Agentic App Experiences with Dynamic Profiles (Foundation Models)

import FoundationModels
import SwiftUI

// MARK: - Session property for storing the chosen craft idea
extension SessionPropertyValues {
    @SessionPropertyEntry var chosenIdea: String? = nil
}

// MARK: - Reusable instructions component
struct BrainstormInstructions: DynamicInstructions {
    var body: some DynamicInstructions {
        "You are a creative craft expert. Suggest three original origami project ideas based on the user's prompt. Be imaginative."
    }
}

// MARK: - Tool that hands the baton to the tutorial phase
struct SelectIdeaTool: Tool {
    static let name = "selectIdea"
    static let description = "Call this when the user has chosen a craft idea to get a tutorial."

    struct Parameters: Encodable {
        let idea: String
    }

    func call(arguments: Parameters, context: ToolContext) async throws -> ToolOutput {
        context.session.properties.chosenIdea = arguments.idea
        return ToolOutput("Idea selected: \(arguments.idea). Switching to tutorial mode.")
    }
}

// MARK: - The orchestrator using DynamicProfile
@Observable
final class OrigamiOrchestrator {
    enum Mode { case brainstorm, tutorial }
    var mode: Mode = .brainstorm
    var response: String = ""

    private let session: LanguageModelSession

    init() {
        session = LanguageModelSession {
            DynamicProfile { [self] in
                switch mode {
                case .brainstorm:
                    Model(PrivateCloudComputeLanguageModel.default)
                    Temperature(1.0)
                    BrainstormInstructions()
                    Tool(SelectIdeaTool())

                case .tutorial:
                    Model(SystemLanguageModel.default)
                    Instructions {
                        "You are a precise origami instructor. Provide a clear, step-by-step tutorial."
                        if let idea = session.properties.chosenIdea {
                            "The user wants to learn: \(idea)"
                        }
                    }
                }
            }
            .onResponse { [self] in
                // Auto-advance to tutorial once an idea is chosen
                if session.properties.chosenIdea != nil, mode == .brainstorm {
                    mode = .tutorial
                }
            }
        }
    }

    func send(_ message: String) async {
        do {
            let result = try await session.respond(to: message)
            response = result.content
        } catch {
            response = "Error: \(error.localizedDescription)"
        }
    }
}

// MARK: - SwiftUI View
struct OrigamiAssistantView: View {
    @State private var orchestrator = OrigamiOrchestrator()
    @State private var input = ""

    var body: some View {
        NavigationStack {
            VStack(alignment: .leading, spacing: 16) {
                Text(orchestrator.mode == .brainstorm ? "🎨 Brainstorming" : "📋 Tutorial")
                    .font(.headline)
                    .foregroundStyle(orchestrator.mode == .brainstorm ? .purple : .green)

                ScrollView {
                    Text(orchestrator.response)
                        .padding()
                        .frame(maxWidth: .infinity, alignment: .leading)
                }
                .background(.regularMaterial, in: RoundedRectangle(cornerRadius: 12))

                HStack {
                    TextField("Ask about origami…", text: $input)
                        .textFieldStyle(.roundedBorder)
                    Button("Send") {
                        let msg = input
                        input = ""
                        Task { await orchestrator.send(msg) }
                    }
                    .buttonStyle(.borderedProminent)
                }
            }
            .padding()
            .navigationTitle("Origami Assistant")
        }
    }
}