using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerHealth : MonoBehaviour
{
    public int maxHealth = 3; // Maximum health the player can have
    private int currentHealth; // Current health value

    public HealthUI healthUI; // Reference to UI component that displays health

    private SpriteRenderer spriteRenderer; // Reference to the player's sprite renderer

    public static event Action OnPlayerDied; // Event triggered when the player dies

    /// <summary>
    /// Called when the script instance is being loaded
    /// </summary>
    void Start()
    {
        ResetHealth(); // Initialize health at start

        spriteRenderer = GetComponent<SpriteRenderer>(); // Cache sprite renderer
        GameController.OnReset += ResetHealth; // Subscribe to reset event
    }

    /// <summary>
    /// Called when the object is being destroyed
    /// </summary>
    private void OnDestroy()
    {
        GameController.OnReset -= ResetHealth; // Unsubscribe from reset event to prevent memory leaks
    }

    /// <summary>
    /// Handles trigger collisions (e.g., with traps)
    /// </summary>
    private void OnTriggerEnter2D(Collider2D collision)
    {
        Trap trap = collision.GetComponent<Trap>(); // Try to get a Trap component
        if (trap && trap.damage > 0)
        {
            TakeDamage(trap.damage); // Apply trap damage
            SoundEffectManager.Play("PlayerHit"); // Play hit sound
        }
    }

    /// <summary>
    /// Resets the player's health and updates the UI
    /// </summary>
    void ResetHealth()
    {
        currentHealth = maxHealth; // Set health to max
        healthUI.SetMaxHearts(maxHealth); // Update heart UI to max
    }

    /// <summary>
    /// Handles taking damage, health update, and death condition
    /// </summary>
    private void TakeDamage(int damage)
    {
        currentHealth -= damage; // Decrease current health
        healthUI.UpdateHearts(currentHealth); // Update heart UI

        StartCoroutine(FlashRed()); // Trigger flash red effect

        if (currentHealth <= 0)
        {
            // Player is dead
            OnPlayerDied?.Invoke(); // Invoke player death event if any listeners
        }
    }

    /// <summary>
    /// Coroutine that flashes the player's sprite red to show damage taken
    /// </summary>
    private IEnumerator FlashRed()
    {
        spriteRenderer.color = Color.red; // Set sprite color to red
        yield return new WaitForSeconds(0.2f); // Wait for 0.2 seconds
        spriteRenderer.color = Color.white; // Reset sprite color
    }
}