//
//  TitleLockup.swift
//  VDS
//
//  Created by Matt Bruce on 12/19/22.
//

import Foundation
import UIKit
import VDSColorTokens
import Combine

@objc(VDSTitleLockup)
open class TitleLockup: View {
    
    //--------------------------------------------------
    // MARK: - Enums
    //--------------------------------------------------
    public enum TextPosition: String, EnumSubset {
        case left, center
        
        public var defaultValue: VDS.TextPosition { .left }
    }
    
    //--------------------------------------------------
    // 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: - Private Properties
    //--------------------------------------------------
    private var stackView = UIStackView().with {
        $0.translatesAutoresizingMaskIntoConstraints = false
        $0.axis = .vertical
        $0.distribution = .fill
    }
    
    //--------------------------------------------------
    // MARK: - Configuration Properties
    //--------------------------------------------------
    // Sizes are from InVision design specs.
    open var standardStyleConfiguration: StandardStyleConfigurationProvider = StandardStyleConfigurationProvider(styleConfigurations: [
        
            .init(deviceType: .iPad,
              titleStandardStyles: [.titleSmall, .titleMedium],
              spacingConfigurations: [
                .init(otherStandardStyles: [.bodySmall, .bodyMedium, .bodyLarge],
                      topSpacing: VDSLayout.Spacing.space2X.value,
                      bottomSpacing: VDSLayout.Spacing.space2X.value)
              ]),
        
            .init(deviceType: .iPad,
                  titleStandardStyles: [.titleLarge],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.bodyLarge, .bodySmall, .bodyMedium, .titleSmall],
                          topSpacing: VDSLayout.Spacing.space3X.value,
                          bottomSpacing: VDSLayout.Spacing.space3X.value)
                  ]),
        
            .init(deviceType: .iPad,
                  titleStandardStyles: [.titleXLarge],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.titleMedium, .bodyLarge],
                          topSpacing: VDSLayout.Spacing.space3X.value,
                          bottomSpacing: VDSLayout.Spacing.space4X.value)
                  ]),
        
            .init(deviceType: .iPad,
                  titleStandardStyles: [.title2XLarge, .featureXSmall],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.bodyLarge],
                          topSpacing: VDSLayout.Spacing.space3X.value,
                          bottomSpacing: VDSLayout.Spacing.space6X.value),
                    
                        .init(otherStandardStyles: [.titleMedium, .titleLarge],
                              topSpacing: VDSLayout.Spacing.space4X.value,
                              bottomSpacing: VDSLayout.Spacing.space6X.value),
                  ]),
        
            .init(deviceType: .iPad,
                  titleStandardStyles: [.featureSmall, .featureMedium],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.titleLarge, .titleMedium],
                          topSpacing: VDSLayout.Spacing.space4X.value,
                          bottomSpacing: VDSLayout.Spacing.space6X.value),
                    
                        .init(otherStandardStyles: [.bodyLarge],
                              topSpacing: VDSLayout.Spacing.space3X.value,
                              bottomSpacing: VDSLayout.Spacing.space6X.value),
                  ]),
        
            .init(deviceType: .iPhone,
                  titleStandardStyles: [.titleSmall],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.bodySmall, .bodyMedium],
                          topSpacing: VDSLayout.Spacing.space2X.value,
                          bottomSpacing: VDSLayout.Spacing.space2X.value)
                  ]),
        
            .init(deviceType: .iPhone,
                  titleStandardStyles: [.titleMedium, .titleLarge],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.bodySmall, .bodyMedium, .bodyLarge],
                          topSpacing: VDSLayout.Spacing.space2X.value,
                          bottomSpacing: VDSLayout.Spacing.space2X.value)
                  ]),
        
            .init(deviceType: .iPhone,
                  titleStandardStyles: [.titleXLarge],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.bodyLarge, .bodySmall, .bodyMedium, .titleMedium],
                          topSpacing: VDSLayout.Spacing.space3X.value,
                          bottomSpacing: VDSLayout.Spacing.space3X.value)
                  ]),
        
            .init(deviceType: .iPhone,
                  titleStandardStyles: [.title2XLarge, .featureXSmall],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.bodyLarge, .bodyMedium, .titleMedium],
                          topSpacing: VDSLayout.Spacing.space3X.value,
                          bottomSpacing: VDSLayout.Spacing.space4X.value)
                  ]),
        
            .init(deviceType: .iPhone,
                  titleStandardStyles: [.featureSmall],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.titleLarge, .bodyLarge],
                          topSpacing: VDSLayout.Spacing.space3X.value,
                          bottomSpacing: VDSLayout.Spacing.space4X.value)
                  ]),
        
            .init(deviceType: .iPhone,
                  titleStandardStyles: [.featureMedium],
                  spacingConfigurations: [
                    .init(otherStandardStyles: [.titleLarge, .titleXLarge],
                          topSpacing: VDSLayout.Spacing.space4X.value,
                          bottomSpacing: VDSLayout.Spacing.space6X.value),
                    
                        .init(otherStandardStyles: [.bodyLarge],
                              topSpacing: VDSLayout.Spacing.space3X.value,
                              bottomSpacing: VDSLayout.Spacing.space6X.value)
                  ]),
    ])

    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    open var textPosition: TextPosition = .left { didSet { setNeedsUpdate() }}
    
    //first row
    open var eyebrowLabel = Label().with {
        $0.setContentCompressionResistancePriority(.required, for: .vertical)
    }
    open var eyebrowModel: EyebrowModel? { didSet { setNeedsUpdate() }}
    
    //second row
    open var titleLabel = Label().with {
        $0.setContentCompressionResistancePriority(.required, for: .vertical)
    }
    open var titleModel: TitleModel? { didSet { setNeedsUpdate() }}
    
    //third row
    open var subTitleLabel = Label().with {
        $0.setContentCompressionResistancePriority(.required, for: .vertical)
    }
    open var subTitleModel: SubTitleModel? { didSet { setNeedsUpdate() }}
    
    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    open override func setup() {
        super.setup()
        
        accessibilityElements = [eyebrowLabel, titleLabel, subTitleLabel]
        addSubview(stackView)
        
        stackView.spacing = 0.0
        
        stackView.addArrangedSubview(eyebrowLabel)
        stackView.addArrangedSubview(titleLabel)
        stackView.addArrangedSubview(subTitleLabel)
        
        //pin stackview to edges
        stackView.pinToSuperView()
        
    }
    
    /// Resets back to this objects default settings.
    open override func reset() {
        super.reset()
        shouldUpdateView = false
        textPosition = .left
        eyebrowModel = nil
        titleModel = nil
        subTitleModel = nil
        shouldUpdateView = true
        setNeedsUpdate()
    }
    
    private var otherStandardStyle: OtherStandardStyle {
        if let subTitleModel, !subTitleModel.text.isEmpty {
            return subTitleModel.standardStyle
        } else if let eyebrowModel, !eyebrowModel.text.isEmpty {
            return eyebrowModel.standardStyle
        } else {
            return .bodyLarge
        }
    }
    
    //--------------------------------------------------
    // MARK: - State
    //--------------------------------------------------
    open override func updateView() {
        super.updateView()

        let allLabelsTextPosition = textPosition.value
        var eyebrowTextIsEmpty = true
        var titleTextIsEmpty = true
        var subTitleTextIsEmpty = true
        
        var topSpacing: CGFloat = 0.0
        var bottomSpacing: CGFloat = 0.0
               
        //get the spacing based on the title style and other style used for eyebrow and subtitle
        if let titleModel,
           let config = standardStyleConfiguration.spacing(for: titleModel.standardStyle, otherStandardStyle: otherStandardStyle) {
            topSpacing = config.topSpacing
            bottomSpacing = config.bottomSpacing
        }
        
        if let eyebrowModel, !eyebrowModel.text.isEmpty {
            eyebrowTextIsEmpty = false
            eyebrowLabel.textPosition = allLabelsTextPosition
            eyebrowLabel.textStyle = eyebrowModel.isBold ? otherStandardStyle.value.bold : otherStandardStyle.value.regular
            eyebrowLabel.text = eyebrowModel.text
            eyebrowLabel.attributes = eyebrowModel.textAttributes
            eyebrowLabel.numberOfLines = eyebrowModel.numberOfLines
            eyebrowLabel.surface = surface
        } else {
            eyebrowLabel.reset()
        }
                
        if let titleModel, !titleModel.text.isEmpty {
            titleTextIsEmpty = false
            titleLabel.textPosition = allLabelsTextPosition
            titleLabel.textStyle = titleModel.textStyle
            titleLabel.text = titleModel.text
            titleLabel.attributes = titleModel.textAttributes
            titleLabel.numberOfLines = titleModel.numberOfLines
            titleLabel.surface = surface
        } else {
            titleLabel.reset()
        }
        
        if let subTitleModel, !subTitleModel.text.isEmpty {
            subTitleTextIsEmpty = false
            subTitleLabel.textPosition = allLabelsTextPosition
            subTitleLabel.textStyle = otherStandardStyle.value.regular
            subTitleLabel.text = subTitleModel.text
            subTitleLabel.attributes = subTitleModel.textAttributes
            subTitleLabel.numberOfLines = subTitleModel.numberOfLines
            subTitleLabel.surface = surface
            subTitleLabel.disabled = subTitleModel.textColor == .secondary
        } else {
            subTitleLabel.reset()
        }
        
        //if both first 2 rows not empty set spacing
        if !eyebrowTextIsEmpty && !titleTextIsEmpty {
            stackView.spacing = topSpacing
        } else {
            stackView.spacing = 0.0
        }
        
        //if either first 2 rows not empty and subtile not empty, create space else collapse
        if (!eyebrowTextIsEmpty || !titleTextIsEmpty) && !subTitleTextIsEmpty {
            stackView.setCustomSpacing(bottomSpacing, after: titleLabel)
        } else if (!eyebrowTextIsEmpty || !titleTextIsEmpty) && subTitleTextIsEmpty {
            stackView.setCustomSpacing(0.0, after: titleLabel)
        }
        
        //hide/show
        eyebrowLabel.isHidden = eyebrowTextIsEmpty
        titleLabel.isHidden = titleTextIsEmpty
        subTitleLabel.isHidden = subTitleTextIsEmpty
    }
}