using FMOD.Studio;
using System.IO;
using System.Linq;
using UnityEngine;

public abstract class NPCController : MonoBehaviour
{
    protected Transform playerTransform;

    [Header("Voiceline Amplitude Timeline Config")]
    public string voicelinesFolder = "CharacterVoicelines";
    public string characterSpecificFolder;
    public string[] voiceLineKeys;


    [Header("Mouth Transform")]
    public Transform mouth;  // assign your billboard mouth object

    [Header("Mouth Animation Settings")]
    public float minScaleY = 0.3f;
    public float maxScaleY = 1.0f;
    public float gain = 30f;      // multiply RMS to make mouth open larger
    public float attack = 0.6f;   // faster opening
    public float release = 0.2f;  // slower closing
    public bool inverted = false;

    private float[] rmsCurve;
    private EventInstance currentVoicelineEvent;
    private bool isSpeaking;
    private float smoothed;

    // If you change RMS window in Python, update this
    private const float FRAME_DURATION = 0.02f;
    private float sampleRate = 1f / FRAME_DURATION;   // RMS samples per second (20ms windows)


    // Start is called before the first frame update
    void Awake()
    {
        
    }

    void Start()
    {
       
    }

    // Update is called once per frame
    void Update()
    {
        if (playerTransform != null)
        {
            // As if player is on same Y coordinate as this object, to not rotate around Y axis.
            Vector3 lookTargetPos = new Vector3(playerTransform.position.x, transform.position.y, playerTransform.position.z);
            transform.LookAt(lookTargetPos);
        }

        if (isSpeaking && rmsCurve != null && currentVoicelineEvent.isValid())
        {
            AnimateMouth();
        }
    }

    private void AnimateMouth()
    {
        // get FMOD timeline position
        currentVoicelineEvent.getTimelinePosition(out int ms);
        float time = ms / 1000f;

        // find sample index
        int index = Mathf.FloorToInt(time * sampleRate);
        index = Mathf.Clamp(index, 0, rmsCurve.Length - 1);

        float amp = rmsCurve[index] * gain;

        // Normal mapping: louder -> larger scale
        float mapped = Mathf.Clamp(minScaleY + amp, minScaleY, maxScaleY);

        // Inverted mapping: louder -> smaller scale
        // Achieve this by mirroring within [min, max]:
        // invertedTarget = min + (max - (min + amp)) = min + (max - min) - amp
        // equivalently:
        float invertedTarget = Mathf.Clamp(minScaleY + (maxScaleY - minScaleY) - (mapped - minScaleY), minScaleY, maxScaleY);
        float targetY = inverted ? invertedTarget : mapped;

        // attack/release smoothing
        if (targetY > smoothed)
            smoothed = Mathf.Lerp(smoothed, targetY, attack);
        else
            smoothed = Mathf.Lerp(smoothed, targetY, release);

        // apply mouth scale
        Vector3 s = mouth.localScale;
        s.y = smoothed;
        Debug.Log("mouth scale: " + smoothed);
        mouth.localScale = s;
    }


    private void StopSpeaking()
    {
        isSpeaking = false;
        smoothed = inverted ? maxScaleY : minScaleY;

        if (mouth != null)
        {
            var scale = mouth.localScale;
            scale.y = smoothed;
            mouth.localScale = scale;
        }
        Debug.Log("mouth scale stopped: " + smoothed);

        currentVoicelineEvent.release();
    }


    private void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.tag == "Player Head")
        {
            playerTransform = other.transform;
            OnPlayerApproach();
        }
    }

    protected virtual void OnPlayerApproach() {}

    private void OnTriggerExit(Collider other)
    {
        if (other.gameObject.tag == "Player Head")
        {
            playerTransform = null;
            OnPlayerLeave();
        }
    }

    protected virtual void OnPlayerLeave() {}


    public void SpeakVoiceLine(int voiceLineId)
    {
        if (voiceLineId < 0 || voiceLineId >= voiceLineKeys.Length)
        {
            Debug.LogError("Invalid voiceLineId!");
            return;
        }

        string key = voiceLineKeys[voiceLineId];
        LoadCurve(key);  // load RMS data

        currentVoicelineEvent = AudioManager.Instance.PlayDialogue(characterSpecificFolder + "/" + key, gameObject);
        if (!currentVoicelineEvent.isValid())
        {
            Debug.LogError("Failed to start dialogue event.");
            return;
        }
        isSpeaking = true;

        // Stop mouth on end
        float voicelineDuration = rmsCurve.Length * FRAME_DURATION;
        Invoke(nameof(StopSpeaking), voicelineDuration + 0.1f);
    }


    // ---------------------------
    //   Load RMS Timeline (.txt)
    // ---------------------------
    private void LoadCurve(string key)
    {
        string folderPath = Path.Combine(Application.streamingAssetsPath, voicelinesFolder, characterSpecificFolder);
        string filePath = Path.Combine(folderPath, key + ".txt");

        if (!File.Exists(filePath))
        {
            Debug.LogError("Missing RMS timeline file: " + filePath);
            rmsCurve = null;
            return;
        }

        var lines = File.ReadAllLines(filePath);
        Debug.Log("read lines: " + lines.Length);
        rmsCurve = lines.Select(l => float.Parse(l, System.Globalization.CultureInfo.InvariantCulture)).ToArray();
    }
}