使用 Gemini API 进行函数调用

// This function calls a hypothetical external API that returns
// a collection of weather information for a given location on a given date.
func fetchWeather(city: String, state: String, date: String) -> JSONObject {

  // TODO(developer): Write a standard function that would call an external weather API.

  // For demo purposes, this hypothetical response is hardcoded here in the expected format.
  return [
    "temperature": .number(38),
    "chancePrecipitation": .string("56%"),
    "cloudConditions": .string("partlyCloudy"),
  ]
}

// This function calls a hypothetical external API that returns
// a collection of weather information for a given location on a given date.
// `location` is an object of the form { city: string, state: string }
data class Location(val city: String, val state: String)

suspend fun fetchWeather(location: Location, date: String): JsonObject {

    // TODO(developer): Write a standard function that would call to an external weather API.

    // For demo purposes, this hypothetical response is hardcoded here in the expected format.
    return JsonObject(mapOf(
        "temperature" to JsonPrimitive(38),
        "chancePrecipitation" to JsonPrimitive("56%"),
        "cloudConditions" to JsonPrimitive("partlyCloudy")
    ))
}

// This function calls a hypothetical external API that returns
// a collection of weather information for a given location on a given date.
// `location` is an object of the form { city: string, state: string }
public JsonObject fetchWeather(Location location, String date) {

  // TODO(developer): Write a standard function that would call to an external weather API.

  // For demo purposes, this hypothetical response is hardcoded here in the expected format.
  return new JsonObject(Map.of(
        "temperature", JsonPrimitive(38),
        "chancePrecipitation", JsonPrimitive("56%"),
        "cloudConditions", JsonPrimitive("partlyCloudy")));
}

// This function calls a hypothetical external API that returns
// a collection of weather information for a given location on a given date.
// `location` is an object of the form { city: string, state: string }
async function fetchWeather({ location, date }) {

  // TODO(developer): Write a standard function that would call to an external weather API.

  // For demo purposes, this hypothetical response is hardcoded here in the expected format.
  return {
    temperature: 38,
    chancePrecipitation: "56%",
    cloudConditions: "partlyCloudy",
  };
}

// This function calls a hypothetical external API that returns
// a collection of weather information for a given location on a given date.
// `location` is an object of the form { city: string, state: string }
Future<Map<String, Object?>> fetchWeather(
  Location location, String date
) async {

  // TODO(developer): Write a standard function that would call to an external weather API.

  // For demo purposes, this hypothetical response is hardcoded here in the expected format.
  final apiResponse = {
    'temperature': 38,
    'chancePrecipitation': '56%',
    'cloudConditions': 'partlyCloudy',
  };
  return apiResponse;
}

let fetchWeatherTool = FunctionDeclaration(
  name: "fetchWeather",
  description: "Get the weather conditions for a specific city on a specific date.",
  parameters: [
    "location": .object(
      properties: [
        "city": .string(description: "The city of the location."),
        "state": .string(description: "The US state of the location."),
      ],
      description: """
      The name of the city and its state for which to get the weather. Only cities in the
      USA are supported.
      """
    ),
    "date": .string(
      description: """
      The date for which to get the weather. Date must be in the format: YYYY-MM-DD.
      """
    ),
  ]
)

val fetchWeatherTool = FunctionDeclaration(
    "fetchWeather",
    "Get the weather conditions for a specific city on a specific date.",
    mapOf(
        "location" to Schema.obj(
            mapOf(
                "city" to Schema.string("The city of the location."),
                "state" to Schema.string("The US state of the location."),
            ),
            description = "The name of the city and its state for which " +
                "to get the weather. Only cities in the " +
                "USA are supported."
        ),
        "date" to Schema.string("The date for which to get the weather." +
                                " Date must be in the format: YYYY-MM-DD."
        ),
    ),
)

FunctionDeclaration fetchWeatherTool = new FunctionDeclaration(
        "fetchWeather",
        "Get the weather conditions for a specific city on a specific date.",
        Map.of("location",
                Schema.obj(Map.of(
                        "city", Schema.str("The city of the location."),
                        "state", Schema.str("The US state of the location."))),
                "date",
                Schema.str("The date for which to get the weather. " +
                              "Date must be in the format: YYYY-MM-DD.")),
        Collections.emptyList());

const fetchWeatherTool = {
  functionDeclarations: [
   {
      name: "fetchWeather",
      description:
        "Get the weather conditions for a specific city on a specific date",
      parameters: Schema.object({
        properties: {
          location: Schema.object({
            description:
              "The name of the city and its state for which to get " +
              "the weather. Only cities in the USA are supported.",
            properties: {
              city: Schema.string(
                description: "The city of the location."
              ),
              state: Schema.string(
                description: "The US state of the location."
              ),
            },
          }),
          date: Schema.string({
            description:
              "The date for which to get the weather. Date must be in the" +
              " format: YYYY-MM-DD.",
          }),
        },
      }),
    },
  ],
};

final fetchWeatherTool = FunctionDeclaration(
    'fetchWeather',
    'Get the weather conditions for a specific city on a specific date.',
    parameters: {
      'location': Schema.object(
        description:
          'The name of the city and its state for which to get'
          'the weather. Only cities in the USA are supported.',
        properties: {
          'city': Schema.string(
             description: 'The city of the location.'
           ),
          'state': Schema.string(
             description: 'The US state of the location.'
          ),
        },
      ),
      'date': Schema.string(
        description:
          'The date for which to get the weather. Date must be in the format: YYYY-MM-DD.'
      ),
    },
  );

import FirebaseVertexAI

// Initialize the Vertex AI service and the generative model.
let model = VertexAI.vertexAI().generativeModel(
  modelName: "gemini-2.0-flash",
  // Provide the function declaration to the model.
  tools: [.functionDeclarations([fetchWeatherTool])]
)

// Initialize the Vertex AI service and the generative model
val model = Firebase.vertexAI.generativeModel(
    modelName = "gemini-2.0-flash",
    // Provide the function declaration to the model.
    tools = listOf(Tool.functionDeclarations(listOf(fetchWeatherTool)))
)

// Initialize the Vertex AI service and the generative model
// Use a model that supports function calling, like a Gemini 1.5 model
GenerativeModelFutures model = GenerativeModelFutures.from(
        FirebaseVertexAI.getInstance()
                .generativeModel("gemini-1.5-flash",
                        null,
                        null,
                        // Provide the function declaration to the model.
                        List.of(Tool.functionDeclarations(List.of(fetchWeatherTool)))));

import { initializeApp } from "firebase/app";
import { getVertexAI, getGenerativeModel } from "firebase/vertexai";

// TODO(developer) Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Vertex AI service
const vertexAI = getVertexAI(firebaseApp);

// Initialize the generative model
const model = getGenerativeModel(vertexAI, {
  model: "gemini-2.0-flash",
  // Provide the function declaration to the model.
  tools: fetchWeatherTool
});

import 'package:firebase_vertexai/firebase_vertexai.dart';
import 'package:firebase_core/firebase_core.dart';

await Firebase.initializeApp();

// Initialize the Vertex AI service and the generative model.
_functionCallModel = FirebaseVertexAI.instance.generativeModel(
       model: 'gemini-2.0-flash',
       // Provide the function declaration to the model.
       tools: [
         Tool.functionDeclarations([fetchWeatherTool]),
       ],
     );

let chat = model.startChat()
let prompt = "What was the weather in Boston on October 17, 2024?"

// Send the user's question (the prompt) to the model using multi-turn chat.
let response = try await chat.sendMessage(prompt)

var functionResponses = [FunctionResponsePart]()

// When the model responds with one or more function calls, invoke the function(s).
for functionCall in response.functionCalls {
  if functionCall.name == "fetchWeather" {
    // TODO(developer): Handle invalid arguments.
    guard case let .object(location) = functionCall.args["location"] else { fatalError() }
    guard case let .string(city) = location["city"] else { fatalError() }
    guard case let .string(state) = location["state"] else { fatalError() }
    guard case let .string(date) = functionCall.args["date"] else { fatalError() }

    functionResponses.append(FunctionResponsePart(
      name: functionCall.name,
      // Forward the structured input data prepared by the model
      // to the hypothetical external API.
      response: fetchWeather(city: city, state: state, date: date)
    ))
  }
  // TODO(developer): Handle other potential function calls, if any.
}

val prompt = "What was the weather in Boston on October 17, 2024?"
val chat = model.startChat()
// Send the user's question (the prompt) to the model using multi-turn chat.
val result = chat.sendMessage(prompt)

val functionCalls = result.functionCalls
// When the model responds with one or more function calls, invoke the function(s).
val fetchWeatherCall = functionCalls.find { it.name == "fetchWeather" }

// Forward the structured input data prepared by the model
// to the hypothetical external API.
val functionResponse = fetchWeatherCall?.let {
    // Alternatively, if your `Location` class is marked as @Serializable, you can use
    // val location = Json.decodeFromJsonElement<Location>(it.args["location"]!!)
    val location = Location(
        it.args["location"]!!.jsonObject["city"]!!.jsonPrimitive.content,
        it.args["location"]!!.jsonObject["state"]!!.jsonPrimitive.content
    )
    val date = it.args["date"]!!.jsonPrimitive.content
    fetchWeather(location, date)
}

String prompt = "What was the weather in Boston on October 17, 2024?";
ChatFutures chatFutures = model.startChat();
// Send the user's question (the prompt) to the model using multi-turn chat.
ListenableFuture<GenerateContentResponse> response =
        chatFutures.sendMessage(new Content("user", List.of(new TextPart(prompt))));

ListenableFuture<JsonObject> handleFunctionCallFuture = Futures.transform(response, result -> {
    for (FunctionCallPart functionCall : result.getFunctionCalls()) {
        if (functionCall.getName().equals("fetchWeather")) {
            Map<String, JsonElement> args = functionCall.getArgs();
            JsonObject locationJsonObject =
                    JsonElementKt.getJsonObject(args.get("location"));
            String city =
                    JsonElementKt.getContentOrNull(
                            JsonElementKt.getJsonPrimitive(
                                    locationJsonObject.get("city")));
            String state =
                    JsonElementKt.getContentOrNull(
                            JsonElementKt.getJsonPrimitive(
                                    locationJsonObject.get("state")));
            Location location = new Location(city, state);

            String date = JsonElementKt.getContentOrNull(
                    JsonElementKt.getJsonPrimitive(
                            args.get("date")));
            return fetchWeather(location, date);
        }
    }
    return null;
}, Executors.newSingleThreadExecutor());

const chat = model.startChat();
const prompt = "What was the weather in Boston on October 17, 2024?";

// Send the user's question (the prompt) to the model using multi-turn chat.
let result = await chat.sendMessage(prompt);
const functionCalls = result.response.functionCalls();
let functionCall;
let functionResult;
// When the model responds with one or more function calls, invoke the function(s).
if (functionCalls.length > 0) {
  for (const call of functionCalls) {
    if (call.name === "fetchWeather") {
      // Forward the structured input data prepared by the model
      // to the hypothetical external API.
      functionResult = await fetchWeather(call.args);
      functionCall = call;
    }
  }
}

final chat = _functionCallModel.startChat();
const prompt = 'What was the weather in Boston on October 17, 2024?';

// Send the user's question (the prompt) to the model using multi-turn chat.
var response = await chat.sendMessage(Content.text(prompt));

final functionCalls = response.functionCalls.toList();
// When the model responds with one or more function calls, invoke the function(s).
if (functionCalls.isNotEmpty) {
  final functionCall = functionCalls.first;
  if (functionCall.name == 'fetchWeather') {
    // Forward the structured input data prepared by the model
    // to the hypothetical external API.
    Map<String, dynamic> location =
        functionCall.args['location']! as Map<String, dynamic>;
    var date = functionCall.args['date']! as String;
    var city = location['city']! as String;
    var state = location['state']! as String;
    final functionResult = await fetchWeather(Location(city, state), date);
    ...
} else {
  throw UnimplementedError(
    'Function not declared to the model: ${functionCall.name}',
  );
}

// Send the response(s) from the function back to the model
// so that the model can use it to generate its final response.
let finalResponse = try await chat.sendMessage(
  [ModelContent(role: "function", parts: functionResponses)]
)

// Log the text response.
print(finalResponse.text ?? "No text in response.")

// Send the response(s) from the function back to the model
// so that the model can use it to generate its final response.
val finalResponse = chat.sendMessage(content("function") {
    part(FunctionResponsePart("fetchWeather", functionResponse!!))
})

// Log the text response.
println(finalResponse.text ?: "No text in response")

ListenableFuture<GenerateContentResponse> modelResponseFuture = Futures.transformAsync(
  handleFunctionCallFuture,
  // Send the response(s) from the function back to the model
  // so that the model can use it to generate its final response.
  functionCallResult -> chatFutures.sendMessage(new Content("function",
  List.of(new FunctionResponsePart(
          "fetchWeather", functionCallResult)))),
  Executors.newSingleThreadExecutor());

Futures.addCallback(modelResponseFuture, new FutureCallback<GenerateContentResponse>() {
@Override
public void onSuccess(GenerateContentResponse result) {
  if (result.getText() != null) {
      // Log the text response.
      System.out.println(result.getText());
  }
}

@Override
public void onFailure(Throwable t) {
  // handle error
}
}, Executors.newSingleThreadExecutor());

// Send the response from the function back to the model
// so that the model can use it to generate its final response.
result = await chat.sendMessage([
  {
    functionResponse: {
      name: functionCall.name, // "fetchWeather"
      response: functionResult,
    },
  },
]);
console.log(result.response.text());

// Send the response from the function back to the model
// so that the model can use it to generate its final response.
response = await chat
     .sendMessage(Content.functionResponse(functionCall.name, functionResult));