"""Thumbnail generation service."""

import pymupdf
from pathlib import Path

from app.config import settings

def generate_thumbnail(file_id: str) -> None:
    """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
        
    try:
        doc = pymupdf.open(pdf_path)
        if len(doc) > 0:
            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")
        doc.close()
    except Exception as e:
        print(f"Failed to generate thumbnail for {file_id}: {e}")

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