using System.Collections.Generic;
using System.Linq;
using Unity.AI.Navigation;
using UnityEngine;
using UnityEngine.AI;
using UnityEngine.XR.ARFoundation;
using UnityEngine.XR.ARSubsystems;
using TMPro;

public class NewIndoorNav : MonoBehaviour
{
    [SerializeField] private Transform player;
    [SerializeField] private ARTrackedImageManager m_TrackedImageManager;
    [SerializeField] private GameObject trackedImagePrefab;
    [SerializeField] private LineRenderer line;

    [SerializeField] private TextMeshProUGUI distanceText;

    private List<NavigationTarget> navigationTargets = new List<NavigationTarget>();
    private NavMeshSurface navMeshSurface;
    private NavMeshPath navMeshPath;

    private GameObject navigationBase;
    private ARTrackedImage currentTrackedImage;

    private string currentImageName = "front";
    public static int targetNumber = StoreDataScript.targetNumber;
    private float m_Distance;

    private void Start()
    {
        navMeshPath = new NavMeshPath();

        // disable screen dimming
        Screen.sleepTimeout = SleepTimeout.NeverSleep;
    }

    private void Update()
    {
        if (navigationBase != null && navigationTargets.Count > 0 && navMeshSurface != null)
        {
            // Check if there are any tracked images
            if (m_TrackedImageManager.trackables.count > 0)
            {
                // Use a foreach loop to get the first tracked image
                foreach (var trackedImage in m_TrackedImageManager.trackables)
                {
                    currentImageName = trackedImage.referenceImage.name; // Get the name of the tracked image
                    Debug.Log(currentImageName);

                    // Determine which navigation target to use based on the tracked image
                    Transform targetTransform = null;

                    targetTransform = navigationTargets[targetNumber].transform;

                    // If a valid target is found, calculate the path
                    if (targetTransform != null)
                    {
                        NavMesh.CalculatePath(player.position, targetTransform.position, NavMesh.AllAreas, navMeshPath);
                        if (navMeshPath.status == NavMeshPathStatus.PathComplete)
                        {
                            line.positionCount = navMeshPath.corners.Length;
                            line.SetPositions(navMeshPath.corners);

                            m_Distance = Vector3.Distance(player.position,targetTransform.position);
                            distanceText.text = m_Distance.ToString("F2");
                        }
                        else
                        {
                            line.positionCount = 0;
                        }
                    }
                    else
                    {
                        // If no valid target is found, clear the line
                        line.positionCount = 0;
                    }

                    // Break after processing the first tracked image
                    break;
                }
            }
            else
            {
                // If no tracked images are available, clear the line
                line.positionCount = 0;
            }
        }
    }

    private void OnEnable() => m_TrackedImageManager.trackablesChanged.AddListener(OnChanged);

    private void OnDisable() => m_TrackedImageManager.trackablesChanged.RemoveListener(OnChanged);

    private void OnChanged(ARTrackablesChangedEventArgs<ARTrackedImage> eventArgs)
    {
        Debug.Log("OnChanged event triggered.");
        Debug.Log(targetNumber);

        // Handle added images
        foreach (var newImage in eventArgs.added)
        {
            string newImageName = newImage.referenceImage.name; // Get the name of the new image
            Debug.Log($"New Image Added: {newImageName}");

            // Stop using the previous image
            if (currentTrackedImage != null && currentTrackedImage != newImage)
            {
                Debug.Log($"Stopping use of previous image: {currentTrackedImage.referenceImage.name}");
                // Destroy any associated game objects here
                if (navigationBase != null)
                {
                    Destroy(navigationBase);
                }
            }

            // Set the new image as the current tracked image
            currentTrackedImage = newImage;
            currentImageName = newImageName;

            // Instantiate a new navigationBase
            navigationBase = GameObject.Instantiate(trackedImagePrefab);
            navigationTargets = navigationBase.transform.GetComponentsInChildren<NavigationTarget>().ToList();
            navMeshSurface = navigationBase.transform.GetComponentInChildren<NavMeshSurface>();
        }

        // Handle updated images
        foreach (var updatedImage in eventArgs.updated)
        {
            if (navigationBase == null)
            {
                continue;
            }

            currentImageName = updatedImage.referenceImage.name; // Update currentImageName
            Debug.Log($"Image Updated: {currentImageName}");

            // Get the current position of navigationBase
            Vector3 currentPosition = navigationBase.transform.position;

            // Calculate the new position based on the updated image's position
            Vector3 newPosition = currentPosition;
            if (currentImageName == "front")
            {
                newPosition = updatedImage.transform.position + new Vector3(-1.22f, -1f, 13f);
            }
            else if (currentImageName == "frontright")
            {
                newPosition = updatedImage.transform.position + new Vector3(-8.65f, -1f, 6.25f);
            }
            else if (currentImageName == "rearright")
            {
                newPosition = updatedImage.transform.position + new Vector3(18f, -1f, 6.25f);
            }
            else if (currentImageName == "frontleft")
            {
                newPosition = updatedImage.transform.position + new Vector3(9.65f, -1f, 7.28f);
            }
            else if (currentImageName == "rearleft")
            {
                newPosition = updatedImage.transform.position + new Vector3(-17f, -1f, 7.28f);
            }
            else if (currentImageName == "rear") 
            {
                newPosition = updatedImage.pose.position + new Vector3(0.78f, -1f, 19.62f);
            } 

            // Check if the new position is significantly different from the current position
            if (Vector3.Distance(currentPosition, newPosition) > 0.1f)
            {
                if (currentImageName == "front")
                {
                    navigationBase.transform.SetPositionAndRotation(newPosition, Quaternion.Euler(0, -updatedImage.transform.rotation.eulerAngles.x, 0));
                }
                else if (currentImageName == "frontright" || currentImageName == "rearright")
                {
                    navigationBase.transform.SetPositionAndRotation(newPosition, Quaternion.Euler(0, 90 + updatedImage.transform.rotation.eulerAngles.x, 0));
                }
                else if (currentImageName == "frontleft" || currentImageName == "rearleft")
                {
                    navigationBase.transform.SetPositionAndRotation(newPosition, Quaternion.Euler(0, 270 + updatedImage.transform.rotation.eulerAngles.x, 0));
                }
                else if (currentImageName == "rear") 
                {
                    navigationBase.transform.SetPositionAndRotation(newPosition, Quaternion.Euler(0, updatedImage.pose.rotation.eulerAngles.x, 0));
                }
            }
        }

        // Handle removed images if necessary
        foreach (var removedImage in eventArgs.removed)
        {
            Debug.Log($"Image Removed: {removedImage.Value.referenceImage.name}");
            if (removedImage.Value == currentTrackedImage)
            {
                currentTrackedImage = null;
                currentImageName = "";
                if (navigationBase != null)
                {
                    Destroy(navigationBase);
                }
            }
        }
    }

    public void HandleDropdown(int val)
    {
        targetNumber = val - 1;
    }

    public void DestroyNavigationBase()
    {
        if (navigationBase != null)
        {
            Debug.Log("Destroying!!");
            Destroy(navigationBase);
        }
    }
}