import torch
from pathlib import Path
from docling.datamodel.base_models import InputFormat
from docling.datamodel.pipeline_options import PdfPipelineOptions
from docling.document_converter import DocumentConverter, PdfFormatOption
from docling_core.types.doc import ImageRefMode, PictureItem

# 1. Hardware Monkeypatch for Apple Silicon M3 CPU routing
torch.backends.mps.is_available = lambda: False
torch.backends.mps.is_built = lambda: False
torch.set_default_device("cpu")

def convert_with_images(pdf_name: str, output_md_name: str, image_folder_name: str = "extracted_images"):
    source = f"./{pdf_name}"
    output_dir = Path(image_folder_name)
    output_dir.mkdir(exist_ok=True)

    # 2. Configure pipeline to capture images
    pipeline_options = PdfPipelineOptions()
    pipeline_options.images_scale = 2.0          # Increase for higher resolution (2.0 = roughly 144 DPI)
    pipeline_options.generate_picture_images = True # Tells the engine to extract figures/diagrams

    # 3. Initialize converter with our custom options
    converter = DocumentConverter(
        format_options={
            InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
        }
    )

    print(f"🚀 Processing {pdf_name} and extracting figures...")
    result = converter.convert(source)

    # 4. Loop through the document items and save the pictures out to your folder
    picture_counter = 0
    for element, _level in result.document.iterate_items():
        if isinstance(element, PictureItem):
            picture_counter += 1
            image_path = output_dir / f"figure_{picture_counter}.png"
            
            # Save the raw image file cleanly using Pillow (built into docling)
            element.get_image(result.document).save(image_path, "PNG")

    # 5. Save the final Markdown file
    # ImageRefMode.REFERENCED automatically adds clean image links like ![](extracted_images/figure_1.png) into your MD file!
    result.document.save_as_markdown(Path(output_md_name), image_mode=ImageRefMode.REFERENCED)
    
    print(f"✅ Success! Saved {output_md_name} and extracted {picture_counter} figures to ./{image_folder_name}/")

# Run it for your textbook
convert_with_images("1-AS_NZS_3000_2018_Wiring_Rules_Standards_Australia.pdf", "1-AS_NZS_3000_2018_Wiring_Rules_Standards_Australia.md")