from typing import List, Dict, Optional
import json
import re

class HealthScoreCalculator:
    def __init__(self):
        # Initialize risk categories and their weights
        self.risk_categories = {
            'preservatives': {
                'weight': 2.0,
                'ingredients': [
                    'sodium benzoate', 'potassium sorbate', 'sulfites', 'nitrites',
                    'BHA', 'BHT', 'propylene glycol', 'sodium nitrate'
                ]
            },
            'artificial_colors': {
                'weight': 1.5,
                'ingredients': [
                    'red 40', 'yellow 5', 'yellow 6', 'blue 1', 'blue 2',
                    'green 3', 'tartrazine', 'brilliant blue'
                ]
            },
            'artificial_sweeteners': {
                'weight': 1.8,
                'ingredients': [
                    'aspartame', 'sucralose', 'saccharin', 'acesulfame k',
                    'neotame', 'advantame'
                ]
            },
            'harmful_chemicals': {
                'weight': 2.5,
                'ingredients': [
                    'parabens', 'phthalates', 'formaldehyde', 'toluene',
                    'triclosan', 'lead acetate', 'petroleum'
                ]
            }
        }

        # Cosmetic-specific categories
        self.cosmetic_categories = {
            'irritants': {
                'weight': 1.7,
                'ingredients': [
                    'sodium lauryl sulfate', 'alcohol denat', 'isopropyl alcohol',
                    'fragrance', 'essential oils'
                ]
            },
            'comedogenic': {
                'weight': 1.3,
                'ingredients': [
                    'coconut oil', 'cocoa butter', 'isopropyl myristate',
                    'sodium chloride', 'laureth-4'
                ]
            }
        }

        # Food-specific categories
        self.food_categories = {
            'trans_fats': {
                'weight': 2.2,
                'ingredients': [
                    'partially hydrogenated', 'hydrogenated oil',
                    'shortening', 'margarine'
                ]
            },
            'added_sugars': {
                'weight': 1.6,
                'ingredients': [
                    'high fructose corn syrup', 'corn syrup', 'dextrose',
                    'maltose', 'sucrose', 'cane sugar', 'brown sugar'
                ]
            }
        }

    def calculate_ingredient_position_weight(self, position: int, total_ingredients: int) -> float:
        """Calculate weight based on ingredient position (earlier ingredients have higher weight)"""
        if total_ingredients == 0:
            return 1.0
        return 1.0 + (1.0 - (position / total_ingredients))

    def identify_risks(self, ingredient: str) -> List[str]:
        """Identify all risk categories an ingredient belongs to"""
        risks = []
        ingredient = ingredient.lower()
        
        # Check all categories
        all_categories = {
            **self.risk_categories,
            **self.cosmetic_categories,
            **self.food_categories
        }
        
        for category, data in all_categories.items():
            if any(risk_ingredient in ingredient for risk_ingredient in data['ingredients']):
                risks.append(category)
        
        return risks

    def calculate_score(self, ingredients: List[str], product_type: str = 'food') -> Dict:
        """Calculate health score and provide risk breakdown"""
        if not ingredients:
            return {
                'score': 500,  # Neutral score if no ingredients
                'risks': {},
                'explanation': "No ingredients provided for analysis"
            }

        total_ingredients = len(ingredients)
        risk_points = 0
        risk_breakdown = {}
        
        # Select relevant categories based on product type
        categories = {**self.risk_categories}
        if product_type.lower() == 'food':
            categories.update(self.food_categories)
        else:
            categories.update(self.cosmetic_categories)

        # Analyze each ingredient
        for position, ingredient in enumerate(ingredients):
            position_weight = self.calculate_ingredient_position_weight(position, total_ingredients)
            risks = self.identify_risks(ingredient)
            
            for risk in risks:
                if risk in categories:
                    risk_weight = categories[risk]['weight']
                    risk_value = risk_weight * position_weight
                    risk_points += risk_value
                    
                    if risk not in risk_breakdown:
                        risk_breakdown[risk] = {
                            'ingredients': [],
                            'total_risk': 0
                        }
                    risk_breakdown[risk]['ingredients'].append(ingredient)
                    risk_breakdown[risk]['total_risk'] += risk_value

        # Calculate final score (1000 = perfectly healthy, 0 = maximum risk)
        base_score = 1000
        risk_multiplier = 100  # Adjust this to control how quickly score decreases
        final_score = max(0, min(1000, base_score - (risk_points * risk_multiplier)))

        # Generate explanation
        explanation = self._generate_explanation(risk_breakdown, final_score)

        return {
            'score': int(final_score),
            'risks': risk_breakdown,
            'explanation': explanation
        }

    def _generate_explanation(self, risk_breakdown: Dict, score: float) -> str:
        """Generate a human-readable explanation of the health score"""
        if score > 800:
            status = "very healthy"
        elif score > 600:
            status = "moderately healthy"
        elif score > 400:
            status = "moderate risk"
        elif score > 200:
            status = "high risk"
        else:
            status = "very high risk"

        explanation = f"This product is considered {status} with a score of {int(score)}."
        
        if risk_breakdown:
            explanation += "\n\nKey concerns:"
            for risk, data in risk_breakdown.items():
                risk_name = risk.replace('_', ' ').title()
                ingredients = ', '.join(data['ingredients'])
                explanation += f"\n- {risk_name}: Found {len(data['ingredients'])} concerning ingredient(s): {ingredients}"
        else:
            explanation += "\n\nNo specific risk factors identified in the ingredients list."

        return explanation

    def analyze_nutrition(self, nutrition_info: Dict) -> Dict:
        """Analyze nutrition information and provide recommendations"""
        analysis = {
            'concerns': [],
            'positives': [],
            'recommendations': []
        }
        
        # Check calories
        if 'calories' in nutrition_info:
            if nutrition_info['calories'] > 400:
                analysis['concerns'].append("High calorie content")
            elif nutrition_info['calories'] < 50:
                analysis['positives'].append("Low calorie content")
        
        # Check protein
        if 'protein' in nutrition_info:
            if nutrition_info['protein'] > 15:
                analysis['positives'].append("Good source of protein")
            elif nutrition_info['protein'] < 5:
                analysis['recommendations'].append("Consider options with more protein")
        
        # Check fat
        if 'fat' in nutrition_info:
            if nutrition_info['fat'] > 15:
                analysis['concerns'].append("High fat content")
        
        # Check sugar
        if 'sugar' in nutrition_info:
            if nutrition_info['sugar'] > 10:
                analysis['concerns'].append("High sugar content")
                analysis['recommendations'].append("Look for options with less sugar")
        
        # Check fiber
        if 'fiber' in nutrition_info:
            if nutrition_info['fiber'] > 5:
                analysis['positives'].append("Good source of fiber")
            elif nutrition_info['fiber'] < 2:
                analysis['recommendations'].append("Consider options with more fiber")
        
        return analysis