// Assets/_Project/Scripts/VFX/SellEffectSpawner.cs
using UnityEngine;
using TD.Audio;

namespace TD.VFX
{
    /// <summary>
    /// Scene singleton that plays the "tower sold" feedback — a burst of gold coins plus a
    /// coin-rustle sound — at a world position. Mirrors <see cref="TD.UI.FloatingTextSpawner"/>:
    /// visual-only, plain <c>MonoBehaviour</c>, invoked on every peer via a ClientRpc so all
    /// players see and hear a sale locally.
    /// </summary>
    /// <remarks>
    /// <b>Who calls this:</b> <see cref="TD.Gameplay.TowerPlacementManager.BroadcastSellEffect"/>
    /// routes a ClientRpc here when a tower is sold.
    ///
    /// <b>Inspector setup:</b> drop this on a <c>SellEffectSpawner</c> GameObject in each Match
    /// scene. The VFX prefab is OPTIONAL — leave it empty to use the built-in
    /// <see cref="CoinBurstVfx"/> placeholder, or assign an authored particle/VFX-graph prefab.
    /// Assign the coin-rustle clip on <see cref="sellSound"/>.
    /// </remarks>
    public class SellEffectSpawner : MonoBehaviour
    {
        // ----- Singleton --------------------------------------------------

        public static SellEffectSpawner Instance { get; private set; }

        // ----- Inspector --------------------------------------------------

        [Tooltip("Optional authored VFX prefab spawned at the sale position. Leave empty to " +
                 "fall back to the built-in code-generated CoinBurstVfx placeholder.")]
        [SerializeField] private GameObject coinBurstPrefab;

        [Tooltip("Coin-rustle sound played (2D, via AudioManager) when a tower is sold.")]
        [SerializeField] private SoundConfig sellSound;

        [Tooltip("Vertical offset above the sale position where the coin burst originates, so " +
                 "it reads as coming from the tower body rather than the ground.")]
        [SerializeField] private float verticalOffset = 0.75f;

        // ----- Lifecycle --------------------------------------------------

        private void Awake()
        {
            if (Instance != null && Instance != this)
            {
                Debug.LogWarning("[SellEffectSpawner] Duplicate instance detected. " +
                                 "Only one should exist per scene.");
                return;
            }
            Instance = this;
        }

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

        // ----- Public API -------------------------------------------------

        /// <summary>Plays the coin burst + rustle sound at <paramref name="worldPos"/>.</summary>
        public void Play(Vector3 worldPos)
        {
            Vector3 spawnPos = worldPos + Vector3.up * verticalOffset;

            if (coinBurstPrefab != null)
            {
                Instantiate(coinBurstPrefab, spawnPos, Quaternion.identity);
            }
            else
            {
                // Zero-art fallback: a self-configuring, self-destroying particle burst.
                var go = new GameObject("CoinBurst");
                go.transform.position = spawnPos;
                go.AddComponent<CoinBurstVfx>();
            }

            if (sellSound.clip != null)
                AudioManager.Instance?.Play(sellSound.clip, AudioCategory.UI,
                                            sellSound.RandomPitch(), sellSound.volume);
        }
    }
}