// Assets/Scripts/Audio/UnderwaterAudioController.cs
// 进入 LiquidZone 时切换水下 DSP 处理（Architecture 21_LiquidPuzzleModule §3.4）
using UnityEngine;
using UnityEngine.Audio;
using BaseGames.Core.Events;
using BaseGames.World.Liquid;

namespace BaseGames.Audio
{
    /// <summary>
    /// 挂载于 PlayerController 所在 GameObject。
    /// 订阅 EVT_LiquidEntered / EVT_LiquidExited 事件频道（与 WaterDangerState、UnderwaterPostProcessingController 一致）。
    /// 切换 AudioMixer Snapshot 以应用/解除水下 DSP 处理。
    /// 仅响应 Water 类型液体；Acid / Lava 不切换水下音频。
    /// </summary>
    public class UnderwaterAudioController : MonoBehaviour
    {
        [SerializeField] private AudioMixer           _mixer;
        [SerializeField] private float                _transitionDuration = 0.3f;

        [Header("Event Channels")]
        [SerializeField] private LiquidEventChannelSO _onLiquidEntered;   // EVT_LiquidEntered
        [SerializeField] private LiquidEventChannelSO _onLiquidExited;    // EVT_LiquidExited

        private readonly CompositeDisposable _subs = new();

        private void OnEnable()
        {
            _onLiquidEntered?.Subscribe(OnLiquidEntered).AddTo(_subs);
            _onLiquidExited?.Subscribe(OnLiquidExited).AddTo(_subs);
        }

        private void OnDisable() => _subs.Clear();

        private void OnLiquidEntered(LiquidEvent evt)
        {
            if (evt.LiquidType == nameof(LiquidType.Water))
                EnterWater();
        }

        private void OnLiquidExited(LiquidEvent evt)
        {
            if (evt.LiquidType == nameof(LiquidType.Water))
                ExitWater();
        }

        /// <summary>切换至水下 AudioMixer Snapshot。</summary>
        public void EnterWater()
        {
            _mixer?.FindSnapshot("Underwater")?.TransitionTo(_transitionDuration);
        }

        /// <summary>切换回默认 AudioMixer Snapshot。</summary>
        public void ExitWater()
        {
            _mixer?.FindSnapshot("Default")?.TransitionTo(_transitionDuration);
        }
    }
}