using UnityEngine;
using FMODUnity;
using FMOD.Studio;

public class FirstPersonOcclusion : MonoBehaviour
{
    [Header("FMOD Event")]
    [SerializeField]
    private FMODUnity.EventReference SelectAudio; 
    private EventInstance AudioOccluded;
    private EventDescription AudioDes;
    private StudioListener Listener;
    private PLAYBACK_STATE pb;

    [Header("Occlusion Options")]
    [SerializeField]
    [Range(0f, 10f)]
    private float SoundOcclusionWidening = 1f;
    [SerializeField]
    [Range(0f, 10f)]
    private float PlayerOcclusionWidening = 1f;
    [SerializeField]
    private LayerMask OcclusionLayer;

    private bool AudioIsVirtual;
    private float MaxDistance;
    private float ListenerDistance;
    private float lineCastHitCount = 0f;
    private Color colour;

    private void Start()
    {
        Debug.Log("--- Start Method ---");
        
        // 1. Event Instance Creation
        AudioOccluded = RuntimeManager.CreateInstance(SelectAudio);
        Debug.Log($"Created FMOD Event Instance for: {SelectAudio.Path}");
        
        // 2. Attaching Instance
        RuntimeManager.AttachInstanceToGameObject(AudioOccluded, gameObject);
        Debug.Log($"Attached FMOD Event Instance to GameObject: {gameObject.name}");
        
        // 3. Starting Audio
        AudioOccluded.start();
        Debug.Log("Started FMOD Event Instance.");
        
        // 4. Releasing Instance (This allows the event to self-manage its lifetime, which is fine)
        AudioOccluded.release();
        Debug.Log("Released FMOD Event Instance.");

        // 5. Getting Event Description and Max Distance
        AudioDes = RuntimeManager.GetEventDescription(SelectAudio);
        AudioDes.getMinMaxDistance(out float minDistance, out MaxDistance);
        Debug.Log($"FMOD Event Min/Max Distance: {minDistance:F2} / {MaxDistance:F2}");

        // 6. Finding Listener
        Listener = FindObjectOfType<StudioListener>();
        if (Listener != null)
        {
            Debug.Log($"Found FMOD StudioListener on GameObject: {Listener.gameObject.name}");
        }
        else
        {
            Debug.LogError("FATAL: Could not find FMOD StudioListener in the scene!");
        }
        Debug.Log("--- End Start Method ---");
    }
    
    private void FixedUpdate()
    {
        // Debug.Log("--- FixedUpdate Method ---"); // Too frequent, only log conditions
        
        AudioOccluded.isVirtual(out AudioIsVirtual);
        AudioOccluded.getPlaybackState(out pb);
        ListenerDistance = Vector3.Distance(transform.position, Listener.transform.position);

        // 7. Check Occlusion Condition
        if (!AudioIsVirtual && pb == PLAYBACK_STATE.PLAYING && ListenerDistance <= MaxDistance)
        {
            Debug.Log($"Occlusion Check: Not Virtual, Playing, Distance {ListenerDistance:F2} <= Max {MaxDistance:F2}. Calling OccludeBetween.");
            OccludeBetween(transform.position, Listener.transform.position);
        }
        else
        {
            // Log reasons why occlusion is NOT being checked
            if (AudioIsVirtual) Debug.Log("Occlusion Skipped: Audio is Virtual.");
            if (pb != PLAYBACK_STATE.PLAYING) Debug.Log($"Occlusion Skipped: Playback State is not PLAYING. State: {pb}");
            if (ListenerDistance > MaxDistance) Debug.Log($"Occlusion Skipped: Distance {ListenerDistance:F2} > Max Distance {MaxDistance:F2}.");
        }

        // 8. Reset Hit Count
        // Debug.Log($"Resetting lineCastHitCount from {lineCastHitCount:F0} to 0.");
        lineCastHitCount = 0f;
    }

    private void OccludeBetween(Vector3 sound, Vector3 listener)
    {
        Debug.Log("--- OccludeBetween Method ---");

        // 9. Calculate Points (Log only a few to avoid clutter)
        Vector3 SoundLeft = CalculatePoint(sound, listener, SoundOcclusionWidening, true);
        Vector3 SoundRight = CalculatePoint(sound, listener, SoundOcclusionWidening, false);
        // Debug.Log($"Sound Positions: Center {sound}, Left {SoundLeft}, Right {SoundRight}");
        
        Vector3 ListenerLeft = CalculatePoint(listener, sound, PlayerOcclusionWidening, true);
        Vector3 ListenerRight = CalculatePoint(listener, sound, PlayerOcclusionWidening, false);
        // Debug.Log($"Listener Positions: Center {listener}, Left {ListenerLeft}, Right {ListenerRight}");

        Vector3 SoundAbove = new Vector3(sound.x, sound.y + SoundOcclusionWidening, sound.z);
        Vector3 SoundBelow = new Vector3(sound.x, sound.y - SoundOcclusionWidening, sound.z);
        Vector3 ListenerAbove = new Vector3(listener.x, listener.y + PlayerOcclusionWidening * 0.5f, listener.z);
        Vector3 ListenerBelow = new Vector3(listener.x, listener.y - PlayerOcclusionWidening * 0.5f, listener.z);

        // 10. Casting Lines (The line casts themselves will log hits)
        CastLine(SoundLeft, ListenerLeft);
        CastLine(SoundLeft, listener);
        CastLine(SoundLeft, ListenerRight);

        CastLine(sound, ListenerLeft);
        CastLine(sound, listener);
        CastLine(sound, ListenerRight);

        CastLine(SoundRight, ListenerLeft);
        CastLine(SoundRight, listener);
        CastLine(SoundRight, ListenerRight);
        
        CastLine(SoundAbove, ListenerAbove);
        CastLine(SoundBelow, ListenerBelow);

        if (PlayerOcclusionWidening == 0f || SoundOcclusionWidening == 0f)
        {
            colour = Color.blue;
        }
        else
        {
            colour = Color.green;
        }

        SetParameter();
        Debug.Log("--- End OccludeBetween Method ---");
    }

    private Vector3 CalculatePoint(Vector3 a, Vector3 b, float m, bool posOrneg)
    {
        // Debug.Log($"Calculating offset point for: {a} to {b} with magnitude {m} and posOrneg {posOrneg}");
        float x;
        float z;
        // n is the 2D distance between a and b
        float n = Vector3.Distance(new Vector3(a.x, 0f, a.z), new Vector3(b.x, 0f, b.z));
        float mn = (m / n);
        
        // Safety check for division by zero (if sound and listener are exactly on top of each other horizontally)
        if (n == 0f) 
        {
            // If points are on the same XZ position, just return the point 'a'
            // Debug.LogWarning("CalculatePoint: Division by zero avoided. Sound and Listener are at the same XZ position.");
            return a;
        }
        
        if (posOrneg)
        {
            x = a.x + (mn * (a.z - b.z));
            z = a.z - (mn * (a.x - b.x));
        }
        else
        {
            x = a.x - (mn * (a.z - b.z));
            z = a.z + (mn * (a.x - b.x));
        }
        return new Vector3(x, a.y, z);
    }

    private void CastLine(Vector3 Start, Vector3 End)
    {
        RaycastHit hit;
        // 11. Raycast result
        bool isHit = Physics.Linecast(Start, End, out hit, OcclusionLayer);

        if (isHit)
        {
            lineCastHitCount++;
            Debug.Log($"Linecast HIT! Hit Count: {lineCastHitCount:F0}/11. Object hit: {hit.collider.name}.");
            Debug.DrawLine(Start, End, Color.red);
        }
        else
        {
            Debug.DrawLine(Start, End, colour);
        }
    }

    private void SetParameter()
    {
        float occlusionValue = lineCastHitCount / 11; // 11 is the total number of line casts
        // 12. Final Parameter Value
        Debug.Log($"Setting FMOD Parameter 'Occlusion' to: {occlusionValue:F2} (Hits: {lineCastHitCount:F0}/11)");
        AudioOccluded.setParameterByName("Occlusion", occlusionValue);
    }
}