"""
Custom power density calculation using efficiency model.
Calculates site-specific power density based on latitude and longitude.
"""

import os
import sys
from pathlib import Path
import numpy as np
from typing import Optional, Tuple

# Path to efficiency_model directory (used in _load_interpolator)
EFFICIENCY_MODEL_PATH = Path(__file__).parent / "efficiency_model"

# Default power densities (baseline kWp/m²)
DEFAULT_POWER_DENSITY = 0.18  # Standard baseline
POWER_DENSITY_RANGE = (0.101, 0.17)  # Expected operating range when lookup is available


class EfficencyAwarePowerDensity:
    """
    Calculate site-specific power density based on solar efficiency.
    Uses the efficiency model to adjust power density for geographic location.
    """
    
    def __init__(self, efficiency_model=None):
        """
        Initialize with optional pre-loaded efficiency model.
        
        Args:
            efficiency_model: Optional pre-loaded SolarEnergyInterpolator instance
        """
        self.interpolator = efficiency_model
        self._load_interpolator()
    
    def _load_interpolator(self):
        """Lazy load the efficiency model interpolator"""
        if self.interpolator is not None:
            return
        
        try:
            # Add efficiency_model to sys.path temporarily
            import sys
            model_path_str = str(EFFICIENCY_MODEL_PATH)
            if model_path_str not in sys.path:
                sys.path.insert(0, model_path_str)
            
            # Import and initialize with data directory path (no cwd change needed)
            from efficiencyMap import SolarEnergyInterpolator
            self.interpolator = SolarEnergyInterpolator(data_dir=model_path_str)
        except Exception as e:
            print(f"Warning: Could not load efficiency model: {str(e)}")
            import traceback
            traceback.print_exc()
            self.interpolator = None
    
    def get_efficiency(self, latitude: float, longitude: float) -> float:
        """
        Get solar efficiency for a location.
        
        Args:
            latitude: Site latitude (-60 to 65)
            longitude: Site longitude (-180 to 180)
        
        Returns:
            float: Solar efficiency as percentage (0-100) or 0 if unavailable
        """
        # Ensure interpolator is loaded
        if self.interpolator is None:
            self._load_interpolator()
        
        if self.interpolator is None:
            return 0
        
        try:
            efficiency = self.interpolator.get_solar_efficiency(latitude, longitude)
            return float(efficiency) if efficiency and efficiency > 0 else 0
        except Exception as e:
            print(f"Warning: Efficiency calculation failed for ({latitude}, {longitude}): {str(e)}")
            return 0
    
    def calculate_power_density(self, latitude: float, longitude: float, 
                                baseline_density: float = DEFAULT_POWER_DENSITY) -> float:
        """
        Calculate site-specific power density based on solar efficiency.
        
        High efficiency areas (e.g., deserts) → Higher power density
        Low efficiency areas (e.g., cloudy regions) → Lower power density
        
        Args:
            latitude: Site latitude
            longitude: Site longitude
            baseline_density: Baseline power density in kWp/m² (default: 0.18)
        
        Returns:
            float: Site-specific power density in kWp/m²
        """
        # Get efficiency (0-100%)
        efficiency = self.get_efficiency(latitude, longitude)
        
        if efficiency == 0:
            # Use baseline if efficiency model unavailable
            return baseline_density
        
        # Map the efficiency percentage directly into the calibrated power-density band.
        adjusted_density = efficiency / 100.0

        # Clamp to the expected operating range.
        adjusted_density = np.clip(adjusted_density, POWER_DENSITY_RANGE[0], POWER_DENSITY_RANGE[1])
        
        return round(adjusted_density, 4)
    
    def get_site_power_density_info(self, latitude: float, longitude: float,
                                     baseline_density: float = DEFAULT_POWER_DENSITY) -> dict:
        """
        Get comprehensive power density information for a site.
        
        Args:
            latitude: Site latitude
            longitude: Site longitude
            baseline_density: Baseline power density
        
        Returns:
            dict: Power density information including efficiency and adjusted value
        """
        efficiency = self.get_efficiency(latitude, longitude)
        adjusted_density = self.calculate_power_density(latitude, longitude, baseline_density)
        
        return {
            'efficiency_percent': efficiency,
            'baseline_density_kwp_m2': baseline_density,
            'adjusted_density_kwp_m2': adjusted_density,
            'density_adjustment_factor': adjusted_density / baseline_density if baseline_density > 0 else 1.0,
            'location': f"{latitude:.4f}°, {longitude:.4f}°"
        }


# Initialize global instance
try:
    power_density_calculator = EfficencyAwarePowerDensity()
except Exception as e:
    print(f"Warning: Could not initialize power density calculator: {str(e)}")
    power_density_calculator = None


def get_power_density_for_site(latitude: float, longitude: float,
                                baseline_density: float = DEFAULT_POWER_DENSITY) -> float:
    """
    Convenience function to get power density for a site.
    
    Args:
        latitude: Site latitude
        longitude: Site longitude
        baseline_density: Baseline power density (default: 0.18 kWp/m²)
    
    Returns:
        float: Site-specific power density in kWp/m²
    """
    # Create fresh instance to ensure no caching issues
    try:
        calculator = EfficencyAwarePowerDensity()
        return calculator.calculate_power_density(latitude, longitude, baseline_density)
    except Exception as e:
        print(f"Error calculating power density: {str(e)}")
        return baseline_density


def get_power_density_info(latitude: float, longitude: float,
                           baseline_density: float = DEFAULT_POWER_DENSITY) -> dict:
    """
    Convenience function to get detailed power density information.
    
    Args:
        latitude: Site latitude
        longitude: Site longitude
        baseline_density: Baseline power density
    
    Returns:
        dict: Detailed power density information
    """
    # Create fresh instance to ensure no caching issues
    try:
        calculator = EfficencyAwarePowerDensity()
        return calculator.get_site_power_density_info(latitude, longitude, baseline_density)
    except Exception as e:
        print(f"Error getting power density info: {str(e)}")
        return {
            'efficiency_percent': 0,
            'baseline_density_kwp_m2': baseline_density,
            'adjusted_density_kwp_m2': baseline_density,
            'density_adjustment_factor': 1.0,
            'location': f"{latitude:.4f}°, {longitude:.4f}°"
        }