"""
Analytics service for processing sensor data and generating insights
"""

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

logger = logging.getLogger(__name__)

class AnalyticsService:
    """Service for analytics and data processing"""
    
    def __init__(self, db, redis_client):
        self.db = db
        self.redis = redis_client
    
    async def query_data(self, query_params) -> Dict[str, Any]:
        """Execute advanced data query"""
        try:
            # Build query
            query = {}
            
            if hasattr(query_params, 'sensor_ids') and query_params.sensor_ids:
                query["sensor_id"] = {"$in": query_params.sensor_ids}
            
            if hasattr(query_params, 'start_time') and query_params.start_time:
                query.setdefault("timestamp", {})["$gte"] = query_params.start_time
            
            if hasattr(query_params, 'end_time') and query_params.end_time:
                query.setdefault("timestamp", {})["$lte"] = query_params.end_time
            
            # Execute query
            cursor = self.db.sensor_readings.find(query)
            
            if hasattr(query_params, 'limit') and query_params.limit:
                cursor = cursor.limit(query_params.limit)
            
            if hasattr(query_params, 'offset') and query_params.offset:
                cursor = cursor.skip(query_params.offset)
            
            cursor = cursor.sort("timestamp", -1)
            
            # Get results
            results = []
            async for reading in cursor:
                reading["_id"] = str(reading["_id"])
                results.append(reading)
            
            # Get total count
            total_count = await self.db.sensor_readings.count_documents(query)
            
            return {
                "data": results,
                "total_count": total_count,
                "query": query_params.__dict__ if hasattr(query_params, '__dict__') else {},
                "execution_time_ms": 0  # Placeholder
            }
        
        except Exception as e:
            logger.error(f"Error executing data query: {e}")
            raise
    
    async def get_analytics_summary(self, hours: int = 24) -> Dict[str, Any]:
        """Get comprehensive analytics summary"""
        try:
            start_time = datetime.utcnow() - timedelta(hours=hours)
            
            # Get basic statistics
            pipeline = [
                {
                    "$match": {
                        "created_at": {"$gte": start_time}
                    }
                },
                {
                    "$group": {
                        "_id": None,
                        "total_readings": {"$sum": 1},
                        "average_value": {"$avg": "$value"},
                        "min_value": {"$min": "$value"},
                        "max_value": {"$max": "$value"},
                        "unique_sensors": {"$addToSet": "$sensor_id"}
                    }
                }
            ]
            
            cursor = self.db.sensor_readings.aggregate(pipeline)
            stats = await cursor.to_list(length=1)
            
            base_stats = stats[0] if stats else {
                "total_readings": 0,
                "average_value": 0,
                "min_value": 0,
                "max_value": 0,
                "unique_sensors": []
            }
            
            # Get room-level statistics
            room_stats = await self._get_room_analytics(hours)
            
            # Get energy trends
            energy_trends = await self._get_energy_trends(hours)
            
            return {
                "period_hours": hours,
                "timestamp": datetime.utcnow().isoformat(),
                "total_readings": base_stats["total_readings"],
                "unique_sensors": len(base_stats["unique_sensors"]),
                "value_statistics": {
                    "average": round(base_stats["average_value"], 2) if base_stats["average_value"] else 0,
                    "minimum": base_stats["min_value"],
                    "maximum": base_stats["max_value"]
                },
                "room_statistics": room_stats,
                "energy_trends": energy_trends
            }
        
        except Exception as e:
            logger.error(f"Error getting analytics summary: {e}")
            raise
    
    async def get_energy_analytics(self, hours: int = 24, room: Optional[str] = None) -> Dict[str, Any]:
        """Get energy-specific analytics"""
        try:
            start_time = datetime.utcnow() - timedelta(hours=hours)
            
            # Build query
            query = {"created_at": {"$gte": start_time}}
            if room:
                query["room"] = room
            
            # Energy consumption over time
            pipeline = [
                {"$match": query},
                {
                    "$group": {
                        "_id": {
                            "hour": {"$hour": "$created_at"},
                            "date": {"$dateToString": {"format": "%Y-%m-%d", "date": "$created_at"}}
                        },
                        "total_energy": {"$sum": "$value"},
                        "reading_count": {"$sum": 1}
                    }
                },
                {"$sort": {"_id.date": 1, "_id.hour": 1}}
            ]
            
            cursor = self.db.sensor_readings.aggregate(pipeline)
            hourly_data = []
            
            async for data in cursor:
                hourly_data.append({
                    "hour": data["_id"]["hour"],
                    "date": data["_id"]["date"],
                    "total_energy": data["total_energy"],
                    "reading_count": data["reading_count"]
                })
            
            # Peak consumption analysis
            peak_analysis = await self._get_peak_consumption_analysis(query)
            
            # Energy efficiency metrics
            efficiency_metrics = await self._get_efficiency_metrics(query)
            
            return {
                "period_hours": hours,
                "room": room,
                "timestamp": datetime.utcnow().isoformat(),
                "hourly_consumption": hourly_data,
                "peak_analysis": peak_analysis,
                "efficiency_metrics": efficiency_metrics,
                "total_consumption": sum(item["total_energy"] for item in hourly_data)
            }
        
        except Exception as e:
            logger.error(f"Error getting energy analytics: {e}")
            raise
    
    async def _get_room_analytics(self, hours: int) -> Dict[str, Any]:
        """Get room-level analytics"""
        try:
            start_time = datetime.utcnow() - timedelta(hours=hours)
            
            pipeline = [
                {
                    "$match": {
                        "created_at": {"$gte": start_time},
                        "room": {"$ne": None}
                    }
                },
                {
                    "$group": {
                        "_id": "$room",
                        "total_readings": {"$sum": 1},
                        "total_energy": {"$sum": "$value"},
                        "average_energy": {"$avg": "$value"},
                        "unique_sensors": {"$addToSet": "$sensor_id"}
                    }
                },
                {"$sort": {"total_energy": -1}}
            ]
            
            cursor = self.db.sensor_readings.aggregate(pipeline)
            room_data = []
            
            async for room in cursor:
                room_data.append({
                    "room": room["_id"],
                    "total_readings": room["total_readings"],
                    "total_energy": room["total_energy"],
                    "average_energy": round(room["average_energy"], 2),
                    "sensor_count": len(room["unique_sensors"])
                })
            
            return {
                "by_room": room_data,
                "total_rooms": len(room_data)
            }
        
        except Exception as e:
            logger.error(f"Error getting room analytics: {e}")
            return {"by_room": [], "total_rooms": 0}
    
    async def _get_energy_trends(self, hours: int) -> Dict[str, Any]:
        """Get energy consumption trends"""
        try:
            start_time = datetime.utcnow() - timedelta(hours=hours)
            
            # Get current period data
            current_query = {"created_at": {"$gte": start_time}}
            current_cursor = self.db.sensor_readings.aggregate([
                {"$match": current_query},
                {"$group": {"_id": None, "total": {"$sum": "$value"}, "count": {"$sum": 1}}}
            ])
            current_data = await current_cursor.to_list(length=1)
            current_total = current_data[0]["total"] if current_data else 0
            current_count = current_data[0]["count"] if current_data else 0
            
            # Get previous period for comparison
            previous_start = start_time - timedelta(hours=hours)
            previous_query = {
                "created_at": {"$gte": previous_start, "$lt": start_time}
            }
            previous_cursor = self.db.sensor_readings.aggregate([
                {"$match": previous_query},
                {"$group": {"_id": None, "total": {"$sum": "$value"}, "count": {"$sum": 1}}}
            ])
            previous_data = await previous_cursor.to_list(length=1)
            previous_total = previous_data[0]["total"] if previous_data else 0
            
            # Calculate trend
            if previous_total > 0:
                trend_percentage = ((current_total - previous_total) / previous_total) * 100
            else:
                trend_percentage = 0
            
            return {
                "current_period": {
                    "total_energy": current_total,
                    "reading_count": current_count,
                    "average_per_reading": current_total / current_count if current_count > 0 else 0
                },
                "previous_period": {
                    "total_energy": previous_total
                },
                "trend": {
                    "percentage_change": round(trend_percentage, 2),
                    "direction": "up" if trend_percentage > 0 else "down" if trend_percentage < 0 else "stable"
                }
            }
        
        except Exception as e:
            logger.error(f"Error getting energy trends: {e}")
            return {}
    
    async def _get_peak_consumption_analysis(self, base_query: Dict[str, Any]) -> Dict[str, Any]:
        """Analyze peak consumption patterns"""
        try:
            pipeline = [
                {"$match": base_query},
                {
                    "$group": {
                        "_id": {"$hour": "$created_at"},
                        "total_consumption": {"$sum": "$value"},
                        "reading_count": {"$sum": 1}
                    }
                },
                {"$sort": {"total_consumption": -1}}
            ]
            
            cursor = self.db.sensor_readings.aggregate(pipeline)
            hourly_consumption = await cursor.to_list(length=None)
            
            if not hourly_consumption:
                return {"peak_hour": None, "peak_consumption": 0, "hourly_pattern": []}
            
            peak_data = hourly_consumption[0]
            
            return {
                "peak_hour": peak_data["_id"],
                "peak_consumption": peak_data["total_consumption"],
                "hourly_pattern": [
                    {
                        "hour": item["_id"],
                        "consumption": item["total_consumption"],
                        "reading_count": item["reading_count"]
                    }
                    for item in hourly_consumption
                ]
            }
        
        except Exception as e:
            logger.error(f"Error analyzing peak consumption: {e}")
            return {"peak_hour": None, "peak_consumption": 0, "hourly_pattern": []}
    
    async def _get_efficiency_metrics(self, base_query: Dict[str, Any]) -> Dict[str, Any]:
        """Calculate energy efficiency metrics"""
        try:
            # Average consumption per sensor
            pipeline = [
                {"$match": base_query},
                {
                    "$group": {
                        "_id": "$sensor_id",
                        "total_consumption": {"$sum": "$value"},
                        "reading_count": {"$sum": 1}
                    }
                },
                {
                    "$group": {
                        "_id": None,
                        "average_per_sensor": {"$avg": "$total_consumption"},
                        "sensor_count": {"$sum": 1},
                        "min_consumption": {"$min": "$total_consumption"},
                        "max_consumption": {"$max": "$total_consumption"}
                    }
                }
            ]
            
            cursor = self.db.sensor_readings.aggregate(pipeline)
            efficiency_data = await cursor.to_list(length=1)
            
            if not efficiency_data:
                return {
                    "average_per_sensor": 0,
                    "sensor_count": 0,
                    "efficiency_score": 0,
                    "variation_coefficient": 0
                }
            
            data = efficiency_data[0]
            
            # Calculate efficiency score (lower variation = higher efficiency)
            if data["average_per_sensor"] > 0:
                variation_coefficient = (data["max_consumption"] - data["min_consumption"]) / data["average_per_sensor"]
                efficiency_score = max(0, 100 - (variation_coefficient * 10))  # Scale to 0-100
            else:
                variation_coefficient = 0
                efficiency_score = 100
            
            return {
                "average_per_sensor": round(data["average_per_sensor"], 2),
                "sensor_count": data["sensor_count"],
                "efficiency_score": round(efficiency_score, 1),
                "variation_coefficient": round(variation_coefficient, 2)
            }
        
        except Exception as e:
            logger.error(f"Error calculating efficiency metrics: {e}")
            return {
                "average_per_sensor": 0,
                "sensor_count": 0,
                "efficiency_score": 0,
                "variation_coefficient": 0
            }