import SwiftUI
import SwiftData

/// Composition boundary: the AR picker receives only neutral project data.
struct LeadARProjectsSheet: View {
    let detail: LeadDetail
    @Environment(\.modelContext) private var context
    @State private var service: LeadARProjectsService?

    var body: some View {
        Group {
            if let service {
                LeadARProjectsContent(service: service)
            } else {
                ProgressView()
            }
        }
        .task {
            if service == nil {
                service = LeadARProjectsService(detail: detail, container: context.container)
            }
        }
    }
}

private struct LeadARProjectsContent: View {
    let service: LeadARProjectsService
    @State private var activeProject: Project?
    @State private var errorMessage: String?

    var body: some View {
        ARProjectsSheet(service: service) { id in
            do { activeProject = try service.resolveProject(id: id) }
            catch { errorMessage = error.localizedDescription }
        }
        .fullScreenCover(item: $activeProject) { project in
            if let context = project.modelContext {
                ARExperienceView(project: project).modelContext(context)
            }
        }
        .alert("AR-Projekt konnte nicht geöffnet werden",
               isPresented: Binding(get: { errorMessage != nil },
                                    set: { if !$0 { errorMessage = nil } })) {
            Button("OK", role: .cancel) { errorMessage = nil }
        } message: { Text(errorMessage ?? "") }
    }
}