//
//  NavigationStack.swift
//  MacBackend
//
//  Created by david-swift on 14.12.2024.
//

import SwiftUI

/// The navigation stack view.
public struct NavigationStack<Component>: SwiftUIWidget where Component: CustomStringConvertible {

    /// The current navigation path.
    @Meta.Binding var path: NavigationPath
    /// The content.
    var content: (Component) -> Body
    /// The initial view.
    var initialView: Body

    /// The wrapped views.
    public var wrappedViews: [String: Meta.AnyView] {
        if let current = path.current {
            _ = current
            return [.mainContent: initialView, current.description: content(current)]
        } else {
            return [.mainContent: initialView]
        }
    }

    /// Initialize the navigation stack.
    /// - Parameters:
    ///   - path: The path.
    ///   - content: The content.
    ///   - initialView: The initial view.
    public init(
        path: Meta.Binding<NavigationPath>,
        @Meta.ViewBuilder content: @escaping (Component) -> Body,
        @Meta.ViewBuilder initialView: () -> Body
    ) {
        self._path = path
        self.content = content
        self.initialView = initialView()
    }

    /// The navigation path.
    public struct NavigationPath {

        /// The path.
        var path: [Component] = []
        /// The current component.
        var current: Component? { path.last }

        /// The path as an array of strings.
        var hashable: [String] {
            get {
                path.map { $0.description }
            }
            set {
                if newValue.count < hashable.count {
                    _ = path.popLast()
                }
            }
        }

        /// Initialize a navigation stack.
        public init() { }

        /// Pop the last element.
        public mutating func pop() {
            _ = path.popLast()
        }

        /// Add a new element.
        /// - Parameter component: The element.
        public mutating func push(_ component: Component) {
            path.append(component)
        }

    }

    /// Receive the SwiftUI view.
    /// - Parameter properties: The properties.
    /// - Returns: The SwiftUI view.
    public static func view(properties: Self) -> some SwiftUI.View {
        SwiftUINavigationStack(path: properties.$path.swiftUI)
    }

}

/// The SwiftUI navigation stack.
struct SwiftUINavigationStack<Component>: SwiftUI.View where Component: CustomStringConvertible {

    /// The path.
    @SwiftUI.Binding var path: NavigationPath<Component>
    /// The views.
    @SwiftUI.Environment(\.views)
    var views

    /// The view's body.
    var body: some SwiftUI.View {
        SwiftUI.NavigationStack(path: $path.hashable) {
            let view = MacBackendView(.mainContent)
            if path.current != nil {
                view
                    .navigationDestination(for: String.self) { string in
                        SwiftUI.VStack {
                            MacBackendView(string)
                                .environment(\.views, views)
                        }
                    }
            } else {
                view
            }
        }
    }

}

/// The navigation path.
public typealias NavigationPath<Component: CustomStringConvertible> = NavigationStack<Component>.NavigationPath