import json
import re
from typing import Dict, List, Any, Optional, Union
import logging

logger = logging.getLogger(__name__)

class JSONParser:
    """Centralized JSON parsing utilities for challenge data"""
    
    @staticmethod
    def extract_json_from_response(response_str: str) -> Optional[Dict]:
        """
        Extract JSON from various response formats
        
        Args:
            response_str: The response string that may contain JSON
            
        Returns:
            Parsed JSON dictionary or None if parsing fails
        """
        try:
            # Convert response to string if it's not already
            response_str = str(response_str)
            
            # Try to extract JSON between custom tags first
            json_match = re.search(r'<JSON_START>\s*(.*?)\s*<JSON_END>', response_str, re.DOTALL)
            if json_match:
                json_str = json_match.group(1).strip()
                return json.loads(json_str)
            
            # Try to extract JSON from markdown code blocks
            json_match = re.search(r'```json\s*(.*?)\s*```', response_str, re.DOTALL)
            if json_match:
                json_str = json_match.group(1).strip()
                return json.loads(json_str)
            
            # Try to find JSON object in the string
            json_match = re.search(r'\{.*\}', response_str, re.DOTALL)
            if json_match:
                json_str = json_match.group(0)
                return json.loads(json_str)
            
            # If no structured format found, try parsing the entire string
            return json.loads(response_str.strip())
            
        except json.JSONDecodeError as e:
            logger.warning(f"JSON decode error: {e}")
            return None
        except Exception as e:
            logger.error(f"Unexpected error parsing JSON: {e}")
            return None
    
    @staticmethod
    def normalize_challenges(challenges_data: Union[Dict, List]) -> List[Dict]:
        """
        Normalize challenge data to a consistent format
        
        Args:
            challenges_data: Raw challenge data in various formats
            
        Returns:
            List of normalized challenge dictionaries
        """
        try:
            # If it's already a list, return it
            if isinstance(challenges_data, list):
                return [JSONParser._normalize_single_challenge(challenge) for challenge in challenges_data]
            
            # If it's a dict with challenges key
            if isinstance(challenges_data, dict):
                if "challenges" in challenges_data:
                    challenges = challenges_data["challenges"]
                    if isinstance(challenges, list):
                        return [JSONParser._normalize_single_challenge(challenge) for challenge in challenges]
                    else:
                        return [JSONParser._normalize_single_challenge(challenges)]
                else:
                    # Treat the entire dict as a single challenge
                    return [JSONParser._normalize_single_challenge(challenges_data)]
            
            return []
            
        except Exception as e:
            logger.error(f"Error normalizing challenges: {e}")
            return []
    
    @staticmethod
    def _normalize_single_challenge(challenge: Dict) -> Dict:
        """Normalize a single challenge to consistent format"""
        normalized = {
            "name": challenge.get("name", challenge.get("title", "Unknown Challenge")),
            "description": challenge.get("description", challenge.get("desc", "")),
            "prize": challenge.get("prize", challenge.get("reward", challenge.get("amount", "$0")))
        }
        
        # Add optional fields if available
        optional_fields = ["id", "url", "track", "deadline", "type", "technologies"]
        for field in optional_fields:
            if field in challenge:
                normalized[field] = challenge[field]
        
        return normalized
    
    @staticmethod
    def create_error_response(raw_response: Any, error_message: str) -> Dict:
        """Create standardized error response with raw data"""
        return {
            "error": error_message,
            "raw_response": str(raw_response),
            "challenges": []
        }
    
    @staticmethod
    def validate_challenge_response(response_data: Dict) -> bool:
        """
        Validate that the response contains valid challenge data
        
        Args:
            response_data: The parsed response data
            
        Returns:
            True if valid, False otherwise
        """
        if not isinstance(response_data, dict):
            return False
        
        # Check if it has challenges
        if "challenges" in response_data:
            challenges = response_data["challenges"]
            if not isinstance(challenges, list):
                return False
            
            # Validate each challenge has required fields
            for challenge in challenges:
                if not isinstance(challenge, dict):
                    return False
                if not all(field in challenge for field in ["name", "description", "prize"]):
                    return False
        
        return True