"""PDF export — saves Plotly figures as PDF files using kaleido."""

import asyncio
import os
import plotly.graph_objects as go


async def export_pdf(fig: go.Figure, filename: str) -> str:
    """
    Export a Plotly figure to PDF. Save to /tmp/{filename}.pdf.
    Uses asyncio.to_thread to avoid blocking.
    Returns the file path on success, empty string on failure.
    """
    path = f"/tmp/{filename}.pdf"
    try:
        await asyncio.to_thread(
            fig.write_image, path, format="pdf", width=1200, height=600
        )
        return path
    except Exception:
        return ""


async def export_multiple_pdf(figures: dict[str, go.Figure]) -> dict[str, str]:
    """Export multiple figures to PDF in parallel."""
    results = await asyncio.gather(
        *[export_pdf(fig, name) for name, fig in figures.items()]
    )
    return dict(zip(figures.keys(), results))