using UnityEngine;
using UnityEngine.UIElements;
using System.Collections.Generic;

/// <summary>
/// Manages the UI Toolkit-based Agent Stats display
/// Shows total active agents and count that have reached an exit
/// </summary>
public class AgentStatsUIController : MonoBehaviour
{
    [Header("UI Settings")]
    [SerializeField] private UIDocument uiDocument;
    [SerializeField] private float updateInterval = 0.25f;

    private Label totalAgentsLabel;
    private Label exitReachedLabel;
    private Label killedLabel;
    private Label monstersKilledLabel;
    private AIAgentManager agentManager;
    private MazeController mazeController;
    private float lastUpdateTime = 0f;
    private int lastTotalCount = -1;
    private int lastExitCount = -1;
    private int lastKilledCount = -1;
    private int lastMonstersKilledCount = -1;

    void Start()
    {
        // Find references in Start instead of Awake for better timing
        if (uiDocument == null)
        {
            uiDocument = GetComponent<UIDocument>();

            // If not on this GameObject, try to find it in the scene
            if (uiDocument == null)
            {
                uiDocument = FindAnyObjectByType<UIDocument>();
                Debug.Log("AgentStatsUIController: Found UIDocument in scene");
            }

            if (uiDocument == null)
            {
                Debug.LogError("AgentStatsUIController: UIDocument not found anywhere in scene!");
                enabled = false;
                return;
            }
        }

        // Get the root and find labels
        var root = uiDocument.rootVisualElement;
        if (root == null)
        {
            Debug.LogError("AgentStatsUIController: Root visual element is null!");
            return;
        }

        totalAgentsLabel = root.Q<Label>("TotalAgentsLabel");
        exitReachedLabel = root.Q<Label>("ExitReachedLabel");
        killedLabel = root.Q<Label>("KilledLabel");
        monstersKilledLabel = root.Q<Label>("MonstersKilledLabel");

        if (totalAgentsLabel == null)
            Debug.LogError("AgentStatsUIController: TotalAgentsLabel not found in UXML!");
        if (exitReachedLabel == null)
            Debug.LogError("AgentStatsUIController: ExitReachedLabel not found in UXML!");
        // killedLabel / monstersKilledLabel are optional – no error if absent

        // Find managers
        mazeController = FindAnyObjectByType<MazeController>();
        if (mazeController == null)
        {
            Debug.LogError("AgentStatsUIController: MazeController not found in scene!");
            return;
        }

        agentManager = mazeController.GetAgentManager();
        if (agentManager == null)
        {
            Debug.LogError("AgentStatsUIController: AgentManager not found in MazeController!");
            return;
        }

        Debug.Log("AgentStatsUIController: Initialized successfully");

        // Do first update immediately
        UpdateDisplay();
    }

    void Update()
    {
        if (agentManager == null || totalAgentsLabel == null) return;

        if (Time.time - lastUpdateTime > updateInterval)
        {
            UpdateDisplay();
            lastUpdateTime = Time.time;
        }
    }

    /// <summary>
    /// Updates the UI display with current agent stats
    /// </summary>
    private void UpdateDisplay()
    {
        int totalAgents = agentManager.GetActiveAgentCount();
        int agentsAtExit = GetAgentsAtExit();
        int agentsKilled = agentManager.AgentsKilledByMonsters;
        int monstersKilled = agentManager.MonstersKilledByAgents;

        // Only update if values changed
        if (totalAgents != lastTotalCount)
        {
            if (totalAgentsLabel != null)
            {
                totalAgentsLabel.text = totalAgents.ToString();
                lastTotalCount = totalAgents;
            }
        }

        if (agentsAtExit != lastExitCount)
        {
            if (exitReachedLabel != null)
            {
                exitReachedLabel.text = agentsAtExit.ToString();
                lastExitCount = agentsAtExit;
            }
        }

        if (agentsKilled != lastKilledCount)
        {
            if (killedLabel != null)
            {
                killedLabel.text = agentsKilled.ToString();
                lastKilledCount = agentsKilled;
            }
        }

        if (monstersKilled != lastMonstersKilledCount)
        {
            if (monstersKilledLabel != null)
            {
                monstersKilledLabel.text = monstersKilled.ToString();
                lastMonstersKilledCount = monstersKilled;
            }
        }
    }

    /// <summary>
    /// Counts how many agents have reached the goal/exit
    /// </summary>
    private int GetAgentsAtExit()
    {
        if (agentManager == null) return 0;

        List<AIAgent> allAgents = agentManager.GetActiveAgents();
        int count = 0;

        foreach (var agent in allAgents)
        {
            if (agent != null && agent.HasReachedGoal)
            {
                count++;
            }
        }

        return count;
    }
}