using System;
using System.Collections.Generic;
using UnityEngine;
namespace ZXKFramework
{
    public static class UnityExtension
    {
        public static bool IsNull<T>(this T selfObj) where T : class
        {
            return null == selfObj;
        }

        public static bool IsNotNull<T>(this T selfObj) where T : class
        {
            return null != selfObj;
        }

        public static Tvalue TryGet<Tkey, Tvalue>(this Dictionary<Tkey, Tvalue> dict, Tkey key)
        {
            Tvalue value;
            dict.TryGetValue(key, out value);
            return value;
        }

        private static readonly List<Transform> s_CachedTransforms = new List<Transform>();

        public static void SetActiveSafe(this GameObject gameObject, bool value)
        {
            if (gameObject.activeInHierarchy != value)
            {
                gameObject.SetActive(value);
            }
        }

        /// <summary>
        /// 获取或增加组件。
        /// </summary>
        /// <typeparam name="T">要获取或增加的组件。</typeparam>
        /// <param name="gameObject">目标对象。</param>
        /// <returns>获取或增加的组件。</returns>
        public static T GetOrAddComponent<T>(this GameObject gameObject) where T : Component
        {
            T component = gameObject.GetComponent<T>();
            if (component == null)
            {
                component = gameObject.AddComponent<T>();
            }
            return component;
        }

        /// <summary>
        /// 获取或增加组件。
        /// </summary>
        /// <param name="gameObject">目标对象。</param>
        /// <param name="type">要获取或增加的组件类型。</param>
        /// <returns>获取或增加的组件。</returns>
        public static Component GetOrAddComponent(this GameObject gameObject, Type type)
        {
            Component component = gameObject.GetComponent(type);
            if (component == null)
            {
                component = gameObject.AddComponent(type);
            }
            return component;
        }

        public static T GetOrAddComponent<T>(this Transform transform) where T : Component
        {
            T component = transform.GetComponent<T>();
            if (component == null)
            {
                component = transform.gameObject.AddComponent<T>();
            }
            return component;
        }

        public static Component GetOrAddComponent(this Transform transform, Type type)
        {
            Component component = transform.GetComponent(type);
            if (component == null)
            {
                component = transform.gameObject.AddComponent(type);
            }
            return component;
        }

        #region 查找模块

        public static GameObject FindFirst(this Transform transform, string objName)
        {
            return FindGameobject(transform, objName);
        }
        public static GameObject FindFirst(this GameObject gameObject, string objName)
        {
            return FindGameobject(gameObject.transform, objName);
        }
        public static T FindFirst<T>(this Transform transform, string objName) where T : Component
        {
            return FindGameobject<T>(transform, objName);
        }
        public static T FindFirst<T>(this GameObject gameObject, string objName) where T : Component
        {
            return FindGameobject<T>(gameObject.transform, objName);
        }

        //查找组件
        public static T FindGameobject<T>(Transform trs, string objName) where T : Component
        {
            GameObject tempObj = FindGameobject(trs, objName);
            if (tempObj != null)
            {
                if (tempObj.GetComponent<T>() != null)
                {
                    return tempObj.GetComponent<T>();
                }
                else
                {
                    Debug.LogError(string.Format("FindTools.FindGameobject 无法找到 {0} 对应的游戏组件 {1}", objName, typeof(T).Name));
                }
            }
            return null;
        }

        //所有提示都已写全
        public static GameObject FindGameobject(Transform trs, string objName)
        {
            if (trs == null)
            {
                Debug.LogError("FindTools.FindGameobject trs = null");
                return null;
            }
            if (string.IsNullOrEmpty(objName))
            {
                Debug.LogError("FindTools.FindGameobject objName = null");
                return null;
            }
            GameObject tempObj = Find(trs, objName);
            if (tempObj == null)
            {
                Debug.LogError(string.Format("FindTools.FindGameobject 无法找到 {0} 对应的游戏物体", objName));
            }
            return tempObj;
        }

        private static GameObject Find(Transform trs, string objName)
        {
            if (trs.name == objName)
            {
                return trs.gameObject;
            }
            if (trs.childCount > 0)
            {
                foreach (Transform tempTrs in trs)
                {
                    GameObject obj = Find(tempTrs, objName);
                    if (obj != null)
                    {
                        return obj;
                    }
                }
            }
            return null;
        }

        #endregion

        /// <summary>
        /// 获取 GameObject 是否在场景中。
        /// </summary>
        /// <param name="gameObject">目标对象。</param>
        /// <returns>GameObject 是否在场景中。</returns>
        /// <remarks>若返回 true，表明此 GameObject 是一个场景中的实例对象；若返回 false，表明此 GameObject 是一个 Prefab。</remarks>
        public static bool InScene(this GameObject gameObject)
        {
            return gameObject.scene.name != null;
        }

        /// <summary>
        /// 递归设置游戏对象的层次。
        /// </summary>
        /// <param name="gameObject"><see cref="GameObject" /> 对象。</param>
        /// <param name="layer">目标层次的编号。</param>
        public static void SetLayerRecursively(this GameObject gameObject, int layer)
        {
            gameObject.GetComponentsInChildren(true, s_CachedTransforms);
            for (int i = 0; i < s_CachedTransforms.Count; i++)
            {
                s_CachedTransforms[i].gameObject.layer = layer;
            }

            s_CachedTransforms.Clear();
        }

        /// <summary>
        /// 取 <see cref="Vector3" /> 的 (x, y, z) 转换为 <see cref="Vector2" /> 的 (x, z)。
        /// </summary>
        /// <param name="vector3">要转换的 Vector3。</param>
        /// <returns>转换后的 Vector2。</returns>
        public static Vector2 ToVector2(this Vector3 vector3)
        {
            return new Vector2(vector3.x, vector3.z);
        }

        /// <summary>
        /// 取 <see cref="Vector2" /> 的 (x, y) 转换为 <see cref="Vector3" /> 的 (x, 0, y)。
        /// </summary>
        /// <param name="vector2">要转换的 Vector2。</param>
        /// <returns>转换后的 Vector3。</returns>
        public static Vector3 ToVector3(this Vector2 vector2)
        {
            return new Vector3(vector2.x, 0f, vector2.y);
        }

        /// <summary>
        /// 取 <see cref="Vector2" /> 的 (x, y) 和给定参数 y 转换为 <see cref="Vector3" /> 的 (x, 参数 y, y)。
        /// </summary>
        /// <param name="vector2">要转换的 Vector2。</param>
        /// <param name="y">Vector3 的 y 值。</param>
        /// <returns>转换后的 Vector3。</returns>
        public static Vector3 ToVector3(this Vector2 vector2, float y)
        {
            return new Vector3(vector2.x, y, vector2.y);
        }

        #region Transform

        /// <summary>
        /// 设置绝对位置的 x 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">x 坐标值。</param>
        public static void SetPositionX(this Transform transform, float newValue)
        {
            Vector3 v = transform.position;
            v.x = newValue;
            transform.position = v;
        }

        /// <summary>
        /// 设置绝对位置的 y 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">y 坐标值。</param>
        public static void SetPositionY(this Transform transform, float newValue)
        {
            Vector3 v = transform.position;
            v.y = newValue;
            transform.position = v;
        }

        /// <summary>
        /// 设置绝对位置的 z 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">z 坐标值。</param>
        public static void SetPositionZ(this Transform transform, float newValue)
        {
            Vector3 v = transform.position;
            v.z = newValue;
            transform.position = v;
        }

        /// <summary>
        /// 增加绝对位置的 x 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">x 坐标值增量。</param>
        public static void AddPositionX(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.position;
            v.x += deltaValue;
            transform.position = v;
        }

        /// <summary>
        /// 增加绝对位置的 y 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">y 坐标值增量。</param>
        public static void AddPositionY(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.position;
            v.y += deltaValue;
            transform.position = v;
        }

        /// <summary>
        /// 增加绝对位置的 z 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">z 坐标值增量。</param>
        public static void AddPositionZ(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.position;
            v.z += deltaValue;
            transform.position = v;
        }

        /// <summary>
        /// 设置相对位置的 x 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">x 坐标值。</param>
        public static void SetLocalPositionX(this Transform transform, float newValue)
        {
            Vector3 v = transform.localPosition;
            v.x = newValue;
            transform.localPosition = v;
        }

        /// <summary>
        /// 设置相对位置的 y 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">y 坐标值。</param>
        public static void SetLocalPositionY(this Transform transform, float newValue)
        {
            Vector3 v = transform.localPosition;
            v.y = newValue;
            transform.localPosition = v;
        }

        /// <summary>
        /// 设置相对位置的 z 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">z 坐标值。</param>
        public static void SetLocalPositionZ(this Transform transform, float newValue)
        {
            Vector3 v = transform.localPosition;
            v.z = newValue;
            transform.localPosition = v;
        }

        /// <summary>
        /// 增加相对位置的 x 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">x 坐标值。</param>
        public static void AddLocalPositionX(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.localPosition;
            v.x += deltaValue;
            transform.localPosition = v;
        }

        /// <summary>
        /// 增加相对位置的 y 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">y 坐标值。</param>
        public static void AddLocalPositionY(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.localPosition;
            v.y += deltaValue;
            transform.localPosition = v;
        }

        /// <summary>
        /// 增加相对位置的 z 坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">z 坐标值。</param>
        public static void AddLocalPositionZ(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.localPosition;
            v.z += deltaValue;
            transform.localPosition = v;
        }

        /// <summary>
        /// 设置相对尺寸的 x 分量。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">x 分量值。</param>
        public static void SetLocalScaleX(this Transform transform, float newValue)
        {
            Vector3 v = transform.localScale;
            v.x = newValue;
            transform.localScale = v;
        }

        /// <summary>
        /// 设置相对尺寸的 y 分量。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">y 分量值。</param>
        public static void SetLocalScaleY(this Transform transform, float newValue)
        {
            Vector3 v = transform.localScale;
            v.y = newValue;
            transform.localScale = v;
        }

        /// <summary>
        /// 设置相对尺寸的 z 分量。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="newValue">z 分量值。</param>
        public static void SetLocalScaleZ(this Transform transform, float newValue)
        {
            Vector3 v = transform.localScale;
            v.z = newValue;
            transform.localScale = v;
        }

        /// <summary>
        /// 增加相对尺寸的 x 分量。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">x 分量增量。</param>
        public static void AddLocalScaleX(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.localScale;
            v.x += deltaValue;
            transform.localScale = v;
        }

        /// <summary>
        /// 增加相对尺寸的 y 分量。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">y 分量增量。</param>
        public static void AddLocalScaleY(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.localScale;
            v.y += deltaValue;
            transform.localScale = v;
        }

        /// <summary>
        /// 增加相对尺寸的 z 分量。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="deltaValue">z 分量增量。</param>
        public static void AddLocalScaleZ(this Transform transform, float deltaValue)
        {
            Vector3 v = transform.localScale;
            v.z += deltaValue;
            transform.localScale = v;
        }

        /// <summary>
        /// 二维空间下使 <see cref="Transform" /> 指向指向目标点的算法，使用世界坐标。
        /// </summary>
        /// <param name="transform"><see cref="Transform" /> 对象。</param>
        /// <param name="lookAtPoint2D">要朝向的二维坐标点。</param>
        /// <remarks>假定其 forward 向量为 <see cref="Vector3.up" />。</remarks>
        public static void LookAt2D(this Transform transform, Vector2 lookAtPoint2D)
        {
            Vector3 vector = lookAtPoint2D.ToVector3() - transform.position;
            vector.y = 0f;

            if (vector.magnitude > 0f)
            {
                transform.rotation = Quaternion.LookRotation(vector.normalized, Vector3.up);
            }
        }

        #endregion Transform
    }
}