#!/usr/bin/env python3
"""
Quick hash calculator for malware samples.
Calculates MD5, SHA1, and SHA256 hashes simultaneously.
"""

import hashlib
import sys
from pathlib import Path


def calculate_hashes(file_path):
    """
    Calculate MD5, SHA1, and SHA256 hashes for a file.

    Args:
        file_path: Path to the file

    Returns:
        dict: Dictionary containing all three hashes
    """
    md5 = hashlib.md5()
    sha1 = hashlib.sha1()
    sha256 = hashlib.sha256()

    try:
        with open(file_path, 'rb') as f:
            # Read in chunks for memory efficiency
            while chunk := f.read(8192):
                md5.update(chunk)
                sha1.update(chunk)
                sha256.update(chunk)

        return {
            'md5': md5.hexdigest(),
            'sha1': sha1.hexdigest(),
            'sha256': sha256.hexdigest()
        }
    except (FileNotFoundError, PermissionError, IsADirectoryError, OSError) as e:
        return {'error': str(e)}


def main():
    if len(sys.argv) < 2:
        print("Usage: python hash_calculator.py <file_path>")
        sys.exit(1)

    file_path = Path(sys.argv[1])

    if not file_path.exists():
        print(f"Error: File '{file_path}' not found")
        sys.exit(1)

    if not file_path.is_file():
        print(f"Error: '{file_path}' is not a file")
        sys.exit(1)

    print(f"Calculating hashes for: {file_path}")
    print(f"File size: {file_path.stat().st_size} bytes")
    print("-" * 70)

    hashes = calculate_hashes(file_path)

    if 'error' in hashes:
        print(f"Error calculating hashes: {hashes['error']}")
        sys.exit(1)

    print(f"MD5:    {hashes['md5']}")
    print(f"SHA1:   {hashes['sha1']}")
    print(f"SHA256: {hashes['sha256']}")


if __name__ == "__main__":
    main()