from PIL import Image, ImageDraw, ImageFont

def add_watermark(image):
    watermark_text = "AI Generated by DarkIdol FeiFei"

    # Ensure the input is an Image object
    if not isinstance(image, Image.Image):
        raise ValueError("Input must be a PIL Image object")

    width, height = image.size

    # Create a drawing object to draw on the image
    draw = ImageDraw.Draw(image)

    # Set the font size for the watermark text
    font_size = 10  # Set font size to 10
    try:
        # Try to use a common font file
        font = ImageFont.truetype("Iansui-Regular.ttf", font_size)
    except IOError:
        # Use the default font if the specified font file is not found
        font = ImageFont.load_default()

    # Calculate the width and height of the watermark text using textbbox
    bbox = draw.textbbox((0, 0), watermark_text, font=font)
    text_width = bbox[2] - bbox[0]
    text_height = bbox[3] - bbox[1]

    # Calculate the position for the watermark text (bottom-right corner)
    x = width - text_width - 10  # 10 is the right margin
    y = height - text_height - 10  # 10 is the bottom margin

    # Add the watermark text to the image
    draw.text((x, y), watermark_text, font=font, fill=(255, 255, 255, 128))

    # Return the modified image object
    return image