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

public class CharacterStats : MonoBehaviour
{
    [Header("Identity & Level")]
    [SerializeField] private string characterName = "Character";
    [SerializeField] private int level = 1;

    [Header("Health Stats")]
    [SerializeField] private float maxHealth = 100f;
    [SerializeField] private float currentHealth;
    [SerializeField] private float healthRegenRate = 0.5f; // per second

    [Header("Mana Stats")]
    [SerializeField] private float maxMana = 50f;
    [SerializeField] private float currentMana;
    [SerializeField] private float manaRegenRate = 1.0f; // per second

    [Header("Stamina Stats")]
    [SerializeField] private float maxStamina = 100f;
    [SerializeField] private float currentStamina;
    [SerializeField] private float staminaRegenRate = 5.0f; // per second

    [Header("Combat Attributes")]
    [SerializeField] private float baseDamage = 10f;
    [SerializeField] private float attackSpeed = 1.0f; // Attacks per second
    [SerializeField] private float attackRange = 2.0f;
    [SerializeField] private float armor = 0f;
    [SerializeField] private float moveSpeedMultiplier = 1.0f;

    [Header("Equipment")]
    [SerializeField] private string currentWeapon = "Unarmed";
    [SerializeField] private GameObject weaponPrefab;

    [Header("Rewards & Drops (For NPCs / Enemies)")]
    [SerializeField] private int expReward = 50;
    [SerializeField] private int goldReward = 25;
    [SerializeField] private List<GameObject> dropReward = new List<GameObject>();

    [Header("Events")]
    public UnityEvent<float, float> onHealthChanged;   // current, max
    public UnityEvent<float, float> onManaChanged;     // current, max
    public UnityEvent<float, float> onStaminaChanged;  // current, max
    public UnityEvent<GameObject> onDeath;             // killer

    public bool IsDead { get; private set; } = false;

    private void Awake()
    {
        currentHealth = maxHealth;
        currentMana = maxMana;
        currentStamina = maxStamina;
    }

    private void Update()
    {
        if (IsDead) return;

        // Passive Regeneration
        RegenerateStats();
    }

    private void RegenerateStats()
    {
        if (currentHealth < maxHealth && healthRegenRate > 0)
        {
            Heal(healthRegenRate * Time.deltaTime);
        }

        if (currentMana < maxMana && manaRegenRate > 0)
        {
            RestoreMana(manaRegenRate * Time.deltaTime);
        }

        if (currentStamina < maxStamina && staminaRegenRate > 0)
        {
            RestoreStamina(staminaRegenRate * Time.deltaTime);
        }
    }

    // --- Damage & Healing Methods ---
    public void TakeDamage(float damageAmount, GameObject attacker = null)
    {
        if (IsDead) return;

        // Apply Armor reduction
        float netDamage = Mathf.Max(damageAmount - armor, 1.0f);
        currentHealth -= netDamage;
        currentHealth = Mathf.Clamp(currentHealth, 0, maxHealth);

        onHealthChanged?.Invoke(currentHealth, maxHealth);
        Debug.Log($"[{gameObject.name}] Took {netDamage} damage from {(attacker != null ? attacker.name : "Unknown")}. HP: {currentHealth}/{maxHealth}");

        if (currentHealth <= 0)
        {
            Die(attacker);
        }
    }

    public void Heal(float amount)
    {
        if (IsDead) return;

        currentHealth += amount;
        currentHealth = Mathf.Clamp(currentHealth, 0, maxHealth);
        onHealthChanged?.Invoke(currentHealth, maxHealth);
    }

    // --- Mana Methods ---
    public bool UseMana(float amount)
    {
        if (currentMana >= amount)
        {
            currentMana -= amount;
            onManaChanged?.Invoke(currentMana, maxMana);
            return true;
        }
        return false;
    }

    public void RestoreMana(float amount)
    {
        currentMana = Mathf.Clamp(currentMana + amount, 0, maxMana);
        onManaChanged?.Invoke(currentMana, maxMana);
    }

    // --- Stamina Methods ---
    public bool UseStamina(float amount)
    {
        if (currentStamina >= amount)
        {
            currentStamina -= amount;
            onStaminaChanged?.Invoke(currentStamina, maxStamina);
            return true;
        }
        return false;
    }

    public void RestoreStamina(float amount)
    {
        currentStamina = Mathf.Clamp(currentStamina + amount, 0, maxStamina);
        onStaminaChanged?.Invoke(currentStamina, maxStamina);
    }

    // --- Death Handling ---
    private void Die(GameObject killer)
    {
        IsDead = true;
        Debug.Log($"<color=red>[{gameObject.name}] has been defeated!</color>");

        onDeath?.Invoke(killer);

        // Spawn Loot Drops if assigned
        SpawnLoot();
    }

    private void SpawnLoot()
    {
        if (dropReward == null || dropReward.Count == 0) return;

        foreach (GameObject lootPrefab in dropReward)
        {
            if (lootPrefab != null)
            {
                Vector3 spawnOffset = new Vector3(UnityEngine.Random.Range(-0.5f, 0.5f), 0.2f, UnityEngine.Random.Range(-0.5f, 0.5f));
                Instantiate(lootPrefab, transform.position + spawnOffset, Quaternion.identity);
            }
        }
    }

    // --- Getters & Setters ---
    public string CharacterName => characterName;
    public int Level => level;
    public float HealthPercentage => currentHealth / maxHealth;
    public float ManaPercentage => currentMana / maxMana;
    public float StaminaPercentage => currentStamina / maxStamina;
    public float AttackSpeed => attackSpeed;
    public float AttackRange => attackRange;
    public float BaseDamage => baseDamage;
    public string CurrentWeapon => currentWeapon;
    public int ExpReward => expReward;
    public int GoldReward => goldReward;
}