layer_info.py

"""
Helper script to display detailed information about PDF layers.
Usage: python layer_info.py <path_to_pdf>
"""

import sys
import fitz  # PyMuPDF
from typing import List, Dict, Any
import argparse
import json

def get_ocg_xrefs(doc) -> List[int]:
    """Get xrefs for all OCGs in the document."""
    try:
        # Check if PDF has an OCG structure
        catalog = doc.pdf_catalog()
        if not catalog or "OCProperties" not in catalog:
            return []
        
        # Use xref querying for the most reliable method
        ocg_xrefs = []
        for xref in range(1, doc.xref_length()):
            try:
                obj = doc.xref_object(xref, compressed=True)
                if obj and obj.startswith(b"/Type/OCG"):
                    ocg_xrefs.append(xref)
            except:
                continue
        return ocg_xrefs
    except Exception as e:
        print(f"Error getting OCG xrefs: {e}")
        return []

def get_layer_info(pdf_path: str) -> Dict[str, Any]:
    """Get full layer information from a PDF using latest PyMuPDF API."""
    doc = fitz.open(pdf_path)
    
    try:
        # Create a result dictionary
        result = {"ocgs": []}
        
        # Try get_ocgs method first (most reliable)
        if hasattr(doc, "get_ocgs"):
            ocgs = doc.get_ocgs()
            if ocgs:
                for xref, name in ocgs:
                    # Try to get detailed OCG info
                    try:
                        if hasattr(doc, "get_oc"):
                            ocg_info = doc.get_oc(xref)
                            if ocg_info:
                                result["ocgs"].append(ocg_info)
                            else:
                                result["ocgs"].append({"id": xref, "name": name})
                        else:
                            result["ocgs"].append({"id": xref, "name": name})
                    except Exception as e:
                        print(f"Error getting OCG details for {name}: {e}")
                        result["ocgs"].append({"id": xref, "name": name})
                return result
        
        # Try fallback approaches
        # First try to get xrefs directly
        ocg_xrefs = get_ocg_xrefs(doc)
        if ocg_xrefs:
            for xref in ocg_xrefs:
                try:
                    # Try to get OCG info
                    if hasattr(doc, "get_oc"):
                        ocg_info = doc.get_oc(xref)
                        if ocg_info:
                            result["ocgs"].append(ocg_info)
                        else:
                            result["ocgs"].append({"id": xref, "name": f"Layer_{xref}"})
                    else:
                        result["ocgs"].append({"id": xref, "name": f"Layer_{xref}"})
                except Exception as e:
                    print(f"Error getting OCG info for xref {xref}: {e}")
                    result["ocgs"].append({"id": xref, "name": f"Layer_{xref}"})
            return result
            
        # Try layer_ui_configs
        if hasattr(doc, "layer_ui_configs"):
            configs = list(doc.layer_ui_configs())
            for cfg in configs:
                result["ocgs"].append({
                    "id": cfg.get("number", 0),
                    "name": cfg.get("text", "Unnamed"),
                    "on": cfg.get("on", False),
                    "locked": cfg.get("locked", False),
                    "usage": {"view": True}
                })
                
        return result
    except Exception as e:
        print(f"Error getting layer info: {e}")
        return {"ocgs": []}
    finally:
        doc.close()

def print_layer_info(pdf_path: str, show_details: bool = False) -> None:
    """Print detailed information about PDF layers."""
    oc_info = get_layer_info(pdf_path)
    
    if not oc_info or "ocgs" not in oc_info or not oc_info["ocgs"]:
        print(f"No layer information found in {pdf_path}")
        return
    
    ocgs = oc_info["ocgs"]
    print(f"Found {len(ocgs)} layers in {pdf_path}:")
    print("-" * 70)
    
    if show_details:
        # Print detailed JSON output
        print(json.dumps(oc_info, indent=2))
        print("-" * 70)
    
    # Print summary table
    print(f"{'ID':<10} {'Name':<30} {'State':<10} {'Locked':<10} {'Intent'}")
    print("-" * 70)
    
    for ocg in ocgs:
        ocg_id = ocg.get("id", "N/A")
        name = ocg.get("name", "Unnamed")
        state = "On" if ocg.get("on", True) else "Off"
        locked = "Yes" if ocg.get("locked", False) else "No"
        
        # Get usage/intent information
        usage = ocg.get("usage", {})
        intent = []
        for k, v in usage.items():
            if v:
                intent.append(k)
        intent_str = ", ".join(intent) if intent else "None"
        
        print(f"{ocg_id:<10} {name:<30} {state:<10} {locked:<10} {intent_str}")
    
    print("-" * 70)

def main():
    parser = argparse.ArgumentParser(description='Display layer information from a PDF file')
    parser.add_argument('pdf_path', help='Path to the PDF file')
    parser.add_argument('--details', '-d', action='store_true', help='Show full layer configuration details')
    
    args = parser.parse_args()
    print_layer_info(args.pdf_path, args.details)

if __name__ == "__main__":
    main()