//
//  MenuCollection.swift
//  MacBackend
//
//  Created by david-swift on 02.08.2024.
//

import AppKit
import Foundation

/// A collection of menus.
public struct MenuCollection: MenuWidget, Wrapper {

    /// The content of the collection.
    var content: Body

    /// Initialize a menu.
    /// - Parameter content: The content of the collection.
    public init(@ViewBuilder content: @escaping () -> Body) {
        self.content = content()
    }

    /// The view storage.
    /// - Parameters:
    ///     - data: The widget data.
    ///     - type: The type of the views.
    /// - Returns: The view storage.
    public func container<Data>(
        data: WidgetData,
        type: Data.Type
    ) -> ViewStorage where Data: ViewRenderData {
        let storages = content.storages(data: data, type: type)
        return .init(nil, content: [.mainContent: storages])
    }

    /// Update the stored content.
    /// - Parameters:
    ///     - storage: The storage to update.
    ///     - data: The widget data.
    ///     - updateProperties: Whether to update the properties.
    ///     - type: The type of the views.
    public func update<Data>(
        _ storage: ViewStorage,
        data: WidgetData,
        updateProperties: Bool,
        type: Data.Type
    ) where Data: ViewRenderData {
        guard let storages = storage.content[.mainContent] else {
            return
        }
        content.update(storages, data: data, updateProperties: updateProperties, type: type)
    }

    /// Render the collection as a menu.
    /// - Parameters:
    ///     - data: The widget data.
    ///     - menu:  The menu.
    /// - Returns: The view storage with the GMenu as the pointer.
    public func getMenu(data: WidgetData, menu: NSMenu? = nil) -> ViewStorage {
        let item = NSMenuItem()
        let menu = menu ?? .init()
        let storage = container(data: data.noModifiers, type: MenuContext.self)
        initializeMenu(menu: menu, storage: storage)
        storage.pointer = item
        item.menu = menu
        return storage
    }

    /// Initialize a menu.
    /// - Parameters:
    ///     - menu: The pointer to the GMenu.
    ///     - storage: The storage for the menu's content.
    ///     - app: The app object.
    ///     - window: The window object.
    func initializeMenu(menu: NSMenu, storage: ViewStorage) {
        if let item = storage.pointer as? NSMenuItem {
            menu.addItem(item)
        } else {
            for element in storage.content[.mainContent] ?? [] {
                initializeMenu(menu: menu, storage: element)
            }
        }
    }

}