using UnityEngine;
using System.Collections;

public class Animation_GenerateJudgementSituationPrefab : MonoBehaviour
{
    private sealed class PooledJudgeTag : MonoBehaviour
    {
        public GameObject prefabSource;
    }

    public static Animation_GenerateJudgementSituationPrefab Instance;

    [Header("Inspector")]
    public GameObject redEffect;
    public GameObject greenEffect;
    public GameObject yellowEffect;
    public GameObject purpleEffect;
    public GameObject blueEffect;

    [Header("Inspector")]
    public GameObject perfect_judge_prefab;
    public GameObject great_judge_prefab;
    public GameObject good_judge_prefab;
    public GameObject miss_judge_prefab;

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

    [Header("Inspector")]
    public float jumpForce = 5.0f;           // Documentation text normalized.
    public float gravity = -16f;             // Documentation text normalized.

    [Header("Inspector")]
    public float fadeInTime = 0.1f;          // Documentation text normalized.
    public float fadeOutStartTime = 0.6f;    // Documentation text normalized.
    public float fadeOutDuration = 0.35f;    // Documentation text normalized.

    // Cache spawn transforms to avoid accessing destroyed GameObject references.
    private Transform redSpawn;
    private Transform greenSpawn;
    private Transform yellowSpawn;
    private Transform purpleSpawn;
    private Transform blueSpawn;
    
    // Track last scene to detect scene changes
    private int lastSceneIndex = -1;
    private Coroutine prewarmJudgeCoroutine;
    private readonly System.Collections.Generic.Dictionary<GameObject, System.Collections.Generic.Stack<GameObject>> judgePools
        = new System.Collections.Generic.Dictionary<GameObject, System.Collections.Generic.Stack<GameObject>>();

    private void Awake()
    {
        if (Instance == null)
        {
            Instance = this;
            // Documentation text normalized.
            // Documentation text normalized.
        }
        else if (Instance != this)
        {
            Destroy(gameObject);
            return;
        }

        CacheSpawnPoints();
        lastSceneIndex = UnityEngine.SceneManagement.SceneManager.GetActiveScene().buildIndex;
    }

    private void Start()
    {
        // Ensure spawn points are cached after all scene objects are initialized
        CacheSpawnPointsIfNeeded();
    }

    private void OnEnable()
    {
        // Detect scene reload and refresh cache
        int currentSceneIndex = UnityEngine.SceneManagement.SceneManager.GetActiveScene().buildIndex;
        if (currentSceneIndex != lastSceneIndex)
        {
            if (JudgeManager.IsDebugEnabled) Debug.Log($"[Animation_Generate] Scene changed detected (from {lastSceneIndex} to {currentSceneIndex}), refreshing spawn point cache");
            lastSceneIndex = currentSceneIndex;
            CacheSpawnPoints();
        }
        else
        {
            CacheSpawnPointsIfNeeded();
        }
    }

    private void CacheSpawnPointsIfNeeded()
    {
        // Only recache if any of the references appear to be invalid (destroyed)
        if (redSpawn == null || greenSpawn == null || yellowSpawn == null || purpleSpawn == null || blueSpawn == null)
        {
            // Check if the effect GameObjects are still valid
            bool anyInvalid = (redEffect == null || redEffect.transform == null) ||
                              (greenEffect == null || greenEffect.transform == null) ||
                              (yellowEffect == null || yellowEffect.transform == null) ||
                              (purpleEffect == null || purpleEffect.transform == null) ||
                              (blueEffect == null || blueEffect.transform == null);

            if (anyInvalid || redSpawn == 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 (JudgeManager.IsDebugEnabled)
        {
            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 (JudgeManager.IsDebugEnabled) Debug.Log($"[Animation_Generate] Spawning judge prefab: color={color}, result={judgeResult}, prefab={prefabToUse.name}");

        GameObject instance = GetPooledJudge(prefabToUse, spawnPoint);
        if (instance == null)
            return;

        instance.transform.localPosition = Vector3.zero;

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

        // Documentation text normalized.
        StartCoroutine(AnimateSprite(instance));
    }

    public void PrewarmJudgePrefabs(int perPrefab = 1)
    {
        if (!Application.isPlaying)
            return;

        if (prewarmJudgeCoroutine != null)
        {
            StopCoroutine(prewarmJudgeCoroutine);
        }

        prewarmJudgeCoroutine = StartCoroutine(PrewarmJudgePrefabsRoutine(Mathf.Max(1, perPrefab)));
    }

    public IEnumerator PrewarmJudgePrefabsRoutine(int perPrefab = 1)
    {
        GameObject[] prefabs =
        {
            perfect_judge_prefab,
            great_judge_prefab,
            good_judge_prefab,
            miss_judge_prefab
        };

        int count = Mathf.Max(1, perPrefab);
        foreach (GameObject prefab in prefabs)
        {
            if (prefab == null)
                continue;

            for (int i = 0; i < count; i++)
            {
                GameObject instance = null;
                try
                {
                    instance = CreatePooledJudge(prefab);
                    ReturnJudgeToPool(instance);
                }
                catch { }

                yield return null;
            }
        }

        prewarmJudgeCoroutine = null;
    }

    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;

        // Documentation text normalized.
        float totalLifeTime = fadeOutStartTime + fadeOutDuration;

        // Documentation text normalized.
        if (sr != null)
        {
            Color c = sr.color;
            c.a = 0f;
            sr.color = c;
        }

        // Documentation text normalized.
        while (elapsed < totalLifeTime)
        {
            if (obj == null) yield break;

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

            // Documentation text normalized.
            vVelocity += gravity * dt;
            currentLocalPos.y += vVelocity * dt;
            obj.transform.localPosition = currentLocalPos;

            // Documentation text normalized.
            if (sr != null)
            {
                float alpha;

                // Documentation text normalized.
                if (elapsed < fadeInTime)
                {
                    alpha = Mathf.InverseLerp(0f, fadeInTime, elapsed);
                }
                // Documentation text normalized.
                else if (elapsed > fadeOutStartTime)
                {
                    // Documentation text normalized.
                    alpha = Mathf.InverseLerp(totalLifeTime, fadeOutStartTime, elapsed);
                }
                // Documentation text normalized.
                else
                {
                    alpha = 1f;
                }

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

            yield return null;
        }

        // Documentation text normalized.
        if (obj != null && sr != null)
        {
            Color c = sr.color;
            c.a = 0f;
            sr.color = c;
        }

        // Documentation text normalized.

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

    private GameObject GetPooledJudge(GameObject prefab, Transform parent)
    {
        if (prefab == null || parent == null)
            return null;

        if (!judgePools.TryGetValue(prefab, out var pool))
        {
            pool = new System.Collections.Generic.Stack<GameObject>();
            judgePools[prefab] = pool;
        }

        GameObject instance = null;
        while (pool.Count > 0 && instance == null)
        {
            instance = pool.Pop();
        }

        if (instance == null)
        {
            instance = CreatePooledJudge(prefab);
        }

        if (instance == null)
            return null;

        instance.transform.SetParent(parent, false);
        instance.SetActive(true);
        return instance;
    }

    private GameObject CreatePooledJudge(GameObject prefab)
    {
        if (prefab == null)
            return null;

        GameObject instance = Instantiate(prefab, transform);
        var tag = instance.GetComponent<PooledJudgeTag>();
        if (tag == null)
            tag = instance.AddComponent<PooledJudgeTag>();
        tag.prefabSource = prefab;
        instance.SetActive(false);
        return instance;
    }

    private void ReturnJudgeToPool(GameObject instance)
    {
        if (instance == null)
            return;

        var tag = instance.GetComponent<PooledJudgeTag>();
        if (tag == null || tag.prefabSource == null)
        {
            Destroy(instance);
            return;
        }

        if (!judgePools.TryGetValue(tag.prefabSource, out var pool))
        {
            pool = new System.Collections.Generic.Stack<GameObject>();
            judgePools[tag.prefabSource] = pool;
        }

        instance.transform.SetParent(transform, false);
        instance.transform.localPosition = new Vector3(99999f, 99999f, 0f);
        instance.transform.localRotation = Quaternion.identity;
        instance.SetActive(false);
        pool.Push(instance);
    }

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

        // Documentation text normalized.

        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;
    }
}