import time
import random
import os


def start_measurement():
    print("\nDrücke 'ENTER', um die Messung zu starten.")
    input()
    print("Status: Warte auf das Signal...\n")

    time.sleep(random.uniform(2, 6))

    print("JETZT!")

    start = time.perf_counter()
    input()
    end = time.perf_counter()

    return end - start


def save_value(file_path, value):
    with open(file_path, "a") as f:
        f.write(f"{value}\n")


def load_values(file_path):
    if not os.path.exists(file_path):
        return []

    values = []
    with open(file_path, "r") as f:
        for line in f:
            line = line.strip()
            if line:
                values.append(float(line))
    return values


def calculate_average(values):
    if not values:
        return None
    return sum(values) / len(values)


def reset_data(file_path):
    if os.path.exists(file_path):
        os.remove(file_path)
        return True
    return False