using UnityEngine;
using TMPro;
using System.Collections;

public class EngineController : MonoBehaviour
{
    public AudioSource[] engineSounds; public TMP_Text speedText;
    [Range(0.1f, 5.0f)] public float basePitch = 0.5f;
    [Range(1.0f, 5.0f)] public float maxPitch = 3.0f;
    public float maxSpeed = 10f;
    [Range(0.01f, 0.1f)] public float speedSmoothing = 0.01f;
    public float gearShiftDelay = 0.05f; public float minVolume = 0.1f;

    private Vector2 lastPosition; private float smoothedSpeed = 0f; private float previousSpeed = 0f; private bool firstPositionUpdate = true;
    private AnimationCurve speedToPitchCurve = new AnimationCurve(new Keyframe(0, 0.5f), new Keyframe(10, 3.0f));

    void Start()
    {
        if (!Input.location.isEnabledByUser)return;
        if (engineSounds == null || engineSounds.Length == 0) return;
        if (speedText == null)return;
        StartCoroutine(StartLocationService());
    }

    void Update()
    {
        if (engineSounds == null || engineSounds.Length == 0 || speedText == null)return;
        UpdateEngineSounds(smoothedSpeed);
    }

    private void UpdateEngineSounds(float speed)
    {
        float clampedSpeed = Mathf.Clamp(speed, 0, maxSpeed);
        float pitch = speedToPitchCurve.Evaluate(clampedSpeed);

        foreach (AudioSource engineSound in engineSounds)
        {
            if (engineSound != null)
            {
                engineSound.pitch = pitch;
                engineSound.volume = Mathf.Lerp(minVolume, 1.0f, clampedSpeed / maxSpeed);
            }
        }
        SimulateGearShifts(clampedSpeed);
    }

    private void SimulateGearShifts(float speed)
    {
        float gearChangeSpeedThreshold = 3f;
        int currentGear = Mathf.FloorToInt(speed / gearChangeSpeedThreshold);
        if (currentGear > Mathf.FloorToInt(smoothedSpeed / gearChangeSpeedThreshold))StartCoroutine(GearShiftCoroutine(gearShiftDelay));
    }

    private IEnumerator GearShiftCoroutine(float delay)
    {
        foreach (AudioSource engineSound in engineSounds)
        {
            if (engineSound != null)engineSound.pitch = Mathf.Clamp(engineSound.pitch - 0.2f, basePitch, maxPitch);
        }
        yield return new WaitForSeconds(delay);
    }

    private IEnumerator StartLocationService()
    {
        Input.location.Start(0.5f, 0.5f);

        int maxWait = 20;
        while (Input.location.status == LocationServiceStatus.Initializing && maxWait > 0)
        {
            yield return new WaitForSeconds(0.1f);
            maxWait--;
        }

        if (Input.location.status == LocationServiceStatus.Failed || maxWait < 1)
        {
            Debug.LogWarning("Location service initialization failed or timed out.");
            yield break;
        }

        while (true)
        {
            UpdateSpeedFromLocation();
            yield return new WaitForSeconds(0.05f);
        }
    }

    private void UpdateSpeedFromLocation()
    {
        if (firstPositionUpdate)
        {
            lastPosition = GetLocationPosition();
            firstPositionUpdate = false;
            return;
        }

        Vector2 currentPosition = GetLocationPosition();
        float distance = Vector2.Distance(lastPosition, currentPosition) * 1000f;
        float speedInMS = distance / Time.deltaTime;
        SmoothSpeed(speedInMS);
        UpdateSpeedText(smoothedSpeed);
        lastPosition = currentPosition;
    }

    private Vector2 GetLocationPosition(){return new Vector2(Input.location.lastData.latitude, Input.location.lastData.longitude);}

    private void SmoothSpeed(float newSpeed)
    {
        float alpha = speedSmoothing;
        smoothedSpeed = alpha * newSpeed + (1 - alpha) * previousSpeed;
        previousSpeed = smoothedSpeed;
    }

    private void UpdateSpeedText(float speedInMS)
    {
        float speedInKmH = Mathf.Clamp(speedInMS * 3.6f, 0, maxSpeed);
        if (speedText != null)speedText.text = $"Speed: {speedInKmH:F2} km/h";
    }
}