#!/usr/bin/env python3
"""
Scenario 1: The Optimized Version
=================================
This version calls the C implementation via ctypes.

SETUP:
    gcc -O2 -fPIC -shared -o libprime.so prime.c

EXERCISES:
1. Compare: time python3 prime_fast.py
2. Profile: py-spy record -o prime_fast.svg -- python3 prime_fast.py
3. Compare the flamegraphs - what changed?
"""

import ctypes
import sys
import os

# Load the shared library
script_dir = os.path.dirname(os.path.abspath(__file__))
lib_path = os.path.join(script_dir, "libprime.so")

try:
    libprime = ctypes.CDLL(lib_path)
except OSError as e:
    print(f"Error: Could not load {lib_path}")
    print("Please compile first: gcc -O2 -fPIC -shared -o libprime.so prime.c")
    sys.exit(1)

# Define function signatures
libprime.is_prime.argtypes = [ctypes.c_int64]
libprime.is_prime.restype = ctypes.c_int

libprime.count_primes.argtypes = [ctypes.c_int64]
libprime.count_primes.restype = ctypes.c_int64


def is_prime(n):
    """Python wrapper for C is_prime."""
    return bool(libprime.is_prime(n))


def count_primes(limit):
    """Count all primes up to limit."""
    count = 0
    for n in range(2, limit + 1):
        if is_prime(n):
            count += 1
    return count

def main():
    limit = 1_000_000
    if len(sys.argv) > 1:
        limit = int(sys.argv[1])
    
    print(f"Counting primes up to {limit} (using C library)...")
    result = count_primes(limit)
    print(f"Found {result} primes")


if __name__ == "__main__":
    main()