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

public class GameManager : MonoBehaviour
{
    public PlayerInputScheme playerInputScheme;
    private InputAction forwardAction;
    private InputAction switchAction;
    public bool isAuto = false;
    public static GameManager instance;


    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;
    public GameObject gameOverScreen;
    

    [Header("Point system")]
    public float pointsMultiplier = 1;
    public float maxMult;
    public float speedMultIncreaseRate = 0.5f;
    public float speedMultDecreaseRate = 2f;
    public float points;
    public float pointsPerSecond = 10; 
    public TMP_Text txt_points;
    public TMP_Text txt_pointsMultiplier;


    [Header("Highscore")]
    public TMP_InputField highscoreNameInput;
    public GameObject highscorePanel;
    public Transform leaderboardItemsParent;
    public GameObject leaderboardItemPrefab;

    [Header("Pause Menu")]
    public GameObject pauseMenu;
    public InputAction pauseAction;

    float startRotationY;



    public void Awake(){
        instance = this;

        playerInputScheme = new PlayerInputScheme();

        forwardAction = playerInputScheme.Car.forward;
        switchAction = playerInputScheme.Car.horizontal;

        switchAction.performed += OnSwitchPerformed;
        pauseAction = playerInputScheme.Car.pause;
        pauseAction.performed += OnPausePerformed;

        Debug.Log("Verifying Inputs:\n" +forwardAction.name + " " + switchAction.name);
    }


    void OnEnable(){
        forwardAction.Enable();
        switchAction.Enable();
        pauseAction.Enable();
    }

    void OnDisable(){
        forwardAction.Disable();
        switchAction.Disable();
        pauseAction.Disable();
    }

    public void Resume(){
        Time.timeScale = 1;
        pauseMenu.SetActive(false);
    }

    public void OnPausePerformed(InputAction.CallbackContext context){
        pauseMenu.SetActive(!pauseMenu.activeSelf);
        if(pauseMenu.activeSelf){
            Time.timeScale = 0.001f;
        }
        else{
            Time.timeScale = 1;
        }
    }

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


    public static void Reset(){
        instance = null;
        SectionTriger.counter=0;

    }

    // Update is called once per frame
    void FixedUpdate()
    {
        if(lives <=0){return;}

        MoveForward();
    }

    void Update(){
        if(isAuto){return;}

        if(lives <=0){return;}

        HandlePoints();
        SwitchLanes();
        TrafficVehicleSpawn();
    }

    void HandlePoints(){
        points += pointsPerSecond * Time.deltaTime * pointsMultiplier;

        float moveMult = movespeed / maxspeed * 10;
        float targetMult = moveMult;

        if(targetMult > pointsMultiplier){
            pointsMultiplier += Time.deltaTime * speedMultIncreaseRate;
        }
        else if(targetMult < pointsMultiplier){
            pointsMultiplier -= Time.deltaTime * speedMultDecreaseRate;
        }

        pointsMultiplier = Mathf.Clamp(pointsMultiplier, 0, maxMult);

        txt_points.text = points.ToString("000000"); // Always display at least 6 digits, pad with zeros
        txt_pointsMultiplier.text = pointsMultiplier.ToString("n1") + " x";

        txt_pointsMultiplier.color = new Color(1, 1, 1, Mathf.Lerp(0.5f, 1f, pointsMultiplier / maxMult));
    }

    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 OnSwitchPerformed(InputAction.CallbackContext context){
        Debug.Log("OnSwitchPerformed: " + context.ReadValue<float>());
        if(context.ReadValue<float>() < 0){
            currentLaneId++;
        }
        else{
            currentLaneId--;
        }
        laneSwitchTime = 0;
    }
    void SwitchLanes(){

        if(displaySpeed < 10){return;}

        float switchSpeedMultiplier = 1 + (displaySpeed/laneSwitchSpeed);

        /// OBSOLETE: Old input method
        // 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 = forwardAction.ReadValue<float>();

        if(isAuto){input = 0; movespeed = maxspeed /3f;}
        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 = isAuto ? 0 : fontSize;
        txtDistance.fontSize = isAuto ? 0 : 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);
        }

        if(lives <=0){
            gameOverScreen.SetActive(true);
            PopulateLeaderboard();
            movespeed=0;

            if(GetHighestScore() < points){
                highscorePanel.SetActive(true);
            }
        }
    }

    public void Retry(){
        Reset();
        SceneManager.LoadScene("GameScene");
    }

    public void MainMenu(){
        Resume();
        Reset();

        SceneManager.LoadScene("MainMenu");
    }

    public void PopulateLeaderboard(){
        for(int i=0; i < leaderboardItemsParent.childCount; i++){
            Destroy(leaderboardItemsParent.GetChild(i).gameObject);
        }
        // Load the locally saved highscore list
        List<HighscoreEntry> highscores = new List<HighscoreEntry>();
        for (int i = 0; i < 10; i++) {
            string nameKey = $"highscore_name_{i}";
            string scoreKey = $"highscore_score_{i}";
            if (PlayerPrefs.HasKey(scoreKey)) {
                string playerName = PlayerPrefs.GetString(nameKey, "");
                int score = PlayerPrefs.GetInt(scoreKey, 0);
                highscores.Add(new HighscoreEntry() { name = playerName, score = score });
            }
        }

        for(int i=0; i < highscores.Count; i++){
            GameObject leaderboardItem = Instantiate(leaderboardItemPrefab, leaderboardItemsParent);
            TMP_Text txtName = leaderboardItem.transform.GetChild(0).GetComponent<TMP_Text>();
            TMP_Text txtScore = leaderboardItem.transform.GetChild(1).GetComponent<TMP_Text>();
            
            txtName.text = highscores[i].name;
            txtScore.text = highscores[i].score.ToString("n0");
            if(i == 0){
                RectTransform rectTransform = leaderboardItem.GetComponent<RectTransform>();
                rectTransform.sizeDelta = new Vector2(rectTransform.sizeDelta.x, rectTransform.sizeDelta.y * 1.4f);

                txtName.color = Color.Lerp(Color.green, Color.white, 0.7f);
                txtScore.color = Color.Lerp(Color.green, Color.white, 0.7f);
                txtName.fontSize *= 1.4f;
                txtScore.fontSize *= 1.4f;
            }else if(i == 1){
                RectTransform rectTransform = leaderboardItem.GetComponent<RectTransform>();
                rectTransform.sizeDelta = new Vector2(rectTransform.sizeDelta.x, rectTransform.sizeDelta.y * 1.2f);

                txtName.color = Color.Lerp(Color.green, Color.white, 0.3f);
                txtScore.color = Color.Lerp(Color.green, Color.white, 0.3f);
                txtName.fontSize *= 1.2f;
                txtScore.fontSize *= 1.2f;
            }
        }
    }

    int GetHighestScore(){
        // Load the locally saved highscore list
        List<HighscoreEntry> highscores = new List<HighscoreEntry>();
        for (int i = 0; i < 10; i++) {
            string nameKey = $"highscore_name_{i}";
            string scoreKey = $"highscore_score_{i}";
            if (PlayerPrefs.HasKey(scoreKey)) {
                string playerName = PlayerPrefs.GetString(nameKey, "");
                int score = PlayerPrefs.GetInt(scoreKey, 0);
                highscores.Add(new HighscoreEntry() { name = playerName, score = score });
            }
        }

        int maxScore = 0;
        foreach (var entry in highscores) {
            if (entry.score > maxScore) maxScore = entry.score;
        }
        return maxScore;
    }

    public void SetHighscore(){
        SetHighscore(highscoreNameInput.text, (int)points);
        highscorePanel.SetActive(false);
        PopulateLeaderboard();
    }

    void SetHighscore(string name, int score){
        // Load list
        List<HighscoreEntry> highscores = new List<HighscoreEntry>();
        for (int i = 0; i < 10; i++) {
            string nameKey = $"highscore_name_{i}";
            string scoreKey = $"highscore_score_{i}";
            if (PlayerPrefs.HasKey(scoreKey)) {
                string playerName = PlayerPrefs.GetString(nameKey, "");
                int oldScore = PlayerPrefs.GetInt(scoreKey, 0);
                highscores.Add(new HighscoreEntry() { name = playerName, score = oldScore });
            }
        }

        // Add new score
        highscores.Add(new HighscoreEntry() { name = name, score = score });

        // Sort descending, keep top 10
        highscores.Sort((a, b) => b.score.CompareTo(a.score));
        if (highscores.Count > 10)
            highscores.RemoveRange(10, highscores.Count - 10);

        // Save
        for (int i = 0; i < highscores.Count; i++) {
            PlayerPrefs.SetString($"highscore_name_{i}", highscores[i].name);
            PlayerPrefs.SetInt($"highscore_score_{i}", highscores[i].score);
        }
        PlayerPrefs.Save();
    }
}

[System.Serializable]
public class HighscoreEntry {
    public string name;
    public int score;
}