math_engine.py

import random

# Levels definition
# Targeting ages 9-10

def generate_question(level: int) -> tuple[str, int]:
    """
    Returns (question_string, correct_answer) for the given level.
    Levels:
      1 - Additions         (1–30)
      2 - Subtractions      (1–30, positive result)
      3 - Multiplications   (2×2 … 9×9)
      4 - Mix               (all of the above, up to 50)
      5 - Hard Mix          (2-digit additions/subtractions, 6×…12× tables)
    """
    if level == 1:
        a = random.randint(1, 30)
        b = random.randint(1, 30)
        return f"{a} + {b}", a + b

    elif level == 2:
        a = random.randint(1, 30)
        b = random.randint(1, a)
        return f"{a} - {b}", a - b

    elif level == 3:
        a = random.randint(2, 9)
        b = random.randint(2, 9)
        return f"{a} × {b}", a * b

    elif level == 4:  # Mix
        op = random.choice(["add", "sub", "mul"])
        if op == "add":
            a = random.randint(10, 50)
            b = random.randint(10, 50)
            return f"{a} + {b}", a + b
        elif op == "sub":
            a = random.randint(10, 50)
            b = random.randint(1, a)
            return f"{a} - {b}", a - b
        else:
            a = random.randint(2, 12)
            b = random.randint(2, 12)
            return f"{a} × {b}", a * b

    else:  # level 5+ — Hard Mix
        op = random.choice(["add", "sub", "mul"])
        if op == "add":
            a = random.randint(10, 99)
            b = random.randint(10, 99)
            return f"{a} + {b}", a + b
        elif op == "sub":
            a = random.randint(20, 99)
            b = random.randint(10, a - 10)   # both operands ≥ 2 digits, result ≥ 10
            return f"{a} - {b}", a - b
        else:
            a = random.randint(6, 12)        # tables ≥ 6
            b = random.randint(6, 12)
            return f"{a} × {b}", a * b


LEVEL_NAMES = {
    1: "➕ Additions",
    2: "➖ Subtractions",
    3: "✖️ Multiplications",
    4: "🎲 Mix",
}

LEVEL_THRESHOLDS = {1: 5, 2: 5, 3: 5, 4: 999}

def level_up_message(level: int) -> str:
    messages = {
        2: "🎉 Next level!",
        3: "🌟 Multiplications!",
        4: "🏆 Expert mode!",
    }
    return messages.get(level, "")