using System;
using System.Collections.Generic;
using OTGIntegrated.Core;
using UnityEngine;

namespace OTGIntegrated.Stats
{
    public sealed class PlayerStats : MonoBehaviour
    {
        [Header("Base Values")]
        [SerializeField] private float baseMaxHealth = 100f;
        [SerializeField] private float baseMaxMana = 100f;
        [SerializeField] private float baseDamage = 10f;
        [SerializeField] private float baseMoveSpeed = 5f;
        [SerializeField] private float baseCriticalChance = 0f;
        [SerializeField] private float baseCooldownReduction = 0f;

        [Header("Runtime")]
        [SerializeField] private float currentHealth = 100f;
        [SerializeField] private float currentMana = 100f;
        [SerializeField] private List<StatModifier> activeModifiers = new List<StatModifier>();

        private readonly Dictionary<StatType, float> baseValues = new Dictionary<StatType, float>();
        private readonly Dictionary<StatType, float> finalValues = new Dictionary<StatType, float>();

        public event Action OnStatsChanged;

        public float MaxHealth => GetStat(StatType.MaxHealth);
        public float CurrentHealth => currentHealth;
        public float MaxMana => GetStat(StatType.MaxMana);
        public float CurrentMana => currentMana;
        public float Damage => GetStat(StatType.Damage);
        public float MoveSpeed => GetStat(StatType.MoveSpeed);
        public float CriticalChance => GetStat(StatType.CriticalChance);
        public float CooldownReduction => GetStat(StatType.CooldownReduction);
        public bool IsAlive => currentHealth > 0f;

        private void Awake()
        {
            RecalculateStats(false);
            currentHealth = Mathf.Clamp(currentHealth <= 0f ? MaxHealth : currentHealth, 0f, MaxHealth);
            currentMana = Mathf.Clamp(currentMana <= 0f ? MaxMana : currentMana, 0f, MaxMana);
        }

        private void OnValidate()
        {
            ClampBaseValues();
            currentHealth = Mathf.Max(0f, currentHealth);
            currentMana = Mathf.Max(0f, currentMana);
            RecalculateStats(false);
        }

        public IReadOnlyList<StatModifier> GetActiveModifiers()
        {
            return activeModifiers;
        }

        public float GetBaseStat(StatType statType)
        {
            EnsureBaseValues();
            return baseValues.TryGetValue(statType, out float value) ? value : 0f;
        }

        public float GetStat(StatType statType)
        {
            if (finalValues.Count == 0)
            {
                RecalculateStats(false);
            }

            return finalValues.TryGetValue(statType, out float value) ? value : GetBaseStat(statType);
        }

        public void AddModifier(StatModifier modifier)
        {
            if (!IsValidNumber(modifier.value))
            {
                return;
            }

            if (string.IsNullOrWhiteSpace(modifier.sourceId))
            {
                modifier.sourceId = "Runtime";
            }

            activeModifiers.Add(modifier);
            RecalculateStats();
        }

        public int RemoveModifiersBySource(string sourceId)
        {
            if (string.IsNullOrWhiteSpace(sourceId))
            {
                return 0;
            }

            int removed = activeModifiers.RemoveAll(modifier => modifier.sourceId == sourceId);
            if (removed > 0)
            {
                RecalculateStats();
            }

            return removed;
        }

        public int RemoveModifiersBySourcePrefix(string sourcePrefix)
        {
            if (string.IsNullOrWhiteSpace(sourcePrefix))
            {
                return 0;
            }

            int removed = activeModifiers.RemoveAll(modifier =>
                !string.IsNullOrEmpty(modifier.sourceId) &&
                modifier.sourceId.StartsWith(sourcePrefix, StringComparison.Ordinal));

            if (removed > 0)
            {
                RecalculateStats();
            }

            return removed;
        }

        public void ClearModifiers()
        {
            if (activeModifiers.Count == 0)
            {
                return;
            }

            activeModifiers.Clear();
            RecalculateStats();
        }

        public void RecalculateStats(bool notify = true)
        {
            float previousMaxHealth = finalValues.TryGetValue(StatType.MaxHealth, out float oldHealth) ? oldHealth : baseMaxHealth;
            float previousMaxMana = finalValues.TryGetValue(StatType.MaxMana, out float oldMana) ? oldMana : baseMaxMana;

            ClampBaseValues();
            EnsureBaseValues();
            finalValues.Clear();

            foreach (StatType statType in Enum.GetValues(typeof(StatType)))
            {
                float flatAdd = 0f;
                float percentAdd = 0f;
                float percentMultiply = 1f;

                for (int i = 0; i < activeModifiers.Count; i++)
                {
                    StatModifier modifier = activeModifiers[i];
                    if (modifier.statType != statType || !IsValidNumber(modifier.value))
                    {
                        continue;
                    }

                    switch (modifier.modifierType)
                    {
                        case ModifierType.FlatAdd:
                            flatAdd += modifier.value;
                            break;
                        case ModifierType.PercentAdd:
                            percentAdd += modifier.value;
                            break;
                        case ModifierType.PercentMultiply:
                            percentMultiply *= Mathf.Max(0f, 1f + modifier.value);
                            break;
                    }
                }

                float value = (GetBaseStat(statType) + flatAdd) * Mathf.Max(0f, 1f + percentAdd) * percentMultiply;
                finalValues[statType] = ClampFinalValue(statType, value);
            }

            if (previousMaxHealth > 0f && MaxHealth > previousMaxHealth)
            {
                currentHealth += MaxHealth - previousMaxHealth;
            }

            if (previousMaxMana > 0f && MaxMana > previousMaxMana)
            {
                currentMana += MaxMana - previousMaxMana;
            }

            ClampVitals();

            if (notify)
            {
                OnStatsChanged?.Invoke();
                GameEvents.RaiseStatsChanged();
            }
        }

        public void TakeDamage(float amount)
        {
            if (amount <= 0f)
            {
                return;
            }

            currentHealth = Mathf.Clamp(currentHealth - amount, 0f, MaxHealth);
            RaiseChanged();
        }

        public void Heal(float amount)
        {
            if (amount <= 0f)
            {
                return;
            }

            currentHealth = Mathf.Clamp(currentHealth + amount, 0f, MaxHealth);
            RaiseChanged();
        }

        public bool SpendMana(float amount)
        {
            if (amount <= 0f)
            {
                return true;
            }

            if (currentMana + 0.001f < amount)
            {
                GameEvents.RaiseNotification("Недостаточно маны");
                return false;
            }

            currentMana = Mathf.Clamp(currentMana - amount, 0f, MaxMana);
            RaiseChanged();
            return true;
        }

        public void RestoreMana(float amount)
        {
            if (amount <= 0f)
            {
                return;
            }

            currentMana = Mathf.Clamp(currentMana + amount, 0f, MaxMana);
            RaiseChanged();
        }

        public float GetNormalizedHealth()
        {
            return MaxHealth <= 0f ? 0f : Mathf.Clamp01(currentHealth / MaxHealth);
        }

        public float GetNormalizedMana()
        {
            return MaxMana <= 0f ? 0f : Mathf.Clamp01(currentMana / MaxMana);
        }

        public void SetRuntimeVitals(float health, float mana)
        {
            currentHealth = Mathf.Clamp(health, 0f, MaxHealth);
            currentMana = Mathf.Clamp(mana, 0f, MaxMana);
            RaiseChanged();
        }

        private void EnsureBaseValues()
        {
            baseValues[StatType.MaxHealth] = Mathf.Max(1f, baseMaxHealth);
            baseValues[StatType.MaxMana] = Mathf.Max(0f, baseMaxMana);
            baseValues[StatType.Damage] = Mathf.Max(0f, baseDamage);
            baseValues[StatType.MoveSpeed] = Mathf.Max(0.1f, baseMoveSpeed);
            baseValues[StatType.CriticalChance] = Mathf.Clamp01(baseCriticalChance);
            baseValues[StatType.CooldownReduction] = Mathf.Clamp(baseCooldownReduction, 0f, 0.9f);
        }

        private void ClampBaseValues()
        {
            baseMaxHealth = Mathf.Max(1f, baseMaxHealth);
            baseMaxMana = Mathf.Max(0f, baseMaxMana);
            baseDamage = Mathf.Max(0f, baseDamage);
            baseMoveSpeed = Mathf.Max(0.1f, baseMoveSpeed);
            baseCriticalChance = Mathf.Clamp01(baseCriticalChance);
            baseCooldownReduction = Mathf.Clamp(baseCooldownReduction, 0f, 0.9f);
        }

        private float ClampFinalValue(StatType statType, float value)
        {
            if (!IsValidNumber(value))
            {
                value = GetBaseStat(statType);
            }

            switch (statType)
            {
                case StatType.MaxHealth:
                    return Mathf.Max(1f, value);
                case StatType.MaxMana:
                case StatType.Damage:
                    return Mathf.Max(0f, value);
                case StatType.MoveSpeed:
                    return Mathf.Max(0.1f, value);
                case StatType.CriticalChance:
                case StatType.CooldownReduction:
                    return Mathf.Clamp(value, 0f, 0.9f);
                default:
                    return Mathf.Max(0f, value);
            }
        }

        private void ClampVitals()
        {
            currentHealth = Mathf.Clamp(currentHealth, 0f, MaxHealth);
            currentMana = Mathf.Clamp(currentMana, 0f, MaxMana);
        }

        private bool IsValidNumber(float value)
        {
            return !float.IsNaN(value) && !float.IsInfinity(value);
        }

        private void RaiseChanged()
        {
            OnStatsChanged?.Invoke();
            GameEvents.RaiseStatsChanged();
        }
    }
}