app.py

import os

from dotenv import load_dotenv
from flask import Flask

app = Flask(__name__)


@app.route("/")
def hello():
    """Returns a simple greeting."""
    return "hello world"


@app.route("/add/<num1>/<num2>")
def add(num1: int, num2: int) -> str:
    """Adds two numbers together.

    Args:
        num1: The first number.
        num2: The second number.

    Returns:
        The sum of the two numbers as a string.
    """
    return str(int(num1) + int(num2))


def fibonacci(n: int) -> int | str:
    """Calculates the nth Fibonacci number.

    Args:
        n: The index of the desired Fibonacci number.

    Returns:
        The nth Fibonacci number, or an error message if the input is invalid.
    """
    if n <= 0:
        return "Invalid input"
    elif n == 1:
        return 0
    elif n == 2:
        return 1
    else:
        a, b = 0, 1
        for _ in range(3, n + 1):
            a, b = b, a + b
        return b


@app.route("/fibonacci/<int:n>")
def get_fibonacci(n: int) -> str:
    """Gets the nth Fibonacci number via the fibonacci function.

    Args:
        n: The index of the desired Fibonacci number.

    Returns:
        The nth Fibonacci number as a string.
    """
    return str(fibonacci(n))


if __name__ == "__main__":
    load_dotenv()
    app.run(debug=os.getenv("ENV") == "dev")