converter.py

"""
LibraryThing to Library Management System converter.

Converts book exports from LibraryThing JSON format to the format
used by the Library Management System.
"""

import json
from datetime import datetime


def convert_library_format(input_filename: str, output_filename: str) -> None:
    """
    Converts a LibraryThing JSON export to the format used by our app,
    ensuring correct handling of UTF-8 characters and adding the date_added field.
    """
    try:
        with open(input_filename, 'r', encoding='utf-8') as f:
            data = json.load(f)
    except FileNotFoundError:
        print(f"Error: The file '{input_filename}' was not found.")
        return
    except json.JSONDecodeError:
        print(f"Error: The file '{input_filename}' is not a valid JSON file.")
        return

    converted_books = []
    for book_id, book_data in data.items():
        title = book_data.get('title', 'N/A')
        author = book_data.get('primaryauthor', 'N/A')
        
        isbn_info = book_data.get('isbn')
        isbn = "N/A"
        if isinstance(isbn_info, dict):
            isbn = isbn_info.get('0', 'N/A')
        elif isinstance(isbn_info, list) and isbn_info:
            isbn = isbn_info[0]
        elif isinstance(isbn_info, str):
            isbn = isbn_info
        
        if isbn == "N/A" and 'originalisbn' in book_data:
            isbn = book_data['originalisbn']

        try:
            year = int(book_data.get('date', '0'))
        except (ValueError, TypeError):
            year = 0
            
        # Use the 'entrydate' from the original file for the 'date_added' field
        # This provides a more meaningful timestamp for your existing books.
        date_added_str = book_data.get('entrydate', datetime.now().strftime('%Y-%m-%d'))
        try:
            # Convert to ISO format for consistent sorting
            date_added_iso = datetime.strptime(date_added_str, '%Y-%m-%d').isoformat()
        except ValueError:
            date_added_iso = datetime.now().isoformat()


        new_book = {
            "title": title,
            "author": author,
            "isbn": isbn,
            "year": year,
            "available": True,
            "date_added": date_added_iso
        }
        converted_books.append(new_book)

    try:
        with open(output_filename, 'w', encoding='utf-8') as f:
            json.dump(converted_books, f, indent=4, ensure_ascii=False)
        print(f"Successfully converted {len(converted_books)} books.")
        print(f"New file saved as '{output_filename}'")
    except IOError as e:
        print(f"Error writing to file '{output_filename}': {e}")


if __name__ == "__main__":
    convert_library_format('librarything_umuthasanoglu.json', 'library.json')