#!/usr/bin/env python3
"""
Binary to Text Converter for IUM files
Converts .bin files to .txt format matching ium11.txt structure
"""

import sys
import os


def bin_to_txt(bin_file_path, txt_file_path=None):
    """
    Convert binary file to text format matching the ium11.txt structure
    
    Args:
        bin_file_path (str): Path to input binary file
        txt_file_path (str): Path to output text file (optional)
    
    Returns:
        str: Path to generated text file
    """
    
    if not os.path.exists(bin_file_path):
        raise FileNotFoundError(f"Binary file not found: {bin_file_path}")
    
    # Generate output filename if not provided
    if txt_file_path is None:
        base_name = os.path.splitext(bin_file_path)[0]
        txt_file_path = f"{base_name}_converted.txt"
    
    # Read binary file
    try:
        with open(bin_file_path, 'rb') as bin_file:
            binary_data = bin_file.read()
    except Exception as e:
        raise Exception(f"Error reading binary file: {e}")
    
    # Convert binary data to text format
    try:
        with open(txt_file_path, 'w') as txt_file:
            # Write start marker
            txt_file.write("start\n")
            
            # Process binary data in 4-byte chunks (32-bit words)
            for i in range(0, len(binary_data), 4):
                chunk = binary_data[i:i+4]
                
                # Pad with zeros if chunk is less than 4 bytes
                if len(chunk) < 4:
                    chunk = chunk + b'\x00' * (4 - len(chunk))
                
                # Convert to little-endian 32-bit hex value
                hex_value = chunk[::-1].hex().upper()  # Reverse bytes for little-endian
                
                # Format as 8-character hex string
                hex_value = hex_value.zfill(8)
                
                # Write hex value
                txt_file.write(f"{hex_value}\n")
            
            # Write end marker
            txt_file.write("end\n")
            txt_file.write("\n")
        
        return txt_file_path
        
    except Exception as e:
        raise Exception(f"Error writing text file: {e}")


def main():
    """Main function to handle command line arguments"""
    
    if len(sys.argv) < 2:
        print("Usage: python bin_to_txt_converter.py <input_bin_file> [output_txt_file]")
        print("\nExample:")
        print("  python bin_to_txt_converter.py ium11.bin")
        print("  python bin_to_txt_converter.py ium11.bin ium11_converted.txt")
        sys.exit(1)
    
    bin_file_path = sys.argv[1]
    txt_file_path = sys.argv[2] if len(sys.argv) > 2 else None
    
    try:
        output_path = bin_to_txt(bin_file_path, txt_file_path)
        print(f"Successfully converted {bin_file_path} to {output_path}")
        
        # Show file sizes for verification
        bin_size = os.path.getsize(bin_file_path)
        txt_size = os.path.getsize(output_path)
        print(f"Binary file size: {bin_size} bytes")
        print(f"Text file size: {txt_size} bytes")
        
    except Exception as e:
        print(f"Error: {e}")
        sys.exit(1)


if __name__ == "__main__":
    main()