using UnityEngine;
using UnityEngine.UI;
using TMPro;
using System.Collections.Generic;
using UnityEngine.EventSystems;

public class Checklist : MonoBehaviour
{
    [SerializeField] private GameObject checklistPanel;
    [SerializeField] private GameObject checklistItemPrefab; // Should be a Toggle with TextMeshPro text child
    [SerializeField] private Transform checklistContent; // Container for checklist items
    [SerializeField] private float fadeAlpha = 0.2f; // Alpha value when faded (20% opacity)
    
    private Dictionary<string, Toggle> objectiveToggles = new Dictionary<string, Toggle>();
    private Dictionary<string, Text> objectiveTexts = new Dictionary<string, Text>();

    private void OnEnable()
    {
        if (LevelManager.Instance != null)
        {
            LevelManager.Instance.OnObjectiveCompleted += OnObjectiveCompleted;
        }
    }

    private void OnDisable()
    {
        if (LevelManager.Instance != null)
        {
            LevelManager.Instance.OnObjectiveCompleted -= OnObjectiveCompleted;
        }
    }

    private void Start()
    {
        // Hide panel initially
        if (checklistPanel != null)
        {
            checklistPanel.SetActive(false);
        }
        
        BuildChecklistFromObjectives();
    }

    private void BuildChecklistFromObjectives()
    {
        if (LevelManager.Instance == null)
        {
            Debug.LogError("Checklist: LevelManager.Instance is NULL!");
            return;
        }

        // Clear existing items
        for (int i = checklistContent.childCount - 1; i >= 0; i--)
        {
            Destroy(checklistContent.GetChild(i).gameObject);
        }
        objectiveToggles.Clear();
        objectiveTexts.Clear();

        // Get all objectives from LevelManager
        List<Objective> objectives = LevelManager.Instance.GetAllObjectives();
        
        Debug.Log($"Checklist: Found {objectives.Count} objectives to display");

        foreach (var objective in objectives)
        {
            if (checklistItemPrefab == null)
            {
                Debug.LogError("Checklist: Item Prefab is NULL! Assign it in the Inspector.");
                return;
            }

            // Instantiate the toggle prefab
            GameObject itemGO = Instantiate(checklistItemPrefab, checklistContent);
            itemGO.name = $"Checklist_{objective.name}";
            
            Toggle toggle = itemGO.GetComponent<Toggle>();
            
            if (toggle == null)
            {
                Debug.LogError($"Checklist: Prefab '{checklistItemPrefab.name}' does not have a Toggle component!");
                Destroy(itemGO);
                continue;
            }

            // Find the TextMeshProUGUI child component
            Text textComponent = itemGO.GetComponentInChildren<Text>();
            if (textComponent == null)
            {
                Debug.LogError($"Checklist: Prefab does not have a TextMeshProUGUI child component!");
                Destroy(itemGO);
                continue;
            }

            // Set the text to objective description
            textComponent.text = objective.description;
            Debug.Log($"Checklist: Created toggle for '{objective.description}'");

            // Set toggle state based on objective completion
            if (objective.isCompleted)
            {
                // Use the same trick for already-completed objectives
                toggle.interactable = true;
                toggle.isOn = true;
                toggle.interactable = false;
                
                // Apply fade effect
                ApplyFadeToText(textComponent);
                
                Debug.Log($"Checklist: Objective '{objective.description}' was already completed");
            }
            else
            {
                toggle.isOn = false;
            }

            // Store references
            objectiveToggles[objective.name] = toggle;
            objectiveTexts[objective.name] = textComponent;

            // Make toggle read-only - prevent player from clicking
            toggle.interactable = false;
        }
        
        Debug.Log($"Checklist: Built {objectiveToggles.Count} checklist items");
    }

    private void OnObjectiveCompleted(string objectiveKey)
    {
        // Update toggle state
        if (objectiveToggles.ContainsKey(objectiveKey))
        {
            Toggle toggle = objectiveToggles[objectiveKey];
            
            // Temporarily enable the toggle so it can update visually
            toggle.interactable = true;
            toggle.isOn = true;
            toggle.interactable = false;
            
            // Force layout rebuild
            LayoutRebuilder.ForceRebuildLayoutImmediate(toggle.GetComponent<RectTransform>());

            // Fade the text
            if (objectiveTexts.ContainsKey(objectiveKey))
            {
                Text textComponent = objectiveTexts[objectiveKey];
                ApplyFadeToText(textComponent);
            }

            Debug.Log($"Checklist: Objective '{objectiveKey}' marked complete");
        }
        else
        {
            Debug.LogWarning($"Checklist: Objective '{objectiveKey}' not found in toggles dictionary!");
        }
    }

    private void ApplyFadeToText(Text textComponent)
    {
        if (textComponent == null) 
        {
            Debug.LogError("Checklist: Text component is NULL!");
            return;
        }
        
        Color textColor = textComponent.color;
        textColor.a = fadeAlpha;
        textComponent.color = textColor;
        
        Debug.Log($"Checklist: Faded text '{textComponent.text}' to alpha {fadeAlpha}");
    }

    public void ToggleChecklist()
    {
        if (checklistPanel != null)
        {
            bool isActive = checklistPanel.activeSelf;
            checklistPanel.SetActive(!isActive);
            
            // Unlock cursor when checklist is open
            if (!isActive)
            {
                Cursor.lockState = CursorLockMode.None;
                Cursor.visible = true;
                Time.timeScale = 0f; // Pause game
            }
            else
            {
                Cursor.lockState = CursorLockMode.Locked;
                Cursor.visible = false;
                Time.timeScale = 1f; // Resume game
            }
        }
    }

    public void ShowChecklist()
    {
        if (checklistPanel != null)
        {
            checklistPanel.SetActive(true);
            Cursor.lockState = CursorLockMode.None;
            Cursor.visible = true;
            Time.timeScale = 0f; // Pause game
        }
    }

    public void HideChecklist()
    {
        if (checklistPanel != null)
        {
            checklistPanel.SetActive(false);
            Cursor.lockState = CursorLockMode.Locked;
            Cursor.visible = false;
            Time.timeScale = 1f; // Resume game
        }
    }
}