"""
Physics simulation module for robot designs.
"""
import pybullet as p
import numpy as np
from typing import Dict, Any, List, Tuple
from src.core.robot_design import RobotDesign

class PhysicsSimulator:
    """Base class for physics simulation."""
    
    def __init__(self):
        """Initialize the physics simulator."""
        self.client = p.connect(p.DIRECT)
        p.setGravity(0, 0, -9.81)
    
    def simulate(self, design: RobotDesign) -> Dict[str, Any]:
        """Simulate the robot design and return performance metrics."""
        raise NotImplementedError("Subclasses must implement simulate()")
    
    def cleanup(self):
        """Clean up simulation resources."""
        p.disconnect(self.client)

class PyBulletSimulator(PhysicsSimulator):
    """PyBullet-based physics simulator implementation."""
    
    def simulate(self, design: RobotDesign) -> Dict[str, Any]:
        """Simulate the robot design using PyBullet."""
        try:
            # Create ground plane
            p.createMultiBody(
                baseMass=0,
                baseCollisionShapeIndex=p.createCollisionShape(p.GEOM_PLANE),
                basePosition=[0, 0, 0]
            )
            
            # Create robot body
            robot_id = p.createMultiBody(
                baseMass=design.mass,
                baseCollisionShapeIndex=p.createCollisionShape(
                    p.GEOM_BOX,
                    halfExtents=[design.dimensions[0]/2, design.dimensions[1]/2, design.dimensions[2]/2]
                ),
                basePosition=[0, 0, design.dimensions[2]/2]
            )
            
            # Run simulation
            results = {
                "stability": self._check_stability(robot_id),
                "performance": self._measure_performance(robot_id, design)
            }
            
            return results
            
        except Exception as e:
            return {"error": str(e)}
        finally:
            self.cleanup()
    
    def _check_stability(self, robot_id: int) -> float:
        """Check robot stability during simulation."""
        # Simple stability check based on final position
        final_pos, _ = p.getBasePositionAndOrientation(robot_id)
        return 1.0 if abs(final_pos[2]) < 0.1 else 0.0
    
    def _measure_performance(self, robot_id: int, design: RobotDesign) -> Dict[str, float]:
        """Measure robot performance metrics."""
        return {
            "speed": design.max_speed,
            "efficiency": design.efficiency,
            "stability": self._check_stability(robot_id)
        }

class SimulationFactory:
    """Factory for creating physics simulators."""
    
    @staticmethod
    def create_simulator(simulator_type: str = "pybullet") -> PhysicsSimulator:
        """Create a physics simulator instance."""
        if simulator_type == "pybullet":
            return PyBulletSimulator()
        else:
            raise ValueError(f"Unsupported simulator type: {simulator_type}")