Spatial SwiftUI: Volume Ornaments

struct Example043: View {

    static let info = ItemInfo(
        title: "Spatial SwiftUI: Volume Ornaments",
        description: "Ornaments on Volumes work much like Ornaments on Windows. Volumes have more anchors and a feature to reorient them when them when a user moves around the volume.",
        scene: .volume
    )

    @State private var ornamentAnchor: UnitPoint3D = .topFront
    @State private var showBounds = true
    @State private var isAutoMode = false
    @State private var autoModeTimer: Timer?
    @State private var animationPhase = 0

    private static let autoAnchors: [UnitPoint3D] = {
        let perimeter: [UnitPoint] = [
            .topLeading, .top, .topTrailing, .trailing,
            .bottomTrailing, .bottom, .bottomLeading, .leading, .topLeading
        ]
        let planes: [UnitPoint3D] = [.front, .center, .back]
        return planes.flatMap { plane in
            perimeter.map { UnitPoint3D(x: $0.x, y: $0.y, z: plane.z) }
        }
    }()

    private func startAutoMode() {
        stopAutoMode()
        animationPhase = 0
        ornamentAnchor = Self.autoAnchors[0]

        autoModeTimer = Timer.scheduledTimer(withTimeInterval: 2.5, repeats: true) { _ in
            Task { @MainActor in
                guard isAutoMode else { return }

                animationPhase = (animationPhase + 1) % Self.autoAnchors.count
                withAnimation(.easeInOut(duration: 2.0)) {
                    ornamentAnchor = Self.autoAnchors[animationPhase]
                }
            }
        }
    }

    private func stopAutoMode() {
        autoModeTimer?.invalidate()
        autoModeTimer = nil
    }

    var body: some View {
        GeometryReader3D { geometry in
            Color.clear
                .frame(width: geometry.size.width, height: geometry.size.height)
                .frame(depth: geometry.size.depth)
                .debugBorder3D(showBounds ? .white : .clear)
        }
        .ornament(attachmentAnchor: .scene(.center)) {
            Example043Controls(
                ornamentAnchor: $ornamentAnchor,
                showBounds: $showBounds,
                isAutoMode: $isAutoMode
            )
        }
        .ornament(attachmentAnchor: .scene(ornamentAnchor)) {
            Text("Ornament")
                .padding(20)
                .background(.stepBlue)
                .clipShape(RoundedRectangle(cornerRadius: 20))
        }
        .onChange(of: isAutoMode) { _, newValue in
            if newValue {
                startAutoMode()
            } else {
                stopAutoMode()
            }
        }
        .onDisappear {
            stopAutoMode()
            isAutoMode = false
        }
    }
}

private struct Example043Controls: View {
    @Binding var ornamentAnchor: UnitPoint3D
    @Binding var showBounds: Bool
    @Binding var isAutoMode: Bool

    private func setDepth(_ point: UnitPoint3D) {
        withAnimation {
            ornamentAnchor.z = point.z
        }
    }

    var body: some View {
        VStack(spacing: 20) {
            HStack(spacing: 32) {
                VStack {
                    Text("Anchor")
                        .font(.headline)
                    Grid {
                        GridRow {
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .topLeading, symbol: "arrow.up.left", title: "Top Leading")
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .top, symbol: "arrow.up", title: "Top")
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .topTrailing, symbol: "arrow.up.right", title: "Top Trailing")
                        }
                        GridRow {
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .leading, symbol: "arrow.left", title: "Leading")
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .center, symbol: "square", title: "Center")
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .trailing, symbol: "arrow.right", title: "Trailing")
                        }
                        GridRow {
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .bottomLeading, symbol: "arrow.down.left", title: "Bottom Leading")
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .bottom, symbol: "arrow.down", title: "Bottom")
                            Example043AnchorButton(anchor: $ornamentAnchor, point: .bottomTrailing, symbol: "arrow.down.right", title: "Bottom Trailing")
                        }
                    }
                }

                VStack {
                    Text("Depth")
                        .font(.headline)
                    Button("Front") { setDepth(.front) }
                    Button("Center") { setDepth(.center) }
                    Button("Back") { setDepth(.back) }
                }
            }
            .disabled(isAutoMode)

            Toggle("Auto Mode", isOn: $isAutoMode)

            Button(showBounds ? "Hide Bounds" : "Show Bounds") {
                showBounds.toggle()
            }
        }
        .padding(24)
        .glassBackgroundEffect()
    }
}

private struct Example043AnchorButton: View {
    @Binding var anchor: UnitPoint3D
    let point: UnitPoint
    let symbol: String
    let title: LocalizedStringKey

    var body: some View {
        Button {
            withAnimation {
                anchor.x = point.x
                anchor.y = point.y
            }
        } label: {
            Image(systemName: symbol)
        }
        .accessibilityLabel(Text(title))
    }
}