using UnityEngine;

/// <summary>
/// Place this on an NPC, Item, or Trigger Zone to easily connect it to the Quest System!
/// </summary>
public class QuestInteractable : MonoBehaviour, IInteractable
{
    [Header("Quest Progression")]
    [Tooltip("What action does this object trigger?")]
    public ObjectiveType objectiveType;
    
    [Tooltip("The unique ID that matches the QuestObjective (e.g., 'wolf', 'ancient_relic')")]
    public string targetID;
    
    [Tooltip("How much to progress the objective (usually 1)")]
    public int progressAmount = 1;

    [Header("Interaction Settings")]
    [Tooltip("Can the player walk up and press E on this object?")]
    public bool isInteractable = false;
    [Tooltip("If true, the player can ONLY interact with this if they currently have the matching quest objective active!")]
    public bool requireActiveObjective = false;
    [Tooltip("The action verb for the prompt (e.g., 'Open', 'Collect', 'Steal')")]
    public string interactAction = "Interact";
    [Tooltip("The secondary text to display (e.g. the name of the item or 'Press E')")]
    public string interactTargetName = "[ E ]";
    
    [Header("Destination/Trigger Settings")]
    [Tooltip("Check this if walking into a Trigger Collider should automatically complete the objective.")]
    public bool completeOnTriggerEnter = false;
    [Tooltip("A visual marker GameObject to enable while active, and disable when completed.")]
    public GameObject destinationMarker;
    [Tooltip("A TMPro text element to show the distance counting down as the player gets closer.")]
    public TMPro.TextMeshProUGUI distanceText;

    [Header("Dynamic Marker Height")]
    [Tooltip("If true, the marker will physically raise into the sky when far away, and lower to the ground when close.")]
    public bool scaleMarkerHeight = true;
    public float maxDistanceForHeight = 50f;
    public float minHeight = 1.5f;
    public float maxHeight = 15f;
    [Tooltip("How far from the center the marker should hit its lowest point. If you have a large Box Collider, set this to half its width (e.g., 3m) so the marker bottoms out right as you touch the edge!")]
    public float arrivalDistanceOffset = 3f;

    [Header("Item Settings")]
    [Tooltip("Check this if this is an item that should destroy itself when collected/triggered")]
    public bool destroyOnTrigger;

    private bool _hasBeenTriggered = false;
    private Transform _playerTransform;

    private void Start()
    {
        // Find player once at start for distance tracking
        GameObject playerObj = GameObject.FindGameObjectWithTag("Player");
        if (playerObj != null)
        {
            _playerTransform = playerObj.transform;
        }
    }

    private void Update()
    {
        // Update distance countdown if marker is active and we haven't triggered
        if (completeOnTriggerEnter && !_hasBeenTriggered && destinationMarker != null && destinationMarker.activeInHierarchy)
        {
            // Fallback: If the 'Player' tag is on a stationary object or missing, track the Main Camera!
            // The Main Camera is guaranteed to move with you, so the distance will always update correctly.
            if (_playerTransform == null || _playerTransform.position == Vector3.zero)
            {
                if (Camera.main != null) _playerTransform = Camera.main.transform;
            }

            if (_playerTransform != null)
            {
                float dist = Vector3.Distance(_playerTransform.position, transform.position);
                
                if (distanceText != null)
                {
                    distanceText.text = $"{Mathf.RoundToInt(dist)}m";
                }

                if (scaleMarkerHeight)
                {
                    // Subtract the offset so it bottoms out at the edge of the collider instead of the exact center
                    float effectiveDist = Mathf.Max(0, dist - arrivalDistanceOffset);
                    
                    // Calculate a 0 to 1 value (0 = at the edge, 1 = max distance away)
                    float t = Mathf.Clamp01(effectiveDist / maxDistanceForHeight);
                    
                    // Lerp between our min and max height clamps
                    float targetY = Mathf.Lerp(minHeight, maxHeight, t);
                    
                    Vector3 localPos = destinationMarker.transform.localPosition;
                    localPos.y = targetY;
                    destinationMarker.transform.localPosition = localPos;
                }
            }
        }
    }

    private void OnTriggerEnter(Collider other)
    {
        if (!completeOnTriggerEnter || _hasBeenTriggered) return;

        // Ensure it's the player that walked into the trigger
        if (other.CompareTag("Player") || other.transform.root.CompareTag("Player") || other.GetComponentInParent<PlayerStats>() != null)
        {
            TriggerQuestProgress();
        }
    }

    // --- IInteractable Implementation ---
    public string GetInteractText()
    {
        return interactAction;
    }

    public string GetSecondaryInteractText()
    {
        return interactTargetName;
    }

    public bool CanInteract()
    {
        if (!isInteractable || _hasBeenTriggered) return false;

        // If this option is checked, we ask the QuestManager if this is our current objective!
        if (requireActiveObjective)
        {
            if (QuestManager.Instance == null) return false;
            return QuestManager.Instance.IsObjectiveActive(objectiveType, targetID);
        }

        return true;
    }

    public void Interact(GameObject player)
    {
        TriggerQuestProgress();
    }
    // ------------------------------------

    /// <summary>
    /// Call this from your existing interaction scripts, or a Unity Event when picking up an item!
    /// </summary>
    public void TriggerQuestProgress()
    {
        if (_hasBeenTriggered) return;

        bool wasSuccessful = false;
        if (QuestManager.Instance != null)
        {
            wasSuccessful = QuestManager.Instance.ProgressObjective(objectiveType, targetID, progressAmount);
        }

        // If the objective wasn't active (or was wrong type), we ignore it so they can try again later
        if (!wasSuccessful) return;

        _hasBeenTriggered = true;

        if (destinationMarker != null)
        {
            destinationMarker.SetActive(false);
        }

        if (destroyOnTrigger)
        {
            Destroy(gameObject);
        }
    }
}