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

public class PlayerHealth : Singleton<PlayerHealth>
{
    // Public property to check if the player is dead
    public bool isDead { get; private set; }
    public GameManager gameManager;

    // Serialized fields visible in the Unity Inspector
    [SerializeField] private int maxHealth = 3;
    [SerializeField] private float knockBackThrustAmount = 10f;
    [SerializeField] private float damageRecoveryTime = 1f;

    // Private variables for health management
    private Slider healthSlider;
    private int currentHealth;
    private bool canTakeDamage = true;
    private Knockback knockback;
    private Flash flash;

    // Constants for scene and UI references
    const string HEALTH_SLIDER_TEXT = "Health Slider";
    const string TOWN_TEXT = "Scene1";
    readonly int DEATH_HASH = Animator.StringToHash("Death");

    protected override void Awake()
    {
        base.Awake();

        // Initialize references
        flash = GetComponent<Flash>();
        knockback = GetComponent<Knockback>();
    }

    private void Start()
    {
        // Initialize health values
        isDead = false;
        currentHealth = maxHealth;

        // Update health slider UI
        UpdateHealthSlider();
    }

    private void OnCollisionStay2D(Collision2D other)
    {
        // Damage player on collision with enemy
        EnemyAI enemy = other.gameObject.GetComponent<EnemyAI>();

        if (enemy)
        {
            TakeDamage(1, other.transform);
        }
    }

    public void HealPlayer()
    {
        // Heal player if not at max health
        if (currentHealth < maxHealth)
        {
            currentHealth += 1;
            UpdateHealthSlider();
        }
    }

    public void TakeDamage(int damageAmount, Transform hitTransform)
    {
        // Take damage if the player can take damage
        if (!canTakeDamage) { return; }

        // Perform damage effects
        ScreenShakeManager.Instance.ShakeScreen();
        knockback.GetKnockedBack(hitTransform, knockBackThrustAmount);
        StartCoroutine(flash.FlashRoutine());
        canTakeDamage = false;
        currentHealth -= damageAmount;
        StartCoroutine(DamageRecoveryRoutine());
        UpdateHealthSlider();
        CheckIfPlayerDeath();
    }

    private void CheckIfPlayerDeath()
    {
        // Check if player health is zero or below and initiate death sequence
        if (currentHealth <= 0 && !isDead)
        {
            isDead = true;
            // Reset the player's gold through EconomyManager
            EconomyManager.Instance?.ResetGold();

            if (gameManager != null)
            {
                gameManager.GameOver();  // Call GameOver
            }

            // Check if ActiveWeapon.Instance and its gameObject are valid
            if (ActiveWeapon.Instance != null && ActiveWeapon.Instance.gameObject != null)
            {
                Destroy(ActiveWeapon.Instance.gameObject); // Destroy weapon on death
            }

            currentHealth = 0;
            GetComponent<Animator>().SetTrigger(DEATH_HASH); // Trigger death animation
            StartCoroutine(DeathLoadSceneRoutine()); // Load death scene after delay
        }
    }

    private IEnumerator DeathLoadSceneRoutine()
    {
        // Delay before loading town scene after player death
        yield return new WaitForSeconds(3f); // Wait for 3 seconds before restarting
        Destroy(gameObject); // Destroy player object
        SceneManager.LoadScene(TOWN_TEXT); // Load town scene
    }

    private IEnumerator DamageRecoveryRoutine()
    {
        // Delay before player can take damage again
        yield return new WaitForSeconds(damageRecoveryTime);
        canTakeDamage = true;
    }

    private void UpdateHealthSlider()
    {
        // Update the UI health slider with current health values
        if (healthSlider == null)
        {
            healthSlider = GameObject.Find(HEALTH_SLIDER_TEXT).GetComponent<Slider>();
        }

        if (healthSlider != null) // Check if healthSlider is found
        {
            healthSlider.maxValue = maxHealth;
            healthSlider.value = currentHealth;
        }
    }
}