# Copyright 2026 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# SPDX-License-Identifier: Apache-2.0
"""Common tools for samples."""
import operator
import random
from .types import (
CalculatorInput,
CurrencyExchangeInput,
WeatherInput,
)
def calculate(input: CalculatorInput) -> dict:
"""Perform basic arithmetic operations.
Uses a dispatch table lookup and handles arithmetic edge cases.
"""
operations = {
'add': operator.add,
'subtract': operator.sub,
'multiply': operator.mul,
'divide': operator.truediv,
}
op_name = input.operation.lower()
handler = operations.get(op_name)
if not handler:
return {'error': f'Unknown operation: {op_name}'}
try:
a, b = float(input.a), float(input.b)
result = handler(a, b)
except ZeroDivisionError:
return {'error': 'Division by zero'}
except (ValueError, TypeError) as e:
return {'error': f'Invalid numeric input: {e}'}
return {
'operation': op_name,
'a': a,
'b': b,
'result': result,
}
def convert_currency(input: CurrencyExchangeInput) -> str:
"""Convert currency amount.
Args:
input: Currency conversion parameters.
Returns:
Converted amount.
"""
# Mock conversion rates
rates = {
('USD', 'EUR'): 0.85,
('EUR', 'USD'): 1.18,
('USD', 'GBP'): 0.73,
('GBP', 'USD'): 1.37,
}
rate = rates.get((input.from_currency, input.to_currency), 1.0)
converted = input.amount * rate
return f'{input.amount} {input.from_currency} = {converted:.2f} {input.to_currency}'
def get_weather(input: WeatherInput) -> str:
"""Return a random realistic weather string for a city name.
Args:
input: Weather input location.
Returns:
Weather information with temperature in degree Celsius.
"""
weather_options = [
'32° C sunny',
'17° C cloudy',
'22° C cloudy',
'19° C humid',
]
return random.choice(weather_options)
