//
//  TooltipAlertViewController.swift
//  VDS
//
//  Created by Matt Bruce on 4/14/23.
//

import Foundation
import UIKit
import Combine
import VDSColorTokens

open class TooltipAlertViewController: UIViewController, Surfaceable {
    
    /// Set of Subscribers for any Publishers for this Control
    public var subscribers = Set<AnyCancellable>()

    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    private var onClickSubscriber: AnyCancellable? {
        willSet {
            if let onClickSubscriber {
                onClickSubscriber.cancel()
            }
        }
    }
    
    private let tooltipDialog = TooltipDialog()

    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    open var surface: Surface = .light { didSet { updateView() }}
    open var titleText: String? { didSet { updateView() }}
    open var contentText: String? { didSet { updateView() }}
    open var contentView: UIView? { didSet { updateView() }}
    open var closeButtonText: String = "Close" { didSet { updateView() }}
    open var presenter: UIView? { didSet { updateView() }}
    //--------------------------------------------------
    // MARK: - Configuration
    //--------------------------------------------------
    private let backgroundColorConfiguration = SurfaceColorConfiguration(VDSColor.backgroundPrimaryDark, VDSColor.backgroundPrimaryLight)

    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    open override func viewDidLoad() {
        super.viewDidLoad()
        isModalInPresentation = true
        setup()
    }
    open override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        UIAccessibility.post(notification: .screenChanged, argument: tooltipDialog)
    }
        
    private func dismiss() {
        dismiss(animated: true) { [weak self] in
            guard let self, let presenter else { return }
            UIAccessibility.post(notification: .layoutChanged, argument: presenter)
        }
    }
    
    open func setup() {
        view.accessibilityElements = [tooltipDialog]
        
        //left-right swipe
        view.publisher(for: UISwipeGestureRecognizer().with{ $0.direction = .right })
            .sink { [weak self] swipe in
                guard let self else { return }
                self.dismiss()
            }.store(in: &subscribers)
        
        //tapping in background
        view.publisher(for: UITapGestureRecognizer().with{ $0.numberOfTapsRequired = 1 })
            .sink { [weak self] swipe in
                guard let self else { return }
                self.dismiss()
            }.store(in: &subscribers)
        
        //clicking button
        onClickSubscriber = tooltipDialog.closeButton.publisher(for: .touchUpInside)
            .sink {[weak self] button in
                guard let self else { return }
                self.dismiss()
            }

        view.addSubview(tooltipDialog)

        // Activate constraints
        NSLayoutConstraint.activate([
            // Constraints for the floating modal view
            tooltipDialog.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            tooltipDialog.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            tooltipDialog.leadingAnchor.constraint(greaterThanOrEqualTo: view.leadingAnchor),
            tooltipDialog.trailingAnchor.constraint(lessThanOrEqualTo: view.trailingAnchor),
            tooltipDialog.topAnchor.constraint(greaterThanOrEqualTo: view.topAnchor),
            tooltipDialog.bottomAnchor.constraint(lessThanOrEqualTo: view.bottomAnchor)
        ])
    }

    open func updateView() {
        view.backgroundColor = backgroundColorConfiguration.getColor(self).withAlphaComponent(0.3)
        tooltipDialog.surface = surface
        tooltipDialog.titleText = titleText
        tooltipDialog.contentText = contentText
        tooltipDialog.contentView = contentView
    }
}

open class TooltipDialog: View, UIScrollViewDelegate {

    private var scrollView = UIScrollView().with {
        $0.translatesAutoresizingMaskIntoConstraints = false
        $0.backgroundColor = .clear
    }

    private let contentStackView = UIStackView().with {
        $0.translatesAutoresizingMaskIntoConstraints = false
        $0.axis = .vertical
        $0.distribution = .fillProportionally
        $0.spacing = 0
    }
    
    private var line = Line().with { instance in
        instance.lineViewColorConfiguration = SurfaceColorConfiguration(VDSColor.elementsLowcontrastOnlight, VDSColor.elementsLowcontrastOndark).eraseToAnyColorable()
    }
        
    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    open var titleText: String? { didSet { setNeedsUpdate() }}
    open var titleLabel = Label().with { label in
        label.textStyle = .boldTitleMedium
    }
    
    open var contentText: String? { didSet { setNeedsUpdate() }}
    open var contentLabel = Label().with { label in
        label.textStyle = .bodyLarge
    }
    
    open var contentView: UIView? = nil

    open var closeButtonText: String = "Close" { didSet { setNeedsUpdate() }}
    
    open lazy var closeButton: UIButton = {
        let button = UIButton(type: .system)
        button.backgroundColor = .clear
        button.setTitle("Close", for: .normal)
        button.titleLabel?.font = TextStyle.bodyLarge.font
        button.translatesAutoresizingMaskIntoConstraints = false
        return button
    }()
        
    //--------------------------------------------------
    // MARK: - Configuration
    //--------------------------------------------------
    private var closeButtonHeight: CGFloat = 44.0
    private var fullWidth: CGFloat = 296
    private var minHeight: CGFloat = 96.0
    private var maxHeight: CGFloat = 312.0
    private let containerViewInset = VDSLayout.Spacing.space4X.value

    private let backgroundColorConfiguration = SurfaceColorConfiguration(VDSColor.backgroundPrimaryLight, VDSColor.backgroundPrimaryDark)
    private let closeButtonTextColorConfiguration = SurfaceColorConfiguration(VDSColor.elementsPrimaryOnlight, VDSColor.elementsPrimaryOndark)

    private var contentStackViewBottomConstraint: NSLayoutConstraint?
    private var heightConstraint: NSLayoutConstraint?

    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    open override func setup() {
        super.setup()
        layer.cornerRadius = 8
        contentStackView.isAccessibilityElement = true
        contentStackView.addArrangedSubview(titleLabel)
        contentStackView.addArrangedSubview(contentLabel)
        scrollView.addSubview(contentStackView)
        addSubview(scrollView)
        addSubview(line)
        addSubview(closeButton)

        // Activate constraints
        NSLayoutConstraint.activate([
            widthAnchor.constraint(equalToConstant: fullWidth),

            // Constraints for the scroll view
            scrollView.topAnchor.constraint(equalTo: topAnchor, constant: VDSLayout.Spacing.space4X.value),
            scrollView.leadingAnchor.constraint(equalTo: leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: trailingAnchor),
            scrollView.bottomAnchor.constraint(equalTo: line.topAnchor),

            line.leadingAnchor.constraint(equalTo: leadingAnchor),
            line.trailingAnchor.constraint(equalTo: trailingAnchor),
        
            closeButton.topAnchor.constraint(equalTo: line.bottomAnchor),
            closeButton.leadingAnchor.constraint(equalTo: leadingAnchor),
            closeButton.trailingAnchor.constraint(equalTo: trailingAnchor),
            closeButton.bottomAnchor.constraint(equalTo: bottomAnchor),
            closeButton.heightAnchor.constraint(equalToConstant: closeButtonHeight),

            contentStackView.topAnchor.constraint(equalTo: scrollView.topAnchor),
            contentStackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor, constant: containerViewInset),
            contentStackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor, constant: -containerViewInset),
            contentStackView.widthAnchor.constraint(equalTo: scrollView.widthAnchor, constant: -(containerViewInset * 2)),

        ])
        contentStackViewBottomConstraint = contentStackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor)
        contentStackViewBottomConstraint?.activate()

        heightConstraint = heightAnchor.constraint(equalToConstant: minHeight)
        heightConstraint?.activate()
    }

    open override func updateView() {
        super.updateView()
                        
        backgroundColor = backgroundColorConfiguration.getColor(self)
        scrollView.indicatorStyle = surface == .light ? .black : .white
        
        titleLabel.removeFromSuperview()
        contentLabel.removeFromSuperview()
        contentView?.removeFromSuperview()
        
        titleLabel.surface = surface
        contentLabel.surface = surface
        line.surface = surface
        
        titleLabel.text = titleText
        contentLabel.text = contentText
        
        titleLabel.sizeToFit()
        contentLabel.sizeToFit()
        
        var addedTitle = false
        
        if let titleText, !titleText.isEmpty {
            contentStackView.addArrangedSubview(titleLabel)
            addedTitle = true
        }
        
        var addedContent = false
        if let contentText, !contentText.isEmpty {
            contentStackView.addArrangedSubview(contentLabel)
            addedContent = true
        } else if let contentView {
            contentView.translatesAutoresizingMaskIntoConstraints = false
            if var surfaceable = contentView as? Surfaceable {
                surfaceable.surface = surface
            }
            let wrapper = View()
            wrapper.addSubview(contentView)
            contentView.pinTop()
            contentView.pinLeading()
            contentView.pinBottom()
            contentView.pinTrailingLessThanOrEqualTo()
            contentView.setNeedsLayout()
            contentStackView.addArrangedSubview(wrapper)
            addedContent = true
        }
        
        if addedTitle && addedContent {
            contentStackView.setCustomSpacing(VDSLayout.Spacing.space1X.value, after: titleLabel)
        }
        
        let closeButtonTextColor = closeButtonTextColorConfiguration.getColor(self)
        closeButton.setTitleColor(closeButtonTextColor, for: .normal)
        closeButton.setTitleColor(closeButtonTextColor, for: .highlighted)
        closeButton.setTitle(closeButtonText, for: .normal)
        closeButton.accessibilityLabel = closeButtonText
        
        contentStackView.setNeedsLayout()
        contentStackView.layoutIfNeeded()
        
        scrollView.setNeedsLayout()
        scrollView.layoutIfNeeded()
        
        //dealing with height
        //we can't really use the minMax height and set constraints for
        //greaterThan or lessThan on the heightAnchor due to scrollView/stackView intrinsic size
        //therefore we can do a little math and manually set the height based off all of the content
        var contentHeight = closeButtonHeight + scrollView.contentSize.height + (containerViewInset * 2)
        
        //reset the bottomConstraint
        contentStackViewBottomConstraint?.constant = 0
        
        if contentHeight < minHeight {
            contentHeight = minHeight
            
        } else if contentHeight > maxHeight {
            contentHeight = maxHeight
            //since we are now scrolling, add padding to the bottom of the
            //stackView between the bottom of the scrollView
            contentStackViewBottomConstraint?.constant = -containerViewInset
        }
                
        heightConstraint?.constant = contentHeight
    }
    
    open override func updateAccessibility() {
        var label = Tooltip.accessibleText(for: titleText, content: contentText, closeButtonText: closeButtonText)
        if !label.isEmpty {
            label += ","
        }
        
        contentStackView.accessibilityLabel = "\(label) Click on the \(closeButtonText) button to close."
        contentStackView.accessibilityHint = "Tooltip"
        contentStackView.accessibilityValue = "expanded"
        accessibilityElements = [contentStackView, closeButton]
    }
}