using UnityEngine;
using System.Collections;

public class Animation_GenerateJudgementSituationPrefab : MonoBehaviour
{
    public static Animation_GenerateJudgementSituationPrefab Instance;

    [Header("生成位置 (五个轨道)")]
    public GameObject redEffect;
    public GameObject greenEffect;
    public GameObject yellowEffect;
    public GameObject purpleEffect;
    public GameObject blueEffect;

    [Header("判定飘字 Prefabs")]
    public GameObject perfect_judge_prefab;
    public GameObject great_judge_prefab;
    public GameObject good_judge_prefab;
    public GameObject miss_judge_prefab;

    [Header("缩放与随机")]
    public float baseScale = 1.0f;
    public bool useRandomScale = true;
    public float minScaleMultiplier = 0.8f;
    public float maxScaleMultiplier = 1.2f;

    [Header("物理跳跃设置")]
    public float jumpForce = 5.0f;           // 向上弹起的初始速度
    public float gravity = -12.0f;           // 重力

    [Header("时间与透明度控制 (秒)")]
    public float fadeInTime = 0.1f;          // 生成后多少秒完成渐显 (0->1)
    public float fadeOutStartTime = 0.6f;    // 生成后第几秒开始渐隐
    public float fadeOutDuration = 0.3f;     // 渐隐动画持续时长

    // Cache spawn transforms to avoid accessing destroyed GameObject references.
    private Transform redSpawn;
    private Transform greenSpawn;
    private Transform yellowSpawn;
    private Transform purpleSpawn;
    private Transform blueSpawn;

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

        CacheSpawnPoints();
    }

    private void Start()
    {
        // Ensure spawn points are cached after all scene objects are initialized
        if (redSpawn == null && redEffect != null)
        {
            CacheSpawnPoints();
        }
    }

    private void OnEnable()
    {
        // In case this object survives scene changes / references are assigned late.
        if (Instance == null)
        {
            Instance = this;
        }
        
        if (redSpawn == null && redEffect != null) 
        {
            CacheSpawnPoints();
        }
    }

    private void CacheSpawnPoints()
    {
        // Important: check Unity "fake null" before accessing .transform
        redSpawn = redEffect != null ? redEffect.transform : null;
        greenSpawn = greenEffect != null ? greenEffect.transform : null;
        yellowSpawn = yellowEffect != null ? yellowEffect.transform : null;
        purpleSpawn = purpleEffect != null ? purpleEffect.transform : null;
        blueSpawn = blueEffect != null ? blueEffect.transform : null;
        
        if (GameConfig.verboseLogs)
        {
            Debug.Log($"[Animation_Generate] Cached spawn points: red={redSpawn!=null}, green={greenSpawn!=null}, yellow={yellowSpawn!=null}, purple={purpleSpawn!=null}, blue={blueSpawn!=null}");
        }
    }

    public void SpawnJudgePrefab(string color, string judgeResult)
    {
        if (string.IsNullOrEmpty(color))
        {
            Debug.LogError("[Animation_Generate] SpawnJudgePrefab called with empty color!");
            return;
        }

        if (string.IsNullOrEmpty(judgeResult))
        {
            Debug.LogError("[Animation_Generate] SpawnJudgePrefab called with empty judgeResult!");
            return;
        }

        Transform spawnPoint = GetSpawnPoint(color);
        if (spawnPoint == null)
        {
            Debug.LogError($"[Animation_Generate] Could not find spawn point for color: {color}");
            return;
        }

        GameObject prefabToUse = GetJudgePrefab(judgeResult);
        if (prefabToUse == null)
        {
            Debug.LogError($"[Animation_Generate] Could not find judge prefab for result: {judgeResult}. Available: perfect={perfect_judge_prefab != null}, great={great_judge_prefab != null}, good={good_judge_prefab != null}, miss={miss_judge_prefab != null}");
            return;
        }

        if (GameConfig.verboseLogs) Debug.Log($"[Animation_Generate] Spawning judge prefab: color={color}, result={judgeResult}, prefab={prefabToUse.name}");

        GameObject instance = Instantiate(prefabToUse, spawnPoint);
        instance.transform.localPosition = Vector3.zero;

        // 处理缩放
        float finalScale = baseScale;
        if (useRandomScale) finalScale *= Random.Range(minScaleMultiplier, maxScaleMultiplier);
        instance.transform.localScale = new Vector3(finalScale, finalScale, 1f);

        // 开启运动逻辑
        StartCoroutine(AnimateSprite(instance));
    }

    private IEnumerator AnimateSprite(GameObject obj)
    {
        if (obj == null) yield break;

        SpriteRenderer sr = obj.GetComponent<SpriteRenderer>();
        float elapsed = 0f;
        float vVelocity = jumpForce;
        Vector3 currentLocalPos = Vector3.zero;

        // 计算总生命周期：开始渐隐的时间 + 渐隐持续的时长
        float totalLifeTime = fadeOutStartTime + fadeOutDuration;

        // 初始透明度
        if (sr != null)
        {
            Color c = sr.color;
            c.a = 0f;
            sr.color = c;
        }

        // 只要没到总寿命，就持续执行
        while (elapsed < totalLifeTime)
        {
            if (obj == null) yield break;

            float dt = Time.deltaTime;
            elapsed += dt;

            // --- 1. 物理位移 ---
            vVelocity += gravity * dt;
            currentLocalPos.y += vVelocity * dt;
            obj.transform.localPosition = currentLocalPos;

            // --- 2. 透明度逻辑 (基于秒数) ---
            if (sr != null)
            {
                float alpha;

                // 渐显阶段：当前时间 < fadeInTime
                if (elapsed < fadeInTime)
                {
                    alpha = Mathf.InverseLerp(0f, fadeInTime, elapsed);
                }
                // 渐隐阶段：当前时间 > fadeOutStartTime
                else if (elapsed > fadeOutStartTime)
                {
                    // 在 fadeOutStartTime 到 totalLifeTime 之间从 1 变到 0
                    alpha = Mathf.InverseLerp(totalLifeTime, fadeOutStartTime, elapsed);
                }
                // 中间完全显示阶段
                else
                {
                    alpha = 1f;
                }

                Color c = sr.color;
                c.a = Mathf.Clamp01(alpha);
                sr.color = c;
            }

            yield return null;
        }

        // --- 确保最后一帧是完全透明的 ---
        if (obj != null && sr != null)
        {
            Color c = sr.color;
            c.a = 0f;
            sr.color = c;
        }

        // 等待渲染完成，防止闪删
        yield return new WaitForEndOfFrame();

        if (obj != null) Destroy(obj);
    }

    private Transform GetSpawnPoint(string color)
    {
        if (string.IsNullOrEmpty(color)) return null;

        // If references were destroyed (Unity fake null) try to rebuild cache once.
        if (redSpawn == null && greenSpawn == null && yellowSpawn == null && purpleSpawn == null && blueSpawn == null)
        {
            if (GameConfig.verboseLogs) Debug.Log("[Animation_Generate] Rebuilding spawn point cache");
            CacheSpawnPoints();
        }

        Transform point = null;
        switch (color.ToLower())
        {
            case "red": point = redSpawn; break;
            case "green": point = greenSpawn; break;
            case "yellow": point = yellowSpawn; break;
            case "purple": point = purpleSpawn; break;
            case "blue": point = blueSpawn; break;
            default: 
                Debug.LogWarning($"[Animation_Generate] Unknown color: {color}");
                return null;
        }

        if (point == null)
        {
            Debug.LogError($"[Animation_Generate] Spawn point for color {color} is null. Check if effects are assigned in inspector. Make sure the effect object is active in the scene.");
        }

        return point;
    }

    private GameObject GetJudgePrefab(string result)
    {
        if (string.IsNullOrEmpty(result)) return null;
        
        GameObject prefab = null;
        switch (result.ToLower())
        {
            case "perfect": prefab = perfect_judge_prefab; break;
            case "great": prefab = great_judge_prefab; break;
            case "good": prefab = good_judge_prefab; break;
            case "miss": prefab = miss_judge_prefab; break;
            default: 
                Debug.LogWarning($"[Animation_Generate] Unknown judge result: {result}");
                return null;
        }

        if (prefab == null)
        {
            Debug.LogError($"[Animation_Generate] Judge prefab for '{result}' is not assigned in inspector! Check Animation_GenerateJudgementSituationPrefab component.");
        }

        return prefab;
    }
}