using System.Collections.Generic;
using UnityEngine;
using Spine.Unity;
using Skill_V2;
using System.Numerics;
using System;

public struct Damage
{
    public BigInteger value;
    public bool isCritical;
}

public class Character : Entity, IBattleEntity
{
    [SerializeField] SkeletonAnimation skeletonAnimation;
    [SerializeField] StateHandler<Character> stateHandler;

    StatData hpStat;

    LayerMask layerMask;

    Skill[] skills = new Skill[0];

    public CharacterData Data { get; private set; }
    public SkeletonAnimation SkeletonAnimation => skeletonAnimation;
    public StateHandler<Character> StateHandler => stateHandler;
    public Bitset32.Mask TargetTags { get; private set; }
    public IReadOnlyList<Skill> Skills => skills;
    public BigInteger CurrentHp { get; private set; }
    public bool IsDead => CurrentHp <= 0;
    public bool IsBattleReady { get; set; }

    public event Action<Character> OnSpawned;
    public event Action<Character> OnDisposed;
    public event Action<Character, Damage> OnDamaged;

    private void Awake()
    {
        if (skeletonAnimation == null)
            skeletonAnimation = GetComponent<SkeletonAnimation>();

        if (stateHandler == null)
            stateHandler = GetComponent<StateHandler<Character>>();

        AddTags(EntityTag.Character);
    }

    private void Update()
    {
        for(int i = 0; i < skills.Length; i++)
            skills[i].UpdateSkillCoolTime();
    }

    private void OnDestroy()
    {
        for (int i = 0; i < skills.Length; i++)
        {
            var skill = skills[i];
            if (skill != null) continue;

            skill.Stop();

            if(skill.gameObject != null)
                Destroy(skill.gameObject);
        }
    }

    public void SetData(CharacterData charData)
    {
        Debug.Assert(charData != null, Logger.LogMessage(LogType.Assert, nameof(SetData), " data is null"));
        Debug.Assert(Data == null, Logger.LogMessage(LogType.Assert, nameof(SetData), " data is already set"));

        Data = charData;

        if (Data.Skills != null)
        {
            skills = new Skill[Data.Skills.Count];

            int i = 0;
            foreach (var skillData in Data.Skills)
            {
                skills[i] = Instantiate(skillData.Prefab);
                skills[i].SetSkillData(skillData);
                skills[i].Stop();
                i++;
            }
        }

        stateHandler.Initialize(this);
        foreach (var component in GetComponents<IOwnedComponent<Character>>())
        {
            component.Initialize(this);
        }
    }

    public void SetTargetTags(LayerMask mask, params EntityTag[] tags)
    {
        layerMask = mask;
        TargetTags = Bitset32.GetMask(Array.ConvertAll(tags, (t) => (Enum)t));

        foreach (var skill in skills)
        {
            skill.SetTargetTags(layerMask, tags);
        }
    }

    public void Spawn(UnityEngine.Vector2 spawnPos)
    {
        Debug.Assert(stateHandler != null, "StateHandler is null");
        Debug.Assert(skeletonAnimation != null, "SkeletonAnimation is null");

        transform.position = spawnPos;

        if (Data.TryGetStat(StatID.Hp, out hpStat))
        {
            CurrentHp = hpStat.Value;
            hpStat.OnValueChanged += OnHpChanged;
        }

        OnSpawned?.Invoke(this);
    }

    public void Dispose()
    {
        if (hpStat != null)
            hpStat.OnValueChanged -= OnHpChanged;

        for (int i = 0; i < skills.Length; i++)
        {
            skills[i].Stop();
        }

        OnDisposed?.Invoke(this);
    }

    private void OnHpChanged()
    {
        if (CurrentHp >= (BigInteger)hpStat.Value)
            CurrentHp = hpStat.Value;
    }

    public bool IsBattleAvail() => IsBattleReady;

    public void GetDamage(BigInteger atk, float critDmgRate, int critRate, int dnum = -1)
    {
        if(CurrentHp <= 0) return;

        bool isCritical = CreatureBase.CheckCritical(critRate);
        if(isCritical)
            atk = CreatureBase.GetCriticalDamage(atk, critDmgRate, critRate);

        Damage dmg = new Damage {
            value = atk,
            isCritical = isCritical
        };

        CurrentHp = BigInteger.Max(0, CurrentHp - dmg.value);
        
        OnDamaged?.Invoke(this, dmg);
    }

    private void OnValidate()
    {
        if (skeletonAnimation == null)
            skeletonAnimation = GetComponent<SkeletonAnimation>();

        if (stateHandler == null)
            stateHandler = GetComponent<StateHandler<Character>>();
    }
}