"""
Configuration Loader
Loads and validates filter pipeline configuration.
"""

import json
import os
import logging
from pathlib import Path
from typing import Dict, List, Any, Optional

logger = logging.getLogger(__name__)


class FilterConfig:
    """Configuration for filter pipeline"""

    def __init__(
        self,
        config_file: str = 'filter_config.json',
        filtersets_file: str = 'filtersets.json'
    ):
        self.config_file = Path(config_file)
        self.filtersets_file = Path(filtersets_file)

        # Load configurations
        self.config = self._load_config()
        self.filtersets = self._load_filtersets()

    def _load_config(self) -> Dict:
        """Load filter_config.json"""
        if not self.config_file.exists():
            logger.warning(f"{self.config_file} not found, using defaults")
            return self._get_default_config()

        try:
            with open(self.config_file, 'r') as f:
                config = json.load(f)
            logger.info(f"Loaded filter config from {self.config_file}")
            return config
        except Exception as e:
            logger.error(f"Error loading {self.config_file}: {e}")
            return self._get_default_config()

    def _load_filtersets(self) -> Dict:
        """Load filtersets.json"""
        if not self.filtersets_file.exists():
            logger.error(f"{self.filtersets_file} not found!")
            return {}

        try:
            with open(self.filtersets_file, 'r') as f:
                filtersets = json.load(f)
            logger.info(f"Loaded {len(filtersets)} filtersets from {self.filtersets_file}")
            return filtersets
        except Exception as e:
            logger.error(f"Error loading {self.filtersets_file}: {e}")
            return {}

    @staticmethod
    def _get_default_config() -> Dict:
        """Get default configuration"""
        return {
            'ai': {
                'enabled': False,  # Disabled by default until API key is configured
                'openrouter_key_file': 'openrouter_key.txt',
                'models': {
                    'cheap': 'meta-llama/llama-3.3-70b-instruct',
                    'smart': 'anthropic/claude-3.5-sonnet'
                },
                'parallel_workers': 10,
                'timeout_seconds': 60
            },
            'cache': {
                'enabled': True,
                'ai_cache_dir': 'data/filter_cache',
                'filterset_cache_ttl_hours': 24
            },
            'pipeline': {
                'default_stages': ['categorizer', 'moderator', 'filter', 'ranker'],
                'batch_size': 50,
                'enable_parallel': True
            },
            'output': {
                'filtered_dir': 'data/filtered',
                'save_rejected': False  # Don't save posts that fail filters
            }
        }

    # ===== AI Configuration =====

    def is_ai_enabled(self) -> bool:
        """Check if AI processing is enabled"""
        return self.config.get('ai', {}).get('enabled', False)

    def get_openrouter_key(self) -> Optional[str]:
        """Get OpenRouter API key"""
        # Try environment variable first
        key = os.getenv('OPENROUTER_API_KEY')
        if key:
            return key

        # Try key file
        key_file = self.config.get('ai', {}).get('openrouter_key_file')
        if key_file and Path(key_file).exists():
            try:
                with open(key_file, 'r') as f:
                    return f.read().strip()
            except Exception as e:
                logger.error(f"Error reading API key from {key_file}: {e}")

        return None

    def get_ai_model(self, model_type: str = 'cheap') -> str:
        """Get AI model name for a given type (cheap/smart)"""
        models = self.config.get('ai', {}).get('models', {})
        return models.get(model_type, 'meta-llama/llama-3.3-70b-instruct')

    def get_parallel_workers(self) -> int:
        """Get number of parallel workers for AI processing"""
        return self.config.get('ai', {}).get('parallel_workers', 10)

    # ===== Cache Configuration =====

    def is_cache_enabled(self) -> bool:
        """Check if caching is enabled"""
        return self.config.get('cache', {}).get('enabled', True)

    def get_cache_dir(self) -> str:
        """Get cache directory path"""
        return self.config.get('cache', {}).get('ai_cache_dir', 'data/filter_cache')

    def get_cache_ttl_hours(self) -> int:
        """Get filterset cache TTL in hours"""
        return self.config.get('cache', {}).get('filterset_cache_ttl_hours', 24)

    # ===== Pipeline Configuration =====

    def get_default_stages(self) -> List[str]:
        """Get default pipeline stages"""
        return self.config.get('pipeline', {}).get('default_stages', [
            'categorizer', 'moderator', 'filter', 'ranker'
        ])

    def get_batch_size(self) -> int:
        """Get batch processing size"""
        return self.config.get('pipeline', {}).get('batch_size', 50)

    def is_parallel_enabled(self) -> bool:
        """Check if parallel processing is enabled"""
        return self.config.get('pipeline', {}).get('enable_parallel', True)

    # ===== Filterset Methods =====

    def get_filterset(self, name: str) -> Optional[Dict]:
        """Get filterset configuration by name"""
        return self.filtersets.get(name)

    def get_filterset_names(self) -> List[str]:
        """Get list of available filterset names"""
        return list(self.filtersets.keys())

    def get_filterset_version(self, name: str) -> Optional[str]:
        """Get version of filterset (for cache invalidation)"""
        filterset = self.get_filterset(name)
        if not filterset:
            return None

        # Use explicit version if present
        if 'version' in filterset:
            return str(filterset['version'])

        # Otherwise compute hash of definition
        import hashlib
        definition_json = json.dumps(filterset, sort_keys=True)
        return hashlib.md5(definition_json.encode()).hexdigest()[:8]

    # ===== Output Configuration =====

    def get_filtered_dir(self) -> str:
        """Get directory for filtered posts"""
        return self.config.get('output', {}).get('filtered_dir', 'data/filtered')

    def should_save_rejected(self) -> bool:
        """Check if rejected posts should be saved"""
        return self.config.get('output', {}).get('save_rejected', False)

    # ===== Utility Methods =====

    def reload(self):
        """Reload configurations from disk"""
        self.config = self._load_config()
        self.filtersets = self._load_filtersets()
        logger.info("Configuration reloaded")

    def get_config_summary(self) -> Dict[str, Any]:
        """Get summary of configuration"""
        return {
            'ai_enabled': self.is_ai_enabled(),
            'cache_enabled': self.is_cache_enabled(),
            'parallel_enabled': self.is_parallel_enabled(),
            'num_filtersets': len(self.filtersets),
            'filterset_names': self.get_filterset_names(),
            'default_stages': self.get_default_stages(),
            'batch_size': self.get_batch_size()
        }