from dataclasses import dataclass
from typing import Dict, Any, Optional

@dataclass
class DishThermalState:
    food_name: str
    macronutrients: Dict[str, float]  # grams of water, fat, protein, carbs
    estimated_mass_g: float
    initial_temp_c: float
    volume_cm3: Optional[float] = None
    
class MicrowaveThermalEngine:
    """Calculates cook parameters based on physical properties"""

    DEFAULT_EFFICIENCY = 0.70  # ~70% magnetron efficiency
    TARGET_TEMP_C = 74.0       # Safe food temperature

    @staticmethod
    def estimate_specific_heat(macros: Dict[str, float], total_weight_g: float) -> float:
        """Estimates Cp in J/(g*C) based on macro composition"""
        if total_weight_g <= 0:
            return 3.5  # Fallback average for mixed meals
            
        w_water = macros.get("water_g", total_weight_g * 0.7) / total_weight_g
        w_protein = macros.get("protein_g", 0.0) / total_weight_g
        w_fat = macros.get("fat_g", 0.0) / total_weight_g
        w_carbs = macros.get("carbs_g", 0.0) / total_weight_g

        return (4.184 * w_water) + (1.71 * w_protein) + (1.67 * w_fat) + (1.42 * w_carbs)

    def calculate_cook_plan(self, state: DishThermalState, microwave_wattage: int) -> Dict[str, Any]:
        cp = self.estimate_specific_heat(state.macronutrients, state.estimated_mass_g)
        delta_t = max(0.0, self.TARGET_TEMP_C - state.initial_temp_c)
        
        # Q = m * c_p * delta_t
        required_joules = state.estimated_mass_g * cp * delta_t
        effective_power_watts = microwave_wattage * self.DEFAULT_EFFICIENCY
        
        total_seconds = required_joules / effective_power_watts if effective_power_watts > 0 else 0
        
        # Determine duty cycle / power level recommendations
        power_level = 100
        if state.initial_temp_c < 0:  # Frozen food requires defrost cycle to prevent edge-cooking
            power_level = 50
            total_seconds *= 1.4

        return {
            "cook_time_seconds": round(total_seconds),
            "recommended_power_level_pct": power_level,
            "estimated_specific_heat": round(cp, 2),
            "energy_joules": round(required_joules)
        }