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

public class GameController : MonoBehaviour
{
    int progressAmount; // Tracks coin progress toward level completion
    public Slider progressSlider; // Reference to UI slider showing progress

    public TMP_Text survivedText; // Text UI for how many levels the player survived
    public TMP_Text levelText;    // UI text that displays the current level

    public GameObject player; // Reference to the player GameObject
    public GameObject LoadCanvas; // UI canvas shown when player can load next level
    public List<GameObject> levels; // List of all levels in the game
    private int currentLevelIndex = 0; // Current level index in the levels list

    public GameObject gameOverScreen; // UI canvas shown on game over
    private int survivedLevelsCount; // Number of levels the player has survived

    public static event Action OnReset; // Event called when game resets

    void Start()
    {
        progressAmount = 0;
        progressSlider.value = 0;

        // Subscribe to events
        Coin.OnCoinCollect += IncreaseProgressAmount;
        HoldToLoadLevel.OnHoldComplete += LoadNextLevel;
        PlayerHealth.OnPlayerDied += HandlePlayerDeath;

        LoadCanvas.SetActive(false); // Hide load UI at start
        gameOverScreen.SetActive(false); // Hide game over screen at start
        Time.timeScale = 1; // Resume time (in case game was paused before)

        // Set initial level text
        levelText.text = "LEVEL " + (currentLevelIndex + 1);
    }

    void HandlePlayerDeath()
    {
        GameOverScreen(); // Show game over screen when player dies
    }

    void GameOverScreen()
    {
        gameOverScreen.SetActive(true); // Show game over UI
        survivedText.text = "YOU SURVIVED " + survivedLevelsCount + " LEVEL";
        if (survivedLevelsCount != 1)
            survivedText.text += "S"; // Pluralize if needed

        Time.timeScale = 0; // Pause the game
    }

    public void ResetGame()
    {
        gameOverScreen.SetActive(false); // Hide game over screen
        survivedLevelsCount = 0; // Reset survived counter
        LoadLevel(0, false); // Reload first level
        OnReset?.Invoke(); // Trigger reset event
        Time.timeScale = 1; // Resume time

        levelText.text = "LEVEL " + (currentLevelIndex + 1); // Reset level text
    }

    public void LoadMainMenu()
    {
        Time.timeScale = 1; // Ensure game isn't paused when loading menu
        SceneManager.LoadScene("StartScenes"); // Load start scene
    }

    public void ExitGame()
    {
#if UNITY_EDITOR
        UnityEditor.EditorApplication.isPlaying = false; // Stop play mode in editor
#else
        Application.Quit(); // Quit application in build
#endif
    }

    void OnDestroy()
    {
        // Unsubscribe from events to prevent memory leaks
        Coin.OnCoinCollect -= IncreaseProgressAmount;
        HoldToLoadLevel.OnHoldComplete -= LoadNextLevel;
        PlayerHealth.OnPlayerDied -= HandlePlayerDeath;
    }

    void IncreaseProgressAmount(int amount)
    {
        progressAmount += amount; // Add collected coin amount
        progressSlider.value = progressAmount; // Update progress bar

        if (progressAmount >= 60)
        {
            LoadCanvas.SetActive(true); // Show load level prompt
            Debug.Log("Level Complete!");
        }
    }

    void LoadLevel(int level, bool wantSurvivedIncrease)
    {
        LoadCanvas.SetActive(false); // Hide load UI

        levels[currentLevelIndex].SetActive(false); // Deactivate current level
        levels[level].SetActive(true); // Activate next level

        player.transform.position = new Vector3(-6.62f, -1.58f, 0f); // Reset player position

        currentLevelIndex = level; // Update level index
        progressAmount = 0; // Reset progress
        progressSlider.value = 0;

        levelText.text = "LEVEL " + (level + 1);  // Update level display

        if (wantSurvivedIncrease) survivedLevelsCount++; // Increment survived counter if applicable
    }

    void LoadNextLevel()
    {
        int nextLevelIndex = currentLevelIndex + 1;
        Debug.Log($"Trying to load level {nextLevelIndex} / total levels {levels.Count}");

        if (nextLevelIndex < levels.Count)
        {
            LoadLevel(nextLevelIndex, true); // Load next level and count as survived
        }
        else
        {
            Debug.Log("Final level completed or no more levels to load.");
            GameOverScreen(); // Show game over if no more levels
        }
    }
}