using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using ColdMint.scripts.camp;
using ColdMint.scripts.damage;
using ColdMint.scripts.debug;
using ColdMint.scripts.health;
using ColdMint.scripts.inventory;
using ColdMint.scripts.map.events;
using ColdMint.scripts.utils;
using ColdMint.scripts.weapon;
using Godot;

namespace ColdMint.scripts.character;

/// <summary>
/// <para>CharacterTemplate</para>
/// <para>角色模板</para>
/// </summary>
/// <remarks>
///<para>Behavior shared by all characters</para>
///<para>所有角色共有的行为</para>
/// </remarks>
public partial class CharacterTemplate : CharacterBody2D
{
    // Get the gravity from the project settings to be synced with RigidBody nodes.
    // 从项目设置中获取与RigidBody节点同步的重力。
    protected float Gravity = ProjectSettings.GetSetting("physics/2d/default_gravity").AsSingle();
    protected const float Speed = 300.0f;

    protected const float JumpVelocity = -240;

    public string? ReadOnlyCharacterName => CharacterName;

    protected string? CharacterName;

    //Item containers are used to store items.
    //物品容器用于存储物品。
    private IItemContainer? _itemContainer;


    public IItemContainer? ItemContainer
    {
        get => _itemContainer;
        set => _itemContainer = value;
    }

    //Items currently held
    //当前持有的物品
    private Node2D? _currentItem;

    public Node2D? CurrentItem
    {
        get => _currentItem;
        set
        {
            _currentItem = value;
            WhenUpdateCurrentItem(_currentItem);
        }
    }

    /// <summary>
    /// <para>When the items the character holds are updated</para>
    /// <para>当角色持有的物品更新时</para>
    /// </summary>
    /// <param name="currentItem">
    ///<para>Update finished items</para>
    ///<para>更新完成后的物品</para>
    /// </param>
    protected virtual void WhenUpdateCurrentItem(Node2D? currentItem)
    {
    }

    //Define a pick up range
    //定义一个拾起范围
    private Area2D? _pickingArea;

    private AnimatedSprite2D? _animatedSprite2D;

    //A marker that defines the location of the item
    //一个标记，定义物品的位置
    protected Marker2D? ItemMarker2D;

    //The original X-coordinate of the item marker
    //物品标记的原始X坐标
    private float _itemMarkerOriginalX;

    protected float ReadOnlyItemMarkerOriginalX => _itemMarkerOriginalX;

    //Face left?
    //面向左边吗
    public bool FacingLeft = false;

    //The force added by the AddForce method
    //由AddForce方法追加的力
    private Vector2 _additionalForce = Vector2.Zero;

    protected int CurrentHp;

    //The initial health of the character after creation
    //角色创建后的初始血量
    private int _initialHp;

    public int MaxHp;

    /// <summary>
    /// <para>The camp ID of the role</para>
    /// <para>角色的阵营ID</para>
    /// </summary>
    public string CampId = null!;

    private DamageNumberNodeSpawn? _damageNumber;

    private HealthBar? _healthBar;
    private DateTime _lastDamageTime;

    /// <summary>
    /// <para>Pick up all items within range</para>
    /// <para>拾捡范围内的所有物品</para>
    /// </summary>
    protected List<Node>? PickingRangeBodiesList;

    public Node[] PickingRangeBodies => PickingRangeBodiesList?.ToArray() ?? Array.Empty<Node>();

    /// <summary>
    /// <para>Resurrected character</para>
    /// <para>复活角色</para>
    /// </summary>
    /// <remarks>
    ///<para>Sets the amount of Hp a character has after resurrection</para>
    ///<para>设置角色复活后拥有的Hp</para>
    /// </remarks>
    public virtual void Revive(int newHp)
    {
        //If the new Hp is less than or equal to 0, there is no need to resurrect
        //如果新的Hp小于等于0，那么不需要复活
        if (newHp <= 0)
        {
            return;
        }

        if (CurrentHp > 0)
        {
            //If the current Hp is greater than 0, there is no need to revive
            //如果当前Hp大于0，那么不需要复活
            return;
        }

        //Check whether the new Hp is greater than the maximum Hp. If yes, set the current Hp to the maximum Hp. If no, set the current Hp to the new HP
        //判断新的Hp是否大于最大Hp，若大于那么将当前Hp设置为最大Hp，否则设置为新的Hp
        CurrentHp = newHp > MaxHp ? MaxHp : newHp;
        Visible = true;
    }

    /// <summary>
    /// <para>Find the nearest item within the pick up area(Does not include items currently held)</para>
    /// <para>在拾捡范围内查找距离最近的物品（不包括当前持有的物品）</para>
    /// </summary>
    /// <returns></returns>
    public Node2D? FindTheNearestItem()
    {
        if (PickingRangeBodiesList == null || PickingRangeBodiesList.Count == 0)
        {
            return null;
        }

        HashSet<Node>? exclude = null;
        if (_currentItem != null)
        {
            //Prevent picking up objects in your hands again.
            //防止再次捡起自己手上的物品。
            exclude = new HashSet<Node> { _currentItem };
        }

        return NodeUtils.GetTheNearestNode(this, PickingRangeBodiesList.ToArray(), exclude);
    }


    /// <summary>
    /// <para>Get all weapons within range of the pick up</para>
    /// <para>获取所有在拾捡范围内的武器</para>
    /// </summary>
    /// <returns></returns>
    public WeaponTemplate[] GetCanPickedWeapon()
    {
        var weaponTemplates = new List<WeaponTemplate>();
        foreach (var pickingRangeBody in PickingRangeBodies)
        {
            if (pickingRangeBody is not WeaponTemplate weaponTemplate) continue;
            if (weaponTemplate.Owner != null)
            {
                continue;
            }

            weaponTemplates.Add(weaponTemplate);
        }

        return weaponTemplates.ToArray();
    }

    public override void _Ready()
    {
        base._Ready();
        PickingRangeBodiesList = new List<Node>();
        CharacterName = GetMeta("Name", Name).AsString();
        CampId = GetMeta("CampId", Config.CampId.Default).AsString();
        MaxHp = GetMeta("MaxHp", Config.DefaultMaxHp).AsInt32();
        if (MaxHp <= 0)
        {
            //If Max blood volume is 0 or less, set Max blood volume to 10
            //若最大血量为0或小于0，则将最大血量设置为10
            MaxHp = Config.DefaultMaxHp;
        }

        _initialHp = GetMeta("InitialHp", "0").AsInt32();
        if (_initialHp <= 0 || _initialHp > MaxHp)
        {
            //If the initial health is less than or equal to 0 or greater than the maximum health, then set it to the maximum health
            //如果初始血量小于等于0或者大于最大血量，那么将其设置为最大血量
            _initialHp = MaxHp;
        }

        CurrentHp = _initialHp;
        //The health bar of a creature may be null.
        //生物的健康条，可能为null。
        _healthBar = GetNodeOrNull<HealthBar>("HealthBar");
        if (_healthBar != null)
        {
            _healthBar.MaxValue = MaxHp;
        }


        ItemMarker2D = GetNode<Marker2D>("ItemMarker2D");
        _itemMarkerOriginalX = ItemMarker2D.Position.X;
        _animatedSprite2D = GetNode<AnimatedSprite2D>("AnimatedSprite2D");
        _pickingArea = GetNode<Area2D>("Area2DPickingArea");
        _damageNumber = GetNode<Marker2D>("DamageNumber") as DamageNumberNodeSpawn;
        if (_pickingArea != null)
        {
            //If true, the zone will detect objects or areas entering and leaving the zone.
            //如果为true，该区域将检测进出该区域的物体或区域。
            _pickingArea.Monitoring = true;
            //Other regions cannot detect our pick region
            //其他区域不能检测到我们的拾取区域
            _pickingArea.Monitorable = false;
            _pickingArea.BodyEntered += EnterThePickingRangeBody;
            _pickingArea.BodyExited += ExitThePickingRangeBody;
        }
    }

    /// <summary>
    /// <para>Pick up the specified items</para>
    /// <para>将指定物品拾起来</para>
    /// </summary>
    /// <param name="pickAbleItem"></param>
    /// <returns>
    ///<para>Whether successfully picked up</para>
    ///<para>是否成功拾起</para>
    /// </returns>
    public bool PickItem(Node2D? pickAbleItem)
    {
        if (pickAbleItem == null)
        {
            return false;
        }

        if (_itemContainer == null)
        {
            return false;
        }

        //Get the currently selected node
        //拿到当前选择的节点
        var itemSlotNode = _itemContainer.GetSelectItemSlotNode();
        if (itemSlotNode == null)
        {
            return false;
        }

        if (pickAbleItem is not IItem item)
        {
            return false;
        }

        //First check if we can pick up the item.
        //先检查我们能否拾起此物品。
        var canPick = _itemContainer.CanAddItem(item);
        if (!canPick)
        {
            return false;
        }

        //Is it successfully added to the container?
        //再检查是否成功的添加到容器内了？
        var addSuccess = _itemContainer.AddItem(item);
        if (!addSuccess)
        {
            return false;
        }

        //Set up routine handling of picked up items.
        //设置捡起物品的常规处理。
        //You can supplement picking up state handling for more types of objects here.
        //您可以在这里补充更多类型对象的捡起状态处理。
        if (pickAbleItem is WeaponTemplate weaponTemplate)
        {
            weaponTemplate.Owner = this;
            weaponTemplate.SetCollisionMaskValue(Config.LayerNumber.Platform, false);
            weaponTemplate.SetCollisionMaskValue(Config.LayerNumber.Ground, false);
            weaponTemplate.EnableContactInjury = false;
            weaponTemplate.Sleeping = true;
        }

        if (itemSlotNode.GetItem() != null && itemSlotNode.GetItem() == item && _currentItem == null)
        {
            //If the selected item slot in the item container is a newly picked item, and there is no item in the hand, then we put the selected item into the hand.
            //如果物品容器内选中的物品槽是刚刚捡到的物品，且手里没有物品持有，那么我们将选中的物品放到手上。
            CurrentItem = pickAbleItem;
        }
        else
        {
            pickAbleItem.Visible = false;
            pickAbleItem.ProcessMode = ProcessModeEnum.Disabled;
        }

        pickAbleItem.Reparent(ItemMarker2D);
        pickAbleItem.Position = Vector2.Zero;
        return true;
    }


    /// <summary>
    /// <para>Use what you have in your hand</para>
    /// <para>使用手中的物品</para>
    /// </summary>
    public bool UseItem(Vector2 position)
    {
        if (_currentItem == null)
        {
            return false;
        }

        if (_currentItem is WeaponTemplate weaponTemplate)
        {
            weaponTemplate.Fire(this, position);
        }

        return true;
    }

    public override void _Process(double delta)
    {
        base._Process(delta);

        //If the time difference between the last injury and the current time is greater than the time displayed in the health bar, the health bar is hidden
        //如果上次受到伤害的时间与当前时间的时间差大于健康条显示时间，则隐藏健康条
        if (_healthBar is { Visible: true })
        {
            var timeSpan = DateTime.Now - _lastDamageTime;
            if (timeSpan > Config.HealthBarDisplaysTime)
            {
                _healthBar.Visible = false;
            }
        }
    }

    /// <summary>
    /// <para>Update the role's health bar</para>
    /// <para>更新角色的健康条</para>
    /// </summary>
    private void UpDataHealthBar(DamageTemplate damageTemplate)
    {
        if (_healthBar == null)
        {
            return;
        }

        if (GameSceneNodeHolder.Player == null)
        {
            //We didn't know who the player was, so we showed it as a hostile color
            //我们不知道玩家是谁，所以我们将其显示为敌对颜色
            _healthBar.SetEnemyTones();
        }
        else
        {
            //If we set up a player node, then compare the injured party ID to the player's party ID
            //如果我们设置了玩家节点，那么将受伤者的阵营ID与玩家的阵营ID进行比较
            var targetCamp = CampManager.GetCamp(CampId);
            var playerCamp = CampManager.GetCamp(GameSceneNodeHolder.Player.CampId);
            if (CampManager.CanCauseHarm(targetCamp, playerCamp))
            {
                if (targetCamp != null && playerCamp != null)
                {
                    if (targetCamp.Id == playerCamp.Id)
                    {
                        //If an attack is allowed and you are on the same side, it is displayed as a friendly color (friend damage).
                        //如果允许攻击，且属于同一阵营，则显示为友好颜色（友伤）
                        _healthBar.SetFriendlyTones();
                    }
                    else
                    {
                        //If the injured target is an enemy of the player, it is displayed as an enemy color
                        //如果受伤的目标是玩家的敌人，则显示为敌对颜色
                        _healthBar.SetEnemyTones();
                    }
                }
            }
            else
            {
                _healthBar.SetFriendlyTones();
            }
        }

        _healthBar.Visible = true;
        _healthBar.Value = CurrentHp;
    }

    /// <summary>
    /// <para>Deal damage to the character</para>
    /// <para>对角色造成伤害</para>
    /// </summary>
    /// <param name="damageTemplate">
    ///<para>Damage template</para>
    ///<para>伤害模板</para>
    /// </param>
    /// <returns>
    ///<para>Return whether the damage was done successfully</para>
    ///<para>返回是否成功造成了伤害</para>
    /// </returns>
    public bool Damage(DamageTemplate damageTemplate)
    {
        _lastDamageTime = DateTime.Now;
        _damageNumber?.Display(damageTemplate);
        CurrentHp -= damageTemplate.Damage;
        OnHit(damageTemplate);
        if (CurrentHp <= 0)
        {
            //Character death
            //角色死亡
            OnDie(damageTemplate);
            return true;
        }

        UpDataHealthBar(damageTemplate);
        return true;
    }

    /// <summary>
    /// <para>Add power to the character</para>
    /// <para>在角色身上添加力</para>
    /// </summary>
    /// <param name="force"></param>
    public void AddForce(Vector2 force)
    {
        _additionalForce = force;
    }

    protected virtual void OnHit(DamageTemplate damageTemplate)
    {
    }

    /// <summary>
    /// <para>Handle the event of character death</para>
    /// <para>处理角色死亡的事件</para>
    /// </summary>
    /// <param name="damageTemplate"></param>
    protected virtual Task OnDie(DamageTemplate damageTemplate)
    {
        //If the attacker is not empty and the role name is not empty, then the role death message is printed
        //如果攻击者不为空，且角色名不为空，那么打印角色死亡信息
        if (damageTemplate.Attacker != null && !string.IsNullOrEmpty(CharacterName))
        {
            if (damageTemplate.Attacker is CharacterTemplate characterTemplate &&
                !string.IsNullOrEmpty(characterTemplate.CharacterName))
            {
                LogCat.LogWithFormat("death_info", CharacterName, characterTemplate.CharacterName);
            }
            else
            {
                LogCat.LogWithFormat("death_info", CharacterName, damageTemplate.Attacker.Name);
            }
        }

        QueueFree();
        return Task.CompletedTask;
    }

    /// <summary>
    /// <para>When an object enters the picking range</para>
    /// <para>当有物体进入拾捡范围时</para>
    /// </summary>
    /// <param name="node"></param>
    protected virtual void EnterThePickingRangeBody(Node node)
    {
        if (node is not IItem)
        {
            return;
        }

        PickingRangeBodiesList?.Add(node);
    }

    /// <summary>
    /// <para>When an object exit the picking range</para>
    /// <para>当有物体离开拾捡范围时</para>
    /// </summary>
    /// <param name="node"></param>
    protected virtual void ExitThePickingRangeBody(Node node)
    {
        if (node is not IItem)
        {
            return;
        }

        PickingRangeBodiesList?.Remove(node);
    }

    /// <summary>
    /// <para>Flip sprites or animations</para>
    /// <para>翻转精灵或动画</para>
    /// </summary>
    protected virtual void Flip()
    {
        if (_animatedSprite2D == null)
        {
            return;
        }

        _animatedSprite2D.FlipH = FacingLeft;
    }


    public sealed override void _PhysicsProcess(double delta)
    {
        //We continuously set the position of the items to prevent them from changing as we zoom in and out of the window.
        //我们持续设置物品的位置，为了防止放大缩小窗口时物品位置的变化。
        if (_currentItem != null)
        {
            _currentItem.Position = Vector2.Zero;
        }

        var velocity = Velocity;
        // Add the gravity.
        //增加重力。
        if (!IsOnFloor())
            velocity.Y += Gravity * (float)delta;
        // The ref keyword passes its pointer to the following method so that it can be modified in the method.
        // ref关键字将其指针传递给下面的方法，以便在方法中修改它。
        HookPhysicsProcess(ref velocity, delta);
        Velocity = velocity + _additionalForce;
        _additionalForce = Vector2.Zero;
        MoveAndSlide();
    }

    /// <summary>
    /// <para>Aim the held item at a point</para>
    /// <para>使持有的物品瞄准某个点</para>
    /// </summary>
    public void AimTheCurrentItemAtAPoint(Vector2 position)
    {
        if (_currentItem == null)
        {
            //Do not currently hold any items.
            //当前没有持有任何物品。
            return;
        }

        // Apply the rotation Angle to the node
        // 将旋转角度应用于节点
        _currentItem.LookAt(position);
    }


    protected virtual void HookPhysicsProcess(ref Vector2 velocity, double delta)
    {
    }
}