#!/usr/bin/env python3
"""
Calculator CLI - A simple command-line calculator.

NOTE: This file contains intentional bugs for testing purposes.

Usage:
    python -m calculator.main 10 5 add
    python -m calculator.main 10 5 sub
    python -m calculator.main 10 5 mul
    python -m calculator.main 10 5 div
"""
import sys

from calculator.operations import add, subtract, multiply, divide


def get_operation(op_name: str):
    """
    Get the operation function by name.

    BUG: No validation - invalid operation names cause KeyError!
    """
    operations = {
        "add": add,
        "sub": subtract,
        "mul": multiply,
        "div": divide,
        # BUG: 'power' is implemented in operations.py but not exposed here
    }
    # BUG: Should handle KeyError gracefully
    return operations[op_name]


def main():
    """Main entry point."""
    if len(sys.argv) != 4:
        print("Usage: python -m calculator.main <a> <b> <operation>")
        print("Operations: add, sub, mul, div")
        sys.exit(1)

    # BUG: No validation that a and b are valid numbers
    a = float(sys.argv[1])
    b = float(sys.argv[2])
    op_name = sys.argv[3]

    # BUG: This will crash with KeyError for invalid operation
    operation = get_operation(op_name)
    result = operation(a, b)

    print(f"Result: {result}")


if __name__ == "__main__":
    main()