//
//  ModalDialogViewController.swift
//  VDS
//
//  Created by Kanamarlapudi, Vasavi on 09/09/24.
//

import Foundation
import UIKit
import Combine
import VDSCoreTokens

@objcMembers
@objc(VDSModalDialogViewController)
open class ModalDialogViewController: UIViewController, Surfaceable  {
    
    /// Set of Subscribers for any Publishers for this Control.
    open var subscribers = Set<AnyCancellable>()
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    private var onClickSubscriber: AnyCancellable? {
        willSet {
            if let onClickSubscriber {
                onClickSubscriber.cancel()
            }
        }
    }
        
    private let modalDialog = ModalDialog()
    
    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    /// Current Surface and this is used to pass down to child objects that implement Surfacable
    open var surface: Surface = .light { didSet { updateView() }}
    open var modalModel = Modal.ModalModel() { didSet { updateView() }}
    open var presenter: UIView? { didSet { updateView() }}
    
    //--------------------------------------------------
    // MARK: - Configuration
    //--------------------------------------------------
    private let backgroundColorConfiguration = SurfaceColorConfiguration(VDSColor.paletteBlack, VDSColor.paletteWhite)
    
    //--------------------------------------------------
    // 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: modalDialog)
    }
        
    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 = [modalDialog]
        
        //left-right swipe
        view.publisher(for: UISwipeGestureRecognizer().with{ $0.direction = .right })
            .sink { [weak self] swipe in
                guard let self, !UIAccessibility.isVoiceOverRunning 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, !UIAccessibility.isVoiceOverRunning else { return }
                self.dismiss()
            }.store(in: &subscribers)
        
        //clicking button
        onClickSubscriber = modalDialog.closeCrossButton.publisher(for: .touchUpInside)
            .sink {[weak self] button in
                guard let self else { return }
                self.dismiss()
            }
        
        view.addSubview(modalDialog)

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

    /// Used to make changes to the View based off a change events or from local properties.
    open func updateView() {
        view.backgroundColor = backgroundColorConfiguration.getColor(self).withAlphaComponent(0.8)
        modalDialog.surface = surface
        modalDialog.modalModel = modalModel
    }
}