color configuration for the textField.
    open var textFieldTextColorConfiguration: AnyColorable = ViewColorConfiguration().with {
        $0.setSurfaceColors(VDSColor.interactiveDisabledOnlight, VDSColor.interactiveDisabledOndark, forDisabled: true)
        $0.setSurfaceColors(VDSColor.elementsPrimaryOnlight, VDSColor.elementsPrimaryOndark, forDisabled: false)
    }.eraseToAnyColorable()
    
    /// Representing the type of input.
    open var fieldType: FieldType = .text { didSet { setNeedsUpdate() } }
    
    open var leftIcon: Icon = Icon().with { $0.size = .medium }
    
    open var actionTextLink = TextLink().with { $0.contentEdgeInsets = .top(-2) }
    
    open var actionTextLinkModel: TextLinkModel? { didSet { setNeedsUpdate() } }
    
    /// The text of this TextField.
    open var text: String? {
        get { textField.text }
        set {
            textField.text = newValue
            setNeedsUpdate()
        }
    }
    
    /// Value for the textField
    open override var value: String? {
        textField.text
    }
    
    var _showError: Bool = false
    /// Whether not to show the error.
    open override var showError: Bool {
        get { _showError }
        set {
            if !showSuccess && _showError != newValue {
                _showError = newValue
                setNeedsUpdate()
            }
        }
    }

    var _showSuccess: Bool = false
    /// Whether not to show the success.
    open var showSuccess: Bool {
        get { _showSuccess }
        set {
            if !showError && _showSuccess != newValue {
                _showSuccess = newValue
                setNeedsUpdate()
            }
        }
    }
        
    /// Override UIControl state to add the .error state if showSuccess is true and if showError is true.
    open override var state: UIControl.State {
        get {
            var state = super.state
            if showSuccess {
                state.insert(.success)
                
            } else if textField.isFirstResponder {
                state.insert(.focused)
            }
            
            return state
        }
    }
    
    /// If given, this will be shown if showSuccess if true.
    open var successText: String? { didSet { setNeedsUpdate() } }
        
    /// Determines the placement of the helper text.
    open var helperTextPlacement: HelperTextPlacement = .bottom { didSet { setNeedsUpdate() } }

    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    /// Called once when a view is initialized and is used to Setup additional UI or other constants and configurations.
    open override func setup() {
        super.setup()

        minWidthConstraint = containerView.widthAnchor.constraint(greaterThanOrEqualToConstant: 0)
        minWidthConstraint?.isActive = true
        
        // stackview for controls in EntryFieldBase.controlContainerView
        let controlStackView = UIStackView().with {
            $0.translatesAutoresizingMaskIntoConstraints = false
            $0.axis = .horizontal
            $0.spacing = VDSLayout.space3X
        }
        controlContainerView.addSubview(controlStackView)
        controlStackView.pinToSuperView()
        
        controlStackView.addArrangedSubview(leftIcon)
        controlStackView.addArrangedSubview(textField)
        
        textField.heightAnchor.constraint(equalToConstant: 20).isActive = true
        textField
            .textPublisher
            .sink { [weak self] newText in
                print("textPublisher newText: \(newText)")
                self?.text = newText
                self?.validate()
                self?.sendActions(for: .valueChanged)
            }.store(in: &subscribers)
        
        textField
            .publisher(for: .editingDidBegin)
            .sink { [weak self] _ in
                self?.setNeedsUpdate()
            }.store(in: &subscribers)

        textField
            .publisher(for: .editingDidEnd)
            .sink { [weak self] _ in
                self?.validate()
            }.store(in: &subscribers)

        stackView.addArrangedSubview(successLabel)
        stackView.setCustomSpacing(8, after: successLabel)
        
        containerStackView.addArrangedSubview(actionTextLink)
        
        successLabel.textColorConfiguration = primaryColorConfiguration.eraseToAnyColorable()
        
        backgroundColorConfiguration.setSurfaceColors(VDSColor.feedbackSuccessBackgroundOnlight, VDSColor.feedbackSuccessBackgroundOndark, forState: .success)
        borderColorConfiguration.setSurfaceColors(VDSColor.feedbackSuccessOnlight, VDSColor.feedbackSuccessOndark, forState: .success)

    }
    
    /// Resets to default settings.
    open override func reset() {
        super.reset()
        textField.text = ""
        
        successLabel.reset()
        successLabel.textStyle = .bodySmall
        
        fieldType = .text
        showSuccess = false
        successText = nil
        helperTextPlacement = .bottom
    }
    
    /// Container for the area in which the user interacts.
    open override func getContainer() -> UIView {
        inputFieldStackView.addArrangedSubview(containerView)
        return inputFieldStackView
    }

    /// Used to make changes to the View based off a change events or from local properties.
    open override func updateView() {

        //update fieldType first
        updateFieldType()

        super.updateView()
        
        textField.isEnabled = isEnabled
        textField.textColor = textFieldTextColorConfiguration.getColor(self)
    }
    
    open override func updateErrorLabel() {
        super.updateErrorLabel()
        
        //show error or success
        if showError, let _ = errorText {
            successLabel.isHidden = true
            
        } else if showSuccess, let successText {
            successLabel.text = successText
            successLabel.surface = surface
            successLabel.isEnabled = isEnabled
            successLabel.isHidden = false
            errorLabel.isHidden = true
            statusIcon.name = .checkmarkAlt
            statusIcon.color = VDSColor.paletteBlack
            statusIcon.surface = surface
            statusIcon.isHidden = !isEnabled
        } else {
            successLabel.isHidden = true
        }

    }
    open override func updateHelperLabel(){
        //remove first
        helperLabel.removeFromSuperview()
        
        super.updateHelperLabel()

        //set the helper label position
        if helperText != nil {
            if helperTextPlacement == .right {
                inputFieldStackView.spacing = 12
                inputFieldStackView.distribution = .fillEqually
                inputFieldStackView.addArrangedSubview(helperLabel)
            } else {
                inputFieldStackView.spacing = 0
                inputFieldStackView.distribution = .fill
                stackView.addArrangedSubview(helperLabel)
            }
        }
    }
        
    open func updateFieldType() {
        
        var minWidth: CGFloat = 40.0
        var leftIconName: Icon.Name?
        var actionModel: InputField.TextLinkModel?
        var toolTipModel: Tooltip.TooltipModel? = tooltipModel
        var isSecureTextEntry = false
        var rules = [AnyRule<String>]()
        
        if self.isRequired {
            let rule = RequiredRule()
            if let errorText {
                rule.errorMessage = errorText
            }
            rules.append(.init(rule))
        }
        
        switch fieldType {
        case .text:
            break
            
        case .number:
            break
            
        case .inlineAction:
            minWidth = 102.0
            
        case .password:
            let isHide = passwordActionType == .hide
            let buttonText =  isHide ?
            hidePasswordButtonText.isEmpty ? "Hide" : hidePasswordButtonText :
            showPasswordButtonText.isEmpty ? "Show" : showPasswordButtonText
            
            isSecureTextEntry = !isHide
            let nextPasswordActionType = passwordActionType.toggle()
            if let text, !text.isEmpty {
                actionModel = .init(text: buttonText,
                                    onClick: { [weak self] _ in
                    guard let self else { return }
                    self.passwordActionType = nextPasswordActionType
                })
            } else {
                passwordActionType = .show
            }
            minWidth = 62.0
            
        case .creditCard:
            minWidth = 288.0
            
        case .tel:
            minWidth = 176.0
            
        case .date:
            minWidth = 114.0
            
        case .securityCode:
            minWidth = 88.0
            
        }
        
        //textField
        textField.isSecureTextEntry = isSecureTextEntry

        //leftIcon
        leftIcon.surface = surface
        leftIcon.color = iconColorConfiguration.getColor(self)
        leftIcon.name = leftIconName
        leftIcon.isHidden = leftIconName == nil
        
        //actionLink
        actionTextLink.surface = surface
        if let actionModel {
            actionTextLink.text = actionModel.text
            actionTextLink.onClick = actionModel.onClick
            actionTextLink.isHidden = false
            containerStackView.setCustomSpacing(VDSLayout.space2X, after: statusIcon)
        } else {
            actionTextLink.isHidden = true
            containerStackView.setCustomSpacing(0, after: statusIcon)
        }

        //set the width constraints
        if let width, width > minWidth  {
            widthConstraint?.constant = width
            widthConstraint?.isActive = true
            minWidthConstraint?.isActive = false
        } else {
            minWidthConstraint?.constant = minWidth
            widthConstraint?.isActive = false
            minWidthConstraint?.isActive = true
        }
        
        //tooltip
        tooltipModel = toolTipModel
    }
    
    /// Used to update any Accessibility properties.
    open override func updateAccessibility() {
        super.updateAccessibility()
        textField.accessibilityLabel = showError ? "error" : nil
    }
    
    open override var accessibilityElements: [Any]? {
        get {
            var elements = [Any]()
            elements.append(contentsOf: [titleLabel, textField])
            if showError {
                elements.append(statusIcon)
                if let errorText, !errorText.isEmpty {
                    elements.append(errorLabel)
                }
            } else if showSuccess, let successText, !successText.isEmpty {
                elements.append(successLabel)
            }
            
            if let helperText, !helperText.isEmpty {
                elements.append(helperLabel)
            }
            
            return elements
        }
        
        set { super.accessibilityElements = newValue }
    }
    
    open override var canBecomeFirstResponder: Bool { true }

    open override func resignFirstResponder() -> Bool {
        if textField.isFirstResponder {
            textField.resignFirstResponder()
        }
        return super.resignFirstResponder()
    }
    
    //--------------------------------------------------
    // MARK: - Password
    //--------------------------------------------------
    enum PasswordAction {
        case show, hide
        
        func toggle() -> PasswordAction {
            self == .hide ? .show : .hide
        }
    }

    internal var passwordActionType: PasswordAction = .show { didSet { setNeedsUpdate() } }

    open var hidePasswordButtonText: String = "Hide" { didSet { setNeedsUpdate() } }
    open var showPasswordButtonText: String = "Show" { didSet { setNeedsUpdate() } }
}

extension InputField.FieldType {
    
    public var keyboardType: UIKeyboardType {
        switch self {
        case .number:
                .numberPad
        case .tel:
                .phonePad
        case .creditCard:
                .numberPad
        case .date:
                .numberPad
        case .securityCode:
                .numberPad
        default:
                .default
        }
    }
}