using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Car {
    private Route route;
    private Road currentRoad;
    public float roadPositon = 0f, speed = 0f, currentDistance;
    private int roadIndex = 0;
    private GameObject gameObject;
    private Config config;
    public Vector3 position;
    public bool isAlive = true;

    public Car(Route route, Transform parent, Config config) {
        this.route = route;
        this.config = config;
        currentRoad = route.roads[0];
        currentRoad.cars.Add(this);

        gameObject = new GameObject();
        FlatCircleRenderer renderer = new FlatCircleRenderer(0.8f, 0.2f, 32);
        gameObject.AddComponent<MeshRenderer>().material = config.carMaterial;
        gameObject.AddComponent<MeshFilter>().mesh = renderer.mesh;
        gameObject.transform.parent = parent;
        CarData carData = gameObject.AddComponent<CarData>();
        carData.car = this;
        position = currentRoad.path.getPosition(0f);
        carData.Update();
    }

    private void incrementRoad() {
        roadPositon -= 1f;
        roadIndex++;
        if (roadIndex == route.roads.Count) {
            GameObject.Destroy(gameObject);
            isAlive = false;
            return;
        }
        currentRoad.cars.Remove(this);
        currentRoad = route.roads[roadIndex];
        currentRoad.cars.Add(this);
    }
    
    public void step(float deltaTime) {
        speed += 
            -(deltaTime*config.carAirResistanceModifier*config.carFrontalArea*config.airDensity*speed*speed) / 
            (2*config.carMass) + 
            (config.carTorque*deltaTime) / (config.carWheelRadius * config.carMass)
            ;
        float distance = deltaTime * speed;
        float currentDeltaT = distance / currentRoad.path.length;
        currentDistance = (position - currentRoad.path.getPosition(roadPositon+currentDeltaT)).magnitude;
        for (int i = 0; i < 10; i++) {
            currentDeltaT += (distance - currentDistance) / currentRoad.path.length;
            while (roadPositon + currentDeltaT > 1f) {
                incrementRoad();
            } 
            currentDistance = (position - currentRoad.path.getPosition(roadPositon+currentDeltaT)).magnitude;
        }
        roadPositon += currentDeltaT;
        while (roadPositon > 1f) {
            incrementRoad();
        }
        position = currentRoad.path.getPosition(roadPositon);
    }
}