using System;
using System.Collections.Generic;
using ColdMint.scripts.camp;
using ColdMint.scripts.damage;
using ColdMint.scripts.health;
using ColdMint.scripts.inventory;
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;

    protected 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>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
        var timeSpan = DateTime.Now - _lastDamageTime;
        if (timeSpan > Config.HealthBarDisplaysTime)
        {
            if (_healthBar != null)
            {
                _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 void OnDie(DamageTemplate damageTemplate)
    {
        QueueFree();
    }

    /// <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)
    {
    }
}