from django.http import HttpResponse
import pandas as pd
from io import BytesIO, StringIO


def export_to_excel(self, data, filename):
    """
    Export data to Excel format.

    Args:
        data: Data to export
        filename: Base filename without extension

    Returns:
        HttpResponse: Response with Excel file
    """

    # Convert data to DataFrame
    df = pd.DataFrame(data)

    # Create Excel file in memory
    excel_file = BytesIO()
    with pd.ExcelWriter(excel_file, engine="xlsxwriter") as writer:
        df.to_excel(writer, sheet_name="Model Analysis", index=False)

        # Auto-adjust columns width
        worksheet = writer.sheets["Model Analysis"]
        for i, col in enumerate(df.columns):
            max_width = max(df[col].astype(str).map(len).max(), len(col)) + 2
            worksheet.set_column(i, i, max_width)

    # Set up response
    excel_file.seek(0)
    response = HttpResponse(
        excel_file.read(),
        content_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
    )
    response["Content-Disposition"] = f'attachment; filename="{filename}.xlsx"'
    return response


def export_to_csv(self, data, filename):
    """
    Export data to CSV format.

    Args:
        data: Data to export
        filename: Base filename without extension

    Returns:
        HttpResponse: Response with CSV file
    """

    # Convert data to DataFrame
    df = pd.DataFrame(data)

    # Create CSV file in memory
    csv_file = StringIO()
    df.to_csv(csv_file, index=False)

    # Set up response
    response = HttpResponse(csv_file.getvalue(), content_type="text/csv")
    response["Content-Disposition"] = f'attachment; filename="{filename}.csv"'
    return response