import FoundationModels

let session = LanguageModelSession()

let session = LanguageModelSession(instructions: """
    You are a friendly barista in a pixel art coffee shop.
    Respond to the player's question concisely.
    """
)

let session = LanguageModelSession(
    tools: [GetWeatherTool()],
    instructions: "Help user with weather forecasts."
)

let session = LanguageModelSession(
    model: SystemLanguageModel(useCase: .contentTagging)
)

func respond(userInput: String) async throws -> String {
    let session = LanguageModelSession(instructions: """
        You are a friendly barista in a world full of pixels.
        Respond to the player's question.
        """
    )
    let response = try await session.respond(to: userInput)
    return response.content
}

@Generable
struct SearchSuggestions {
    @Guide(description: "A list of suggested search terms", .count(4))
    var searchTerms: [String]
}

let prompt = """
    Generate a list of suggested search terms for an app about visiting famous landmarks.
    """

let response = try await session.respond(
    to: prompt,
    generating: SearchSuggestions.self
)

print(response.content) // SearchSuggestions instance

let response = try await session.respond(
    to: prompt,
    options: GenerationOptions(sampling: .greedy)
)

let response = try await session.respond(
    to: prompt,
    options: GenerationOptions(temperature: 0.5)
)

let response = try await session.respond(
    to: prompt,
    options: GenerationOptions(temperature: 2.0)
)

let response = try await session.respond(
    to: prompt,
    generating: Person.self,
    options: GenerationOptions(includeSchemaInPrompt: false)
)

let session = LanguageModelSession()

// First turn
let firstHaiku = try await session.respond(to: "Write a haiku about fishing")
print(firstHaiku.content)
// Silent waters gleam,
// Casting lines in morning mist—
// Hope in every cast.

// Second turn - model remembers context
let secondHaiku = try await session.respond(to: "Do another one about golf")
print(secondHaiku.content)
// Silent morning dew,
// Caddies guide with gentle words—
// Paths of patience tread.

print(session.transcript) // Shows full history

let transcript = session.transcript

for entry in transcript.entries {
    print("Entry: \(entry.content)")
}

struct HaikuView: View {
    @State private var session = LanguageModelSession()
    @State private var haiku: String?

    var body: some View {
        if let haiku {
            Text(haiku)
        }

        Button("Go!") {
            Task {
                haiku = try await session.respond(
                    to: "Write a haiku about something you haven't yet"
                ).content
            }
        }
        // Gate on `isResponding`
        .disabled(session.isResponding)
    }
}

@Generable
struct Person {
    let name: String
    let age: Int
}

let response = try await session.respond(
    to: "Generate a person",
    generating: Person.self
)

let person = response.content // Type-safe Person instance

@Generable
struct NPC {
    let name: String
    let encounter: Encounter

    @Generable
    enum Encounter {
        case orderCoffee(String)
        case wantToTalkToManager(complaint: String)
    }
}

@Generable
struct Itinerary {
    var destination: String
    var days: Int
    var budget: Float
    var rating: Double
    var requiresVisa: Bool
    var activities: [String]
    var emergencyContact: Person
    var relatedItineraries: [Itinerary] // Recursive!
}

@Generable
struct NPC {
    @Guide(description: "A full name")
    let name: String
}

@Generable
struct Character {
    @Guide(.range(1...10))
    let level: Int
}

@Generable
struct Suggestions {
    @Guide(.count(3))
    let attributes: [Attribute]
}

@Generable
struct Result {
    @Guide(.maximumCount(3))
    let topics: [String]
}

@Generable
struct NPC {
    @Guide(Regex {
        Capture {
            ChoiceOf {
                "Mr"
                "Mrs"
            }
        }
        ". "
        OneOrMore(.word)
    })
    let name: String
}

session.respond(to: "Generate a fun NPC", generating: NPC.self)
// > {name: "Mrs. Brewster"}

@Generable
struct Itinerary {
    var name: String        // Generated FIRST
    var days: [DayPlan]     // Generated SECOND
    var summary: String     // Generated LAST
}

@Generable
struct Itinerary {
    var name: String
    var days: [DayPlan]
}

// Compiler generates:
extension Itinerary {
    struct PartiallyGenerated {
        var name: String?        // All properties optional!
        var days: [DayPlan]?
    }
}

@Generable
struct Itinerary {
    var name: String
    var days: [Day]
}

let stream = session.streamResponse(
    to: "Craft a 3-day itinerary to Mt. Fuji.",
    generating: Itinerary.self
)

for try await partial in stream {
    print(partial) // Incrementally updated Itinerary.PartiallyGenerated
}

struct ItineraryView: View {
    let session: LanguageModelSession
    let dayCount: Int
    let landmarkName: String

    @State
    private var itinerary: Itinerary.PartiallyGenerated?

    var body: some View {
        VStack {
            if let name = itinerary?.name {
                Text(name).font(.title)
            }

            if let days = itinerary?.days {
                ForEach(days, id: \.self) { day in
                    DayView(day: day)
                }
            }

            Button("Start") {
                Task {
                    do {
                        let prompt = """
                            Generate a \(dayCount) itinerary \
                            to \(landmarkName).
                            """

                        let stream = session.streamResponse(
                            to: prompt,
                            generating: Itinerary.self
                        )

                        for try await partial in stream {
                            self.itinerary = partial
                        }
                    } catch {
                        print(error)
                    }
                }
            }
        }
    }
}

if let name = itinerary?.name {
    Text(name)
        .transition(.opacity)
}

// ✅ GOOD - Stable identity
ForEach(days, id: \.id) { day in
    DayView(day: day)
}

// ❌ BAD - Identity changes
ForEach(days.indices, id: \.self) { index in
    DayView(day: days[index])
}

// ✅ GOOD - Title first for streaming
@Generable
struct Article {
    var title: String      // Shows immediately
    var summary: String    // Shows second
    var fullText: String   // Shows last
}

protocol Tool {
    var name: String { get }
    var description: String { get }

    associatedtype Arguments: Generable

    func call(arguments: Arguments) async throws -> ToolOutput
}

import FoundationModels
import WeatherKit
import CoreLocation

struct GetWeatherTool: Tool {
    let name = "getWeather"
    let description = "Retrieve the latest weather information for a city"

    @Generable
    struct Arguments {
        @Guide(description: "The city to fetch the weather for")
        var city: String
    }

    func call(arguments: Arguments) async throws -> ToolOutput {
        let places = try await CLGeocoder().geocodeAddressString(arguments.city)
        let weather = try await WeatherService.shared.weather(for: places.first!.location!)
        let temperature = weather.currentWeather.temperature.value

        let content = GeneratedContent(properties: ["temperature": temperature])
        let output = ToolOutput(content)

        // Or if your tool's output is natural language:
        // let output = ToolOutput("\(arguments.city)'s temperature is \(temperature) degrees.")

        return output
    }
}

let session = LanguageModelSession(
    tools: [GetWeatherTool()],
    instructions: "Help the user with weather forecasts."
)

let response = try await session.respond(
    to: "What is the temperature in Cupertino?"
)

print(response.content)
// It's 71˚F in Cupertino!

import FoundationModels
import Contacts

struct FindContactTool: Tool {
    let name = "findContact"
    let description = "Finds a contact from a specified age generation."

    @Generable
    struct Arguments {
        let generation: Generation

        @Generable
        enum Generation {
            case babyBoomers
            case genX
            case millennial
            case genZ
        }
    }

    func call(arguments: Arguments) async throws -> ToolOutput {
        let store = CNContactStore()

        let keysToFetch = [CNContactGivenNameKey, CNContactBirthdayKey] as [CNKeyDescriptor]
        let request = CNContactFetchRequest(keysToFetch: keysToFetch)

        var contacts: [CNContact] = []
        try store.enumerateContacts(with: request) { contact, stop in
            if let year = contact.birthday?.year {
                if arguments.generation.yearRange.contains(year) {
                    contacts.append(contact)
                }
            }
        }

        guard let pickedContact = contacts.randomElement() else {
            return ToolOutput("Could not find a contact.")
        }

        return ToolOutput(pickedContact.givenName)
    }
}

class FindContactTool: Tool {
    let name = "findContact"
    let description = "Finds a contact from a specified age generation."

    var pickedContacts = Set<String>() // State!

    @Generable
    struct Arguments {
        let generation: Generation

        @Generable
        enum Generation {
            case babyBoomers
            case genX
            case millennial
            case genZ
        }
    }

    func call(arguments: Arguments) async throws -> ToolOutput {
        // Fetch contacts...
        contacts.removeAll(where: { pickedContacts.contains($0.givenName) })

        guard let pickedContact = contacts.randomElement() else {
            return ToolOutput("Could not find a contact.")
        }

        pickedContacts.insert(pickedContact.givenName) // Update state
        return ToolOutput(pickedContact.givenName)
    }
}

import FoundationModels
import EventKit

struct GetContactEventTool: Tool {
    let name = "getContactEvent"
    let description = "Get an event with a contact."

    let contactName: String

    @Generable
    struct Arguments {
        let day: Int
        let month: Int
        let year: Int
    }

    func call(arguments: Arguments) async throws -> ToolOutput {
        // Fetch events from Calendar...
        let eventStore = EKEventStore()
        // ... implementation ...
        return ToolOutput(/* event details */)
    }
}

return ToolOutput("Temperature is 71°F")

let content = GeneratedContent(properties: ["temperature": 71])
return ToolOutput(content)

let session = LanguageModelSession(
    tools: [
        GetWeatherTool(),
        FindRestaurantTool(),
        FindHotelTool()
    ],
    instructions: "Plan travel itineraries."
)

// Model autonomously decides which tools to call and when

@Generable
struct Riddle {
    let question: String
    let answers: [Answer]

    @Generable
    struct Answer {
        let text: String
        let isCorrect: Bool
    }
}

struct LevelObjectCreator {
    var properties: [DynamicGenerationSchema.Property] = []

    mutating func addStringProperty(name: String) {
        let property = DynamicGenerationSchema.Property(
            name: name,
            schema: DynamicGenerationSchema(type: String.self)
        )
        properties.append(property)
    }

    mutating func addBoolProperty(name: String) {
        let property = DynamicGenerationSchema.Property(
            name: name,
            schema: DynamicGenerationSchema(type: Bool.self)
        )
        properties.append(property)
    }

    mutating func addArrayProperty(name: String, customType: String) {
        let property = DynamicGenerationSchema.Property(
            name: name,
            schema: DynamicGenerationSchema(
                arrayOf: DynamicGenerationSchema(referenceTo: customType)
            )
        )
        properties.append(property)
    }

    var root: DynamicGenerationSchema {
        DynamicGenerationSchema(
            name: name,
            properties: properties
        )
    }
}

// Create riddle schema
var riddleBuilder = LevelObjectCreator(name: "Riddle")
riddleBuilder.addStringProperty(name: "question")
riddleBuilder.addArrayProperty(name: "answers", customType: "Answer")

// Create answer schema
var answerBuilder = LevelObjectCreator(name: "Answer")
answerBuilder.addStringProperty(name: "text")
answerBuilder.addBoolProperty(name: "isCorrect")

let riddleDynamicSchema = riddleBuilder.root
let answerDynamicSchema = answerBuilder.root