import base64
import zipfile
from io import BytesIO
from IPython.display import HTML, display

qb = QuantBook()

folder_name = "Database"
file_name = "financials_and_prices.db"
object_store_db_key = f"{folder_name}/{file_name}"
zip_file_name = "financials_and_prices.zip"

# Use ContainsKey (standard QuantConnect API)
if qb.ObjectStore.ContainsKey(object_store_db_key):
    
    # 1. THE FIX: Read as raw binary bytes instead of text
    sqlite_bytes = qb.ObjectStore.ReadBytes(object_store_db_key)
    
    zip_buffer = BytesIO()
    
    with zipfile.ZipFile(zip_buffer, 'w', zipfile.ZIP_DEFLATED) as zf:
        # 2. writestr safely accepts byte arrays, preserving the SQLite architecture
        zf.writestr(object_store_db_key, sqlite_bytes)
        
    zip_bytes = zip_buffer.getvalue()
    b64 = base64.b64encode(zip_bytes).decode('utf-8')
    
    html_payload = f'''
    <a download="{zip_file_name}" 
       href="data:application/zip;base64,{b64}" 
       target="_blank" 
       style="padding: 10px 15px; background-color: #1a73e8; color: white; text-decoration: none; border-radius: 4px; font-weight: bold;">
       ⬇️ Download {zip_file_name}
    </a>
    '''
    
    display(HTML(html_payload))
    print("Click the button to download your SQLite database.")
    
else:
    print(f"File '{object_store_db_key}' not found in the Object Store.")