using UnityEngine;
using System.Collections.Generic;
using System.Linq;

/// <summary>
/// AI Agent that navigates the maze with limited knowledge
/// Only knows about the room it's currently in and rooms visited by same character type
/// </summary>
public class AIAgent : MonoBehaviour
{
    [Header("Agent Identity")]
    [SerializeField] private string agentCharacterType = "Default";
    [SerializeField] private int agentId;

    [Header("Agent Personalization")]
    private string agentName;
    private AgentStats agentStats;

    [Header("AI Settings")]
    [SerializeField] private float movementSpeed = 2f;
    [SerializeField] private float pathUpdateInterval = 0.5f;
    [SerializeField] private float stoppingDistance = 0.1f;

    private float actualMovementSpeed; // Per-agent speed variation to reduce synchronization

    [Header("Pathfinding")]
    [Tooltip("Disable for large agent counts to avoid LineRenderer overhead.")]
    [SerializeField] private bool showPath = false;
    [SerializeField] private LineRenderer pathRenderer;
    [SerializeField] private Color pathColor = Color.yellow;

    private MazeController mazeController;
    private MazeData maze;
    private MazePathfinder pathfinder;
    private AIRoomMemory roomMemory;

    private List<Vector2Int> currentPath = new();
    private int currentPathIndex = 0;
    private float lastPathUpdate = 0f;
    private Vector2Int currentRoom = Vector2Int.zero;
    private Vector2Int targetRoom = Vector2Int.zero;
    private Vector2Int targetExitTile = Vector2Int.zero; // Target hallway exit to move toward
    private Queue<int> recentRooms = new Queue<int>(); // Track last N rooms to avoid backtracking
    private const int RECENT_ROOMS_BUFFER_SIZE = 10; // Larger buffer = less backtracking
    private MazeRoom lastRoomExitedFrom = null; // Track which room we exited to prevent immediate backtracking
    private bool hasReachedGoal = false; // Track if agent has reached the goal room
    private bool commitedToExit = false; // Track if agent has committed to a specific hallway exit
    private float nextRandomWait = 0f; // Random wait time before exploring new areas
    private float agentRandomOffset = 0f; // Per-agent random offset to desync movement
    private bool pathRequestPending = false; // True while waiting for async pathfinding result

    // Intelligence-driven disposition (seeded at spawn from Intelligence stat)
    // Will drive group-up logic, risk assessment, and future combat decisions
    private float groupUpAffinity;  // 0-1: likelihood to seek allies over going solo
    private float riskTolerance;    // 0-1: willingness to enter dangerous/unknown situations
    private bool knowsExitLocation = false; // True once agent has "seen" the exit room

    // ----- Group membership -----
    private AgentGroup currentGroup = null;
    private bool isGroupFollower = false; // True when this agent defers movement to the leader

    // ----- Combat -----
    private Weapon weapon;
    private float lastAttackTime = 0f;
    private const float ATTACK_COOLDOWN = 1.0f;
    /// <summary>Agent advantage multiplier on hit rolls (can improve with experience/weapons later).</summary>
    private const float AGENT_HIT_ADVANTAGE = 1.3f;
    private bool isDead = false;
    /// <summary>True while a monster is within melee range – halts path-following.</summary>
    private bool isInCombat = false;
    /// <summary>Monsters this agent is currently fighting (for fight tracking).</summary>
    private HashSet<Monster> fightingMonsters = new();

    // ----- Room danger / avoidance -----
    /// <summary>Room IDs the agent has decided to avoid (too dangerous to fight through).</summary>
    private readonly HashSet<int> avoidedRooms = new();
    /// <summary>Speed threshold: agents above this fraction of max speed may try to run through.</summary>
    private const float RUN_THROUGH_SPEED_FRACTION = 0.6f; // Speed stat > 60 enables sprinting

    // ----- Cached maze data (set once in Start, never changes) -----
    private MazeRoom[] _allRooms;          // Array copy is faster to iterate than List
    private HashSet<MazeRoom> _goalRooms;  // Constant set for O(1) Contains checks

    void Start()
    {
        mazeController = FindAnyObjectByType<MazeController>();
        if (mazeController == null)
        {
            Debug.LogError("AIAgent: MazeController not found in scene!");
            enabled = false;
            return;
        }

        maze = mazeController.GetCurrentMaze();
        if (maze == null)
        {
            Debug.LogError("AIAgent: Current maze is null!");
            enabled = false;
            return;
        }

        pathfinder = new MazePathfinder(maze);
        roomMemory = AIRoomMemoryManager.GetMemory(agentCharacterType);

        // Cache room data once – avoids List allocations and LINQ on every Update
        _allRooms = maze.Rooms.ToArray();
        _goalRooms = new HashSet<MazeRoom>(maze.GetRoomsByType(MazeRoom.RoomType.End));
        if (_goalRooms.Count == 0)
            Debug.LogWarning($"[Agent] No goal rooms found! Agents will never exit.");
        else
            Debug.Log($"[Agent] {_goalRooms.Count} goal room(s) cached for exit detection.");

        // Initialize personalization
        agentName = AgentNameGenerator.GenerateRandomName();
        agentStats = new AgentStats();
        gameObject.name = $"Agent_{agentId} ({agentName})";

        // Seed intelligence-driven disposition from stats
        groupUpAffinity = agentStats.GroupUpAffinity;
        riskTolerance = agentStats.RiskTolerance;

        // Equip fists as default weapon
        weapon = Weapon.Fists();

        // Initialize with a random start point
        if (maze.StartPoints.Count > 0)
        {
            int startIndex = agentId % maze.StartPoints.Count; // Distribute agents across start points
            Vector2Int startPos = maze.StartPoints[startIndex];

            // Get the start room and spawn randomly within it
            MazeRoom startRoom = maze.GetRoomAtTile(startPos.x, startPos.y);
            if (startRoom != null)
            {
                // Spawn at random position within start room
                Vector2Int randomPosInRoom = new Vector2Int(
                    Random.Range(startRoom.MinX + 1, startRoom.MaxX),
                    Random.Range(startRoom.MinY + 1, startRoom.MaxY)
                );
                transform.position = new Vector3(randomPosInRoom.x + 0.5f, 1f, randomPosInRoom.y + 0.5f);
            }
            else
            {
                // Fallback to exact start point
                transform.position = new Vector3(startPos.x + 0.5f, 1f, startPos.y + 0.5f);
            }

            // Rotate to be visible from above - 90 degrees around X axis
            transform.rotation = Quaternion.Euler(90, 0, 0);
            UpdateCurrentRoom(); // This will add to recentRooms and visit room
        }
        else
        {
            Debug.LogError("AIAgent: No start points found in maze!");
            enabled = false;
            return;
        }

        // Setup per-agent random offset to desync decision timings (prevents all agents moving in sync)
        agentRandomOffset = Random.Range(0f, pathUpdateInterval * 0.5f);
        nextRandomWait = Time.time + Random.Range(2f, 4f); // Random initial wait before first decision

        // Scale movement speed by the agent's Speed stat:
        // Speed=1 → ~1× base, Speed=100 → 2× base, plus ±10% desync jitter
        float speedMultiplier = 1f + (agentStats.Speed / 100f);
        actualMovementSpeed = movementSpeed * speedMultiplier * Random.Range(0.9f, 1.1f);

        // Suppress per-agent spawn log for large counts; enable only when debugging individuals
        // Debug.Log($"[Agent {agentId}] {agentName} | {agentStats} | GroupUp: {groupUpAffinity:P0} | Risk: {riskTolerance:P0}");

        // Setup path renderer
        if (showPath && pathRenderer == null)
        {
            pathRenderer = gameObject.AddComponent<LineRenderer>();
            pathRenderer.startWidth = 0.1f;
            pathRenderer.endWidth = 0.1f;
            pathRenderer.material = new Material(Shader.Find("Sprites/Default"));
            pathRenderer.startColor = pathColor;
            pathRenderer.endColor = pathColor;
        }

    }

    void Update()
    {
        if (maze == null) return;

        // Dead bodies persist forever - just stop updating logic
        if (isDead)
        {
            return;
        }

        // Agent has reached the exit - stop all movement
        if (hasReachedGoal)
        {
            return;
        }

        // Followers defer all movement to the group leader
        if (isGroupFollower)
        {
            if (currentGroup != null && currentGroup.Leader != null)
                transform.position = currentGroup.Leader.transform.position;
            // Followers still check for exit rooms
            UpdateCurrentRoom();
            // Followers still fight monsters in range
            CombatUpdate();
            return;
        }

        // Fight any adjacent monsters
        CombatUpdate();

        // Update current room
        UpdateCurrentRoom();

        // Update pathfinding periodically – skip if an async request is already in-flight
        if (!pathRequestPending && Time.time - lastPathUpdate > pathUpdateInterval + agentRandomOffset)
        {
            UpdatePathToGoal();
            lastPathUpdate = Time.time;
        }

        // Move along path – suppressed while fighting
        if (!isInCombat)
            FollowPath();

        // Debug visualization – only update for agents near the camera to save draw calls
        if (showPath && pathRenderer != null && IsNearCamera(80f))
        {
            UpdatePathVisualization();
        }
    }

    private static Camera _mainCam;
    private static float _lastCamFetch;

    /// <summary>Returns true if this agent is within <paramref name="sqrDist"/> world units of the main camera.</summary>
    private bool IsNearCamera(float sqrDist)
    {
        if (_mainCam == null || Time.time - _lastCamFetch > 2f)
        {
            _mainCam = Camera.main;
            _lastCamFetch = Time.time;
        }
        if (_mainCam == null) return true;
        return (transform.position - _mainCam.transform.position).sqrMagnitude < sqrDist * sqrDist;
    }

    private Vector2Int _lastRoomCheckTile = new Vector2Int(-9999, -9999);

    /// <summary>
    /// Updates the current room based on position.
    /// Only queries the maze when the agent has moved to a different tile.
    /// Also checks if we've reached the goal room immediately.
    /// </summary>
    private void UpdateCurrentRoom()
    {
        Vector2Int tilePos = WorldToTile(transform.position);
        // Skip if we're still on the same tile – saves GetRoomAtTile call every frame
        if (tilePos == _lastRoomCheckTile) return;
        _lastRoomCheckTile = tilePos;

        MazeRoom room = maze.GetRoomAtTile(tilePos.x, tilePos.y);

        if (room != null)
        {
            // CHECK FOR GOAL ROOM FIRST - every tile, regardless of room change
            if (!hasReachedGoal && _goalRooms.Contains(room))
            {
                hasReachedGoal = true;
                currentPath.Clear();
                currentPathIndex = 0;
                commitedToExit = false;

                // If this agent is in a group, mark all members as having reached the goal
                if (currentGroup != null)
                {
                    foreach (var member in currentGroup.Members)
                    {
                        if (member != null && !member.HasReachedGoal)
                        {
                            member.hasReachedGoal = true;
                        }
                    }
                }

                Debug.Log($"[Agent {agentId}] {agentName} reached the exit!");
                return; // Stop immediately
            }

            if (currentRoom.x != room.Id)
            {
                currentRoom = new Vector2Int(room.Id, 0);
                roomMemory.VisitRoom(room.Id);

                // Track recent rooms to avoid immediate backtracking
                recentRooms.Enqueue(room.Id);
                if (recentRooms.Count > RECENT_ROOMS_BUFFER_SIZE)
                    recentRooms.Dequeue();
            }
        }
    }

    /// <summary>
    /// Updates pathfinding to reach the goal
    /// Agent only knows about current room and visited rooms
    /// NEW LOGIC: Pick a hallway exit from current room and move straight to it
    /// </summary>
    private void UpdatePathToGoal()
    {
        if (maze.ExitPoints.Count == 0)
        {
            Debug.LogWarning($"AIAgent {agentId}: No exit points in maze!");
            return;
        }

        Vector2Int currentPos = WorldToTile(transform.position);
        MazeRoom currentRoomData = maze.GetRoomAtTile(currentPos.x, currentPos.y);

        // CHECK FOR GOAL ROOM FIRST - this should work even while following path
        if (currentRoomData != null && _goalRooms.Contains(currentRoomData))
        {
            if (!hasReachedGoal)
            {
                hasReachedGoal = true;
                currentPath.Clear();
                currentPathIndex = 0;
                commitedToExit = false;

                // If this agent is in a group, mark all members as having reached the goal
                if (currentGroup != null)
                {
                    foreach (var member in currentGroup.Members)
                    {
                        if (member != null && !member.HasReachedGoal)
                        {
                            member.hasReachedGoal = true;
                        }
                    }
                }
            }
            return; // Stay stopped
        }

        // If we already have a valid path and we're following it, don't recalculate (stay committed)
        if (currentPath.Count > 0 && currentPathIndex < currentPath.Count)
        {
            return; // Keep following existing path
        }

        // If we've committed to reaching an exit and haven't reached it yet, keep trying.
        // Guard with pathRequestPending to avoid writing currentPath from two places.
        if (commitedToExit && targetExitTile != Vector2Int.zero && !pathRequestPending)
        {
            if (currentPath.Count == 0 && currentRoomData != null)
            {
                pathRequestPending = true;
                var capturedExit = targetExitTile;
                var capturedRoom = currentRoomData;
                if (PathfindingScheduler.Instance != null)
                {
                    PathfindingScheduler.Instance.RequestPath(new PathRequest
                    {
                        AgentId = agentId,
                        Start = currentPos,
                        Goal = capturedExit,
                        RoomContext = capturedRoom,
                        IsHallwayMode = false,
                        Callback = result =>
                        {
                            pathRequestPending = false;
                            if (result.Count > 0)
                            {
                                currentPath = result;
                                currentPathIndex = 0;
                            }
                        }
                    });
                }
                else
                {
                    currentPath = FindPathInRoom(currentPos, capturedExit, capturedRoom);
                    currentPathIndex = 0;
                    pathRequestPending = false;
                }
                return;
            }
        }

        // If in hallway (no room), just keep moving along current path
        // The hallway pathfinding will naturally move us toward exits
        if (currentRoomData == null)
        {
            // If we have a current path, keep following it through hallway
            if (currentPath.Count > 0 && currentPathIndex < currentPath.Count)
            {
                return; // Keep following path
            }

            // In hallway with no path - find next room to enter
            // PRIORITY 1: Find unvisited rooms, avoid the room we just exited

            // Collect all unvisited rooms
            List<MazeRoom> unvisitedRooms = new();
            foreach (var room in _allRooms)
            {
                // Skip the room we just exited (backtracking prevention)
                if (lastRoomExitedFrom != null && room.Id == lastRoomExitedFrom.Id)
                    continue;

                // Prioritize unvisited rooms
                if (!roomMemory.HasVisited(room.Id))
                {
                    unvisitedRooms.Add(room);
                }
            }

            MazeRoom targetRoom = null;

            // Random decision: 70% closest unvisited, 30% random unvisited (increases exploration variety)
            if (unvisitedRooms.Count > 0)
            {
                if (Random.value < 0.7f && unvisitedRooms.Count > 0)
                {
                    // Pick closest unvisited room
                    float closestUnvisitedDistance = float.MaxValue;
                    foreach (var room in unvisitedRooms)
                    {
                        Vector2Int roomCenter = room.GetCenter();
                        float distance = Vector2Int.Distance(currentPos, roomCenter);
                        if (distance < closestUnvisitedDistance)
                        {
                            closestUnvisitedDistance = distance;
                            targetRoom = room;
                        }
                    }
                }
                else
                {
                    // Pick random unvisited room for variety
                    targetRoom = unvisitedRooms[Random.Range(0, unvisitedRooms.Count)];
                }
            }

            // If no unvisited room found, pick nearest room (except the one we came from)
            if (targetRoom == null)
            {
                float closestDistance = float.MaxValue;
                foreach (var room in _allRooms)
                {
                    // Skip the room we just exited
                    if (lastRoomExitedFrom != null && room.Id == lastRoomExitedFrom.Id)
                        continue;

                    Vector2Int roomCenter = room.GetCenter();
                    float distance = Vector2Int.Distance(currentPos, roomCenter);
                    if (distance < closestDistance)
                    {
                        closestDistance = distance;
                        targetRoom = room;
                    }
                }
            }

            // Exit-room caution: if the chosen target is the exit room and we spotted
            // it through a short corridor, smarter agents may hesitate or route around.
            // (Low intelligence agents rush straight in; high intelligence agents are cautious
            //  and may wait for allies — once group logic is implemented.)
            if (targetRoom != null)
            {
                if (_goalRooms.Contains(targetRoom))
                {
                    knowsExitLocation = true;
                    // High-intelligence agents (INT > 50) pause briefly to "assess"
                    // before committing — placeholder for future ally/fight evaluation
                    if (agentStats.Intelligence > 50)
                    {
                        nextRandomWait = Time.time + (agentStats.Intelligence / 100f) * 2f;
                    }
                }
            }

            if (targetRoom != null)
            {
                // Request async path – result arrives next frame via callback
                if (PathfindingScheduler.Instance != null)
                {
                    pathRequestPending = true;
                    var capturedRoom = targetRoom;
                    PathfindingScheduler.Instance.RequestPath(new PathRequest
                    {
                        AgentId = agentId,
                        Start = currentPos,
                        Goal = capturedRoom.GetCenter(),
                        IsHallwayMode = true,
                        Callback = result =>
                        {
                            pathRequestPending = false;
                            if (result.Count > 0)
                            {
                                currentPath = result;
                                currentPathIndex = 0;
                            }
                            // else: fallback handled next update cycle
                        }
                    });
                }
                else
                {
                    // Fallback: synchronous (scheduler not ready yet)
                    currentPath = FindPathToNearestRoom(currentPos, targetRoom);
                    currentPathIndex = 0;
                }
                return;
            }

            Debug.LogWarning($"AIAgent {agentId}: In hallway but no reachable rooms!");
            return;
        }



        // MAIN LOGIC: In regular room, find a hallway exit and path to it
        // Get all hallway tiles adjacent to this room
        List<Vector2Int> hallwayExits = FindHallwayExits(currentRoomData, currentPos);

        if (hallwayExits.Count > 0)
        {
            // Peek through each exit: if the corridor leads directly to the exit room
            // or a dangerous room, apply intelligence/danger avoidance logic.
            List<Vector2Int> safeExits = new List<Vector2Int>(hallwayExits);
            foreach (var exit in hallwayExits)
            {
                MazeRoom peekedRoom = PeekCorridorDestination(exit, currentRoomData);
                if (peekedRoom == null) continue;

                // Check if exit leads to the goal room
                if (!knowsExitLocation && _goalRooms.Contains(peekedRoom))
                {
                    knowsExitLocation = true;
                    if (agentStats.Intelligence > 40 && safeExits.Count > 1)
                        safeExits.Remove(exit);
                }

                // Check if exit leads to a monster-heavy room
                if (ShouldAvoidRoom(peekedRoom) && safeExits.Count > 1)
                {
                    avoidedRooms.Add(peekedRoom.Id);
                    safeExits.Remove(exit);
                    Debug.Log($"[Agent {agentId}] {agentName}: avoiding room {peekedRoom.Id} (threat {MonsterSpawner.GetRoomThreat(peekedRoom.Id)})");
                }
            }
            if (safeExits.Count == 0) safeExits = hallwayExits; // No alternative – must go through

            // Pick a random hallway exit from the (possibly filtered) list
            Vector2Int chosenExit = safeExits[Random.Range(0, safeExits.Count)];

            // Request path asynchronously via scheduler
            if (PathfindingScheduler.Instance != null)
            {
                pathRequestPending = true;
                var capturedExit = chosenExit;
                var capturedRoom = currentRoomData;
                PathfindingScheduler.Instance.RequestPath(new PathRequest
                {
                    AgentId = agentId,
                    Start = currentPos,
                    Goal = capturedExit,
                    RoomContext = capturedRoom,
                    IsHallwayMode = false,
                    Callback = result =>
                    {
                        pathRequestPending = false;
                        if (result.Count > 0)
                        {
                            currentPath = result;
                            currentPathIndex = 0;
                            targetExitTile = capturedExit;
                            commitedToExit = true;
                            nextRandomWait = Time.time + Random.Range(1.5f, 3.5f);
                        }
                        else
                        {
                            commitedToExit = false;
                        }
                    }
                });
            }
            else
            {
                // Fallback: synchronous
                currentPath = FindPathInRoom(currentPos, chosenExit, currentRoomData);
                currentPathIndex = 0;
                if (currentPath.Count > 0)
                {
                    targetExitTile = chosenExit;
                    commitedToExit = true;
                    nextRandomWait = Time.time + Random.Range(1.5f, 3.5f);
                }
                else
                {
                    commitedToExit = false;
                }
            }
        }
        else
        {
            Debug.LogWarning($"AIAgent {agentId}: No hallway exits found from room {currentRoomData.Id}");
            commitedToExit = false;
        }
    }

    /// <summary>
    /// Chooses the next room to move to
    /// Searches around the current room to find adjacent rooms
    /// Avoids recently visited rooms to prevent backtracking
    /// </summary>
    private MazeRoom ChooseNextRoom(MazeRoom currentRoom)
    {
        // Find all adjacent rooms by checking walkable tiles in all directions from room boundaries
        List<MazeRoom> connectedRooms = new();
        Vector2Int roomCenter = currentRoom.GetCenter();

        // Check from each direction outward from the room center
        Vector2Int[] directions = new Vector2Int[]
        {
            Vector2Int.up, Vector2Int.down, Vector2Int.left, Vector2Int.right,
            Vector2Int.up + Vector2Int.left, Vector2Int.up + Vector2Int.right,
            Vector2Int.down + Vector2Int.left, Vector2Int.down + Vector2Int.right
        };

        // Shuffle directions for randomness
        for (int i = directions.Length - 1; i > 0; i--)
        {
            int randomIndex = Random.Range(0, i + 1);
            var temp = directions[i];
            directions[i] = directions[randomIndex];
            directions[randomIndex] = temp;
        }

        // Try each direction and look for tiles that lead to other rooms
        foreach (var dir in directions)
        {
            for (int dist = 1; dist < 20; dist++) // Search up to 20 tiles away
            {
                Vector2Int testPos = roomCenter + (dir * dist);

                if (!maze.IsInBounds(testPos.x, testPos.y) || !maze.IsWalkable(testPos.x, testPos.y))
                    continue;

                MazeRoom testRoom = maze.GetRoomAtTile(testPos.x, testPos.y);
                if (testRoom != null && testRoom.Id != currentRoom.Id && !connectedRooms.Contains(testRoom))
                {
                    connectedRooms.Add(testRoom);
                    break; // Found a room in this direction, move to next direction
                }
            }
        }

        if (connectedRooms.Count == 0)
        {
            Debug.LogWarning($"AIAgent {agentId}: No adjacent rooms found from room {currentRoom.Id}");
            return null;
        }

        // Filter out recently visited rooms (to avoid backtracking)
        List<MazeRoom> nonRecentRooms = connectedRooms.Where(r => !recentRooms.Contains(r.Id)).ToList();

        // PRIORITY 1: Strongly prefer completely unvisited rooms (not recently visited either)
        var completelyUnvisited = nonRecentRooms.Where(r => !roomMemory.HasVisited(r.Id)).ToList();
        if (completelyUnvisited.Count > 0)
        {
            MazeRoom chosen = completelyUnvisited[Random.Range(0, completelyUnvisited.Count)];
            return chosen;
        }

        // PRIORITY 2: Try non-recent rooms even if visited by this character type
        if (nonRecentRooms.Count > 0)
        {
            // Among non-recent rooms, prefer unvisited by this agent's character type
            var unvisitedByType = nonRecentRooms.Where(r => !roomMemory.HasVisited(r.Id)).ToList();
            if (unvisitedByType.Count > 0)
            {
                MazeRoom chosen = unvisitedByType[Random.Range(0, unvisitedByType.Count)];
                return chosen;
            }

            // Otherwise just pick a random non-recent room
            MazeRoom chosen2 = nonRecentRooms[Random.Range(0, nonRecentRooms.Count)];
            return chosen2;
        }

        // PRIORITY 3: If all rooms are recent, pick one that's been visited least recently
        // Find the room in connectedRooms that was added to recentRooms earliest (will be dequeued first)
        MazeRoom leastRecentRoom = connectedRooms[0];
        foreach (var room in connectedRooms)
        {
            if (!roomMemory.HasVisited(room.Id))
            {
                leastRecentRoom = room;
                break;
            }
        }

        Debug.Log($"AIAgent {agentId}: All rooms recent, choosing least-recent room {leastRecentRoom.Id}");
        return leastRecentRoom;
    }

    /// <summary>
    /// Finds the nearest room from a position (used when in hallway)
    /// </summary>
    private MazeRoom FindNearestRoom(Vector2Int position)
    {
        MazeRoom nearest = null;
        float nearestDistance = float.MaxValue;

        foreach (var room in maze.Rooms)
        {
            Vector2Int roomCenter = room.GetCenter();
            float distance = Vector2Int.Distance(position, roomCenter);
            if (distance < nearestDistance)
            {
                nearestDistance = distance;
                nearest = room;
            }
        }

        return nearest;
    }

    /// <summary>
    /// Finds all hallway exit tiles adjacent to a room
    /// These are walkable tiles just outside the room boundary
    /// </summary>
    /// <summary>
    /// Peeks along a corridor starting from a hallway exit tile.
    /// Follows walkable non-room tiles up to a short distance and returns
    /// the first room found at the other end, or null if no room is close.
    /// Used by intelligence logic to detect if an exit leads straight to the goal.
    /// </summary>
    private MazeRoom PeekCorridorDestination(Vector2Int exitTile, MazeRoom sourceRoom, int maxPeekDistance = 12)
    {
        // BFS outward from the exit tile, staying in non-room (hallway) tiles
        var visited = new HashSet<Vector2Int> { exitTile };
        var queue = new Queue<Vector2Int>();
        queue.Enqueue(exitTile);

        while (queue.Count > 0)
        {
            Vector2Int tile = queue.Dequeue();
            Vector2Int[] dirs = {
                new(tile.x + 1, tile.y), new(tile.x - 1, tile.y),
                new(tile.x, tile.y + 1), new(tile.x, tile.y - 1)
            };
            foreach (var next in dirs)
            {
                if (!maze.IsInBounds(next.x, next.y) || !maze.IsWalkable(next.x, next.y)) continue;
                if (visited.Contains(next)) continue;

                MazeRoom nextRoom = maze.GetRoomAtTile(next.x, next.y);
                if (nextRoom != null && nextRoom.Id != sourceRoom.Id)
                    return nextRoom; // Found the room at the end of this corridor

                // Only continue through hallway tiles and within peek distance
                if (nextRoom == null && Vector2Int.Distance(exitTile, next) < maxPeekDistance)
                {
                    visited.Add(next);
                    queue.Enqueue(next);
                }
            }
        }
        return null;
    }

    private List<Vector2Int> FindHallwayExits(MazeRoom room, Vector2Int currentPos)
    {
        List<Vector2Int> exits = new();
        HashSet<Vector2Int> addedExits = new();

        // Check all tiles on the boundary of the room
        // North boundary
        for (int x = room.MinX; x <= room.MaxX; x++)
        {
            int y = room.MinY - 1;
            if (maze.IsInBounds(x, y) && maze.IsWalkable(x, y) && !addedExits.Contains(new Vector2Int(x, y)))
            {
                exits.Add(new Vector2Int(x, y));
                addedExits.Add(new Vector2Int(x, y));
            }
        }

        // South boundary
        for (int x = room.MinX; x <= room.MaxX; x++)
        {
            int y = room.MaxY + 1;
            if (maze.IsInBounds(x, y) && maze.IsWalkable(x, y) && !addedExits.Contains(new Vector2Int(x, y)))
            {
                exits.Add(new Vector2Int(x, y));
                addedExits.Add(new Vector2Int(x, y));
            }
        }

        // West boundary
        for (int y = room.MinY; y <= room.MaxY; y++)
        {
            int x = room.MinX - 1;
            if (maze.IsInBounds(x, y) && maze.IsWalkable(x, y) && !addedExits.Contains(new Vector2Int(x, y)))
            {
                exits.Add(new Vector2Int(x, y));
                addedExits.Add(new Vector2Int(x, y));
            }
        }

        // East boundary
        for (int y = room.MinY; y <= room.MaxY; y++)
        {
            int x = room.MaxX + 1;
            if (maze.IsInBounds(x, y) && maze.IsWalkable(x, y) && !addedExits.Contains(new Vector2Int(x, y)))
            {
                exits.Add(new Vector2Int(x, y));
                addedExits.Add(new Vector2Int(x, y));
            }
        }

        return exits;
    }

    /// <summary>
    /// Finds a path from current position to the nearest room (when in hallway).
    /// Uses a min-heap open set for O(n log n) instead of O(n²).
    /// </summary>
    private List<Vector2Int> FindPathToNearestRoom(Vector2Int start, MazeRoom targetRoom)
    {
        var openSet = new MinHeap<Vector2Int>();
        var cameFrom = new Dictionary<Vector2Int, Vector2Int>();
        var gScore = new Dictionary<Vector2Int, float> { [start] = 0f };
        var targetCenter = targetRoom.GetCenter();

        openSet.Enqueue(start, Heuristic(start, targetCenter));

        const int maxIterations = 2000;
        int iterations = 0;

        while (openSet.Count > 0 && iterations++ < maxIterations)
        {
            Vector2Int current = openSet.Dequeue();

            // Reached the target room
            MazeRoom roomAtCurrent = maze.GetRoomAtTile(current.x, current.y);
            if (roomAtCurrent != null && roomAtCurrent.Id == targetRoom.Id)
                return ReconstructPath(cameFrom, current);

            Vector2Int[] dirs = {
                new(current.x + 1, current.y), new(current.x - 1, current.y),
                new(current.x, current.y + 1), new(current.x, current.y - 1)
            };
            foreach (var nb in dirs)
            {
                if (!maze.IsInBounds(nb.x, nb.y) || !maze.IsWalkable(nb.x, nb.y)) continue;

                float tentativeG = gScore[current] + 1f;
                if (!gScore.TryGetValue(nb, out float existingG) || tentativeG < existingG)
                {
                    cameFrom[nb] = current;
                    gScore[nb] = tentativeG;
                    float f = tentativeG + Heuristic(nb, targetCenter);
                    if (openSet.Contains(nb, out _)) openSet.UpdatePriority(nb, f);
                    else openSet.Enqueue(nb, f);
                }
            }
        }

        return new List<Vector2Int>();
    }

    private static float Heuristic(Vector2Int a, Vector2Int b)
        => Mathf.Abs(a.x - b.x) + Mathf.Abs(a.y - b.y);

    /// <summary>
    /// Finds a boundary tile of the current room that points toward the next room
    /// </summary>
    private Vector2Int FindBoundaryTileToward(MazeRoom currentRoom, MazeRoom nextRoom, Vector2Int currentPos)
    {
        Vector2Int nextRoomCenter = nextRoom.GetCenter();
        Vector2Int closestBoundary = currentRoom.GetCenter();
        float closestDistance = float.MaxValue;

        // Check all boundary tiles of current room
        for (int x = currentRoom.MinX; x <= currentRoom.MaxX; x++)
        {
            for (int y = currentRoom.MinY; y <= currentRoom.MaxY; y++)
            {
                // Only check boundary and walkable tiles
                if ((x == currentRoom.MinX || x == currentRoom.MaxX || y == currentRoom.MinY || y == currentRoom.MaxY) &&
                    maze.IsWalkable(x, y))
                {
                    // Find boundary tile closest to next room center
                    float distToNext = Vector2Int.Distance(new Vector2Int(x, y), nextRoomCenter);
                    if (distToNext < closestDistance)
                    {
                        closestDistance = distToNext;
                        closestBoundary = new Vector2Int(x, y);
                    }
                }
            }
        }

        return closestBoundary;
    }

    /// <summary>
    /// Finds a path within a single room (limited knowledge).
    /// Uses a min-heap open set for O(n log n) performance instead of O(n²).
    /// </summary>
    private List<Vector2Int> FindPathInRoom(Vector2Int start, Vector2Int goal, MazeRoom room)
    {
        var openSet = new MinHeap<Vector2Int>();
        var cameFrom = new Dictionary<Vector2Int, Vector2Int>();
        var gScore = new Dictionary<Vector2Int, float> { [start] = 0f };

        openSet.Enqueue(start, Heuristic(start, goal));

        const int maxIterations = 1000;
        int iterations = 0;

        while (openSet.Count > 0 && iterations++ < maxIterations)
        {
            Vector2Int current = openSet.Dequeue();

            if (current == goal)
                return ReconstructPath(cameFrom, current);

            foreach (var nb in GetRoomNeighbors(current, room))
            {
                float tentativeG = gScore[current] + 1f;
                if (!gScore.TryGetValue(nb, out float existingG) || tentativeG < existingG)
                {
                    cameFrom[nb] = current;
                    gScore[nb] = tentativeG;
                    float f = tentativeG + Heuristic(nb, goal);
                    if (openSet.Contains(nb, out _)) openSet.UpdatePriority(nb, f);
                    else openSet.Enqueue(nb, f);
                }
            }
        }

        return new List<Vector2Int>();
    }

    /// <summary>
    /// Gets walkable neighbors within a room or at room boundary
    /// Allows pathfinding to reach hallway exits outside room
    /// </summary>
    private List<Vector2Int> GetRoomNeighbors(Vector2Int position, MazeRoom room)
    {
        var neighbors = new List<Vector2Int>();
        Vector2Int[] directions = new[]
        {
            new Vector2Int(position.x + 1, position.y),
            new Vector2Int(position.x - 1, position.y),
            new Vector2Int(position.x, position.y + 1),
            new Vector2Int(position.x, position.y - 1),
        };

        foreach (var dir in directions)
        {
            // Allow tiles within room OR immediately adjacent to room (boundary)
            bool inBounds = maze.IsInBounds(dir.x, dir.y);
            bool isWalkable = maze.IsWalkable(dir.x, dir.y);
            bool inRoom = room.Contains(dir.x, dir.y);
            bool nearBoundary = (dir.x == room.MinX - 1 || dir.x == room.MaxX + 1 ||
                                 dir.y == room.MinY - 1 || dir.y == room.MaxY + 1);

            if (inBounds && isWalkable && (inRoom || nearBoundary))
            {
                neighbors.Add(dir);
            }
        }

        return neighbors;
    }

    /// <summary>
    /// Reconstructs path from A* results.
    /// Uses Add+Reverse (O(n)) instead of Insert(0,...) (O(n²)).
    /// </summary>
    private static List<Vector2Int> ReconstructPath(Dictionary<Vector2Int, Vector2Int> cameFrom, Vector2Int current)
    {
        var path = new List<Vector2Int>();
        while (cameFrom.TryGetValue(current, out var prev))
        {
            path.Add(current);
            current = prev;
        }
        path.Add(current); // start node
        path.Reverse();
        return path;
    }

    /// <summary>
    /// Follows the current path
    /// </summary>
    private void FollowPath()
    {
        if (currentPath.Count == 0) return;

        Vector2Int currentTarget = currentPath[currentPathIndex];
        // Maze coordinates: X,Y → World: X,Z (Y=0 is ground level)
        // Keep Y at 1f to stay above the maze floor
        Vector3 targetWorldPos = new Vector3(currentTarget.x + 0.5f, 1f, currentTarget.y + 0.5f);

        Vector3 direction = (targetWorldPos - transform.position).normalized;
        // Move directly instead of using Translate (no rigidbody)
        transform.position += direction * actualMovementSpeed * Time.deltaTime;

        // Check if we've exited the room (entered hallway)
        Vector2Int currentPos = WorldToTile(transform.position);
        MazeRoom roomAtPos = maze.GetRoomAtTile(currentPos.x, currentPos.y);
        if (roomAtPos == null && currentRoom.x != -1)
        {
            // We've entered a hallway - track which room we came from to prevent immediate backtracking
            lastRoomExitedFrom = maze.GetRoomById(currentRoom.x);
            commitedToExit = false; // No longer committed to that exit, now in hallway
            targetExitTile = Vector2Int.zero; // Clear the target exit
        }

        // Move to next waypoint when close enough
        if (Vector3.Distance(transform.position, targetWorldPos) < stoppingDistance)
        {
            currentPathIndex++;
            if (currentPathIndex >= currentPath.Count)
            {
                currentPath.Clear();
            }
        }
    }

    /// <summary>
    /// Updates the path visualization
    /// </summary>
    private void UpdatePathVisualization()
    {
        if (currentPath.Count == 0)
        {
            pathRenderer.positionCount = 0;
            return;
        }

        var positions = new Vector3[currentPath.Count];
        for (int i = 0; i < currentPath.Count; i++)
        {
            // Maze coordinates: X,Y → World: X,Z (Y=0 is ground level)
            // Keep Y at 1f to stay above the maze floor
            positions[i] = new Vector3(currentPath[i].x + 0.5f, 1f, currentPath[i].y + 0.5f);
        }

        pathRenderer.positionCount = positions.Length;
        pathRenderer.SetPositions(positions);
    }

    /// <summary>
    /// Converts world position to tile coordinate
    /// Maze coordinates: X,Y ← World: X,Z (Y=0 is ground level)
    /// </summary>
    private Vector2Int WorldToTile(Vector3 worldPos)
    {
        return new Vector2Int(Mathf.FloorToInt(worldPos.x), Mathf.FloorToInt(worldPos.z));
    }

    /// <summary>
    /// Gets agent ID
    /// </summary>
    public int AgentId => agentId;

    /// <summary>
    /// Gets agent character type
    /// </summary>
    public string CharacterType => agentCharacterType;

    /// <summary>
    /// Gets current room
    /// </summary>
    public Vector2Int CurrentRoom => currentRoom;

    /// <summary>
    /// Gets room memory
    /// </summary>
    public AIRoomMemory RoomMemory => roomMemory;

    /// <summary>
    /// Gets agent ID (public accessor for triggers)
    /// </summary>
    public int GetAgentId() => agentId;

    /// <summary>
    /// Called by ExitRoomTrigger when agent enters the goal room
    /// Immediately stops all movement
    /// Also marks all group members as having reached the goal
    /// </summary>
    public void StopAtGoal()
    {
        hasReachedGoal = true;
        currentPath.Clear();
        currentPathIndex = 0;
        commitedToExit = false;

        // If this agent is in a group, mark all members as having reached the goal
        if (currentGroup != null)
        {
            foreach (var member in currentGroup.Members)
            {
                if (member != null && !member.HasReachedGoal)
                {
                    member.hasReachedGoal = true;
                }
            }
        }
    }

    /// <summary>
    /// Gets whether this agent has reached the goal
    /// </summary>
    public bool HasReachedGoal => hasReachedGoal;

    /// <summary>True once the agent's health reaches 0.</summary>
    public bool IsDead => isDead;

    /// <summary>Current health points (mirrors AgentStats).</summary>
    public int CurrentHealth => agentStats?.CurrentHealth ?? 0;

    // ------------------------------------------------------------------ //
    //  Combat                                                              //
    // ------------------------------------------------------------------ //

    /// <summary>
    /// Called by monsters when they deal damage to this agent.
    /// </summary>
    public void TakeDamage(int amount, Monster source)
    {
        if (isDead) return;
        agentStats.ApplyDamage(amount);
        if (agentStats.IsDead)
            Die();
    }

    private void Die()
    {
        if (isDead) return;
        isDead = true;
        currentPath.Clear();

        // End all fights this agent is in
        foreach (var monster in fightingMonsters)
        {
            if (monster != null)
                FightTracker.Instance.EndFight(this, monster);
        }
        fightingMonsters.Clear();

        // Change visual to show dead (grayscale/dark with white X)
        var renderer = GetComponent<Renderer>();
        if (renderer != null)
        {
            var material = new Material(renderer.material);
            material.color = new Color(0.4f, 0.4f, 0.4f, 0.9f); // Dark gray, opaque
            renderer.material = material;
        }

        // Add X marker BEFORE disabling (must happen while enabled)
        AddDeadMarker();

        // Disable pathfinding AFTER adding marker
        if (pathRenderer != null)
            pathRenderer.enabled = false;

        Debug.Log($"[Agent {agentId}] {agentName} has died!");

        // Notify the manager so death stats can be tracked
        var manager = FindAnyObjectByType<AIAgentManager>();
        manager?.RegisterAgentDeath(this);

        // Leave group cleanly
        currentGroup?.RemoveMember(this);
    }

    /// <summary>
    /// Adds a white X marker to indicate the body is dead.
    /// Uses a child GameObject so it doesn't conflict with the path LineRenderer.
    /// </summary>
    private void AddDeadMarker()
    {
        try
        {
            if (gameObject == null)
                return;

            // Use a dedicated child GameObject so it doesn't clash with pathRenderer
            var markerGO = new GameObject("DeadMarker");
            markerGO.transform.SetParent(transform, worldPositionStays: false);
            markerGO.transform.localPosition = Vector3.zero;

            var lineRenderer = markerGO.AddComponent<LineRenderer>();
            if (lineRenderer == null)
            {
                Debug.LogWarning("Failed to add LineRenderer component");
                return;
            }

            // Set material first before configuring the renderer
            Shader lineShader = Shader.Find("Unlit/Color");
            if (lineShader == null)
                lineShader = Shader.Find("Sprites/Default");
            if (lineShader == null)
                lineShader = Shader.Find("Standard");
            if (lineShader != null)
            {
                lineRenderer.material = new Material(lineShader);
            }
            else
            {
                Debug.LogWarning("No suitable shader found for dead marker");
                return;
            }

            // Now configure the line
            lineRenderer.positionCount = 4;
            lineRenderer.useWorldSpace = true;

            float offset = 0.35f;
            // Lift the X marker above the body so the top-down camera can see it
            Vector3 markerBase = transform.position + Vector3.up * 0.6f;

            // Draw a white X in XZ plane (visible from top-down camera)
            lineRenderer.SetPosition(0, markerBase + Vector3.left * offset + Vector3.forward * offset);
            lineRenderer.SetPosition(1, markerBase + Vector3.right * offset + Vector3.back * offset);

            lineRenderer.SetPosition(2, markerBase + Vector3.right * offset + Vector3.forward * offset);
            lineRenderer.SetPosition(3, markerBase + Vector3.left * offset + Vector3.back * offset);

            lineRenderer.startWidth = 0.15f;
            lineRenderer.endWidth = 0.15f;
            lineRenderer.startColor = Color.white;
            lineRenderer.endColor = Color.white;
        }
        catch (System.Exception ex)
        {
            Debug.LogWarning($"Failed to add dead marker: {ex.Message}\n{ex.StackTrace}");
        }
    }

    /// <summary>
    /// Combat tick: find the nearest in-range monster and attack it.
    /// Sets isInCombat to halt movement while a monster is close.
    /// </summary>
    private void CombatUpdate()
    {
        // Scan for the nearest living monster within melee range
        Monster nearestMonster = null;
        float bestDist = weapon.MeleeRange * weapon.MeleeRange;

        foreach (var m in FindObjectsByType<Monster>())
        {
            if (m.IsDead) continue;
            float sqDist = (m.transform.position - transform.position).sqrMagnitude;
            if (sqDist < bestDist)
            {
                bestDist = sqDist;
                nearestMonster = m;
            }
        }

        // Update combat lock – halts FollowPath while a monster is adjacent
        isInCombat = nearestMonster != null;

        // Track fight start
        if (nearestMonster != null && !fightingMonsters.Contains(nearestMonster))
        {
            fightingMonsters.Add(nearestMonster);
            FightTracker.Instance.StartFight(this, nearestMonster);
        }

        // Track fight end for monsters no longer in range
        var monstersToRemove = new List<Monster>();
        foreach (var monster in fightingMonsters)
        {
            if (monster == null || monster.IsDead)
            {
                monstersToRemove.Add(monster);
            }
            else
            {
                float dist = (monster.transform.position - transform.position).sqrMagnitude;
                if (dist > weapon.MeleeRange * weapon.MeleeRange)
                {
                    monstersToRemove.Add(monster);
                }
            }
        }

        foreach (var monster in monstersToRemove)
        {
            fightingMonsters.Remove(monster);
            if (monster != null)
                FightTracker.Instance.EndFight(this, monster);
        }

        if (nearestMonster == null) return;

        // Attack on cooldown
        if (Time.time - lastAttackTime < ATTACK_COOLDOWN) return;
        lastAttackTime = Time.time;

        // Agents have advantage on hit
        if (weapon.TryHit(AGENT_HIT_ADVANTAGE))
        {
            int dmg = weapon.RollDamage();
            bool killed = nearestMonster.TakeDamage(dmg);
            Debug.Log($"[Agent {agentId}] {agentName} hit monster for {dmg} (monster HP left: {nearestMonster.CurrentHealth})");
            if (killed)
            {
                var manager = FindAnyObjectByType<AIAgentManager>();
                manager?.RegisterMonsterKill();
            }
        }
        else
        {
            Debug.Log($"[Agent {agentId}] {agentName} missed monster");
        }
    }

    // ------------------------------------------------------------------ //
    //  Room danger assessment                                              //
    // ------------------------------------------------------------------ //

    /// <summary>
    /// Returns the perceived danger score of a room.
    /// Uses MonsterSpawner's threat lookup (0 = safe, higher = more dangerous).
    /// </summary>
    private int GetRoomThreat(MazeRoom room)
    {
        if (room == null) return 0;
        return MonsterSpawner.GetRoomThreat(room.Id);
    }

    /// <summary>
    /// Decides whether to avoid, run through, or fight through a room.
    /// Called before committing to an exit that leads to a dangerous room.
    /// Returns true if the agent should avoid the target room.
    /// </summary>
    private bool ShouldAvoidRoom(MazeRoom targetRoom)
    {
        if (targetRoom == null) return false;
        int threat = GetRoomThreat(targetRoom);
        if (threat == 0) return false;

        // Estimate own fighting power: health * (Strength / 50)
        float power = agentStats.CurrentHealth * (agentStats.Strength / 50f);
        // Risk tolerance 0=cautious, 1=reckless
        float dangerThreshold = Mathf.Lerp(0.5f, 2.0f, riskTolerance);

        bool tooRisky = threat > power * dangerThreshold;

        if (!tooRisky) return false;

        // Fast agents (Speed > 60) might choose to sprint through instead of avoiding
        if (agentStats.Speed > 60)
        {
            float runChance = (agentStats.Speed - 60f) / 40f; // 0 at spd=60, 1 at spd=100
            if (Random.value < runChance)
            {
                Debug.Log($"[Agent {agentId}] {agentName}: sprinting through dangerous room {targetRoom.Id}!");
                return false; // Will run, not avoid
            }
        }

        return true; // Should avoid
    }

    /// <summary>
    /// Gets agent's personalized name
    /// </summary>
    public string AgentName => agentName;

    /// <summary>
    /// Gets agent's stats
    /// </summary>
    public AgentStats Stats => agentStats;

    /// <summary>
    /// 0-1 tendency to seek allies over going solo (driven by Intelligence)
    /// </summary>
    public float GroupUpAffinity => groupUpAffinity;

    /// <summary>
    /// 0-1 willingness to take risks in combat or unknown rooms (driven by Intelligence)
    /// </summary>
    public float RiskTolerance => riskTolerance;

    /// <summary>
    /// Whether this agent has spotted the exit room (through corridor peeking or direct entry)
    /// </summary>
    public bool KnowsExitLocation => knowsExitLocation;

    void OnMouseDown()
    {
        // If this agent is in a group, clicking any member shows the group panel
        if (currentGroup != null)
            AgentInfoPanel.ShowGroupInfo(currentGroup);
        else
            AgentInfoPanel.ShowAgentInfo(this);
    }

    public void SetShowPath(bool show)
    {
        showPath = show;
        if (pathRenderer != null)
        {
            pathRenderer.enabled = show;
        }
    }

    public bool GetShowPath() => showPath;

    // ------------------------------------------------------------------ //
    //  Group API                                                           //
    // ------------------------------------------------------------------ //

    /// <summary>Called by AgentGroup when this agent is added.</summary>
    public void JoinGroup(AgentGroup group)
    {
        currentGroup = group;
        isGroupFollower = group.Leader != this;
        Debug.Log($"[Agent {agentId}] {agentName} joined group {group.GroupId} as {(isGroupFollower ? "follower" : "leader")}");
    }

    /// <summary>Called by AgentGroup when this agent leaves or group dissolves.</summary>
    public void LeaveGroup()
    {
        currentGroup = null;
        isGroupFollower = false;

        // Restore own renderer
        var mr = GetComponent<MeshRenderer>();
        if (mr != null) mr.enabled = true;
        var lr = GetComponent<LineRenderer>();
        if (lr != null) lr.enabled = showPath;
    }

    /// <summary>The group this agent belongs to, or null if solo.</summary>
    public AgentGroup Group => currentGroup;

    /// <summary>True if another agent is driving this agent's position.</summary>
    public bool IsGroupFollower => isGroupFollower;

    /// <summary>True if this agent leads a group (is not a follower but group exists).</summary>
    public bool IsGroupLeader => currentGroup != null && !isGroupFollower;
}