"""
Metadata Agent
Generates structured metadata for proof objects.
"""

from typing import Dict, Any
from datetime import datetime, timezone

from core.agent_base import Agent
from core.errors import MetadataError


class MetadataAgent(Agent):
    """
    Creates comprehensive metadata for proof generation.
    """
    
    def execute(self, input_data: Dict[str, Any]) -> Dict[str, Any]:
        """
        Generate metadata object.
        
        Expected input_data:
            {
                "content_type": str,
                "size": int,
                "filename": str | None,
                "content_hash": str,
                "hash_algorithm": str,
                "hash_timestamp": str,
                "validation_status": str,
                ...
            }
        
        Returns:
            {
                "metadata": {
                    "content_type": str,
                    "content_size": int,
                    "filename": str | None,
                    "hash_reference": str,
                    "created_at": str,
                    "validation_status": str,
                },
                ...passes through input_data...
            }
        """
        try:
            metadata = {
                "content_type": input_data.get("content_type"),
                "content_size": input_data.get("size"),
                "filename": input_data.get("filename"),
                "hash_reference": input_data.get("content_hash"),
                "hash_algorithm": input_data.get("hash_algorithm"),
                "created_at": datetime.now(timezone.utc).isoformat(),
                "validation_status": input_data.get("validation_status"),
            }
            
            # Validate required fields
            required = ["content_type", "content_size", "hash_reference"]
            missing = [k for k in required if metadata.get(k) is None]
            
            if missing:
                raise MetadataError(f"Missing required fields: {', '.join(missing)}")
            
            result = input_data.copy()
            result["metadata"] = metadata
            
            return result
            
        except Exception as e:
            if isinstance(e, MetadataError):
                raise
            raise MetadataError(f"Metadata generation failed: {str(e)}") from e