//
//  AlertViewController.swift
//  VDS
//
//  Created by Matt Bruce on 6/24/24.
//

import Foundation
import UIKit
import Combine
import VDSCoreTokens

@objcMembers
@objc(VDSAlertViewController)
open class AlertViewController: 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()
            }
        }
    }
    
    //--------------------------------------------------
    // 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 presenter: UIView? { didSet { updateView() }}
    open var dialog: UIView!

    //--------------------------------------------------
    // 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: dialog)
    }
        
    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() {
        guard let dialog else { return }
        view.accessibilityElements = [dialog]
        view.addSubview(dialog)

        // Activate constraints
        NSLayoutConstraint.activate([
            // Constraints for the floating modal view
            dialog.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            dialog.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            dialog.leadingAnchor.constraint(greaterThanOrEqualTo: view.leadingAnchor, constant: 10),
            dialog.trailingAnchor.constraint(lessThanOrEqualTo: view.trailingAnchor, constant: -10),
            dialog.topAnchor.constraint(greaterThanOrEqualTo: view.topAnchor, constant: 10),
            dialog.bottomAnchor.constraint(lessThanOrEqualTo: view.bottomAnchor, constant: -10)
        ])
    }
    
    open override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touch = touches.first else { return }
        let location = touch.location(in: view)
        if dialog.frame.contains(location) {
            super.touchesBegan(touches, with: event)
        } else {
            dismiss()
        }
    }

    /// 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(0.3)
        if var dialog = dialog as? Surfaceable {
            dialog.surface = surface
        }
    }
}