import os

try:
    from PIL import Image
except Exception:
    print("\nimg2pdf.py: Import error: PIL.Image")
    input("Install: pip install Pillow\n")


def image_to_pdf(input_path, output_path=None):
    """
    画像ファイルをPDFに変換します。
    成功時は output_path を返し、失敗時は None を返します。
    """
    input_path = os.path.abspath(input_path)
    if output_path is None:
        output_path = os.path.splitext(input_path)[0] + ".pdf"
    else:
        output_path = os.path.abspath(output_path)

    print(f"  Converting '{os.path.basename(input_path)}' to PDF...")

    image = None
    try:
        if not os.path.exists(input_path):
            print(f"  Error converting '{input_path}' to PDF: file does not exist")
            return None

        if os.path.getsize(input_path) == 0:
            print(f"  Error converting '{input_path}' to PDF: file is empty")
            return None

        image = Image.open(input_path)

        # PDF保存時はRGB系が安全
        if image.mode in ("RGBA", "LA", "P"):
            image = image.convert("RGB")
        elif image.mode != "RGB":
            image = image.convert("RGB")

        image.save(output_path, "PDF", resolution=100.0)
        print(f"  Successfully converted to PDF: '{output_path}'")
        return output_path

    except Exception as e:
        print(f"  Error converting '{input_path}' to PDF: {e}")
        return None
    finally:
        if image is not None:
            try:
                image.close()
            except Exception:
                pass


if __name__ == "__main__":
    import sys

    input_path = sys.argv[1] if len(sys.argv) > 1 else None
    output_path = sys.argv[2] if len(sys.argv) > 2 else None

    if not input_path:
        print("Usage: python img2pdf_importable.py input_image [output.pdf]")
        input("\nPress ENTER to terminate>>\n")
        raise SystemExit(1)

    image_to_pdf(input_path, output_path)
    print("\nProgram execution completed.")
    input("\nPress ENTER to terminate>>\n")