using UnityEngine;
using System.Collections.Generic;
using Assets.WasapiAudio.Scripts.Unity;

// only slightly different from the SpectrumMaterialBinder
// in that it modifies a single material for a shader
// instead of the renderer's instance of that material

[RequireComponent(typeof(Material))]
public class SpectrumShaderBinder : MonoBehaviour
{
    public WasapiAudioSource source;
    public Material material;

    private Texture2D _texture;
    private Color[] _colorCache;

    [SerializeReference]
    [SerializeReferenceButton]
    public List<SpectrumTransformer> Transformers = new List<SpectrumTransformer>();

    [SpectrumDataPreview]
    public SpectrumData Preview;

    private void Start() {
        if (source == null) {
            Debug.Log("Material Binder needs WASAPI Source.");
            gameObject.SetActive(false);
        }
    }

    private void Update() {
        UpdateTexture();
        UpdateBinding();
    }

    private void InitialiseTexture() {
        Debug.Log("Reinitialising spectrum texture...");
        _texture = new Texture2D(source.SpectrumSize, 1, TextureFormat.RFloat, false);
        _colorCache = new Color[source.SpectrumSize];
        _texture.name = $"AudioSpectrum{source.SpectrumSize}";
    }

    private float[] GetSpectrumData() {
        // Get raw / unmodified spectrum data
        var spectrumData = source.GetSpectrumData();

        // Run spectrum data through all configured transformers
        if (Transformers != null && Transformers.Count > 0) {
            foreach (var transformer in Transformers) {
                spectrumData = transformer.Transform(spectrumData);
            }
        }

        Preview.Values = spectrumData;

        return spectrumData;
    }

    private void UpdateTexture() {
        // init
        if (_texture == null) InitialiseTexture();

        var spectrumData = GetSpectrumData();

        for (int i = 0; i < source.SpectrumSize; i++) {
            _colorCache[i] = new Color(spectrumData[i], 0, 0, 0);
        }

        _texture.SetPixels(_colorCache);
        _texture.Apply();
    }

    public void UpdateBinding() {
        UpdateTexture();

        // !!!!
        // you must set these via a literal string for some raeson
        // having them as a public property didn't work
        material.SetFloat("_SpectrumSize", source.SpectrumSize);
        material.SetTexture("_SpectrumTexture", _texture);
    }

    public string ToString() {
        return "Spectrum Material Binder";
    }
}