using UnityEngine;
using UnityEngine.Tilemaps;

namespace Platformer.Mechanics
{
    /// <summary>
    /// 게임 시작 시 프레임·렌더·물리 기본 최적화 + One-Way Platform 자동 적용.
    /// BT5-Dev 발판 시스템 영구 영역 (2026-05-08 PD 정합 마무리).
    ///
    /// 동작 요약:
    ///   1. Layer Matrix: Player(13) ↔ Enemy(14) 충돌 OFF.
    ///   2. Level Tilemap = Layer 0 (지면·벽 영구 충돌). 그 외 비-trigger Collider2D = Layer 16 강제.
    ///   3. PD Foreground GameObject = 가림막 시각만 (TilemapCollider2D 제거).
    ///   4. AutoForeground GameObject (Grid 자식·Tilemap·TilemapCollider·Layer 16) = 자동 분류 발판.
    ///   5. 자동 분류 (Level → AutoForeground):
    ///      - colliderType=None Tile (tree·plant·fence·house) 제외
    ///      - 이름 prefix "TileGround" Tile (지면·벽) 제외
    ///      - 임계값 (worldY >= playerY+1.5) 또는 작은 공중 발판 (가로≤8 + 위·아래 빈) 분류
    ///      - SetColliderType(Sprite) 강제
    /// </summary>
    public static class GameOptimizer
    {
        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
        static void Init()
        {
            Application.targetFrameRate = 60;
            QualitySettings.vSyncCount = 0;
            Time.fixedDeltaTime = 1f / 60f;

            // Layer Matrix: Player(13) ↔ Enemy(14) 충돌 OFF.
            Physics2D.IgnoreLayerCollision(13, 14, true);
        }

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.AfterSceneLoad)]
        static void SetupJumpThroughPlatforms()
        {
            // 1. Level Tilemap = Layer 0 보존. 그 외 비-trigger Collider2D = Layer 16 강제 (Drop-Through).
            int applied = 0, excluded = 0, levelKept = 0;
            var allColliders = Object.FindObjectsByType<Collider2D>(FindObjectsSortMode.None);
            foreach (var c in allColliders)
            {
                if (c == null) continue;
                if (c.isTrigger) { excluded++; continue; }
                if (c.GetComponent<PlayerController>() != null
                    || c.GetComponent<EnemyController>() != null
                    || c.GetComponent<DeathZone>() != null
                    || c.GetComponent<TokenInstance>() != null
                    || c.GetComponent<VictoryZone>() != null
                    || c.GetComponent<AttackHitbox>() != null)
                {
                    excluded++;
                    continue;
                }

                if (c.GetComponent<UnityEngine.Tilemaps.TilemapCollider2D>() != null && c.gameObject.name == "Level")
                {
                    if (c.gameObject.layer == 16) c.gameObject.layer = 0;
                    var lvlEffector = c.GetComponent<PlatformEffector2D>();
                    if (lvlEffector != null) Object.Destroy(lvlEffector);
                    c.usedByEffector = false;
                    levelKept++;
                    continue;
                }

                var effector = c.GetComponent<PlatformEffector2D>();
                if (effector != null) Object.Destroy(effector);
                c.usedByEffector = false;
                c.gameObject.layer = 16;
                applied++;
            }

            // 2. PD Foreground = 가림막 시각만 (TilemapCollider2D 제거 → 충돌 X).
            var pdForeground = GameObject.Find("Foreground");
            if (pdForeground != null)
            {
                var pdFgTc = pdForeground.GetComponent<UnityEngine.Tilemaps.TilemapCollider2D>();
                if (pdFgTc != null) Object.Destroy(pdFgTc);
            }

            // 3. AutoForeground GameObject (Grid 자식·신규) — 자동 분류 발판 전용.
            //    transform.localPosition = PD Foreground/Level과 동기화 (시각 위치 정합).
            GameObject gridGo = (pdForeground != null && pdForeground.transform.parent != null)
                                ? pdForeground.transform.parent.gameObject
                                : GameObject.Find("Grid");
            GameObject autoFg = GameObject.Find("AutoForeground");
            UnityEngine.Tilemaps.Tilemap fgTilemap = null;
            UnityEngine.Tilemaps.TilemapCollider2D fgTc = null;
            if (autoFg == null && gridGo != null)
            {
                autoFg = new GameObject("AutoForeground");
                autoFg.transform.SetParent(gridGo.transform, false);
            }
            if (autoFg != null)
            {
                autoFg.layer = 16;
                var refGo = pdForeground != null ? pdForeground : GameObject.Find("Level");
                if (refGo != null) autoFg.transform.localPosition = refGo.transform.localPosition;
                fgTilemap = autoFg.GetComponent<UnityEngine.Tilemaps.Tilemap>();
                if (fgTilemap == null) fgTilemap = autoFg.AddComponent<UnityEngine.Tilemaps.Tilemap>();
                if (autoFg.GetComponent<UnityEngine.Tilemaps.TilemapRenderer>() == null)
                    autoFg.AddComponent<UnityEngine.Tilemaps.TilemapRenderer>();
                fgTc = autoFg.GetComponent<UnityEngine.Tilemaps.TilemapCollider2D>();
                if (fgTc == null) fgTc = autoFg.AddComponent<UnityEngine.Tilemaps.TilemapCollider2D>();
            }

            // 4. Level → AutoForeground 자동 분류:
            //    - colliderType=None (배경) 제외 / 이름 prefix "TileGround" (지면·벽) 제외
            //    - 임계값 위 OR 작은 공중 발판 = Foreground 이동 + Sprite 강제
            var levelGo = GameObject.Find("Level");
            if (levelGo != null && fgTilemap != null)
            {
                var levelTilemap = levelGo.GetComponent<UnityEngine.Tilemaps.Tilemap>();
                var player = Object.FindFirstObjectByType<PlayerController>();
                if (levelTilemap != null && player != null)
                {
                    float playerY = player.transform.position.y;
                    float airThresholdY = playerY + 1.5f;
                    const int MAX_PLATFORM_WIDTH = 8;
                    var bounds = levelTilemap.cellBounds;
                    int movedHigh = 0, movedSmall = 0;
                    for (int x = bounds.xMin; x <= bounds.xMax; x++)
                    {
                        for (int y = bounds.yMin; y <= bounds.yMax; y++)
                        {
                            var pos = new Vector3Int(x, y, 0);
                            if (!levelTilemap.HasTile(pos)) continue;

                            var tileAsset = levelTilemap.GetTile<UnityEngine.Tilemaps.Tile>(pos);
                            if (tileAsset != null && tileAsset.colliderType == UnityEngine.Tilemaps.Tile.ColliderType.None) continue;
                            string nm = tileAsset != null ? tileAsset.name : string.Empty;
                            if (nm.StartsWith("TileGround")) continue;

                            Vector3 worldPos = levelTilemap.CellToWorld(pos);
                            bool aboveThreshold = worldPos.y >= airThresholdY;
                            bool isSmallAir = !aboveThreshold && IsSmallAirPlatform(levelTilemap, pos, MAX_PLATFORM_WIDTH);
                            if (!aboveThreshold && !isSmallAir) continue;

                            var tile = levelTilemap.GetTile(pos);
                            fgTilemap.SetTile(pos, tile);
                            fgTilemap.SetColliderType(pos, UnityEngine.Tilemaps.Tile.ColliderType.Sprite);
                            levelTilemap.SetTile(pos, null);
                            if (aboveThreshold) movedHigh++;
                            else movedSmall++;
                        }
                    }
                    if (fgTc != null) fgTc.ProcessTilemapChanges();
                    var lvlTc = levelGo.GetComponent<UnityEngine.Tilemaps.TilemapCollider2D>();
                    if (lvlTc != null) lvlTc.ProcessTilemapChanges();
                    Debug.Log($"[GameOptimizer] AutoForeground moved={movedHigh + movedSmall} (high={movedHigh} small={movedSmall} threshold={airThresholdY:F2}) / Layer16 applied={applied} levelKept0={levelKept} excluded={excluded}");
                }
            }
        }

        /// <summary>
        /// 작은 공중 발판 판별: 위·아래 인접 Tile이 모두 빈 공간 + 가로 연속 길이 maxWidth 이하.
        /// 일반 지면(10+ tile 가로) 잘못 분류 방지.
        /// </summary>
        static bool IsSmallAirPlatform(UnityEngine.Tilemaps.Tilemap tm, Vector3Int pos, int maxWidth)
        {
            if (tm.HasTile(pos + Vector3Int.up)) return false;
            if (tm.HasTile(pos + Vector3Int.down)) return false;
            int width = 1;
            for (int dx = 1; dx <= maxWidth; dx++)
            {
                if (!tm.HasTile(pos + new Vector3Int(dx, 0, 0))) break;
                width++;
                if (width > maxWidth) return false;
            }
            for (int dx = 1; dx <= maxWidth; dx++)
            {
                if (!tm.HasTile(pos + new Vector3Int(-dx, 0, 0))) break;
                width++;
                if (width > maxWidth) return false;
            }
            return width <= maxWidth;
        }
    }
}