"""Thumbnail generation service."""

import pymupdf

from app.config import settings


def generate_thumbnail(file_id: str) -> bool:
    """Generate a PNG thumbnail for the first page of a PDF."""
    pdf_path = settings.PDF_STORAGE_PATH / f"{file_id}.pdf"
    thumb_path = settings.THUMBNAILS_PATH / f"{file_id}.png"

    if not pdf_path.exists():
        return False

    try:
        with pymupdf.open(pdf_path) as doc:
            if len(doc) == 0:
                return False
            page = doc[0]
            # Zoom to approximately 600px width
            rect = page.rect
            zoom = 600.0 / rect.width if rect.width > 0 else 1.0
            mat = pymupdf.Matrix(zoom, zoom)

            # Render pixmap
            pix = page.get_pixmap(matrix=mat, alpha=False)

            # Save as PNG
            pix.save(thumb_path, output="png")
        return True
    except Exception as err:
        print(f"Failed to generate thumbnail for {file_id}: {err}")
        return False


def delete_thumbnail(file_id: str) -> None:
    """Delete a thumbnail file."""
    thumb_path = settings.THUMBNAILS_PATH / f"{file_id}.png"
    thumb_path.unlink(missing_ok=True)