#!/usr/bin/env python3
"""
RiskEngine - Regelbaserad riskanalys
"""
from dataclasses import dataclass
from typing import List, Optional

@dataclass
class RiskScore:
    road_id: int
    road_type: str
    risk_type: str
    severity: str  # low, medium, high, critical
    score: float  # 0.0 - 1.0
    description: str
    factors: List[str]

class RiskEngine:
    def __init__(self):
        self.rules = [
            self._ice_rule,
            self._flooding_rule,
            self._wind_rule,
            self._heat_rule
        ]
    
    def _ice_rule(self, road_type, temperature, precipitation, wind):
        """Isrisk: Temp < 0 + nederbörd"""
        if temperature is None:
            return None
        
        if temperature < -5:
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="ice",
                severity="critical",
                score=0.9,
                description="Mycket kallt, hög risk för is",
                factors=[f"temp={temperature}°C"]
            )
        elif temperature < 0:
            if precipitation and precipitation > 0:
                return RiskScore(
                    road_id=0, road_type=road_type,
                    risk_type="black_ice",
                    severity="critical",
                    score=0.95,
                    description="Svartisrisk vid nederbörd och minusgrader",
                    factors=[f"temp={temperature}°C", f"precip={precipitation}mm"]
                )
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="ice",
                severity="high",
                score=0.7,
                description="Risk för isbildning",
                factors=[f"temp={temperature}°C"]
            )
        return None
    
    def _flooding_rule(self, road_type, temperature, precipitation, wind):
        """Översvämningsrisk: Kraftigt regn"""
        if precipitation is None:
            return None
        
        if precipitation > 20:
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="flooding",
                severity="critical",
                score=0.9,
                description="Kraftig nederbörd, översvämningsrisk",
                factors=[f"precip={precipitation}mm"]
            )
        elif precipitation > 10:
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="flooding",
                severity="high",
                score=0.7,
                description="Hög nederbörd, risk för vatten på vägbanan",
                factors=[f"precip={precipitation}mm"]
            )
        elif precipitation > 5:
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="wet_road",
                severity="medium",
                score=0.4,
                description="Blöt vägbana",
                factors=[f"precip={precipitation}mm"]
            )
        return None
    
    def _wind_rule(self, road_type, temperature, precipitation, wind):
        """Vindrisk: Kraftig vind"""
        if wind is None:
            return None
        
        if wind > 20:
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="falling_objects",
                severity="high",
                score=0.8,
                description="Kraftig vind, risk för nedfallande föremål",
                factors=[f"wind={wind}m/s"]
            )
        elif wind > 15:
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="strong_wind",
                severity="medium",
                score=0.5,
                description="Stark vind",
                factors=[f"wind={wind}m/s"]
            )
        return None
    
    def _heat_rule(self, road_type, temperature, precipitation, wind):
        """Värmerisk: Extrem värme"""
        if temperature is None:
            return None
        
        if temperature > 30:
            return RiskScore(
                road_id=0, road_type=road_type,
                risk_type="asphalt_stress",
                severity="medium",
                score=0.5,
                description="Extrem värme, risk för asfaltpåfrestning",
                factors=[f"temp={temperature}°C"]
            )
        return None
    
    def calculate_risk(self, road_id, road_type, temperature=None, precipitation=None, wind=None):
        """Beräkna risk för en väg"""
        risks = []
        
        for rule in self.rules:
            risk = rule(road_type, temperature, precipitation, wind)
            if risk:
                risk.road_id = road_id
                risks.append(risk)
        
        return risks

if __name__ == "__main__":
    engine = RiskEngine()
    
    # Testa med olika scenarion
    tests = [
        (1, "primary", -5, 0, 5, "Vinter"),
        (2, "secondary", 2, 15, 10, "Regn + kallt"),
        (3, "primary", 22, 3, 5, "Sommar"),
    ]
    
    for road_id, road_type, temp, precip, wind, name in tests:
        risks = engine.calculate_risk(road_id, road_type, temp, precip, wind)
        print(f"\n{name}:")
        for risk in risks:
            print(f"  {risk.risk_type}: {risk.severity} (score: {risk.score})")