using System;
using System.Collections.Generic;
using Godot;
using Godot.Collections;

namespace TBL.GodotSharp
{
    /// <summary>
    /// Godot 扩展工具类
    /// </summary>
    public static class Extension
    {
        /// <summary>
        /// 使节点在世界变换下保持只有八方向旋转
        /// </summary>
        public static void SetDir8(this Spatial node)
        {
            node.Rotation = new Vector3(node.Rotation.x, 0, node.Rotation.z);
            var angle = node.GlobalTransform.basis.GetEuler().y;
            var diff = Mathf.PosMod(angle, Mathf.Deg2Rad(45.0f));
            node.RotateY(-diff);
            if (Mathf.Abs(diff) > Mathf.Deg2Rad(22.5f))
            {
                node.RotateY(Mathf.Deg2Rad(45.0f) * Mathf.Sign(diff));
            }
        }

        /// <summary>
        /// 使节点在世界变换下保持只有八方向旋转
        /// </summary>
        public static void SetDir8(this Node node)
        {
            if (node is Spatial spatial)
                SetDir8(spatial);
        }

        /// <summary>
        /// 遍历所有子节点
        /// </summary>
        public static IEnumerable<T> EnumChildrenNodes<T>(this Node node, bool recursive = true)
            where T : Node
        {
            for (int i = 0, count = node.GetChildCount(); i < count; i++)
            {
                var child = node.GetChild(i);
                if (child == null)
                    continue;
                if (child is T target)
                    yield return target;
                if (recursive)
                    foreach (var next in EnumChildrenNodes<T>(child, true))
                        yield return next;
            }
        }

        /// <summary>
        /// 获取所有此类型的子节点到列表中
        /// <para>获取前不会清空 <see cref="result"/> 请留意</para>
        /// </summary>
        public static void GetAllNodesOfType<T>(this Node root, Array<T> result, bool recursive = true)
            where T : Node
        {
            foreach ( var node in EnumChildrenNodes<T>(root, recursive) )
                result.Add(node);
        }

        /// <summary>
        /// 设置铺满父节点
        /// </summary>
        public static void SetFullParent(this Control canvasItem)
        {
            canvasItem.AnchorLeft = canvasItem.AnchorTop = 0;
            canvasItem.AnchorRight = canvasItem.AnchorBottom = 1;
            canvasItem.MarginLeft = canvasItem.MarginRight = canvasItem.MarginTop = canvasItem.MarginBottom = 0;
        }
        
        /// <summary>
        /// 设置铺满父节点
        /// </summary>
        public static void SetCenterParent(this Control canvasItem, bool withMargin = false)
        {
            canvasItem.AnchorLeft = canvasItem.AnchorTop = canvasItem.AnchorRight = canvasItem.AnchorBottom = 0.5f;
            if (withMargin)
            {
                var size = canvasItem.GetParentControl().RectSize;
                canvasItem.MarginLeft = -size.x * 0.5f;
                canvasItem.MarginRight = size.x * 0.5f;
                canvasItem.MarginTop = -size.y * 0.5f;
                canvasItem.MarginBottom = size.y * 0.5f;
            }
            else
                canvasItem.MarginLeft = canvasItem.MarginRight = canvasItem.MarginTop = canvasItem.MarginBottom = 0;
        }

        /// <summary>
        /// 退出场景树并销毁
        /// </summary>
        public static void QueueFreeAndExitTree(this Node node)
        {
            try
            {
                node.GetParent()?.RemoveChild(node);
                node.QueueFree();
            }
            catch (ObjectDisposedException)
            {
            }
        }
        
        /// <summary>
        /// 获取完整路径
        /// </summary>
        public static string GetFullPath(this string name, string dir, string ext) => $"{dir}/{name}{ext}";

        /// <summary>
        /// 削除所有动画
        /// </summary>
        public static void RemoveAllAnimations(this AnimationPlayer animationPlayer)
        {
            foreach (var name in animationPlayer.GetAnimationList())
            {
                animationPlayer.RemoveAnimation(name);
            }
        }

        /// <summary>
        /// 将本地节点变为 <see cref="PackedScene"/>
        /// 多用作快捷预制体
        /// </summary>
        public static PackedScene MakePrefab(this Godot.Node node, bool deferredFree = true)
        {
            var prefab = new PackedScene();
            prefab.Pack(node);
            if (deferredFree)
                node.QueueFreeAndExitTree();
            else
                node.Free();
            return prefab;
        }
    }
}