using Godot;

/// <summary>
/// 角色身上的枪套, 存储角色携带的武器
/// </summary>
public class Holster
{
    /// <summary>
    /// 插槽类
    /// </summary>
    public class GunSlot
    {
        /// <summary>
        /// 是否启用
        /// </summary>
        public bool Enable = false;
        /// <summary>
        /// 当前插槽存放的武器类型
        /// </summary>
        public GunWeightType Type = GunWeightType.MainWeapon;
        /// <summary>
        /// 插槽存放的武器
        /// </summary>
        public Gun Gun;
    }

    /// <summary>
    /// 归属者
    /// </summary>
    public Role Master { get; }

    /// <summary>
    /// 当前使用的武器对象
    /// </summary>
    public Gun ActiveGun { get; private set; }

    /// <summary>
    /// 当前使用的武器的索引
    /// </summary>
    public int ActiveIndex { get; private set; } = 0;

    public GunSlot[] SlotList { get; } = new GunSlot[4];

    public Holster(Role master)
    {
        Master = master;

        //创建枪的插槽, 默认前两个都是启用的
        GunSlot slot1 = new GunSlot();
        slot1.Enable = true;
        SlotList[0] = slot1;

        GunSlot slot2 = new GunSlot();
        slot2.Enable = true;
        slot2.Type = GunWeightType.DeputyWeapon;
        SlotList[1] = slot2;

        GunSlot slot3 = new GunSlot();
        SlotList[2] = slot3;

        GunSlot slot4 = new GunSlot();
        slot4.Type = GunWeightType.DeputyWeapon;
        SlotList[3] = slot4;
    }

    /// <summary>
    /// 拾起武器, 存入枪套中, 返回存放在枪套的位置, 如果容不下这把武器, 则会返回 -1
    /// </summary>
    /// <param name="gun">武器对象</param>
    public int PickupGun(Gun gun)
    {
        for (int i = 0; i < SlotList.Length; i++)
        {
            var item = SlotList[i];
            if (item.Enable && gun.Attribute.WeightType == item.Type && item.Gun == null)
            {
                item.Gun = gun;
                ExchangeByIndex(i);
                gun._PickUpGun(Master);
                return i;
            }
        }
        GD.PrintErr("存入武器失败!");
        return -1;
    }

    /// <summary>
    /// 移除指定位置的武器, 并返回这个武器对象, 如果移除正在使用的这把武器, 则会自动切换到上一把武器
    /// </summary>
    /// <param name="index">所在枪套的位置索引</param>
    public Gun RmoveGun(int index)
    {
        if (index < 0 || index >= SlotList.Length)
        {
            return null;
        }
        var slot = SlotList[index];
        if (slot.Gun == null)
        {
            return null;
        }
        var gun = slot.Gun;
        gun.GetParent().RemoveChild(gun);
        slot.Gun = null;

        //如果是当前手持的武器, 就需要调用切换武器操作
        if (index == ActiveIndex)
        {
            //没有其他武器了
            if (ExchangePrev() == index)
            {
                ActiveIndex = 0;
                ActiveGun = null;
            }
        }
        gun._ThrowOutGun();
        return gun;
    }

    /// <summary>
    /// 切换到上一个武器
    /// </summary>
    public int ExchangePrev()
    {
        var index = ActiveIndex - 1;
        do
        {
            if (index < 0)
            {
                index = SlotList.Length - 1;
            }
            if (ExchangeByIndex(index))
            {
                return index;
            }
        } while (index-- != ActiveIndex);
        return -1;
    }

    /// <summary>
    /// 切换到下一个武器, 
    /// </summary>
    public int ExchangeNext()
    {
        var index = ActiveIndex + 1;
        do
        {
            if (index >= SlotList.Length)
            {
                index = 0;
            }
            if (ExchangeByIndex(index))
            {
                return index;
            }
        }
        while (index++ != ActiveIndex);
        return -1;
    }

    /// <summary>
    /// 切换到指定索引的武器
    /// </summary>
    public bool ExchangeByIndex(int index)
    {
        if (index == ActiveIndex && ActiveGun != null) return true;
        if (index < 0 || index > SlotList.Length) return false;
        var slot = SlotList[index];
        if (slot == null || slot.Gun == null) return false;

        //将上一把武器放到背后
        if (ActiveGun != null)
        {
            var tempParent = ActiveGun.GetParentOrNull<Node2D>();
            if (tempParent != null)
            {
                tempParent.RemoveChild(ActiveGun);
                Master.BackMountPoint.AddChild(ActiveGun);
                if (ActiveIndex == 0)
                {
                    ActiveGun.Position = new Vector2(0, 5);
                    ActiveGun.RotationDegrees = 50;
                    ActiveGun.Scale = new Vector2(-1, 1);
                }
                else if (ActiveIndex == 1)
                {
                    ActiveGun.Position = new Vector2(0, 0);
                    ActiveGun.RotationDegrees = 120;
                    ActiveGun.Scale = new Vector2(1, -1);
                }
                else if (ActiveIndex == 2)
                {
                    ActiveGun.Position = new Vector2(0, 5);
                    ActiveGun.RotationDegrees = 310;
                    ActiveGun.Scale = new Vector2(1, 1);
                }
                else if (ActiveIndex == 3)
                {
                    ActiveGun.Position = new Vector2(0, 0);
                    ActiveGun.RotationDegrees = 60;
                    ActiveGun.Scale = new Vector2(1, 1);
                }
                ActiveGun._Conceal();
            }
        }

        //更改父节点
        var parent = slot.Gun.GetParentOrNull<Node>();
        if (parent == null)
        {
            Master.MountPoint.AddChild(slot.Gun);
        }
        else if (parent != Master.MountPoint)
        {
            parent.RemoveChild(slot.Gun);
            Master.MountPoint.AddChild(slot.Gun);
        }

        slot.Gun.Position = Vector2.Zero;
        slot.Gun.Scale = Vector2.One;
        slot.Gun.RotationDegrees = 0;
        ActiveGun = slot.Gun;
        ActiveIndex = index;
        ActiveGun._Active();
        return true;
    }
}
