//
//  TestVideoLeakOneImmersiveViewApp.swift
//  TestVideoLeakOneImmersiveView
//

import OSLog
import SwiftUI

let SUBSYSTEM = Bundle.main.bundleIdentifier!
let scaleForAttachements = SIMD3(2.5, 2.5, 2.5)

@main
struct TestVideoLeakOneImmersiveViewApp: App {
    let logger = Logger(subsystem: SUBSYSTEM, category: "TestVideoLeakOneImmersiveViewApp")
    @Environment(\.openImmersiveSpace) var openImmersiveSpace
    @Environment(\.dismissImmersiveSpace) var dismissImmersiveSpace
    @Environment(\.scenePhase) var scenePhase
    @State private var appModel = AppModel()
    var body: some Scene {
        Group {
            ImmersiveSpace(id: "InitialImmersiveView") {
                InitialImmersiveView()
                    .environment(appModel)
                    .onAppear {
                        appModel.immersiveSpaceState = .open
                        
                        // When app backgrounds, `immersiveSpaceID` will remain no matter which scene was showing prior to background.
                        // Since `InitialImmersiveView` is the first scene of the app, visionOS will display
                        // `InitialImmersiveView` when foregrounded.
                        // Setting immersiveSpaceID to `InitialImmersiveView` ensures that when it is changed
                        // in `InitialImmersiveView`, the listener here below will execute upon changing of `immersiveSpaceID`
                        appModel.immersiveSpaceID = "InitialImmersiveView"
                    }
                    .onDisappear {
                        appModel.immersiveSpaceState = .closed
                    }
            }
            .immersionStyle(selection: .constant(.mixed), in: .mixed)

            ImmersiveSpace(id: "ImmersiveView") {
                ImmersiveView()
                    .environment(appModel)
                    .onAppear {
                        appModel.immersiveSpaceState = .open
                    }
                    .onDisappear {
                        appModel.immersiveSpaceState = .closed
                    }
            }
            .immersionStyle(selection: .constant(.mixed), in: .mixed)
        }
        .onChange(of: appModel.immersiveSpaceID) { oldValue, newValue in
            logger.info("\(#function) \(#line) `.onChange(of: appModel.immersiveSpaceID` oldValue \(String(describing: oldValue)) newValue \(String(describing: newValue))")
            
            Task {
                guard scenePhase == .active else {
                    logger.info("\(#function) \(#line) escaping since scene is not active")
                    return
                }

                logger.info("\(#function) \(#line) opening appModel.immersiveSpaceID: \(appModel.immersiveSpaceID)")
                await dismissImmersiveSpace()
                let result = await openImmersiveSpace(id: appModel.immersiveSpaceID)
                switch result {
                case .opened:
                    logger.info("\(#function) \(#line) should be presenting appModel.immersiveSpaceID: \(appModel.immersiveSpaceID)")
                case .error:
                    logger.error("\(#function) \(#line) could not open scene appModel.immersiveSpaceID: \(appModel.immersiveSpaceID)")
                    assertionFailure("could not open scene")
                case .userCancelled:
                    logger.info("\(#function) \(#line) userCancelled the openning of the scene appModel.immersiveSpaceID: \(appModel.immersiveSpaceID)")
                    fallthrough
                @unknown default:
                    logger.error("\(#function) \(#line) unhandled result \(String(describing: result))")
                    assertionFailure("could not open scene")
                }
            }
        }
        .onChange(of: scenePhase, { oldValue, newValue in
            logger.info("\(#function) \(#line) `onChange(of: scenePhase` scenePhase oldValue \(String(describing: oldValue)) scenePhase newValue \(String(describing: newValue))")
            switch newValue {
            case .active:
                logger.info("\(#function) \(#line) scenePhase newValue \(String(describing: newValue))")
            case .background:
                logger.info("\(#function) \(#line) scenePhase newValue \(String(describing: newValue))")
                // reset appmodel for initial immersive space
            case .inactive:
                logger.info("\(#function) \(#line) scenePhase newValue \(String(describing: newValue))")
            @unknown default:
                logger.warning("\(#function) \(#line) scenePhase newValue \(String(describing: newValue))")
            }
        })
     }
}