using BaseGames.Core;
using UnityEngine;

namespace BaseGames.Audio
{
    /// <summary>
    /// 材质感知脚步声播放器。挂在玩家 GameObject 上，由 PlayerFeedback.PlayFootstep() 驱动。
    /// 每次触发时向下 OverlapCircle 探测脚下碰撞体，读取 FootstepMaterialMarker 决定材质，
    /// 再从 FootstepAudioConfigSO 随机选取 Clip 并叠加 Pitch 扰动后播放。
    /// 未探测到 Marker 时回落到 FootstepMaterial.Stone。
    /// </summary>
    public class FootstepSoundPlayer : MonoBehaviour
    {
        [Header("音效配置")]
        [SerializeField] private FootstepAudioConfigSO _config;

        [Header("地面探测")]
        [Tooltip("通常复用 PlayerMovement 下的 GroundCheck 子对象")]
        [SerializeField] private Transform _groundProbe;
        [SerializeField] private LayerMask _groundLayer;
        [SerializeField] private float     _probeRadius = 0.15f;

        private AudioSource         _audioSource;
        private readonly Collider2D[] _probeBuffer = new Collider2D[4];

        private void Awake()
        {
            // 优先使用同对象已有的 AudioSource，否则自动添加
            _audioSource = GetComponent<AudioSource>();
            if (_audioSource == null)
                _audioSource = gameObject.AddComponent<AudioSource>();

            _audioSource.spatialBlend = 0f;   // 始终 2D
            _audioSource.playOnAwake  = false;
        }

        /// <summary>
        /// 由 PlayerFeedback.PlayFootstep() 调用。
        /// </summary>
        public void Play()
        {
            if (_config == null) return;

            var material = DetectGroundMaterial();
            var entry    = _config.GetEntry(material);
            if (entry == null) return;

            var e = entry.Value;
            if (e.clips == null || e.clips.Length == 0) return;

            var clip = e.clips[Random.Range(0, e.clips.Length)];
            if (clip == null) return;

            // pitchVariance 为 [0.8, 1.2]，以 1.0 为中心扩展偏移区间
            float half  = e.pitchVariance - 1f;
            _audioSource.pitch = Random.Range(1f - half, 1f + half);
            _audioSource.PlayOneShot(clip, e.volume);
        }

        // ── 地面材质探测 ──────────────────────────────────────────────────────

        private FootstepMaterial DetectGroundMaterial()
        {
            Vector2 origin = _groundProbe != null
                ? (Vector2)_groundProbe.position
                : (Vector2)transform.position + Vector2.down * 0.5f;

            int count = Physics2D.OverlapCircleNonAlloc(origin, _probeRadius, _probeBuffer, _groundLayer);

            for (int i = 0; i < count; i++)
            {
                var marker = _probeBuffer[i].GetComponent<FootstepMaterialMarker>();
                if (marker != null)
                    return marker.material;
            }

            return FootstepMaterial.Stone; // 默认回落
        }

#if UNITY_EDITOR
        private void OnDrawGizmosSelected()
        {
            Gizmos.color = new Color(0.6f, 1f, 0.6f, 0.5f);
            Vector3 origin = _groundProbe != null
                ? _groundProbe.position
                : transform.position + Vector3.down * 0.5f;
            Gizmos.DrawWireSphere(origin, _probeRadius);
        }
#endif
    }
}