import SwiftUI

/// An adaptable stack view that switches between `HStack` and `VStack` based on the dynamic text size.
struct AdaptableStack<Content>: View where Content: View {
    @Environment(\.dynamicTypeSize) private var size: DynamicTypeSize
    /// The primary axis along which the stack arranges its children.
    private var axis: StackAxis
    /// The dynamic type size threshold above which the stack axis will switch.
    private var sizeThreshold: DynamicTypeSize
    /// Alignment of children along the X-axis for vertical stack.
    private var vAlignment: HorizontalAlignment
    /// Spacing between children for vertical stack.
    private var vSpacing: CGFloat?
    /// Alignment of children along the Y-axis for horizontal stack.
    private var hAlignment: VerticalAlignment
    /// Spacing between children for horizontal stack.
    private var hSpacing: CGFloat?
    /// Closure providing the stack's content.
    private var content: () -> Content

    /// Creates an `AdaptableStack` with the given properties.
    ///
    /// - Parameters:
    ///   - axis: The primary axis for the stack (`vertical` or `horizontal`).
    ///   - sizeThreshold: The size above which to switch the axis. Default is `.accessibility1`.
    ///   - vAlignment: The X-axis alignment for a vertical stack. Default is `.center`.
    ///   - vSpacing: The spacing for a vertical stack. Default is `nil`.
    ///   - hAlignment: The Y-axis alignment for a horizontal stack. Default is `.center`.
    ///   - hSpacing: The spacing for a horizontal stack. Default is `nil`.
    ///   - content: The content of the stack.
    init(
        _ axis: StackAxis,
        sizeThreshold: DynamicTypeSize = .accessibility1,
        vAlignment: HorizontalAlignment = .center,
        vSpacing: CGFloat? = nil,
        hAlignment: VerticalAlignment = .center,
        hSpacing: CGFloat? = nil,
        @ViewBuilder content: @escaping () -> Content
    ) {
        self.axis = axis
        self.sizeThreshold = sizeThreshold
        self.vAlignment = vAlignment
        self.vSpacing = vSpacing
        self.hAlignment = hAlignment
        self.hSpacing = hSpacing
        self.content = content
    }

    var body: some View {
        layout {
            content()
        }
    }
}

extension AdaptableStack {
    /// Enum to represent the primary axis for the stack.
    enum StackAxis {
        case vertical
        case horizontal
    }
}

private extension AdaptableStack {
    /// Determines the layout to use based on the `axis` and `size`.
    var layout: AnyLayout {
        switch axis {
        case .vertical:
            return size > threshold
                ? AnyLayout(HStackLayout(alignment: hAlignment, spacing: hSpacing))
                : AnyLayout(VStackLayout(alignment: vAlignment, spacing: vSpacing))
        case .horizontal:
            return size > threshold
                ? AnyLayout(VStackLayout(alignment: vAlignment, spacing: vSpacing))
                : AnyLayout(HStackLayout(alignment: hAlignment, spacing: hSpacing))
        }
    }
}