import numpy as np
from pdf2image import convert_from_bytes, convert_from_path
from PIL import Image


class PdfConverter:
    """
    A service to convert PDF files to images and resize images,
    using pypdfium2 for PDFs and Pillow for images.
    """

    def __init__(self, dpi: int):
        self._pdfium_initialized = False  # Track if PDFium needs explicit init/deinit
        self._dpi = dpi

    def convert_pdf_to_jpg(self, file_path: str) -> list[Image.Image]:
        """
        Converts a PDF file to JPG images at different scales.
        """
        pil_images = convert_from_path(file_path, dpi=self._dpi)
        return pil_images

    def resize_image(self, img: Image.Image, size: tuple[int, int]) -> Image.Image:
        """
        Resizes a PIL Image to the specified size.
        """
        return img.resize(size, Image.LANCZOS)

    @staticmethod
    def save_image_as_png(img: Image.Image, file_path: str):
        """
        Saves a PIL Image as a PNG file.
        """
        img.save(file_path, format="PNG")

    @staticmethod
    def to_cv2_image(img: Image.Image):
        open_cv_image = np.array(img.convert("RGB"))
        return open_cv_image[:, :, ::-1].copy()

    def convert_pdf_bytes_to_jpg(self, pdf_bytes: bytes) -> list[Image.Image]:
        """
        Converts PDF bytes to JPG images at different scales.
        """
        pil_images = convert_from_bytes(pdf_bytes, dpi=self._dpi)
        return pil_images