"""PDF generation from Markdown using markdown-pdf."""
from io import BytesIO
from pathlib import Path
from typing import Optional

from markdown_pdf import MarkdownPdf, Section

_PROJECT_ROOT = Path(__file__).resolve().parent.parent


def markdown_to_pdf(
    md_text: str,
    toc_level: int = 2,
    logo_path: Optional[str] = None,
) -> BytesIO:
    """Convert Markdown to PDF using markdown-pdf (PyMuPDF + markdown-it-py).

    Supports UTF-8, tables, links, images, and TOC from headings.
    Optionally adds a dedicated logo section at the top (centered) if logo_path is set.
    """
    if logo_path is None:
        try:
            from config.settings import settings
            logo_path = getattr(settings, "pdf_logo_path", None)
        except Exception:
            logo_path = None

    pdf = MarkdownPdf(toc_level=toc_level, optimize=True)

    # Section 1: logo centered at top (if file exists)
    logo_file = _PROJECT_ROOT / logo_path if logo_path else None
    if logo_file and logo_file.is_file():
        logo_md = f"![Logo]({logo_path})"
        logo_css = "img { display: block; margin-left: auto; margin-right: auto; }"
        logo_section = Section(logo_md, toc=False)
        logo_section.root = str(_PROJECT_ROOT)
        pdf.add_section(logo_section, user_css=logo_css)

    # Section 2: main content (réduit la police)
    content_css = (
        "body, p, li, ul, ol, td, th { font-size: 9pt; } "
        "h1 { font-size: 14pt; } h2 { font-size: 12pt; } h3 { font-size: 10pt; }"
    )
    content_section = Section(md_text)
    content_section.root = str(_PROJECT_ROOT)
    pdf.add_section(content_section, user_css=content_css)

    buffer = BytesIO()
    pdf.save_bytes(buffer)
    buffer.seek(0)
    return buffer