using UnityEngine;
using UnityEngine.Audio;

public class SoundManager : MonoBehaviour
{
    public static SoundManager Instance { get; private set; }

    [SerializeField] private AudioSource _bgmSource;
    [SerializeField] private AudioSource _sfxSource;
    [SerializeField] private AudioMixer _mixer;

    [Header("SFX")]
    [SerializeField] private AudioClip SFX_UIHover;

    private const string BGM_VOLUME_PARAM = "BGMVolume";
    private const string SFX_VOLUME_PARAM = "SFXVolume";

    private void Awake()
    {
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }
        Instance = this;
    }

    private void OnDestroy()
    {
        if (Instance == this) Instance = null;
    }

    public void PlaySFX(AudioClip clip)
    {
        if(_sfxSource == null || clip == null) return;
        _sfxSource.PlayOneShot(clip);
    }

    public void PlayBGM(AudioClip clip)
    {
        if (_bgmSource == null || clip == null) return;
        _bgmSource.clip = clip;
        _bgmSource.loop = true;
        _bgmSource.Play();
    }

    public void StopBGM()
    {
        if (_bgmSource == null) return;
        _bgmSource.Stop();
    }

    public async Awaitable CrossfadeBGM(AudioClip next, float duration = 1f)
    {
        if (_bgmSource == null || next == null) return;

        float startVolume = _bgmSource.volume;

        for (float t = 0f; t < duration; t += Time.deltaTime)
        {
            _bgmSource.volume = Mathf.Lerp(startVolume, 0f, t / duration);
            await Awaitable.NextFrameAsync();
        }

        _bgmSource.Stop();
        _bgmSource.clip = next;
        _bgmSource.loop = true;
        _bgmSource.Play();

        for (float t = 0f; t < duration; t += Time.deltaTime)
        {
            _bgmSource.volume = Mathf.Lerp(0f, startVolume, t / duration);
            await Awaitable.NextFrameAsync();
        }

        _bgmSource.volume = startVolume;
    }

    public void SetBGMVolume(float linear) => SetMixerVolume(BGM_VOLUME_PARAM, linear);
    public void SetSFXVolume(float linear) => SetMixerVolume(SFX_VOLUME_PARAM, linear);

    private void SetMixerVolume(string parameter, float linear)
    {
        if (_mixer == null) return;
        float db = linear > 0.0001f ? Mathf.Log10(linear) * 20f : -80f;
        _mixer.SetFloat(parameter, db);
    }

    public void SFXPlay_UIHover()
    {
        PlaySFX(SFX_UIHover);
    }
}