using Cysharp.Threading.Tasks;
using System.Threading;
using UnityEngine;
using UnityEngine.Audio;

public class MixerController : MonoBehaviour
{
    const string LowpassCutoffFreq = "LowpassCutoffFreq";
    const string LowpassResonance = "LowpassResonance";

    [SerializeField] AudioMixer mixer;

    [Header("Фильтры над водой")]
    [SerializeField] float upCutoff = 22000f;
    [SerializeField] float upResonance = 1f;
    [SerializeField] float upSpeed = 0.5f;

    [Header("Фильтры под водой")]
    [SerializeField] float downCutoff = 1000f;
    [SerializeField] float downResonance = 2f;
    [SerializeField] float downSpeed = 1.5f;

    private CancellationTokenSource cts;
    private bool initialized = false;
    private float t = 1;
    
    public void Init()
    {
        G.PlayerStateModel.PlayerComponent.DiveSystem.Dived += DiveSystem_Dived;
        G.PlayerStateModel.PlayerComponent.DiveSystem.Surfaced += DiveSystem_Surfaced;

        mixer.SetFloat(LowpassCutoffFreq, upCutoff);
        mixer.SetFloat(LowpassResonance, upResonance);

        initialized = true;
    }

    private void DiveSystem_Surfaced() => SetUnderwater(goingDown: false);
    private void DiveSystem_Dived() => SetUnderwater(goingDown: true);

    public void SetUnderwater(bool goingDown)
    {

        cts?.Cancel();
        cts?.Dispose();
        cts = new();

        var speed = goingDown ? downSpeed : upSpeed;
        SetFiltersAsync(goingDown, speed, cts.Token).Forget();
    }

    private async UniTask SetFiltersAsync(bool goingDown, float speed, CancellationToken token)
    {
        float targetT = goingDown ? 0 : 1;
        while(t != targetT && !token.IsCancellationRequested)
        {
            float delta = Time.deltaTime * speed;
            t = Mathf.MoveTowards(t, targetT, delta);

            var cutoff = Mathf.Lerp(downCutoff, upCutoff, t);
            var resonance = Mathf.Lerp(downResonance, upResonance, t);

            mixer.SetFloat(LowpassCutoffFreq, cutoff);
            mixer.SetFloat(LowpassResonance, resonance);

            await UniTask.Yield(PlayerLoopTiming.Update, token);
        }
    }

    private void OnDestroy()
    {
        cts?.Cancel();
        cts?.Dispose();

        mixer.SetFloat(LowpassCutoffFreq, upCutoff);
        mixer.SetFloat(LowpassResonance, upResonance);

        if(initialized)
        {
            G.PlayerStateModel.PlayerComponent.DiveSystem.Dived -= DiveSystem_Dived;
            G.PlayerStateModel.PlayerComponent.DiveSystem.Surfaced -= DiveSystem_Surfaced;
        }
    }


}