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

import Foundation
import UIKit
import VDSColorTokens
import VDSFormControlsTokens
import Combine

open class EntryField<ModelType: EntryFieldModel>: Control<ModelType> {
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    internal var stackView: UIStackView = {
        return UIStackView().with {
            $0.translatesAutoresizingMaskIntoConstraints = false
            $0.axis = .vertical
            $0.distribution = .fill
        }
    }()
        
    internal var titleLabel = Label().with {
        $0.setContentCompressionResistancePriority(.required, for: .vertical)
    }
    
    internal var errorLabel = Label().with {
        $0.setContentCompressionResistancePriority(.required, for: .vertical)
    }
    
    internal var helperLabel = Label().with {
        $0.setContentCompressionResistancePriority(.required, for: .vertical)
    }
    
    internal var containerView: UIView = {
        return UIView().with {
            $0.translatesAutoresizingMaskIntoConstraints = false
        }
    }()
    
    internal var tooltipView: UIView?
    
    //--------------------------------------------------
    // MARK: - Configuration Properties
    //--------------------------------------------------
    // Sizes are from InVision design specs.
    internal let containerSize = CGSize(width: 45, height: 45)
    
    internal let primaryColorConfig =  DisabledSurfaceColorConfiguration().with {
        $0.disabled.lightColor = VDSColor.interactiveDisabledOnlight
        $0.disabled.darkColor = VDSColor.interactiveDisabledOndark
        $0.enabled.lightColor = VDSColor.elementsPrimaryOnlight
        $0.enabled.darkColor = VDSColor.elementsPrimaryOndark
    }
    
    internal let secondaryColorConfig = DisabledSurfaceColorConfiguration().with {
        $0.disabled.lightColor = VDSColor.interactiveDisabledOnlight
        $0.disabled.darkColor = VDSColor.interactiveDisabledOndark
        $0.enabled.lightColor = VDSColor.elementsSecondaryOnlight
        $0.enabled.darkColor = VDSColor.elementsSecondaryOndark
    }
    
    internal lazy var backgroundColorConfiguration: AnyColorable = {
        return getBackgroundConfig()
    }()

    internal lazy var borderColorConfiguration: AnyColorable = {
        return getBorderConfig()
    }()

    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    @Proxy(\.model.labelText)
    open var labelText: String?
    
    @Proxy(\.model.helperText)
    open var helperText: String?
    
    @Proxy(\.model.showError)
    open var showError: Bool
    
    @Proxy(\.model.errorText)
    open var errorText: String?
            
    @Proxy(\.model.tooltipTitle)
    open var tooltipTitle: String?
    
    @Proxy(\.model.tooltipContent)
    open var tooltipContent: String?
    
    @Proxy(\.model.transparentBackground)
    open var transparentBackground: Bool
    
    @Proxy(\.model.width)
    open var width: CGFloat?
    
    @Proxy(\.model.maxLength)
    open var maxLength: Int?
    
    @Proxy(\.model.inputId)
    open var inputId: String?
    
    @Proxy(\.model.value)
    open var value: AnyHashable?
    
    @Proxy(\.model.defaultVaue)
    open var defaultValue: AnyHashable?
    
    @Proxy(\.model.required)
    open var required: Bool
    
    @Proxy(\.model.readOnly)
    open var readOnly: Bool
    
    
    //--------------------------------------------------
    // MARK: - Constraints
    //--------------------------------------------------
    internal var heightConstraint: NSLayoutConstraint?
    internal var widthConstraint: NSLayoutConstraint?
        
    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    open override func setup() {
        super.setup()
        
        //add tapGesture to self
        publisher(for: UITapGestureRecognizer()).sink { [weak self] _ in
            self?.sendActions(for: .touchUpInside)
        }.store(in: &subscribers)
        
        isAccessibilityElement = true
        accessibilityTraits = .button
        addSubview(stackView)
        
        //create the wrapping view
        heightConstraint = containerView.heightAnchor.constraint(greaterThanOrEqualToConstant: containerSize.height)
        heightConstraint?.isActive = true
        
        widthConstraint = containerView.widthAnchor.constraint(equalToConstant: 0)
                
        let container = getContainer()
        stackView.addArrangedSubview(titleLabel)
        stackView.addArrangedSubview(container)
        stackView.addArrangedSubview(errorLabel)
        stackView.addArrangedSubview(helperLabel)

        stackView.setCustomSpacing(4, after: titleLabel)
        stackView.setCustomSpacing(8, after: container)
        stackView.setCustomSpacing(8, after: errorLabel)

        stackView.topAnchor.constraint(equalTo: topAnchor).isActive = true
        stackView.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        stackView.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
        stackView.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
                
        titleLabel.textColorConfiguration = primaryColorConfig.eraseToAnyColorable()
        errorLabel.textColorConfiguration = primaryColorConfig.eraseToAnyColorable()
        helperLabel.textColorConfiguration = secondaryColorConfig.eraseToAnyColorable()
    }
    
    open func getContainer() -> UIView {
        return containerView
    }
    
    open func getBackgroundConfig() -> AnyColorable {
        return ErrorDisabledSurfaceColorConfiguration().with {
            $0.enabled.lightColor = VDSFormControlsColor.backgroundOnlight
            $0.enabled.darkColor = VDSFormControlsColor.backgroundOndark
            $0.disabled.lightColor = VDSFormControlsColor.backgroundOnlight
            $0.disabled.darkColor = VDSFormControlsColor.backgroundOndark
            
            //error doesn't care enabled/disable
            $0.error.lightColor = VDSColor.feedbackErrorBackgroundOnlight
            $0.error.darkColor = VDSColor.feedbackErrorBackgroundOndark
        }.eraseToAnyColorable()
    }
    
    open func getBorderConfig() -> AnyColorable {
        return ErrorDisabledSurfaceColorConfiguration().with {
            $0.enabled.lightColor = VDSFormControlsColor.borderOnlight
            $0.enabled.darkColor = VDSFormControlsColor.borderOnlight
            $0.disabled.lightColor = VDSColor.interactiveDisabledOnlight
            $0.disabled.darkColor = VDSColor.interactiveDisabledOndark
            
            //error doesn't care enabled/disable
            $0.error.lightColor = VDSColor.feedbackErrorOnlight
            $0.error.darkColor = VDSColor.feedbackErrorOndark
        }.eraseToAnyColorable()
    }
    
    open func getToolTipView(viewModel: ModelType) -> UIView? {
        guard let toolTipTitleModel = viewModel.tooltipTitleModel, let toolTipContentModel = viewModel.tooltipContentModel else {
           return nil
        }
        let stack = UIStackView().with {
            $0.translatesAutoresizingMaskIntoConstraints = false
            $0.axis = .vertical
            $0.distribution = .fill
            $0.spacing = 4
        }
        
        let title = Label().with {
            $0.setContentCompressionResistancePriority(.required, for: .vertical)
        }
        title.set(with: toolTipTitleModel)
        
        let content = Label().with {
            $0.setContentCompressionResistancePriority(.required, for: .vertical)
        }
        content.set(with: toolTipContentModel)
        
        stack.addArrangedSubview(title)
        stack.addArrangedSubview(content)
        
        stack.backgroundColor = backgroundColorConfiguration.getColor(viewModel)

        return stack
    }
    
    open func showToolTipView(){
        
    }
    
    public override func reset() {
        super.reset()
        setAccessibilityLabel()
    }
    
    //--------------------------------------------------
    // MARK: - State
    //--------------------------------------------------
    open override func updateView(viewModel: ModelType) {
        
        containerView.backgroundColor = backgroundColorConfiguration.getColor(viewModel)
        containerView.layer.borderColor = borderColorConfiguration.getColor(viewModel).cgColor
        containerView.layer.borderWidth = 1
        containerView.layer.cornerRadius = 4

        updateTitleLabel(viewModel: viewModel)
        updateErrorLabel(viewModel: viewModel)
        updateHelperLabel(viewModel: viewModel)
        
        setAccessibilityHint()
        backgroundColor = viewModel.surface.color
        setNeedsLayout()
        layoutIfNeeded()
    }
    
    open func updateTitleLabel(viewModel: ModelType) {
        //update the title model if the required flag is false
        var titleLabelModel = viewModel.labelModel
            .addOptional(required: viewModel.required, colorConfiguration: secondaryColorConfig)
        
        //tooltip action
        if let view = getToolTipView(viewModel: viewModel) {
            tooltipView = view
            let toolTipAction = PassthroughSubject<Void, Never>()
            titleLabelModel = titleLabelModel.addToolTip(action: toolTipAction, colorConfiguration: primaryColorConfig)
            toolTipAction.sink { [weak self] in
                self?.showToolTipView()
            }.store(in: &subscribers)
        } else {
            tooltipView = nil
        }
        
        titleLabel.set(with: titleLabelModel)
    }
    
    open func updateErrorLabel(viewModel: ModelType){
        if viewModel.showError, let errorLabelModel = viewModel.errorLabelModel {
            errorLabel.set(with: errorLabelModel)
            errorLabel.isHidden = false
        } else {
            errorLabel.isHidden = true
        }
    }
    
    open func updateHelperLabel(viewModel: ModelType){
        //set the helper label position
        if let helperLabelModel = viewModel.helperLabelModel {
            helperLabel.set(with: helperLabelModel)
            helperLabel.isHidden = false
        } else {
            helperLabel.isHidden = true
        }
    }
}

//--------------------------------------------------
// MARK: - Color Class Configurations
//--------------------------------------------------
internal class ErrorDisabledSurfaceColorConfiguration: DisabledSurfaceColorable {
    typealias ModelType = Errorable & Surfaceable & Disabling
    var error = SurfaceColorConfiguration()
    var disabled = SurfaceColorConfiguration()
    var enabled = SurfaceColorConfiguration()
    
    required public init(){}

    func getColor(_ viewModel: any ModelType) -> UIColor {
        //only show error is enabled and showError == true
        let showErrorColor = !viewModel.disabled && viewModel.showError

        if showErrorColor {
            return error.getColor(viewModel)
        } else {
            return getDisabledColor(viewModel)
        }
    }
}

extension DefaultLabelModel {
    public func addOptional(required: Bool, colorConfiguration: DisabledSurfaceColorConfiguration) -> DefaultLabelModel {
        guard let text = text, !required else { return self}
        let optionColorAttr = ColorLabelAttribute(location: text.count + 2,
                                                  length: 8,
                                                  color: colorConfiguration.getColor(self))
        
        let newText = "\(text)  Optional"
        return copyWith {
            $0.text = newText
            $0.attributes = [optionColorAttr]
        }
    }
    
    public func addToolTip(action: PassthroughSubject<Void, Never>, colorConfiguration: DisabledSurfaceColorConfiguration) -> DefaultLabelModel {
        guard let text = text else { return self}
        var newAttributes = attributes ?? []
        let newText = "\(text)  " //create a little space between the final character and tooltip image
        let toolTip = ToolTipLabelAttribute(action: action,
                                            location: newText.count,
                                            length: 1,
                                            tintColor: colorConfiguration.getColor(self))
        newAttributes.append(toolTip)
        return copyWith {
            $0.text = newText
            $0.attributes = newAttributes
        }
    }
}