#!/usr/bin/env python3
"""Extract text and metadata from PDF files.

This script demonstrates reading JSON arguments from stdin,
processing them, and outputting results in JSON format.

Environment Variables:
- SKILL_NAME: Name of the parent skill
- SKILL_BASE_DIR: Base directory of the skill
- SKILL_VERSION: Version of the skill
- SKILLKIT_VERSION: Version of skillkit
"""
import sys
import json
import os


def extract_pdf(file_path: str, pages: str | list):
    """
    Extract text from PDF file (mock implementation).

    In a real implementation, this would use a library like PyPDF2 or pdfplumber.

    Args:
        file_path: Path to the PDF file
        pages: "all" or list of page numbers

    Returns:
        dict with extracted text and metadata
    """
    # Mock implementation for demonstration
    return {
        "text": f"Extracted text from {file_path}",
        "metadata": {
            "title": "Sample Document",
            "author": "skillkit",
            "pages": 10,
            "file_path": file_path,
            "requested_pages": pages
        },
        "environment": {
            "skill_name": os.getenv("SKILL_NAME"),
            "skill_base_dir": os.getenv("SKILL_BASE_DIR"),
            "skill_version": os.getenv("SKILL_VERSION"),
            "skillkit_version": os.getenv("SKILLKIT_VERSION")
        }
    }


def main():
    """Main entry point for the PDF extraction script."""
    try:
        # Read JSON arguments from stdin
        args = json.load(sys.stdin)

        # Validate required arguments
        if "file_path" not in args:
            raise ValueError("Missing required argument: file_path")

        # Extract optional arguments
        file_path = args["file_path"]
        pages = args.get("pages", "all")

        # Perform extraction
        result = extract_pdf(file_path, pages)

        # Output result as JSON
        print(json.dumps(result, indent=2))
        sys.exit(0)

    except json.JSONDecodeError as e:
        error = {
            "error": "Invalid JSON input",
            "details": str(e)
        }
        print(json.dumps(error), file=sys.stderr)
        sys.exit(1)

    except ValueError as e:
        error = {
            "error": "Invalid arguments",
            "details": str(e)
        }
        print(json.dumps(error), file=sys.stderr)
        sys.exit(1)

    except Exception as e:
        error = {
            "error": "Unexpected error",
            "details": str(e)
        }
        print(json.dumps(error), file=sys.stderr)
        sys.exit(1)


if __name__ == "__main__":
    main()