"""MongoDB query utilities for filtering documents by update timestamp."""

__author__ = 'Wendell Jones'

from typing import Any, Dict, List, Optional
from datetime import datetime, timedelta, timezone
import logging

logger = logging.getLogger(__name__)


class MongoQueryUtils:
    """Utilities for querying MongoDB collections."""

    @staticmethod
    def get_recent_updates(
        collection: Any,
        minutes: int = 60,
        updated_field: str = 'updated',
        query_filter: Optional[Dict] = None,
    ) -> List[Dict[str, Any]]:
        """
        Find documents updated in the last N minutes.
        
        Handles both epoch timestamps (int/float) and ISO datetime strings.
        
        Args:
            collection: PyMongo collection object.
            minutes: Number of minutes to look back (default: 60).
            updated_field: Name of the updated timestamp field (default: 'updated').
            query_filter: Additional MongoDB query filter to apply (optional).
            
        Returns:
            List of documents updated within the time window.
            
        Example:
            from db.query_utils import MongoQueryUtils
            
            recent = MongoQueryUtils.get_recent_updates(
                collection=mongo_db['series'],
                minutes=60,
                updated_field='updated',
            )
            print(f"Found {len(recent)} recently updated documents")
        """
        if query_filter is None:
            query_filter = {}
        
        # Calculate cutoff time (60 minutes ago)
        now = datetime.now(timezone.utc)
        cutoff_time = now - timedelta(minutes=minutes)
        cutoff_epoch = int(cutoff_time.timestamp())
        
        logger.info(
            f"Searching for documents updated in last {minutes} minutes "
            f"(since {cutoff_time.isoformat()})"
        )
        
        # Build query for documents updated after cutoff
        # Support both epoch timestamps and ISO datetime strings
        query = {
            **query_filter,
            '$or': [
                # Epoch timestamp (int/float)
                {updated_field: {'$gte': cutoff_epoch}},
                # ISO datetime string
                {updated_field: {'$gte': cutoff_time.isoformat()}},
            ]
        }
        
        documents = list(collection.find(query))
        logger.info(f"Found {len(documents)} documents matching criteria")
        
        return documents

    @staticmethod
    def get_recent_updates_by_id(
        collection: Any,
        minutes: int = 60,
        updated_field: str = 'updated',
        id_field: str = 'id',
        query_filter: Optional[Dict] = None,
    ) -> List[int]:
        """
        Get IDs of documents updated in the last N minutes.
        
        Useful for batch processing or sync operations.
        
        Args:
            collection: PyMongo collection object.
            minutes: Number of minutes to look back (default: 60).
            updated_field: Name of the updated timestamp field (default: 'updated').
            id_field: Name of the ID field (default: 'id').
            query_filter: Additional MongoDB query filter (optional).
            
        Returns:
            List of document IDs that were recently updated.
            
        Example:
            ids = MongoQueryUtils.get_recent_updates_by_id(
                collection=mongo_db['series'],
                minutes=60,
            )
            print(f"Series IDs to update: {ids}")
        """
        docs = MongoQueryUtils.get_recent_updates(
            collection=collection,
            minutes=minutes,
            updated_field=updated_field,
            query_filter=query_filter,
        )
        
        ids = [doc.get(id_field) for doc in docs if id_field in doc]
        return ids

    @staticmethod
    def get_updates_since(
        collection: Any,
        since_timestamp: Optional[Any] = None,
        minutes: int = 60,
        updated_field: str = 'updated',
        query_filter: Optional[Dict] = None,
    ) -> List[Dict[str, Any]]:
        """
        Find documents updated since a specific timestamp or N minutes ago.
        
        Args:
            collection: PyMongo collection object.
            since_timestamp: Epoch int, float, or ISO datetime string (optional).
                            If None, defaults to N minutes ago (see minutes parameter).
            minutes: If since_timestamp is None, look back this many minutes (default: 60).
            updated_field: Name of the updated timestamp field (default: 'updated').
            query_filter: Additional MongoDB query filter (optional).
            
        Returns:
            List of documents updated since the timestamp.
            
        Example:
            # Get updates since a specific timestamp
            cutoff = 1704067200  # Epoch timestamp
            docs = MongoQueryUtils.get_updates_since(
                collection=mongo_db['series'],
                since_timestamp=cutoff,
            )
            
            # Or use default 60 minutes ago
            docs = MongoQueryUtils.get_updates_since(
                collection=mongo_db['series'],
            )
            
            # Or specify different time window
            docs = MongoQueryUtils.get_updates_since(
                collection=mongo_db['series'],
                minutes=120,  # Last 2 hours
            )
        """
        if query_filter is None:
            query_filter = {}
        
        # If no timestamp provided, use minutes parameter to calculate cutoff
        if since_timestamp is None:
            now = datetime.now(timezone.utc)
            cutoff_time = now - timedelta(minutes=minutes)
            since_timestamp = int(cutoff_time.timestamp())
            logger.info(f"Using default {minutes} minutes ago: {cutoff_time.isoformat()}")
        
        query = {
            **query_filter,
            '$or': [
                {updated_field: {'$gte': since_timestamp}},
                {updated_field: {'$gte': str(since_timestamp)}},
            ]
        }
        
        documents = list(collection.find(query))
        logger.info(f"Found {len(documents)} documents updated since {since_timestamp}")
        
        return documents

    @staticmethod
    def count_recent_updates(
        collection: Any,
        minutes: int = 60,
        updated_field: str = 'updated',
        query_filter: Optional[Dict] = None,
    ) -> int:
        """
        Count documents updated in the last N minutes.
        
        Args:
            collection: PyMongo collection object.
            minutes: Number of minutes to look back (default: 60).
            updated_field: Name of the updated timestamp field (default: 'updated').
            query_filter: Additional MongoDB query filter (optional).
            
        Returns:
            Count of recently updated documents.
            
        Example:
            count = MongoQueryUtils.count_recent_updates(
                collection=mongo_db['series'],
                minutes=60,
            )
            print(f"{count} series were updated in the last hour")
        """
        if query_filter is None:
            query_filter = {}
        
        now = datetime.now(timezone.utc)
        cutoff_time = now - timedelta(minutes=minutes)
        cutoff_epoch = int(cutoff_time.timestamp())
        
        query = {
            **query_filter,
            '$or': [
                {updated_field: {'$gte': cutoff_epoch}},
                {updated_field: {'$gte': cutoff_time.isoformat()}},
            ]
        }
        
        count = collection.count_documents(query)
        return count


# Convenience functions
def get_recent_updates(
    collection: Any,
    minutes: int = 60,
    updated_field: str = 'updated',
    query_filter: Optional[Dict] = None,
) -> List[Dict[str, Any]]:
    """Find documents updated in the last N minutes."""
    return MongoQueryUtils.get_recent_updates(
        collection=collection,
        minutes=minutes,
        updated_field=updated_field,
        query_filter=query_filter,
    )


def get_recent_ids(
    collection: Any,
    minutes: int = 60,
    updated_field: str = 'updated',
    id_field: str = 'id',
    query_filter: Optional[Dict] = None,
) -> List[int]:
    """Get IDs of documents updated in the last N minutes."""
    return MongoQueryUtils.get_recent_updates_by_id(
        collection=collection,
        minutes=minutes,
        updated_field=updated_field,
        id_field=id_field,
        query_filter=query_filter,
    )


def count_recent(
    collection: Any,
    minutes: int = 60,
    updated_field: str = 'updated',
    query_filter: Optional[Dict] = None,
) -> int:
    """Count documents updated in the last N minutes."""
    return MongoQueryUtils.count_recent_updates(
        collection=collection,
        minutes=minutes,
        updated_field=updated_field,
        query_filter=query_filter,
    )