#!/usr/bin/env python3
"""Two-pass PDF generator: WeasyPrint + pikepdf page numbering."""

from weasyprint import HTML
import pikepdf
import io, os, re

def generate_sds_with_page_numbers(html, output_path):
    """Generate PDF with 'Page X of Y' numbering on each page."""
    
    # Pass 1: generate PDF, measure pages
    buf = io.BytesIO()
    HTML(string=html).write_pdf(buf)
    buf.seek(0)
    
    pdf = pikepdf.Pdf.open(buf)
    total_pages = len(pdf.pages)
    
    if total_pages <= 1:
        pdf.save(output_path)
        pdf.close()
        return total_pages
    
    # Pass 2: add page numbers via PDF annotation objects
    # We add a simple text annotation at the bottom center of each page
    
    # Load font info - we need standard fonts
    for page_num, page in enumerate(pdf.pages, 1):
        # Get page dimensions
        mediabox = page.media_box
        width = float(mediabox[2])
        bottom_y = 56  # ~1.5cm from bottom
        
        text = f"Page {page_num} of {total_pages}"
        
        # Create a content stream for the page number
        content = pikepdf.ContentStream(pdf)
        # PDF operators for text rendering
        content.operations.extend([
            pikepdf.StreamOperation('BT', []),
            pikepdf.StreamOperation('q', []),
            pikepdf.StreamOperation('1 0 0 1 0 0 cm', []), 
            pikepdf.StreamOperation('0.357 0.400 0.435 RG', []),  # #5B6670 RGB
            pikepdf.StreamOperation('0.357 0.400 0.435 rg', []),
            # No custom fonts - use built-in Helvetica
            pikepdf.StreamOperation('/Helvetica 7 Tf', []),
            # Position
            pikepdf.StreamOperation(f'{width/2:.0f} {bottom_y} Td', []),
            pikepdf.StreamOperation(f'({text}) Tj', []),
            pikepdf.StreamOperation('Q', []),
            pikepdf.StreamOperation('ET', []),
        ])
        
        page.add_content(content)
    
    pdf.save(output_path)
    pdf.close()
    return total_pages


if __name__ == '__main__':
    # Test
    test_html = """<html><body>
<style>
@page { size: A4; margin: 2cm; }
body { font-family: sans-serif; }
</style>
<p>Page 1 content</p>
<p>Page 2 content</p>
<p>Page 3 content</p>
</body></html>"""
    
    n = generate_sds_with_page_numbers(test_html, '/tmp/test_numbered.pdf')
    print(f'Generated {n} pages')
    
    # Verify
    with pikepdf.Pdf.open('/tmp/test_numbered.pdf') as pdf:
        for i, page in enumerate(pdf.pages, 1):
            print(f'Page {i}: {len(page.contents)} content streams')