using System.Collections;
using System.Collections.Generic;
using Cinemachine;
using TMPro;
using UnityEngine;
using static UnityEngine.ParticleSystem;

public class GameManager : MonoBehaviour
{
    public static GameManager instance;
    public void Awake(){
        instance = this;
    }
    public static float movespeed = 0f;
    public float acceleration = 5;

    public float maxspeed = 30f;
    public CinemachineVirtualCamera cam;
    public ParticleSystem speedLinesEffect;
    public float minFov = 50;
    public float maxFov = 90;
    public float Distance;

    public float max_shake_ferquency = 2f;
    public float max_shake_amplitude = 0.08f;

    public TMP_Text txtSpeed;
    public TMP_Text txtDistance;
    public float FovRange => maxFov - minFov;

    [Header("Obstacle avoidance")]
    public int currentLaneId = 0;
    public float laneSwitchSpeed = 10f;
    public float laneSwitchRotationMultiplier = 0.2f;
    public float[] laneXs = {-1.5f, 0f, 1.5f};
    public Transform car;
    public CollisionDetector collisionDetector;

    EmissionModule speedLinesEmission;
    public CinemachineImpulseSource impulseSource;
    public GameObject trafficVehiclePrefab;
    public List<GameObject> trafficVehicles = new List<GameObject>();
    public int maxTrafficVehicles = 10;
    public float trafficVehicleSpawnInterval = 5f;
    float trafficVehicleSpawnTimer =0f;

    float startRotationY;
    void Start()
    {
        speedLinesEmission = speedLinesEffect.emission;
        startRotationY = car.eulerAngles.y;
        collisionDetector.OnEnter += OnTriggerEnter;
    }

    // Update is called once per frame
    void FixedUpdate()
    {
        MoveForward();
    }

    void Update(){
        SwitchLanes();
        TrafficVehicleSpawn();
    }

    void TrafficVehicleSpawn(){
        trafficVehicleSpawnTimer += Time.deltaTime * movespeed / maxspeed;
        if(trafficVehicleSpawnTimer >= trafficVehicleSpawnInterval){
            trafficVehicleSpawnTimer = 0;
            SpawnNextTrafficVehicle();
        }
    }

    void SpawnNextTrafficVehicle(){
        trafficVehicles.RemoveAll(item => item == null);

        if(trafficVehicles.Count < maxTrafficVehicles){
            GameObject trafficVehicle = Instantiate(trafficVehiclePrefab, new Vector3(laneXs[currentLaneId], 0, -500), Quaternion.Euler(0,-90,0));
            trafficVehicles.Add(trafficVehicle);
        }
    }

    float laneSwitchTime =0;
    void SwitchLanes(){

        if(displaySpeed < 10){return;}

        float switchSpeedMultiplier = 1 + (displaySpeed/laneSwitchSpeed);

        if(Input.GetKeyDown(KeyCode.LeftArrow)){
            currentLaneId--;
            laneSwitchTime = 0;
        }
        else if(Input.GetKeyDown(KeyCode.RightArrow)){
            currentLaneId++;
            laneSwitchTime = 0;
        }

        if(laneSwitchTime < 1){
            laneSwitchTime += Time.deltaTime * 2;
        }

        currentLaneId = Mathf.Clamp(currentLaneId, 0, laneXs.Length - 1);
        float lerper = switchSpeedMultiplier*Time.deltaTime * laneSwitchTime;
        car.position = new Vector3(Mathf.Lerp(car.position.x,laneXs[currentLaneId],lerper), car.position.y, car.position.z);

        float xDist = (car.position.x - laneXs[currentLaneId]);

        Vector3 targetRotation = new Vector3(car.eulerAngles.x, startRotationY + Mathf.Atan2(xDist, 1) * Mathf.Rad2Deg * laneSwitchRotationMultiplier * (1-(movespeed/maxspeed)), car.eulerAngles.z);
        car.eulerAngles = Vector3.Lerp(car.eulerAngles, targetRotation, lerper);
    }

float displaySpeed = 0;
    void MoveForward(){
        float input = Input.GetAxis("Vertical");
        movespeed += input * acceleration * Time.deltaTime;
        movespeed = Mathf.Clamp(movespeed, 0, maxspeed);

        float x = (FovRange / maxspeed) * movespeed;

        cam.m_Lens.FieldOfView = minFov + x;
        cam.GetCinemachineComponent<CinemachineBasicMultiChannelPerlin>().m_FrequencyGain = max_shake_ferquency * movespeed / maxspeed;
        cam.GetCinemachineComponent<CinemachineBasicMultiChannelPerlin>().m_AmplitudeGain = max_shake_amplitude * movespeed / maxspeed;
        
        displaySpeed = movespeed * 2.5f;

        txtSpeed.text = displaySpeed.ToString("n0") + " km/h";
        Distance += displaySpeed * Time.deltaTime / 3600;
        txtDistance.text = Distance.ToString("n2") + " km";

        float fontSize = Mathf.Lerp(10f, 15f, movespeed / maxspeed);
        txtSpeed.fontSize = fontSize;
        txtDistance.fontSize = fontSize;

        speedLinesEmission.rateOverTime = displaySpeed > 100 ? displaySpeed : 0;
    }

    public int lives = 3;

    void OnTriggerEnter(Collider other)
    {
        Debug.Log("OnTriggerEnter: " + other.gameObject.name + " : " + other.gameObject.tag);
        string objectNameLowered = other.gameObject.name.ToLower();
        if(objectNameLowered.Contains("section")){
            return;
        }

        if(objectNameLowered.Contains("player")){
            return;
        }

        movespeed = maxspeed / 10f;
        lives--;
        LivesVisualizer.instance.SetLives(lives);
        impulseSource.GenerateImpulse();

        //Snap to lane
        car.position = new Vector3(laneXs[currentLaneId], car.position.y, car.position.z);

        if(other.GetComponent<TrafficVehicle>()!=null){
            Destroy(other.gameObject);
        }
    }

}