main.py

import os
from dotenv import load_dotenv
from google import genai
from google.genai import types
from argparse import ArgumentParser
from prompts import system_prompt
from call_functions import available_functions, call_function
from config import MAX_ITERS

parser = ArgumentParser()
parser.add_argument("user_prompt", type=str, help="User prompt")
parser.add_argument("--verbose", action="store_true", help="Enable verbose output")
args = parser.parse_args()

load_dotenv()
api_key = os.environ.get("GEMINI_API_KEY")

client = genai.Client(api_key=api_key)
model = "gemini-2.5-flash"
contents = args.user_prompt
messages = [types.Content(role="user", parts=[types.Part(text=args.user_prompt)])]
response = None

for _ in range(MAX_ITERS):
    response = client.models.generate_content(
        model=model,
        contents=messages,
        config=types.GenerateContentConfig(
            system_instruction=system_prompt,
            temperature=0,
            tools=[available_functions],
        ),
    )

    if response.candidates and response.candidates[0].content:
        messages.append(response.candidates[0].content)

    function_calls = response.function_calls
    function_results = []

    if function_calls is not None:
        for call in function_calls:
            function_call_result = call_function(call)

            if not function_call_result.parts:
                raise Exception("Can't call a function.")

            if not function_call_result.parts[0].function_response:
                raise Exception("There are no function response.")

            function_results.append(function_call_result.parts[0])

            if args.verbose:
                print("User prompt:", contents)

                if response.usage_metadata:
                    prompt_token = response.usage_metadata.prompt_token_count
                    response_token = response.usage_metadata.candidates_token_count

                    print(f"Prompt tokens: {prompt_token}")
                    print(f"Response tokens: {response_token}")
                    print(
                        f"-> {function_call_result.parts[0].function_response.response}"
                    )
                else:
                    raise RuntimeError("Usage metadata not found")

        messages.append(types.Content(role="user", parts=function_results))

    else:
        print("Response:")
        print(response.text)
        break

if not response:
    print(
        f"Error: reached {MAX_ITERS} iterations, but the model never produced a final response."
    )
    raise SystemExit(1)