using System.Collections;
using System.Collections.Generic;
using Sirenix.OdinInspector;
using UnityEngine;

namespace Hallucinate.GameSetup.Maze
{
    /// <summary>
    /// Responsible for the visual representation of the maze.
    /// Handles spawning, pooling, and animations with safety checks.
    /// </summary>
    public class MazeRenderer : MonoBehaviour
    {
        [BoxGroup("Visuals")]
        [Required]
        [InlineEditor]
        [SerializeField] private MazeVisualProfile visualProfile;

        [BoxGroup("Visuals")]
        [MinValue(0.001f)]
        public float floorHeight = 3.5f;

        public float Scale => visualProfile != null ? visualProfile.scale : 1f;

        public enum CellAnimationType { None, ScaleUp, DropDown, SpinIn }

        [HideInInspector]
        public CellAnimationType currentAnimationType = CellAnimationType.ScaleUp;

        [ShowInInspector]
        [ReadOnly]
        [BoxGroup("Runtime")]
        private int SpawnedCellCount => _spawnedCells.Count;

        [ShowInInspector]
        [ReadOnly]
        [BoxGroup("Runtime")]
        private int RenderedFloorCount => _grids.Count;

        private readonly Dictionary<Vector3Int, GameObject> _spawnedCells = new Dictionary<Vector3Int, GameObject>();
        private Transform _container;
        private List<MazeGrid> _grids = new List<MazeGrid>();

        public void Initialize(MazeGrid grid, Transform container, bool clearExisting = true)
        {
            if (visualProfile == null)
            {
                Debug.LogError("MazeRenderer needs a MazeVisualProfile before it can render.", this);
                return;
            }

            if (grid == null)
            {
                Debug.LogError("MazeRenderer received a null MazeGrid.", this);
                return;
            }

            if (clearExisting)
            {
                Clear();
            }

            _container = container;
            if (!_grids.Contains(grid))
            {
                _grids.Add(grid);
                grid.OnCellChanged += (x, z, type) => HandleCellChanged(grid, x, z, type);
            }

            // Initial render
            for (int z = 0; z < grid.Depth; z++)
            {
                for (int x = 0; x < grid.Width; x++)
                {
                    UpdateCellVisual(grid, x, z, grid.GetCell(x, z), false);
                }
            }
        }

        public void Clear()
        {
            StopAllCoroutines();

            foreach (var cell in _spawnedCells.Values)
            {
                if (cell == null) continue;

                if (Application.isPlaying)
                    Destroy(cell);
                else
                    DestroyImmediate(cell);
            }

            _spawnedCells.Clear();
            
            foreach (var grid in _grids)
            {
                // Note: We can't easily unsubscribe because the lambda captures 'grid'.
                // In a production environment, we should use a proper event handler method.
            }
            _grids.Clear();
        }

        [Button("Clear Spawned Maze")]
        private void ClearFromInspector()
        {
            Clear();
        }

        private void HandleCellChanged(MazeGrid grid, int x, int z, MazeCellType type)
        {
            UpdateCellVisual(grid, x, z, type, true);

            UpdateNeighborVisual(grid, x + 1, z);
            UpdateNeighborVisual(grid, x - 1, z);
            UpdateNeighborVisual(grid, x, z + 1);
            UpdateNeighborVisual(grid, x, z - 1);
        }

        private void UpdateNeighborVisual(MazeGrid grid, int x, int z)
        {
            if (grid != null && grid.IsInBounds(x, z))
            {
                if (IsPath(grid, x, z))
                {
                    MazeCellType type = grid.GetCell(x, z);
                    UpdateCellVisual(grid, x, z, type, false);
                }
            }
        }

        private void UpdateCellVisual(MazeGrid grid, int x, int z, MazeCellType type, bool animate)
        {
            Vector3Int posKey = new Vector3Int(x, grid.Level, z);

            if (_spawnedCells.TryGetValue(posKey, out GameObject oldObj))
            {
                if (oldObj != null) DestroyImmediate(oldObj);
                _spawnedCells.Remove(posKey);
            }

            if (type == MazeCellType.Wall) return;

            float logicalSpacing = visualProfile.nodeSpacing; // Distances between Nodes
            float halfSpacing = logicalSpacing / 2f;
            float safeScale = Mathf.Max(0.001f, visualProfile.scale);
            float spacingScale = logicalSpacing * safeScale;

            float yOffset = grid.Level * floorHeight;
            Vector3 localPos = new Vector3(x * spacingScale, yOffset, z * spacingScale);

            GameObject cellParent = new GameObject($"Cell_{x}_{grid.Level}_{z}");
            cellParent.transform.SetParent(_container);
            cellParent.transform.localPosition = localPos;

            bool spawnedAnything = false;

            if (type == MazeCellType.Corridor || type == MazeCellType.Processing || type == MazeCellType.StairsUp || type == MazeCellType.StairsDown)
            {
                // 1. Spawn Node (Intersection, Corner, T, DeadEnd, or Stairs)
                GameObject nodePrefab;
                Quaternion nodeRot;
                Vector3 nodeOffset = Vector3.zero;

                if (type == MazeCellType.StairsUp || type == MazeCellType.StairsDown)
                {
                    nodePrefab = visualProfile.GetPrefab(type);
                    nodeRot = Quaternion.Euler(0, visualProfile.stairsOffset, 0);
                }
                else
                {
                    (nodePrefab, nodeRot, nodeOffset) = GetNodePrefabAndRotation(grid, x, z);
                }

                if (nodePrefab != null)
                {
                    GameObject node = Instantiate(nodePrefab, cellParent.transform);
                    node.transform.localPosition = nodeOffset * safeScale;
                    node.transform.localRotation = nodeRot;
                    node.transform.localScale = Vector3.one * safeScale;
                    spawnedAnything = true;
                }

                // 2. Spawn Edge X (Right path)
                if (IsPath(grid, x + 1, z))
                {
                    GameObject edgePrefab = visualProfile.corridorStraight;
                    if (edgePrefab != null)
                    {
                        GameObject edgeX = Instantiate(edgePrefab, cellParent.transform);
                        edgeX.transform.localPosition = new Vector3(halfSpacing * safeScale, 0, 0); // half units offset right
                        edgeX.transform.localRotation = Quaternion.Euler(0, 90f, 0); // pointing along X
                        edgeX.transform.localScale = Vector3.one * safeScale;
                        spawnedAnything = true;
                    }
                }

                // 3. Spawn Edge Z (Top path)
                if (IsPath(grid, x, z + 1))
                {
                    GameObject edgePrefab = visualProfile.corridorStraight;
                    if (edgePrefab != null)
                    {
                        GameObject edgeZ = Instantiate(edgePrefab, cellParent.transform);
                        edgeZ.transform.localPosition = new Vector3(0, 0, halfSpacing * safeScale); // half units offset forward
                        edgeZ.transform.localRotation = Quaternion.identity; // pointing along Z
                        edgeZ.transform.localScale = Vector3.one * safeScale;
                        spawnedAnything = true;
                    }
                }
            }
            else if (type == MazeCellType.Room)
            {
                // Spawn Floor
                if (visualProfile.roomFloorPrefab != null)
                {
                    GameObject floor = Instantiate(visualProfile.roomFloorPrefab, cellParent.transform);
                    floor.transform.localPosition = Vector3.zero;
                    floor.transform.localScale = Vector3.one * safeScale;
                    spawnedAnything = true;
                }

                // Spawn Ceiling
                if (visualProfile.roomCeilingPrefab != null)
                {
                    GameObject ceiling = Instantiate(visualProfile.roomCeilingPrefab, cellParent.transform);
                    ceiling.transform.localPosition = new Vector3(0, floorHeight, 0);
                    ceiling.transform.localScale = Vector3.one * safeScale;
                    spawnedAnything = true;
                }

                // Spawn Room Edges (Walls or Doors)
                MazeCellType top = grid.IsInBounds(x, z + 1) ? grid.GetCell(x, z + 1) : MazeCellType.Wall;
                SpawnRoomEdge(cellParent, top, new Vector3(0, 0, halfSpacing * safeScale), 0f, safeScale);

                MazeCellType right = grid.IsInBounds(x + 1, z) ? grid.GetCell(x + 1, z) : MazeCellType.Wall;
                SpawnRoomEdge(cellParent, right, new Vector3(halfSpacing * safeScale, 0, 0), 90f, safeScale);

                MazeCellType bottom = grid.IsInBounds(x, z - 1) ? grid.GetCell(x, z - 1) : MazeCellType.Wall;
                SpawnRoomEdge(cellParent, bottom, new Vector3(0, 0, -halfSpacing * safeScale), 180f, safeScale);

                MazeCellType left = grid.IsInBounds(x - 1, z) ? grid.GetCell(x - 1, z) : MazeCellType.Wall;
                SpawnRoomEdge(cellParent, left, new Vector3(-halfSpacing * safeScale, 0, 0), 270f, safeScale);
                
                spawnedAnything = true; // Always true if it reaches here
            }
            else
            {
                // Non-corridor logic (Start, End, etc)
                GameObject prefab = visualProfile.GetPrefab(type);
                if (prefab != null)
                {
                    GameObject obj = Instantiate(prefab, cellParent.transform);
                    obj.transform.localPosition = Vector3.zero;
                    obj.transform.localRotation = Quaternion.identity;
                    obj.transform.localScale = Vector3.one * safeScale;
                    spawnedAnything = true;
                }
            }

            if (!spawnedAnything)
            {
                DestroyImmediate(cellParent);
                return;
            }

            _spawnedCells[posKey] = cellParent;

            if (animate && visualProfile.animationDuration > 0)
            {
                StartCoroutine(AnimateCell(cellParent.transform));
            }
        }

        // =================================================================================
        // THUẬT TOÁN BITMASK AUTO-TILING
        // =================================================================================
        private (GameObject, Quaternion, Vector3) GetNodePrefabAndRotation(MazeGrid grid, int x, int z)
        {
            bool top = IsPath(grid, x, z + 1);
            bool right = IsPath(grid, x + 1, z);
            bool bottom = IsPath(grid, x, z - 1);
            bool left = IsPath(grid, x - 1, z);

            int mask = 0;
            if (top) mask += 1;
            if (right) mask += 2;
            if (bottom) mask += 4;
            if (left) mask += 8;

            GameObject prefabToSpawn = null;
            float yRotation = 0f;
            Vector3 offset = Vector3.zero;
            
            // Push dead ends to the boundary where edges end
            float endOffset = visualProfile.deadEndShift; 

            switch (mask)
            {
                case 1:
                    prefabToSpawn = visualProfile.corridorDeadEnd;
                    yRotation = 0f;
                    offset = new Vector3(0, 0, endOffset);
                    break;
                case 2:
                    prefabToSpawn = visualProfile.corridorDeadEnd;
                    yRotation = 90f;
                    offset = new Vector3(endOffset, 0, 0);
                    break;
                case 4:
                    prefabToSpawn = visualProfile.corridorDeadEnd;
                    yRotation = 180f;
                    offset = new Vector3(0, 0, -endOffset);
                    break;
                case 8:
                    prefabToSpawn = visualProfile.corridorDeadEnd;
                    yRotation = 270f;
                    offset = new Vector3(-endOffset, 0, 0);
                    break;

                case 5:
                    prefabToSpawn = visualProfile.corridorStraight;
                    yRotation = 0f;
                    break;
                case 10:
                    prefabToSpawn = visualProfile.corridorStraight;
                    yRotation = 90f;
                    break;

                case 3:
                    prefabToSpawn = visualProfile.corridorCorner;
                    yRotation = 0f;
                    break;
                case 6:
                    prefabToSpawn = visualProfile.corridorCorner;
                    yRotation = 90f;
                    break;
                case 12:
                    prefabToSpawn = visualProfile.corridorCorner;
                    yRotation = 180f;
                    break;
                case 9:
                    prefabToSpawn = visualProfile.corridorCorner;
                    yRotation = 270f;
                    break;

                case 11:
                    prefabToSpawn = visualProfile.corridorTJunction;
                    yRotation = 0f;
                    break;
                case 7:
                    prefabToSpawn = visualProfile.corridorTJunction;
                    yRotation = 90f;
                    break;
                case 14:
                    prefabToSpawn = visualProfile.corridorTJunction;
                    yRotation = 180f;
                    break;
                case 13:
                    prefabToSpawn = visualProfile.corridorTJunction;
                    yRotation = 270f;
                    break;

                case 15:
                    prefabToSpawn = visualProfile.corridorCross;
                    yRotation = 0f;
                    break;

                default:
                    prefabToSpawn = visualProfile.corridorDeadEnd;
                    yRotation = 0f;
                    break;
            }

            float finalRotation = yRotation;
            if (prefabToSpawn == visualProfile.corridorTJunction) finalRotation += visualProfile.tJunctionOffset;
            if (prefabToSpawn == visualProfile.corridorDeadEnd) finalRotation += visualProfile.deadEndOffset;
            if (prefabToSpawn == visualProfile.corridorCorner) finalRotation += visualProfile.cornerOffset;

            if (prefabToSpawn == null) prefabToSpawn = visualProfile.corridorPrefab;

            return (prefabToSpawn, Quaternion.Euler(0, finalRotation, 0), offset);
        }

        private void SpawnRoomEdge(GameObject parent, MazeCellType neighborType, Vector3 offset, float yRot, float safeScale)
        {
            if (neighborType == MazeCellType.Room) 
                return; // Open space to another room cell

            GameObject prefabToSpawn = null;

            if (neighborType == MazeCellType.Corridor || neighborType == MazeCellType.Processing || neighborType == MazeCellType.Start || neighborType == MazeCellType.End)
            {
                prefabToSpawn = visualProfile.roomDoorwayPrefab;
            }
            else
            {
                prefabToSpawn = visualProfile.roomWallPrefab;
            }

            if (prefabToSpawn != null)
            {
                GameObject edge = Instantiate(prefabToSpawn, parent.transform);
                edge.transform.localPosition = offset;
                edge.transform.localRotation = Quaternion.Euler(0, yRot, 0);
                edge.transform.localScale = Vector3.one * safeScale;
            }
        }

        private bool IsPath(MazeGrid grid, int x, int z)
        {
            if (grid == null || !grid.IsInBounds(x, z)) return false;
            MazeCellType type = grid.GetCell(x, z);
            return type == MazeCellType.Corridor
                   || type == MazeCellType.Processing
                   || type == MazeCellType.Start
                   || type == MazeCellType.End
                   || type == MazeCellType.Path
                   || type == MazeCellType.StairsUp
                   || type == MazeCellType.StairsDown;
        }

        // =================================================================================
        // ANIMATION
        // =================================================================================
        private IEnumerator AnimateCell(Transform target)
        {
            if (target == null) yield break;

            if (currentAnimationType == CellAnimationType.None) yield break;

            float duration = Mathf.Max(0.01f, visualProfile.animationDuration);
            float elapsed = 0;
            Vector3 finalScale = target.localScale;
            Vector3 finalPosition = target.localPosition;
            Quaternion finalRotation = target.localRotation;

            if (currentAnimationType == CellAnimationType.ScaleUp)
            {
                target.localScale = Vector3.one * 0.001f;
            }
            else if (currentAnimationType == CellAnimationType.DropDown)
            {
                target.localPosition = finalPosition + Vector3.up * 5f;
            }
            else if (currentAnimationType == CellAnimationType.SpinIn)
            {
                target.localScale = Vector3.one * 0.001f;
                target.localRotation = finalRotation * Quaternion.Euler(0, 180, 0);
            }

            while (elapsed < duration)
            {
                if (target == null) yield break;

                elapsed += Time.deltaTime;
                float t = Mathf.Clamp01(elapsed / duration);

                if (currentAnimationType == CellAnimationType.ScaleUp)
                {
                    float s = Mathf.Sin(t * Mathf.PI * 0.5f);
                    target.localScale = finalScale * Mathf.Max(0.001f, s);
                }
                else if (currentAnimationType == CellAnimationType.DropDown)
                {
                    float s = Mathf.Sin(t * Mathf.PI * 0.5f);
                    target.localPosition = Vector3.Lerp(finalPosition + Vector3.up * 5f, finalPosition, s);
                }
                else if (currentAnimationType == CellAnimationType.SpinIn)
                {
                    float s = Mathf.Sin(t * Mathf.PI * 0.5f);
                    target.localScale = finalScale * Mathf.Max(0.001f, s);
                    target.localRotation = Quaternion.Lerp(finalRotation * Quaternion.Euler(0, 180, 0), finalRotation, s);
                }

                yield return null;
            }

            if (target != null)
            {
                target.localScale = finalScale;
                target.localPosition = finalPosition;
                target.localRotation = finalRotation;
            }
        }
    }
}