visionOS/RootWindowView.swift

//
//  RootWindowView.swift
//  visionOS
//
//  Created by Saagar Jha on 10/21/23.
//

import AVFoundation
import SwiftUI

struct RootWindowView: View {
	let remote: Remote
	let window: Window

	@State
	var children = [Window]()

	@State
	var appIcon: Data?

	var body: some View {
		GeometryReader { geometry in
			ZStack {
				WindowView(remote: remote, window: window)
				ForEach(children) { child in
					let width = child.frame.width / window.frame.width * geometry.size.width
					let height = child.frame.height / window.frame.height * geometry.size.height
					let x = (child.frame.minX - window.frame.minX + child.frame.width / 2) / window.frame.width * geometry.size.width / geometry.size.width
					let y = (child.frame.minY - window.frame.minY + child.frame.height / 2) / window.frame.height * geometry.size.height / geometry.size.height

					Color.clear
						.ornament(attachmentAnchor: .scene(.init(x: x, y: y))) {
							WindowView(remote: remote, window: child)
								.frame(width: width, height: height)
						}
				}
			}
			.ornament(attachmentAnchor: .scene(.init(x: 0.5, y: 1 + 64 / geometry.size.height))) {
				WindowToolbarView(title: window.title!, icon: appIcon)
			}
		}
		.background {
			AspectRatioConstrainingView(size: window.frame.size)
		}
		.task {
			do {
				// TODO: Scale appropriately
				appIcon = try await remote.appIcon(for: window.id, size: .init(width: 128, height: 128))
			} catch {}
			do {
				for await children in try await remote.children(of: window.id) {
					let windows = try await remote.windows
					self.children = children.compactMap { child in
						windows.first {
							$0.id == child
						}
					}
				}
			} catch {}
		}
	}
}

struct AspectRatioConstrainingView: UIViewRepresentable {
	let size: CGSize

	class _View: UIView {
		var _size = CGSize.zero {
			didSet {
				window?.windowScene?.requestGeometryUpdate(.Vision(size: _size, resizingRestrictions: .uniform))
			}
		}

		override func didMoveToWindow() {
			_size = { _size }()
		}
	}

	func makeUIView(context: Context) -> _View {
		_View()
	}

	func updateUIView(_ uiView: UIViewType, context: Context) {
		uiView._size = size
	}
}