"""Handler for importing PDF files into Obsidian."""

import shutil
from pathlib import Path

from utils.config import ensure_unique_path, sanitize_filename


def handle_pdf(file_path: Path, vault_path: Path) -> Path:
    """Import a PDF file into the Obsidian vault.

    - Converts PDF content to a new Obsidian markdown note.
    - Creates a hidden folder for extracted images and the original PDF.
    - Embeds extracted images and links to the original PDF.
    """
    try:
        import fitz  # pymupdf
    except ImportError:
        raise ImportError(
            "PDF handling requires 'pymupdf'. Install it with:\n  pip install pymupdf"
        )

    title = sanitize_filename(file_path.stem)
    note_name = f"{title}.md"
    note_path = ensure_unique_path(vault_path / note_name)

    # Hidden assets folder: .{title}_assets
    assets_folder_name = f".{title}_assets"
    assets_folder = vault_path / assets_folder_name
    counter = 1
    while assets_folder.exists():
        assets_folder_name = f".{title}_assets_{counter}"
        assets_folder = vault_path / assets_folder_name
        counter += 1
    assets_folder.mkdir(parents=True, exist_ok=True)

    # Copy original PDF into assets folder
    pdf_copy_name = f"{title}.pdf"
    pdf_copy_path = ensure_unique_path(assets_folder / pdf_copy_name)
    shutil.copy2(file_path, pdf_copy_path)

    # Open PDF and extract content + images
    doc = fitz.open(file_path)
    markdown_lines = [f"# {title}", ""]

    # Link to original PDF
    rel_pdf_path = f"{assets_folder_name}/{pdf_copy_path.name}"
    markdown_lines.append(f"**Original PDF:** [{pdf_copy_path.name}]({rel_pdf_path})")
    markdown_lines.append("")

    # Extract images and text per page
    image_entries = []  # list of (page_num, img_path, rel_path)
    for page_num in range(len(doc)):
        page = doc.load_page(page_num)

        # Extract images
        img_list = page.get_images(full=True)
        for img_index, img in enumerate(img_list):
            xref = img[0]
            try:
                base_image = doc.extract_image(xref)
                image_bytes = base_image["image"]
                ext = base_image["ext"]
                img_filename = f"page_{page_num + 1}_img_{img_index + 1}.{ext}"
                img_path = assets_folder / img_filename
                # Handle duplicates
                img_path = ensure_unique_path(img_path)
                img_path.write_bytes(image_bytes)
                rel_img = f"{assets_folder_name}/{img_path.name}"
                image_entries.append((page_num + 1, img_path, rel_img))
            except Exception as e:
                print(
                    f"[PDF] Warning: could not extract image {img_index} on page {page_num + 1}: {e}"
                )

        # Extract text
        text = page.get_text()
        if text.strip():
            markdown_lines.append(f"## Page {page_num + 1}")
            markdown_lines.append("")
            markdown_lines.append(text.strip())
            markdown_lines.append("")

    doc.close()

    # Add image section if any images were extracted
    if image_entries:
        markdown_lines.append("## Extracted Images")
        markdown_lines.append("")
        for page_num, img_path, rel_img in image_entries:
            markdown_lines.append(f"### Page {page_num}")
            markdown_lines.append(f"![{img_path.name}]({rel_img})")
            markdown_lines.append("")

    note_path.write_text("\n".join(markdown_lines), encoding="utf-8")
    print(f"[PDF] Created note: {note_path}")
    print(f"[PDF] Assets folder: {assets_folder}")
    return note_path